Mineral metabolism in isolated mouse long bones: Opposite effects of microgravity on mineralization and resorption

NASA Technical Reports Server (NTRS)

Veldhuijzen, Jean Paul; Vanloon, Jack J. W. A.

1994-01-01

An experiment using isolated skeletal tissues under microgravity, is reported. Fetal mouse long bones (metatarsals) were cultured for 4 days in the Biorack facility of Spacelab during the IML-1 (International Microgravity Laboratory) mission of the Space Shuttle. Overall growth was not affected, however glucose consumption was significantly reduced under microgravity. Mineralization of the diaphysis was also strongly reduced under microgravity as compared to the on-board 1 g group. In contrast, mineral resorption by osteoclasts was signficantly increased. These results indicate that these fetal mouse long bones are a sensitive and useful model to further study the cellular mechanisms involved in the changed mineral metabolism of skeletal tissues under microgravity.

Changes in gravitational force induce alterations in gene expression that can be monitored in the live, developing zebrafish heart

NASA Astrophysics Data System (ADS)

Gillette-Ferguson, I.; Ferguson, D. G.; Poss, K. D.; Moorman, S. J.

2003-10-01

Little is known about the effect of microgravity on gene expression, particularly in vivo during embryonic development. Using transgenic zebrafish that express the gfp gene under the influence of a β-actin promoter, we examined the affect of simulated-microgravity on GFP expression in the heart. Zebrafish embryos, at the 18-20 somite-stage, were exposed to simulated-microgravity for 24 hours. The intensity of GFP fluorescence associated with the heart was then determined using fluorescence microscopy. Our measurements indicated that simulated-microgravity induced a 23.9% increase in GFP-associated fluorescence in the heart. In contrast, the caudal notochord showed a 17.5% increase and the embryo as a whole showed only an 8.5% increase in GFP-associated fluorescence. This suggests that there are specific effects on the heart causing the more dramatic increase. These studies indicate that microgravity can influence gene expression and demonstrate the usefulness of this in vivo model of "reporter-gene" expression for studying the effects of microgravity.

Activation of nuclear transcription factor-kappaB in mouse brain induced by a simulated microgravity environment

NASA Technical Reports Server (NTRS)

Wise, Kimberly C.; Manna, Sunil K.; Yamauchi, Keiko; Ramesh, Vani; Wilson, Bobby L.; Thomas, Renard L.; Sarkar, Shubhashish; Kulkarni, Anil D.; Pellis, Neil R.; Ramesh, Govindarajan T.

2005-01-01

Microgravity induces inflammatory responses and modulates immune functions that may increase oxidative stress. Exposure to a microgravity environment induces adverse neurological effects; however, there is little research exploring the etiology of these effects resulting from exposure to such an environment. It is also known that spaceflight is associated with increase in oxidative stress; however, this phenomenon has not been reproduced in land-based simulated microgravity models. In this study, an attempt has been made to show the induction of reactive oxygen species (ROS) in mice brain, using ground-based microgravity simulator. Increased ROS was observed in brain stem and frontal cortex with concomitant decrease in glutathione, on exposing mice to simulated microgravity for 7 d. Oxidative stress-induced activation of nuclear factor-kappaB was observed in all the regions of the brain. Moreover, mitogen-activated protein kinase kinase was phosphorylated equally in all regions of the brain exposed to simulated microgravity. These results suggest that exposure of brain to simulated microgravity can induce expression of certain transcription factors, and these have been earlier argued to be oxidative stress dependent.

RCCS bioreactor-based modelled microgravity induces significant changes on in vitro 3D neuroglial cell cultures.

PubMed

Morabito, Caterina; Steimberg, Nathalie; Mazzoleni, Giovanna; Guarnieri, Simone; Fanò-Illic, Giorgio; Mariggiò, Maria A

2015-01-01

We propose a human-derived neuro-/glial cell three-dimensional in vitro model to investigate the effects of microgravity on cell-cell interactions. A rotary cell-culture system (RCCS) bioreactor was used to generate a modelled microgravity environment, and morphofunctional features of glial-like GL15 and neuronal-like SH-SY5Y cells in three-dimensional individual cultures (monotypic aggregates) and cocultures (heterotypic aggregates) were analysed. Cell survival was maintained within all cell aggregates over 2 weeks of culture. Moreover, compared to cells as traditional static monolayers, cell aggregates cultured under modelled microgravity showed increased expression of specific differentiation markers (e.g., GL15 cells: GFAP, S100B; SH-SY5Y cells: GAP43) and modulation of functional cell-cell interactions (e.g., N-CAM and Cx43 expression and localisation). In conclusion, this culture model opens a wide range of specific investigations at the molecular, biochemical, and morphological levels, and it represents an important tool for in vitro studies into dynamic interactions and responses of nervous system cell components to microgravity environmental conditions.

RCCS Bioreactor-Based Modelled Microgravity Induces Significant Changes on In Vitro 3D Neuroglial Cell Cultures

PubMed Central

Mazzoleni, Giovanna; Fanò-Illic, Giorgio; Mariggiò, Maria A.

2015-01-01

We propose a human-derived neuro-/glial cell three-dimensional in vitro model to investigate the effects of microgravity on cell-cell interactions. A rotary cell-culture system (RCCS) bioreactor was used to generate a modelled microgravity environment, and morphofunctional features of glial-like GL15 and neuronal-like SH-SY5Y cells in three-dimensional individual cultures (monotypic aggregates) and cocultures (heterotypic aggregates) were analysed. Cell survival was maintained within all cell aggregates over 2 weeks of culture. Moreover, compared to cells as traditional static monolayers, cell aggregates cultured under modelled microgravity showed increased expression of specific differentiation markers (e.g., GL15 cells: GFAP, S100B; SH-SY5Y cells: GAP43) and modulation of functional cell-cell interactions (e.g., N-CAM and Cx43 expression and localisation). In conclusion, this culture model opens a wide range of specific investigations at the molecular, biochemical, and morphological levels, and it represents an important tool for in vitro studies into dynamic interactions and responses of nervous system cell components to microgravity environmental conditions. PMID:25654124

Analysis of Pdeudomonas aeruginosa Growth and Virulence in Modelled Microgravity

NASA Technical Reports Server (NTRS)

Guadarrama, Seratna; deL. Pulcini, Elinor; Broadaway, Susan C.; Pyle, Barry H.

2005-01-01

Stress, radiation and microgravity cause astronauts to experience secondary immunosuppression. Spaceflight conditions enhance bacterial growth and alter antimicrobial susceptibility. Clinostats are used to model microgravity effects at lxg. In controls rotated on the vertical axis, the g-vector acts on cells as in static cultures. Salmonella enterica serovar Typhimurium virulence genes are up-regulated in modelled microgravity (MMG); a MMG regulon has been postulated. We hypothesize that the virulence of P. aeruginosa (PA) may be affected similarly by microgravity, which could be observed in MMG. This study focused on regulation of the ETA protein by PA during growth in MMG. PA103 was grown in an ETA production medium at 37 C. One series of media was inoculated with frozen cultures and grown using horizontal (MMG) or static incubation. Another series inoculated with refrigerated cultures included vertical rotating controls. Analyses included optical density (OD), agar plate counts (PC) on R2A, ETA ELISA, and protein expression by 2-D gel analyses. Growth and ETA results differed depending on inoculum, with minor effects of MMG. Proteomic analysis of 2-D gels indicate differences in protein expression with MMG. Growth and ETA results show that consistent methodology is critical when studying environmental effects. This study provides information on the relationships between environmental changes and virulence regulation, especially for flight experiments, when ground experiments are used to predict potential spaceflight effects.

Analysis of Pseudomonas aeruginosa growth and virulence in modelled microgravity

NASA Astrophysics Data System (ADS)

Guadarrama, Seratna; Pulcini, Elinor de L.; Broadaway, Susan C.; Pyle, Barry H.

2005-08-01

Stress, radiation and microgravity cause astronauts to experience secondary immunosuppression. Spaceflight conditions enhance bacterial growth and alter antimicrobial susceptibility. Clinostats are used to model microgravity effects at 1xg. In controls rotated on the vertical axis, the g-vector acts on cells as in static cultures. Salmonella enterica serovar T yphimurium virulence genes are up-regulated in modelled microgravity (MMG); a MMG regulon has been postulated. We hypothesize that the virulence of P. aeruginosa (PA) may be affected similarly by microgravity, which could be observed in MMG. This study focused on regulation of the ETA protein by PA during growth in MMG. PA103 was grown in an ETA production medium at 37°C. One series of media was inoculated with frozen cultures and grown using horizontal (MMG) or static incubation. Another series inoculated with refrigerated cultures included vertical rotating controls. Analyses included optical density (OD), agar plate counts (PC) on R2A, ETA ELISA, and protein expression by 2-D gel analyses. Growth and ETA results differed depending on inoculum, with minor effects of MMG. Proteomic analysis of 2-D gels indicate differences in protein expression with MMG. Growth and ETA results show that consistent methodology is critical when studying environmental effects. This study provides information on the relationships between environmental changes and virulence regulation, especially for flight experiments, when ground experiments are used to predict potential spaceflight effects.

Countermeasure for space flight effects on immune system: nutritional nucleotides

NASA Technical Reports Server (NTRS)

Kulkarni, A. D.; Yamauchi, K.; Sundaresan, A.; Ramesh, G. T.; Pellis, N. R.

2005-01-01

Microgravity and its environment have adverse effects on the immune system. Abnormal immune responses observed in microgravity may pose serious consequences, especially for the recent directions of NASA for long-term space missions to Moon, Mars and deep Space exploration. The study of space flight immunology is limited due to relative inaccessibility, difficulty of performing experiments in space, and inadequate provisions in this area in the United States and Russian space programs (Taylor 1993). Microgravity and stress experienced during space flights results in immune system aberration (Taylor 1993). In ground-based mouse models for some of the microgravity effects on the human body, hindlimb unloading (HU) has been reported to cause abnormal cell proliferation and cytokine production (Armstrong et al., 1993, Chapes et al. 1993). In this report, we document that a nutritional nucleotide supplementation as studied in ground-based microgravity analogs, has potential to serve as a countermeasure for the immune dysfunction observed in space travel.

Candle Flames in Microgravity

NASA Technical Reports Server (NTRS)

Dietrich, D. L.; Ross, H. D.; Chang, P.; T'ien, J. S.

2001-01-01

The goal of this work is to study both experimentally and numerically the behavior of a candle flame burning in a microgravity environment. Two space experiments (Shuttle and Mir) have shown the candle flame in microgravity to be small (approximately 1.5 cm diameter), dim blue, and hemispherical. Near steady flames with very long flame lifetimes (up to 45 minutes in some tests) existed for many of the tests. Most of the flames spontaneously oscillated with a period of approximately 1 Hz just prior to extinction). In a previous model of candle flame in microgravity, a porous sphere wetted with liquid fuel simulated the evaporating wick. The sphere, with a temperature equal to the boiling temperature of the fuel, was at the end of an inert cone that had a prescribed temperature. This inert cone produces the quenching effect of the candle wax in the real configuration. Although the computed flame shape resembled that observed in the microgravity experiment, the model was not able to differentiate the effect of wick geometry, e.g., a long vs. a short wick. This paper presents recent developments in the numerical model of the candle flame. The primary focus has been to more realistically account for the actual shape of the candle.

Convection Effects During Bulk Transparent Alloy Solidification in DECLIC-DSI and Phase-Field Simulations in Diffusive Conditions

NASA Astrophysics Data System (ADS)

Mota, F. L.; Song, Y.; Pereda, J.; Billia, B.; Tourret, D.; Debierre, J.-M.; Trivedi, R.; Karma, A.; Bergeon, N.

2017-08-01

To study the dynamical formation and evolution of cellular and dendritic arrays under diffusive growth conditions, three-dimensional (3D) directional solidification experiments were conducted in microgravity on a model transparent alloy onboard the International Space Station using the Directional Solidification Insert in the DEvice for the study of Critical LIquids and Crystallization. Selected experiments were repeated on Earth under gravity-driven fluid flow to evidence convection effects. Both radial and axial macrosegregation resulting from convection are observed in ground experiments, and primary spacings measured on Earth and microgravity experiments are noticeably different. The microgravity experiments provide unique benchmark data for numerical simulations of spatially extended pattern formation under diffusive growth conditions. The results of 3D phase-field simulations highlight the importance of accurately modeling thermal conditions that strongly influence the front recoil of the interface and the selection of the primary spacing. The modeling predictions are in good quantitative agreements with the microgravity experiments.

Modeled Microgravity Disrupts Collagen I/Integrin Signaling During Osteoblastic Differentiation of Human Mesenchymal Stem Cells

NASA Technical Reports Server (NTRS)

Meyers, Valerie E.; Zayzafoon, Majd; Gonda, Steven R.; Gathings, William E.; McDonald, Jay M.

2004-01-01

Spaceflight leads to reduced bone mineral density in weight bearing bones that is primarily attributed to a reduction in bone formation. We have previously demonstrated severely reduced osteoblastogenesis of human mesenchymal stem cells (hMSC) following seven days culture in modeled microgravity. One potential mechanism for reduced osteoblastic differentiation is disruption of type I collagen-integrin interactions and reduced integrin signaling. Integrins are heterodimeric transmembrane receptors that bind extracellular matrix proteins and produce signals essential for proper cellular function, survival, and differentiation. Therefore, we investigated the effects of modeled microgravity on integrin expression and function in hMSC. We demonstrate that seven days of culture in modeled microgravity leads to reduced expression of the extracellular matrix protein, type I collagen (Col I). Conversely, modeled microgravity consistently increases Col I-specific alpha2 and beta1 integrin protein expression. Despite this increase in integrin sub-unit expression, autophosphorylation of adhesion-dependent kinases, focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK2), is significantly reduced. Activation of Akt is unaffected by the reduction in FAK activation. However, reduced downstream signaling via the Ras-MAPK pathway is evidenced by a reduction in Ras and ERK activation. Taken together, our findings indicate that modeled microgravity decreases integrin/MAPK signaling, which likely contributes to the observed reduction in osteoblastogenesis.

Microgravity Effects on Transendothelial Transport

NASA Technical Reports Server (NTRS)

Tarbell, John M.

1996-01-01

The Endothelial Cell (EC) layer which lines blood vessels from the aorta to the capillaries provides the principal barrier to transport of water and solutes between blood and underlying tissue. Endothelial cells are continuously exposed to the mechanical shearing force (shear stress) and normal force (pressure) imposed by flowing blood on their surface, and they are adapted to this mechanical environment. When the cardiovascular system is exposed to microgravity, the mechanical environmental of endothelial cells is perturbed drastically and the transport properties of EC layers are altered in response. We have shown recently that step changes in shear stress have an acute effect on transport properties of EC layers in a cell culture model, and several recent studies in different vessels of live animals have confirmed the shear-dependent transport properties of the endothelium. We hypothesize that alterations in mechanical forces induced by microgravity and their resultant influence on transendothelial transport of water and solutes are, in large measure, responsible for the characteristic cephalad fluid shift observed in humans experiencing microgravity. To study the effects of altered mechanical forces on transendothelial transport and to test pharmacologic agents as counter measures to microgravity induced fluid shifts we have proposed ground-based studies using well defined cell culture models.

Premixed Turbulent Flame Propagation in Microgravity

NASA Technical Reports Server (NTRS)

Menon, S.; Disseau, M.; Chakravarthy, V. K.; Jagoda, J.

1997-01-01

Papers included address the following topics: (1) Turbulent premixed flame propagation in microgravity; (2) The effect of gravity on turbulent premixed flame propagation - a preliminary cold flow study; and (3) Characteristics of a subgrid model for turbulent premixed combustion.

Effect of Low Shear Modeled Microgravity (LSMMG) on the Probiotic Lactobacillus Acidophilus ATCC 4356

NASA Technical Reports Server (NTRS)

Stahl, S.; Voorhies, A.; Lorenzi, H.; Castro-Wallace, S.; Douglas, G.

2016-01-01

The introduction of generally recognized as safe (GRAS) probiotic microbes into the spaceflight food system has the potential for use as a safe, non-invasive, daily countermeasure to crew microbiome and immune dysregulation. However, the microgravity effects on the stress tolerances and genetic expression of probiotic bacteria must be determined to confirm translation of strain benefits and to identify potential for optimization of growth, survival, and strain selection for spaceflight. The work presented here demonstrates the translation of characteristics of a GRAS probiotic bacteria to a microgravity analog environment. Lactobacillus acidophilus ATCC 4356 was grown in the low shear modeled microgravity (LSMMG) orientation and the control orientation in the rotating wall vessel (RWV) to determine the effect of LSMMG on the growth, survival through stress challenge, and gene expression of the strain. No differences were observed between the LSMMG and control grown L. acidophilus, suggesting that the strain will behave similarly in spaceflight and may be expected to confer Earth-based benefits.

The effects of detailed chemistry and transport on microgravity droplet combustion

NASA Technical Reports Server (NTRS)

Marchese, A. J.; Lee, J. C.; Held, T. J.; Dryer, F. L.

1995-01-01

A brief overview of recent advances in the theoretical study of microgravity droplet combustion is presented. Much of this work has centered on the development and utilization of sphero-symmetric transient numerical models which consider detailed gas phase chemistry and transport as well as energy and/or species transport within a regressing condensed phase. Numerical results for microgravity combustion and vaporization of methanol, methanol/water, heptane, and heptane/hexadecane droplets are summarized along with refinements in chemical kinetics and the development of a new two-dimensional axi-symmetric model.

Effect of Simulated Microgravity on the Activity of Regulatory Enzymes of Glycolysis and Gluconeogenesis in Mice Liver

NASA Astrophysics Data System (ADS)

Ramirez, Joaquin; Periyakaruppan, Adaikkappan; Sarkar, Shubhashish; Ramesh, Govindarajan T.; Sharma, S. Chidananda

2014-02-01

Gravity supports all the life activities present on earth. Microgravity environments have effect on the biological functions and physiological status of an individual. The present study was undertaken to investigate the effect of simulated microgravity on important regulatory enzymes of carbohydrate metabolism in liver using HLS mice model. Following hind limb unloading of mice for 11 days the animal's average body weights were found to be not different, while the liver weights were decreased and found to be significantly different ( p < 0.05) from control mice. Further, in liver the specific activity of hexokinase enzyme was reduced ( p < 0.02) and the phosphoenolpyruvate carboxykinase activity was significantly increased in simulated microgravity subjected mice compared to control ( p < 0.003). Immunoblot analysis show decreased phosphofructokinase-2 activity in HLS mice compared to control. Liver lactate dehydrogenase activity significantly reduced in simulated microgravity subjected mice ( p < 0.005). Thus in our study the rodents have adapted to simulated microgravity conditions, with decreased glycolysis and increased gluconeogenesis in liver and reciprocally regulated.

Lymphocyte Functions in Microgravity

NASA Technical Reports Server (NTRS)

Pellis, Neal R.; Risin, Diane; Sundaresan, A.; Cooper, D.; Dawson, David L. (Technical Monitor)

1999-01-01

To understand the mechanism of immunity impairment in space it is important to analyze the direct effects of space-related conditions on different lymphocytes functions. Since 1992, we are investigating the effect of modeled and true microgravity (MG) on numerous lymphocyte functions. We had shown that modeled (MMG) and true microgravity inhibit lymphocyte locomotion through type I collagen. Modeled microgravity also suppresses polyclonal and antigen-specific lymphocyte activation. Polyclonal activation of lymphocytes prior to exposure to MMG abrogates the MG-induced inhibition of lymphocyte locomotion. The relationship between activation deficits and the loss of locomotion in MG was investigated using PKC activation by phorbol ester (PMA) and calcium ionophore (ionomycin). Direct activation of PKC by PMA substantially restored the MMG-inhibited lymphocyte locomotion and PHA-induced lymphocyte activation lonomycin by itself did not restore either locomotion or activation of the lymphocytes, indicating that these changes are not related to the impairment in the calcium flux in MMG. Treatment of lymphocytes with PMA before exposure to MMG prevented the loss of locomotion. It was observed that DNA synthesis is not necessary for restoration of locomotion since mitomicin C treated and untreated cells recovered their locomotion to the same level after PKC activation. Our recent data indicate that microgravity may selectively effect the expression of novel Ca2+ independent isoforms of PKC, in particularly PKC sigma and delta. This provides a new insight in understanding of the mechanisms of MG-sensitive cellular functions.

Studies of Two-Phase Gas-Liquid Flow in Microgravity. Ph.D. Thesis, Dec. 1994

NASA Technical Reports Server (NTRS)

Bousman, William Scott

1995-01-01

Two-phase gas-liquid flows are expected to occur in many future space operations. Due to a lack of buoyancy in the microgravity environment, two-phase flows are known to behave differently than those in earth gravity. Despite these concerns, little research has been conducted on microgravity two-phase flow and the current understanding is poor. This dissertation describes an experimental and modeling study of the characteristics of two-phase flows in microgravity. An experiment was operated onboard NASA aircraft capable of producing short periods of microgravity. In addition to high speed photographs of the flows, electronic measurements of void fraction, liquid film thickness, bubble and wave velocity, pressure drop and wall shear stress were made for a wide range of liquid and gas flow rates. The effects of liquid viscosity, surface tension and tube diameter on the behavior of these flows were also assessed. From the data collected, maps showing the occurrence of various flow patterns as a function of gas and liquid flow rates were constructed. Earth gravity two-phase flow models were compared to the results of the microgravity experiments and in some cases modified. Models were developed to predict the transitions on the flow pattern maps. Three flow patterns, bubble, slug and annular flow, were observed in microgravity. These patterns were found to occur in distinct regions of the gas-liquid flow rate parameter space. The effect of liquid viscosity, surface tension and tube diameter on the location of the boundaries of these regions was small. Void fraction and Weber number transition criteria both produced reasonable transition models. Void fraction and bubble velocity for bubble and slug flows were found to be well described by the Drift-Flux model used to describe such flows in earth gravity. Pressure drop modeling by the homogeneous flow model was inconclusive for bubble and slug flows. Annular flows were found to be complex systems of ring-like waves and a substrate film. Pressure drop was best fitted with the Lockhart- Martinelli model. Force balances suggest that droplet entrainment may be a large component of the total pressure drop.

Effect of Magnetic Fields on g-jitter Induced Convection and Solute Striation During Space Processing of Single Crystals

NASA Technical Reports Server (NTRS)

deGroh, H. C.; Li, K.; Li, B. Q.

2002-01-01

A 2-D finite element model is presented for the melt growth of single crystals in a microgravity environment with a superimposed DC magnetic field. The model is developed based on the deforming finite element methodology and is capable of predicting the phenomena of the steady and transient convective flows, heat transfer, solute distribution, and solid-liquid interface morphology associated with the melt growth of single crystals in microgravity with and without an applied magnetic field. Numerical simulations were carried out for a wide range of parameters including idealized microgravity conditions, the synthesized g-jitter and the real g-jitter data taken by on-board accelerometers during space flights. The results reveal that the time varying g-jitter disturbances, although small in magnitude, cause an appreciable convective flow in the liquid pool, which in turn produces detrimental effects during the space processing of single crystal growth. An applied magnetic field of appropriate strength, superimposed on microgravity, can be very effective in suppressing the deleterious effects resulting from the g-jitter disturbances.

Fluid Flow and Solidification Under Combined Action of Magnetic Fields and Microgravity

NASA Technical Reports Server (NTRS)

Li, B. Q.; Shu, Y.; Li, K.; deGroh, H. C.

2002-01-01

Mathematical models, both 2-D and 3-D, are developed to represent g-jitter induced fluid flows and their effects on solidification under combined action of magnetic fields and microgravity. The numerical model development is based on the finite element solution of governing equations describing the transient g-jitter driven fluid flows, heat transfer and solutal transport during crystal growth with and without an applied magnetic field in space vehicles. To validate the model predictions, a ground-based g-jitter simulator is developed using the oscillating wall temperatures where timely oscillating fluid flows are measured using a laser PIV system. The measurements are compared well with numerical results obtained from the numerical models. Results show that a combined action derived from magnetic damping and microgravity can be an effective means to control the melt flow and solutal transport in space single crystal growth systems.

Microgravity ignition experiment

NASA Technical Reports Server (NTRS)

Motevalli, Vahid; Elliott, William; Garrant, Keith

1992-01-01

The purpose of this project is to develop a flight ready apparatus of the microgravity ignition experiment for the GASCan 2 program. This involved redesigning, testing, and making final modifications to the existing apparatus. The microgravity ignition experiment is intended to test the effect of microgravity on the time to ignition of a sample of alpha-cellulose paper. An infrared heat lamp is used to heat the paper sample within a sealed canister. The interior of the canister was redesigned to increase stability and minimize conductive heat transfer to the sample. This design was fabricated and tested and a heat transfer model of the paper sample was developed.

Altered tumor cell growth and tumorigenicity in models of microgravity

NASA Astrophysics Data System (ADS)

Yamauchi, K.; Taga, M.; Furian, L.; Odle, J.; Sundaresan, A.; Pellis, N.; Andrassy, R.; Kulkarni, A.

Spaceflight environment and microgravity (MG) causes immune dysfunction and is a major health risk to humans, especially during long-term space missions. The effects of microgravity environment on tumor growth and carcinogenesis are yet unknown. Hence, we investigated the effects of simulated MG (SMG) on tumor growth and tumorigenicity using in vivo and in vitro models. B16 melanoma cells were cultured in static flask (FL) and rotating wall vessel bioreactors (BIO) to measure growth and properties, melanin production and apoptosis. BIO cultures had 50% decreased growth (p<0.01), increased doubling time and a 150% increase in melanin production (p<0.05). Flow cytometric analysis showed increased apoptosis in BIO. When BIO cultured melanoma cells were inoculated sc in mice there was a significant increase in tumorigenicity as compared to FL cells. Thus SMG may have supported &selected highly tumorigenic cells and it is pos sible that in addition to decreased immune function MG may alter tumor cell characteristics and invasiveness. Thus it is important to study effects of microgravity environment and its stressors using experimental tumors and SMG to understand and evaluate carcinogenic responses to true microgravity. Further studies on carcinogenic events and their mechanisms will allow us develop and formulate countermeasures and protect space travelers. Additional results will be presented. (Supported by NASA NCC8-168 grant, ADK)

The effects of microgravity on gametogenesis, fertilization, and early embryogenesis

NASA Astrophysics Data System (ADS)

Tan, X.

Gametogenesis fertilization and early embryogenesis are crucial periods for normal development afterwards In past three decades many experiments have been conducted in space and in simulated weightlessness induced by clinostats to elucidate the issue Different animal species including Drosophila wasp shrimp fish amphibian mouse rats etc have been used for the study Oogenesis and spermatogenesis are affected by microgravity in different ways Some researches found that microgravity condition perturbed the process of oogenesis in many species A significant increased frequency of chromosomal non-disjunction was found in Drosophila females resulting the loss of chromosomes during meiosis and inhibition of cell division Studies on wasp showed a decreased hatchability and accumulation of unhatched eggs when the insects were exposed to spaceflight at different stages of oogenesis For experiments conducted on vertebrate animal models the results are somehow different however Microgravity has no significant effect for fish Medaka etc amphibian South African clawed toad Xenopus laevis or mammals mouse Spermatogenesis on the other hand is more significantly affected by microgravity condition Some researches indicated sperm are sensitive to changes in gravitational force and this sensitivity affects the ability of sperm to fertilize eggs Sperm swim with higher velocity in microgravity which is coupled with altered protein phosphorylation level in sperm under microgravity condition Microgravity also induced activation of the

Gravity amplifies and microgravity decreases circumnutations in Arabidopsis thaliana stems: results from a space experiment.

PubMed

Johnsson, A; Solheim, B G B; Iversen, T-H

2009-01-01

In a microgravity experiment onboard the International Space Station, circumnutations of Arabidopsis thaliana were studied. Plants were cultivated on rotors under a light:dark (LD) cycle of 16 : 8 h, and it was possible to apply controlled centrifugation pulses. Time-lapse images of inflorescence stems (primary, primary axillary and lateral inflorescences) documented the effect of microgravity on the circumnutations. Self-sustained circumnutations of side stems were present in microgravity but amplitudes were mostly very small. In darkness, centrifugation at 0.8 g increased the amplitude by a factor of five to ten. The period at 0.8 g was c. 85 min, in microgravity roughly of the same magnitude. In white light the period decreased to c. 60 min at 0.8 g (microgravity value not measurable). Three-dimensional data showed that under 0.8 g side stems rotated in both clockwise and counter-clockwise directions. Circumnutation data for the main stem in light showed a doubling of the amplitude and a longer period at 0.8 g than in microgravity (c. 80 vs 60 min). For the first time, the importance of gravity in amplifying minute oscillatory movements in microgravity into high-amplitude circumnutations was unequivocally demonstrated. The importance of these findings for the modelling of gravity effects on self-sustained oscillatory movements is discussed.

Diffusion, Viscosity and Crystal Growth in Microgravity

NASA Technical Reports Server (NTRS)

Myerson, Allan S.

1996-01-01

The diffusivity of TriGlycine Sulfate (TGS), Potassium Dihydrogen Phosphate (KDP), Ammonium Dihydrogen Phosphate (ADF) and other compounds of interest to microgravity crystal growth, in supersaturated solutions as a function of solution concentration, 'age' and 'history was studied experimentally. The factors that affect the growth of crystals from water solutions in microgravity have been examined. Three non-linear optical materials have been studied, potassium dihydrogen phosphate (KDP), ammonium dihydrogen phosphate (ADP) and triglycine sulfate (TGC). The diffusion coefficient and viscosity of supersaturated water solutions were measured. Also theoretical model of diffusivity and viscosity in a metastable state, model of crystal growth from solution including non-linear time dependent diffusivity and viscosity effect and computer simulation of the crystal growth process which allows simulation of the microgravity crystal growth were developed.

Microgravity Investigation of Capillary Driven Imbibition

NASA Astrophysics Data System (ADS)

Dushin, V. R.; Nikitin, V. F.; Smirnov, N. N.; Skryleva, E. I.; Tyurenkova, V. V.

2018-05-01

The goal of the present paper is to investigate the capillary driven filtration in porous media under microgravity conditions. New mathematical model that allows taking into account the blurring of the front due to the instability of the displacement that is developing at the front is proposed. The constants in the mathematical model were selected on the basis of the experimental data on imbibition into unsaturated porous media under microgravity conditions. The flow under the action of a combination of capillary forces and a constant pressure drop or a constant flux is considered. The effect of capillary forces and the type of wettability of the medium on the displacement process is studied. A criterion in which case the capillary effects are insignificant and can be neglected is established.

[Effect of simulated microgravity on peripheral oxygen saturation in rats].

PubMed

Chen, Guangfei; Zhang, Yahui; Yuan, Ming; He, Shilin; Ying, Jun; Li, Chen

2018-02-01

To study the effect of microgravity on peripheral oxygen saturation (SpO 2 ) in rats, tail-suspended rats were applied to simulate microgravity environment. SpO 2 and arterial oxygen saturation (SaO 2 ) were measured by pulse oximeter and arterial blood gas analyzer (ABGA) respectively on the 14th day, 21st day and 28th day in tail-suspended group and control group. Paired t -test shows that SpO 2 was significantly lower than SaO 2 in tail-suspended group on the 14th day ( P < 0.05), the 21st day ( P < 0.05) and the 28th day ( P < 0.01). The ANOVA results shows that modeling time had significant effect on SpO 2 value but no effect on SaO 2 value in tail-suspended group. These results indicate that pulse oximeter may be not suitable for oxygen saturation test in microgravity environment.

Microgravity effects on standardized cognitive performance measures

NASA Technical Reports Server (NTRS)

Schiflett, Samuel G.

1992-01-01

The purpose of this experiment, selected to fly on the International Microgravity Laboratory (IML-2) Spacelab mission, is to determine the effects of microgravity upon the cognitive skills which are critical to successful performance of many tasks on board the Space Shuttle. Six tests from the Unified Tri-service Cognitive Performance Assessment Battery (UTC-PAB) will be administered to the Mission Specialists to fulfill the goals of this experiment. These tests are based upon current theoretical models of human performance and the hypothesized effects of microgravity. The principle objective is the identification of the effects of microgravity upon specific information processing skills affecting performance from those of fatigue and shifts in work/rest cycles. Multiple measures of both short and long term fatigue will be obtained and used as a major independent variable for the analysis of these performance data. Scientific supporting studies will determine optimum practice and performance testing schedules for the astronauts. The same tests will be used post-flight to collect data on the recovery of any cognitive performance impairment compared with pre-flight, baseline levels.

Erythroid cell growth and differentiation in vitro in the simulated microgravity environment of the NASA rotating wall vessel bioreactor

NASA Technical Reports Server (NTRS)

Sytkowski, A. J.; Davis, K. L.

2001-01-01

Prolonged exposure of humans and experimental animals to the altered gravitational conditions of space flight has adverse effects on the lymphoid and erythroid hematopoietic systems. Although some information is available regarding the cellular and molecular changes in lymphocytes exposed to microgravity, little is known about the erythroid cellular changes that may underlie the reduction in erythropoiesis and resultant anemia. We now report a reduction in erythroid growth and a profound inhibition of erythropoietin (Epo)-induced differentiation in a ground-based simulated microgravity model system. Rauscher murine erythroleukemia cells were grown either in tissue culture vessels at 1 x g or in the simulated microgravity environment of the NASA-designed rotating wall vessel (RWV) bioreactor. Logarithmic growth was observed under both conditions; however, the doubling time in simulated microgravity was only one-half of that seen at 1 x g. No difference in apoptosis was detected. Induction with Epo at the initiation of the culture resulted in differentiation of approximately 25% of the cells at 1 x g, consistent with our previous observations. In contrast, induction with Epo at the initiation of simulated microgravity resulted in only one-half of this degree of differentiation. Significantly, the growth of cells in simulated microgravity for 24 h prior to Epo induction inhibited the differentiation almost completely. The results suggest that the NASA RWV bioreactor may serve as a suitable ground-based microgravity simulator to model the cellular and molecular changes in erythroid cells observed in true microgravity.

Microgravity: Teacher's guide with activities for physical science

NASA Technical Reports Server (NTRS)

Vogt, Gregory L.; Wargo, Michael J.; Rosenberg, Carla B. (Editor)

1995-01-01

This guide is an educational tool for teachers of grades 5 through 12. It is an introduction to microgravity and its application to spaceborne laboratory experiments. Specific payloads and missions are mentioned with limited detail, including Spacelab, the International Microgravity Laboratory, and the United States Microgravity Laboratory. Activities for students demonstrate chemistry, mathematics, and physics applications of microgravity. Activity objectives include: modeling how satellites orbit Earth; demonstrating that free fall eliminates the local effects of gravity; measuring the acceleration environments created by different motions; using a plasma sheet to observe acceleration forces that are experienced on board a space vehicle; demonstrating how mass can be measured in microgravity; feeling how inertia affects acceleration; observing the gravity-driven fluid flow that is caused by differences in solution density; studying surface tension and the fluid flows caused by differences in surface tension; illustrating the effects of gravity on the burning rate of candles; observing candle flame properties in free fall; measuring the contact angle of a fluid; illustrating the effects of gravity and surface tension on fiber pulling; observing crystal growth phenomena in a 1-g environment; investigating temperature effects on crystal growth; and observing crystal nucleation and growth rate during directional solidification. Each activity includes a background section, procedure, and follow-up questions.

Liquid-Gas-Like Phase Transition in Sand Flow Under Microgravity

NASA Astrophysics Data System (ADS)

Huang, Yu; Zhu, Chongqiang; Xiang, Xiang; Mao, Wuwei

2015-06-01

In previous studies of granular flow, it has been found that gravity plays a compacting role, causing convection and stratification by density. However, there is a lack of research and analysis of the characteristics of different particles' motion under normal gravity contrary to microgravity. In this paper, we conduct model experiments on sand flow using a model test system based on a drop tower under microgravity, within which the characteristics and development processes of granular flow under microgravity are captured by high-speed cameras. The configurations of granular flow are simulated using a modified MPS (moving particle simulation), which is a mesh-free, pure Lagrangian method. Moreover, liquid-gas-like phase transitions in the sand flow under microgravity, including the transitions to "escaped", "jumping", and "scattered" particles are highlighted, and their effects on the weakening of shear resistance, enhancement of fluidization, and changes in particle-wall and particle-particle contact mode are analyzed. This study could help explain the surface geology evolution of small solar bodies and elucidate the nature of granular interaction.

The impact of microgravity on bone in humans.

PubMed

Grimm, Daniela; Grosse, Jirka; Wehland, Markus; Mann, Vivek; Reseland, Janne Elin; Sundaresan, Alamelu; Corydon, Thomas Juhl

2016-06-01

Experiencing real weightlessness in space is a dream for many of us who are interested in space research. Although space traveling fascinates us, it can cause both short-term and long-term health problems. Microgravity is the most important influence on the human organism in space. The human body undergoes dramatic changes during a long-term spaceflight. In this review, we will mainly focus on changes in calcium, sodium and bone metabolism of space travelers. Moreover, we report on the current knowledge on the mechanisms of bone loss in space, available models to simulate the effects of microgravity on bone on Earth as well as the combined effects of microgravity and cosmic radiation on bone. The available countermeasures applied in space will also be evaluated. Copyright © 2016 Elsevier Inc. All rights reserved.

Flame-Vortex Interactions in Microgravity to Improve Models of Turbulent Combustion

NASA Technical Reports Server (NTRS)

Driscoll, James F.

1999-01-01

A unique flame-vortex interaction experiment is being operated in microgravity in order to obtain fundamental data to assess the Theory of Flame Stretch which will be used to improve models of turbulent combustion. The experiment provides visual images of the physical process by which an individual eddy in a turbulent flow increases the flame surface area, changes the local flame propagation speed, and can extinguish the reaction. The high quality microgravity images provide benchmark data that are free from buoyancy effects. Results are used to assess Direct Numerical Simulations of Dr. K. Kailasanath at NRL, which were run for the same conditions.

A numerical study of biofilm growth in a microgravity environment

NASA Astrophysics Data System (ADS)

Aristotelous, A. C.; Papanicolaou, N. C.

2017-10-01

A mathematical model is proposed to investigate the effect of microgravity on biofilm growth. We examine the case of biofilm suspended in a quiescent aqueous nutrient solution contained in a rectangular tank. The bacterial colony is assumed to follow logistic growth whereas nutrient absorption is assumed to follow Monod kinetics. The problem is modeled by a coupled system of nonlinear partial differential equations in two spatial dimensions solved using the Discontinuous Galerkin Finite Element method. Nutrient and biofilm concentrations are computed in microgravity and normal gravity conditions. A preliminary quantitative relationship between the biofilm concentration and the gravity field intensity is derived.

Effects of Microgravity on Streptoccoccus Pneumonia

NASA Technical Reports Server (NTRS)

2003-01-01

These gels were obtained by two-dimensional (2D) electrophoresis, in which proteins move different substances through a polyacrylamide gel matrix based on their molecular weight and total charge in an electric field. The gels illustrate principal investigator David Niesel's findings that exposure to modeled microgravity results in some Streptoccoccus Pneumonia's proteins being upregulated and others being downregulated. In 2D protein profiles of whole cell lysates of Streptoccoccus Pneumonia, 6,304 cultured under normal gravity (left), appear to be expressed at higher levels indicated with black circles. Red circles (right) indicate proteins that were grown under modeled microgravity in a high aspect ratio vessel HARV).

The Influence of Microgravity on Invasive Growth in Saccharomyces cerevisiae

NASA Astrophysics Data System (ADS)

Van Mulders, Sebastiaan E.; Stassen, Catherine; Daenen, Luk; Devreese, Bart; Siewers, Verena; van Eijsden, Rudy G. E.; Nielsen, Jens; Delvaux, Freddy R.; Willaert, Ronnie

2011-01-01

This study investigates the effects of microgravity on colony growth and the morphological transition from single cells to short invasive filaments in the model eukaryotic organism Saccharomyces cerevisiae. Two-dimensional spreading of the yeast colonies grown on semi-solid agar medium was reduced under microgravity in the Σ1278b laboratory strain but not in the CMBSESA1 industrial strain. This was supported by the Σ1278b proteome map under microgravity conditions, which revealed upregulation of proteins linked to anaerobic conditions. The Σ1278b strain showed a reduced invasive growth in the center of the yeast colony. Bud scar distribution was slightly affected, with a switch toward more random budding. Together, microgravity conditions disturb spatially programmed budding patterns and generate strain-dependent growth differences in yeast colonies on semi-solid medium.

Baroreflex dysfunction induced by microgravity: potential relevance to postflight orthostatic intolerance

NASA Technical Reports Server (NTRS)

Ertl, A. C.; Diedrich, A.; Biaggioni, I.; Robertson, D. (Principal Investigator)

2000-01-01

Microgravity imposes adaptive changes in the human body. This review focuses on the changes in baroreflex function produced by actual spaceflight, or by experimental models that simulate microgravity, e.g., bed rest. We will analyze separately studies involving baroreflexes arising from carotid sinus and aortic arch afferents ("high-pressure baroreceptors"), and cardiopulmonary afferents ("low-pressure receptors"). Studies from unrelated laboratories using different techniques have concluded that actual or simulated exposure to microgravity reduces baroreflex function arising from carotid sinus afferents ("carotic-cardiac baroreflex"). The techniques used to study the carotid-cardiac baroreflex, using neck suction and compression to simulate changes in blood pressure, have been extensively validated. In contrast, it is more difficult to selectively study aortic arch or cardiopulmonary baroreceptors. Nonetheless, studies that have examined these baroreceptors suggest that microgravity produces the opposite effect, ie, an increase in the gain of aortic arch and cardiopulmonary baroreflexes. Furthermore, most studies have focus on instantaneous changes in heart rate, which almost exclusively examines the vagal limb of the baroreflex. In comparison, there is limited information about the effect of microgravity on sympathetic function. A substantial proportion of subjects exposed to microgravity develop transient orthostatic intolerance. It has been proposed that alterations in baroreflex function play a role in the orthostatic intolerance induced by microgravity. The evidence in favor and against this hypothesis is reviewed.

An Integrated Model of the Cardiovascular and Central Nervous Systems for Analysis of Microgravity Induced Fluid Redistribution

NASA Technical Reports Server (NTRS)

Price, R.; Gady, S.; Heinemann, K.; Nelson, E. S.; Mulugeta, L.; Ethier, C. R.; Samuels, B. C.; Feola, A.; Vera, J.; Myers, J. G.

2015-01-01

A recognized side effect of prolonged microgravity exposure is visual impairment and intracranial pressure (VIIP) syndrome. The medical understanding of this phenomenon is at present preliminary, although it is hypothesized that the headward shift of bodily fluids in microgravity may be a contributor. Computational models can be used to provide insight into the origins of VIIP. In order to further investigate this phenomenon, NASAs Digital Astronaut Project (DAP) is developing an integrated computational model of the human body which is divided into the eye, the cerebrovascular system, and the cardiovascular system. This presentation will focus on the development and testing of the computational model of an integrated model of the cardiovascular system (CVS) and central nervous system (CNS) that simulates the behavior of pressures, volumes, and flows within these two physiological systems.

Modeled Microgravity Inhibits Apoptosis in Peripheral Blood Lymphocytes

NASA Technical Reports Server (NTRS)

Risin, Diana; Pellis, Neal R.

1999-01-01

Impairment of the immunity in astronauts and cosmonauts even in short term flights is a recognized risk. Long term orbital space missions and anticipated interplanetary flights increase the concern for more pronounced effects on the immune system with potential clinical consequences. Impairment of the immunity in space may be due tonumerous physiological changes caused by space-related factors, which in turn affect the immune system, or alternatively, it may be due to direct effects of different factors encountered in space on lymphoid cells and their interactions. Indeed, in modeled microgravity (MMG) experiments on Earth we and others showed that microgravity directly affects multiple lymphocyte functions. It interferes with expression of cell surface molecules, causes inhibition of lymphocyte locomotion, suppresses polyclopal and antigen-specific lymphocyte activation, selectively inhibits protein kinase C (PKC) isoforms. Some of these effects were also confirmed in cell culture experiments in real space conditions during Spacelab, Biokosmos and Shuttle Missions. The results of these studies, taken together, strongly indicated that microgravity interferes with fundamental biological processes associated with functional and structural changes in cell surface membranes, cell surface molecules and in their interaction. Based on the data and on their interpretation, we hypothesized that microgravity in addition to observed functional changes affects programmed cell death (PCD) in lymphocyte populations and that this mechanism could contribute to the impairment of the immunity.

Effect of gamma-ray irradiation on the unloaded animal model

NASA Astrophysics Data System (ADS)

Choi, Jong-Il; Yoon, Min-Chul; Sung, Nak-Yoon; Kim, Jae-Hun; Jong Lee, Yun; Lee, Ki-Soo; Choi, In-Ho; Nam, Gung Uk; Lee, Ju-Woon

During the space flight, human beings encountered the extreme conditions such as the cosmic ray irradiation and microgravity. There have been developed the animal models to simulate the microgravity condition in laboratory, but no study was carried out to investigate the combined effect of microgravity and exposure to irradiation. In this study, it was examined the effect of gamma irradiation on the suspension model. Rats were divided into four groups, Group I was loaded and not exposed to gamma irradiation, Group 2 was unloaded and not exposed, Group 3 was loaded and exposed to gamma irradiation at the dose of 50 mSV, and Group 4 was unloaded and exposed to gamma irradiation at the same dose. It was measured body, muscles and tissues weights and the biological analysis and the hematological response in blood samples were conducted. Anti-gravity tissue weight was only changed between loading and un-loading condition. However, there was no difference between irradiation exposed and not exposed unloaded groups. To know the difference of protein expression in anti-gravity tissues, 2 dimensional electrophoresis was performed. It has been found that the expression levels of several proteins were different by unloading condition and by irradiation exposed condition, respectively. These results provided the information on the combined effect of irradiation and microgravity to simulate space flight, and could be useful to search the candidate material for the countermeasure against space environment.

Transfection of the IHH gene into rabbit BMSCs in a simulated microgravity environment promotes chondrogenic differentiation and inhibits cartilage aging.

PubMed

Liu, Peng-Cheng; Liu, Kuan; Liu, Jun-Feng; Xia, Kuo; Chen, Li-Yang; Wu, Xing

2016-09-27

The effect of overexpressing the Indian hedgehog (IHH) gene on the chondrogenic differentiation of rabbit bone marrow-derived mesenchymal stem cells (BMSCs) was investigated in a simulated microgravity environment. An adenovirus plasmid encoding the rabbit IHH gene was constructed in vitro and transfected into rabbit BMSCs. Two large groups were used: conventional cell culture and induction model group and simulated microgravity environment group. Each large group was further divided into blank control group, GFP transfection group, and IHH transfection group. During differentiation induction, the expression levels of cartilage-related and cartilage hypertrophy-related genes and proteins in each group were determined. In the conventional model, the IHH transfection group expressed high levels of cartilage-related factors (Coll2 and ANCN) at the early stage of differentiation induction and expressed high levels of cartilage hypertrophy-related factors (Coll10, annexin 5, and ALP) at the late stage. Under the simulated microgravity environment, the IHH transfection group expressed high levels of cartilage-related factors and low levels of cartilage hypertrophy-related factors at all stages of differentiation induction. Under the simulated microgravity environment, transfection of the IHH gene into BMSCs effectively promoted the generation of cartilage and inhibited cartilage aging and osteogenesis. Therefore, this technique is suitable for cartilage tissue engineering.

The Effect of Simulated Microgravity Environment of RWV Bioreactors on Surface Reactions and Adsorption of Serum Proteins on Bone-bioactive Microcarriers

NASA Technical Reports Server (NTRS)

Radin, Shula; Ducheyne, P.; Ayyaswamy, P. S.

2003-01-01

Biomimetically modified bioactive materials with bone-like surface properties are attractive candidates for use as microcarriers for 3-D bone-like tissue engineering under simulated microgravity conditions of NASA designed rotating wall vessel (RWV) bioreactors. The simulated microgravity environment is attainable under suitable parametric conditions of the RWV bioreactors. Ca-P containing bioactive glass (BG), whose stimulatory effect on bone cell function had been previously demonstrated, was used in the present study. BG surface modification via reactions in solution, resulting formation of bone-like minerals at the surface and adsorption of serum proteins is critical for obtaining the stimulatory effect. In this paper, we report on the major effects of simulated microgravity conditions of the RWV on the BG reactions surface reactions and protein adsorption in physiological solutions. Control tests at normal gravity were conducted at static and dynamic conditions. The study revealed that simulated microgravity remarkably enhanced reactions involved in the BG surface modification, including BG dissolution, formation of bone-like minerals at the surface and adsorption of serum proteins. Simultaneously, numerical models were developed to simulate the mass transport of chemical species to and from the BG surface under normal gravity and simulated microgravity conditions. The numerical results showed an excellent agreement with the experimental data at both testing conditions.

Preparation for microgravity - The role of the Microgravity Material Science Laboratory

NASA Technical Reports Server (NTRS)

Johnston, J. Christopher; Rosenthal, Bruce N.; Meyer, Maryjo B.; Glasgow, Thomas K.

1988-01-01

Experiments at the NASA Lewis Research Center's Microgravity Material Science Laboratory using physical and mathematical models to delineate the effects of gravity on processes of scientific and commercial interest are discussed. Where possible, transparent model systems are used to visually track convection, settling, crystal growth, phase separation, agglomeration, vapor transport, diffusive flow, and polymer reactions. Materials studied include metals, alloys, salts, glasses, ceramics, and polymers. Specific technologies discussed include the General Purpose furnace used in the study of metals and crystal growth, the isothermal dendrite growth apparatus, the electromagnetic levitator/instrumented drop tube, the high temperature directional solidification furnace, the ceramics and polymer laboratories and the center's computing facilities.

The effects and mechanisms of clinorotation on proliferation and differentiation in bone marrow mesenchymal stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Ming; Wang, Yongchun; Yang, Min

Data from human and rodent studies have demonstrated that microgravity induces observed bone loss in real spaceflight or simulated experiments. The decrease of bone formation and block of maturation may play important roles in bone loss induced by microgravity. The aim of this study was to investigate the changes of proliferation and differentiation in bone marrow mesenchymal stem cells (BMSCs) induced by simulated microgravity and the mechanisms underlying it. We report here that clinorotation, a simulated model of microgravity, decreased proliferation and differentiation in BMSCs after exposure to 48 h simulated microgravity. The inhibited proliferation are related with blocking the cellmore » cycle in G2/M and enhancing the apoptosis. While alterations of the osteoblast differentiation due to the decreased SATB2 expression induced by simulated microgravity in BMSCs. - Highlights: • Simulated microgravity inhibited proliferation and differentiation in BMSCs. • The decreased proliferation due to blocked cell cycle and enhanced the apoptosis. • The inhibited differentiation accounts for alteration of SATB2, Hoxa2 and Cbfa1.« less

Response of Human Prostate Cancer Cells to Mitoxantrone Treatment in Simulated Microgravity Environment

NASA Astrophysics Data System (ADS)

Zhang, Ye; Wu, Honglu

2012-07-01

RESPONSE OF HUMAN PROSTATE CANCER CELLS TO MITOXANTRONE TREATMENT IN SIMULATED MICROGRAVITY ENVIRONMENT Ye Zhang1,2, Christopher Edwards3, and Honglu Wu1 1 NASA-Johnson Space Center, Houston, TX 2 Wyle Integrated Science and Engineering Group, Houston, TX 3 Oregon State University, Corvallis, OR This study explores the changes in growth of human prostate cancer cells (LNCaP) and their response to the treatment of an antineoplastic agent, mitoxantrone, under the simulated microgravity condition. In comparison to static 1g, microgravity and simulated microgravity have been shown to alter global gene expression patterns and protein levels in various cultured cell models or animals. However, very little is known about the effect of altered gravity on the responses of cells to the treatment of drugs, especially chemotherapy drugs. To test the hypothesis that zero gravity would result in altered regulations of cells in response to antineoplastic agents, we cultured LNCaP cells in either a High Aspect Ratio Vessel (HARV) bioreactor at the rotating condition to model microgravity in space or in the static condition as control, and treated the cells with mitoxantrone. Cell growth, as well as expressions of oxidative stress related genes, were analyzed after the drug treatment. Compared to static 1g controls, the cells cultured in the simulated microgravity environment did not present significant differences in cell viability, growth rate, or cell cycle distribution. However, after mitoxantrone treatment, a significant proportion of bioreactor cultured cells became apoptotic or was arrested in G2. Several oxidative stress related genes also showed a higher expression level post mitoxantrone treatment. Our results indicate that simulated microgravity may alter the response of LNCaP cells to mitoxantrone treatment. Understanding the mechanisms by which cells respond to drugs differently in an altered gravity environment will be useful for the improvement of cancer treatment on the ground. This study explores the changes in growth of human prostate cancer cells (LNCaP) and their response to the treatment of an antineoplastic agent, mitoxantrone, under the simulated microgravity condition. In comparison to static 1g, microgravity and simulated microgravity have been shown to alter global gene expression patterns and protein levels in various cultured cell models or animals. However, very little is known about the effect of altered gravity on the responses of cells to the treatment of drugs, especially chemotherapy drugs. To test the hypothesis that zero gravity would result in altered regulations of cells in response to antineoplastic agents, we cultured LNCaP cells in either a High Aspect Ratio Vessel (HARV) bioreactor at the rotating condition to model microgravity in space or in the static condition as control, and treated the cells with mitoxantrone. Cell growth, as well as expressions of oxidative stress related genes, were analyzed after the drug treatment. Compared to static 1g controls, the cells cultured in the simulated microgravity environment did not present significant differences in cell viability, growth rate, or cell cycle distribution. However, after mitoxantrone treatment, a significant proportion of bioreactor cultured cells became apoptotic or was arrested in G2. Several oxidative stress related genes also showed a higher expression level post mitoxantrone treatment. Our results indicate that simulated microgravity may alter the response of LNCaP cells to mitoxantrone treatment. Understanding the mechanisms by which cells respond to drugs differently in an altered gravity environment will be useful for the improvement of cancer treatment on the ground.

Space research on organs and tissues

NASA Technical Reports Server (NTRS)

Tischler, Marc E.; Morey-Holton, Emily

1992-01-01

The effects of microgravity on various physiological systems are reviewed focusing on muscle, bone, cardiovascular, pulmonary, neurovestibular, liver, and endocrine systems. It is noted that certain alterations of organs and tissues caused by microgravity are not reproducible in earth-bound animal or human models. Thus space research on organs and tissues is essential for both validating the earth-bound models used in laboratories and studying the adaptations to weightlessness which cannot be mimicked on earth.

Analytical determination of space station response to crew motion and design of suspension system for microgravity experiments

NASA Technical Reports Server (NTRS)

Liu, F. C.

1986-01-01

The objective of this investigation is to make analytical determination of the acceleration produced by crew motion in an orbiting space station and define design parameters for the suspension system of microgravity experiments. A simple structural model for simulation of the IOC space station is proposed. Mathematical formulation of this model provides the engineers a simple and direct tool for designing an effective suspension system.

Impact of simulated microgravity on the normal developmental time line of an animal-bacteria symbiosis

PubMed Central

Foster, Jamie S.; Khodadad, Christina L. M.; Ahrendt, Steven R.; Parrish, Mirina L.

2013-01-01

The microgravity environment during space flight imposes numerous adverse effects on animal and microbial physiology. It is unclear, however, how microgravity impacts those cellular interactions between mutualistic microbes and their hosts. Here, we used the symbiosis between the host squid Euprymna scolopes and its luminescent bacterium Vibrio fischeri as a model system. We examined the impact of simulated microgravity on the timeline of bacteria-induced development in the host light organ, the site of the symbiosis. To simulate the microgravity environment, host squid and symbiosis-competent bacteria were incubated together in high-aspect ratio rotating wall vessel bioreactors and examined throughout the early stages of the bacteria-induced morphogenesis. The host innate immune response was suppressed under simulated microgravity; however, there was an acceleration of bacteria-induced apoptosis and regression in the host tissues. These results suggest that the space flight environment may alter the cellular interactions between animal hosts and their natural healthy microbiome. PMID:23439280

Human Modeling Evaluations in Microgravity Workstation and Restraint Development

NASA Technical Reports Server (NTRS)

Whitmore, Mihriban; Chmielewski, Cynthia; Wheaton, Aneice; Hancock, Lorraine; Beierle, Jason; Bond, Robert L. (Technical Monitor)

1999-01-01

The International Space Station (ISS) will provide long-term missions which will enable the astronauts to live and work, as well as, conduct research in a microgravity environment. The dominant factor in space affecting the crew is "weightlessness" which creates a challenge for establishing workstation microgravity design requirements. The crewmembers will work at various workstations such as Human Research Facility (HRF), Microgravity Sciences Glovebox (MSG) and Life Sciences Glovebox (LSG). Since the crew will spend considerable amount of time at these workstations, it is critical that ergonomic design requirements are integral part of design and development effort. In order to achieve this goal, the Space Human Factors Laboratory in the Johnson Space Center Flight Crew Support Division has been tasked to conduct integrated evaluations of workstations and associated crew restraints. Thus, a two-phase approach was used: 1) ground and microgravity evaluations of the physical dimensions and layout of the workstation components, and 2) human modeling analyses of the user interface. Computer-based human modeling evaluations were an important part of the approach throughout the design and development process. Human modeling during the conceptual design phase included crew reach and accessibility of individual equipment, as well as, crew restraint needs. During later design phases, human modeling has been used in conjunction with ground reviews and microgravity evaluations of the mock-ups in order to verify the human factors requirements. (Specific examples will be discussed.) This two-phase approach was the most efficient method to determine ergonomic design characteristics for workstations and restraints. The real-time evaluations provided a hands-on implementation in a microgravity environment. On the other hand, only a limited number of participants could be tested. The human modeling evaluations provided a more detailed analysis of the setup. The issues identified during the real-time testing were investigated in the human modeling analyses. In some cases, the opposite was true where preliminary human modeling analyses provided the design engineers with critical issues that needed to be addressed further. This extensive approach provided an effective means to fully address ergonomic design considerations and accurately identify critical issues.

In vivo nuclear magnetic resonance imaging

NASA Technical Reports Server (NTRS)

Leblanc, A.; Evans, H.; Bryan, R. N.; Johnson, P.; Schonfeld, E.; Jhingran, S. G.

1984-01-01

A number of physiological changes have been demonstrated in bone, muscle and blood after exposure of humans and animals to microgravity. Determining mechanisms and the development of effective countermeasures for long duration space missions is an important NASA goal. The advent of tomographic nuclear magnetic resonance imaging (NMR or MRI) gives NASA a way to greatly extend early studies of this phenomena in ways not previously possible; NMR is also noninvasive and safe. NMR provides both superb anatomical images for volume assessments of individual organs and quantification of chemical/physical changes induced in the examined tissues. The feasibility of NMR as a tool for human physiological research as it is affected by microgravity is demonstrated. The animal studies employed the rear limb suspended rat as a model of mucle atrophy that results from microgravity. And bedrest of normal male subjects was used to simulate the effects of microgravity on bone and muscle.

Weightlessness and the human skeleton: A new perspective

NASA Technical Reports Server (NTRS)

Holick, Michael F.

1994-01-01

It is now clear after more than two decades of space exploration that one of the major short- and long-term effects of microgravity on the human body is the loss of bone. The purpose of this presentation will be to review the data regarding the impact of microgravity and bed rest on calcium and bone metabolism. The author takes the position in this Socratic debate that the effect of microgravity on bone metabolism can be either reversed or mitigated. As we begins to contemplate long-duration space flight and habitation of Space Station Freedom and the moon, one of the issues that needs to be addressed is whether humans need to maintain a skeleton that has been adapted for the one-g force on earth. Clearly, in the foreseeable future, a healthy and structurally sound skeleton will be required for astronauts to shuttle back and forth from earth to the moon, space station, and Mars. Based on most available data from bed-rest studies and the short- and long-duration microgravity experiences by astronauts and cosmonauts, bone loss is a fact of life in this environment. With the rapid advances in understanding of bone physiology it is now possible to contemplate measures that can prevent or mitigate microgravity-induced bone loss. Will the new therapeutic approaches for enhancing bone mineralization be useful for preventing significant bone loss during long-term space flight? Are there other approaches such as exercise and electrical stimulation that can be used to mitigate the impact of microgravity on the skeleton? A recent study that evaluated the effect of microgravity on bone modeling in developing chick embryos may perhaps provide a new perspective about the impact of microgravity on bone metabolism.

Categorization of Brazil nut effect and its reverse under less-convective conditions for microgravity geology

NASA Astrophysics Data System (ADS)

Chujo, Toshihiro; Mori, Osamu; Kawaguchi, Junichiro; Yano, Hajime

2018-03-01

Due to its important role in the sorting of particles on microgravity bodies by size, Brazil nut effect (BNE) is a major subject of study for understanding the evolution of planetesimals. Recent studies have revealed that the mechanism for the BNE on microgravity bodies is the percolation of particles or void-filling, rather than granular convection. This study also considers the mechanism for the BNE under `less-convective' conditions and introduces three categories of behaviour for particles that mainly depend on the dimensionless acceleration of vibration Γ (ratio of maximum acceleration to gravitational acceleration), using a simplified analytical model. The conditions for Γ proposed by the model for each category are verified by both numerical simulations and laboratory experiments. `Less-convective' conditions are realized by reducing the friction force between particles and the wall. We found three distinct behaviours of the particles when Γ > 1: the (i) `slow BNE', (ii) `fast BNE', and (iii) `fluid motion' (the reverse BNE may be induced), and the thresholds for Γ correspond well with those proposed by the simple model. We also applied this categorization to low-gravity environments and found that the categorization scales with gravity level. These results imply that laboratory experiments can provide knowledge of granular mobility on the surface of microgravity bodies.

The sea urchin larva, a suitable model for biomineralisation studies in space (IML-2 ESA Biorack experiment '24-F urchin').

PubMed

Marthy, H J; Gasset, G; Tixador, R; Schatt, P; Eche, B; Dessommes, A; Giacomini, T; Tap, G; Gorand, D

1996-06-27

By the ESA Biorack 'F-24 urchin' experiment of the IML-2 mission, for the first time the biomineralisation process in developing sea urchin larvae could be studied under real microgravity conditions. The main objectives were to determine whether in microgravity the process of skeleton formation does occur correctly compared to normal gravity conditions and whether larvae with differentiated skeletons do 'de-mineralise'. These objectives have been essentially achieved. Postflight studies on the recovered 'sub-normal' skeletons focused on qualitative, statistical and quantitative aspects. Clear evidence is obtained that the basic biomineralisation process does actually occur normally in microgravity. No significant differences are observed between flight and ground samples. The sub-normal skeleton architectures indicate, however, that the process of positioning of the skeletogenic cells (determining primarily shape and size of the skeleton) is particularly sensitive to modifications of environmental factors, potentially including gravity. The anatomical heterogeneity of the recovered skeletons, interpreted as long term effect of an accidental thermal shock during artificial egg fertilisation (break of climatisation at LSSF), masks possible effects of microgravity. No pronounced demineralisation appears to occur in microgravity; the magnesium component of the skeleton seems yet less stable than the calcium. On the basis of these results, a continuation of biomineralisation studies in space, with the sea urchin larva as model system, appears well justified and desirable.

Delineating the Impact of Weightlessness on Human Physiology Using Computational Models

NASA Technical Reports Server (NTRS)

Kassemi, Mohammad

2015-01-01

Microgravity environment has profound effects on several important human physiological systems. The impact of weightlessness is usually indirect as mediated by changes in the biological fluid flow and transport and alterations in the deformation and stress fields of the compliant tissues. In this context, Fluid-Structural and Fluid-Solid Interaction models provide a valuable tool in delineating the physical origins of the physiological changes so that systematic countermeasures can be devised to reduce their adverse effects. In this presentation, impact of gravity on three human physiological systems will be considered. The first case involves prediction of cardiac shape change and altered stress distributions in weightlessness. The second, presents a fluid-structural-interaction (FSI) analysis and assessment of the vestibular system and explores the reasons behind the unexpected microgravity caloric stimulation test results performed aboard the Skylab. The last case investigates renal stone development in microgravity and the possible impact of re-entry into partial gravity on the development and transport of nucleating, growing, and agglomerating renal calculi in the nephron. Finally, the need for model validation and verification and application of the FSI models to assess the effects of Artificial Gravity (AG) are also briefly discussed.

Simulation of Cardiovascular Response to the Head-Up/Head-Down Tilt at Different Angles

NASA Astrophysics Data System (ADS)

Liu, Yang; Lu, Hong-Bing; Jiao, Chun; Zhang, Li-Fan

2008-06-01

The disappearance of hydrostatic pressure is the original factor that causes the changes of cardiovascular system under microgravity. The hydrostatical changes can be simulated by postural changes. Especially the head-down position can be used to simulate the effects of microgravity. The goal of this investigation was to develop a mathematical model for simulation of the human cardiovascular responses to acute and prolonged exposure under microgravity environment. We were particularly interested in the redistribution of transmural pressures, flows, blood volume, and the consequent alterations in local hemodynamics in different cardiovascular compartments during acute exposure and chronic adjustments. As a preliminary study, we first developed a multi-element, distributed hemodynamic model of human cardiovascular system, and verified the model to simulate cardiovascular changes during head up/down tilt at various angles.

Effect of gravity-like torque on goal-directed arm movements in microgravity.

PubMed

Bringoux, L; Blouin, J; Coyle, T; Ruget, H; Mouchnino, L

2012-05-01

Gravitational force level is well-known to influence arm motor control. Specifically, hyper- or microgravity environments drastically change pointing accuracy and kinematics, particularly during initial exposure. These modifications are thought to partly reflect impairment in arm position sense. Here we investigated whether applying normogravitational constraints at joint level during microgravity episodes of parabolic flights could restore movement accuracy equivalent to that observed on Earth. Subjects with eyes closed performed arm reaching movements toward predefined sagittal angular positions in four environment conditions: normogravity, hypergravity, microgravity, and microgravity with elastic bands attached to the arm to mimic gravity-like torque at the shoulder joint. We found that subjects overshot and undershot the target orientations in hypergravity and microgravity, respectively, relative to a normogravity baseline. Strikingly, adding gravity-like torque prior to and during movements performed in microgravity allowed subjects to be as accurate as in normogravity. In the former condition, arm movement kinematics, as notably illustrated by the relative time to peak velocity, were also unchanged relative to normogravity, whereas significant modifications were found in hyper- and microgravity. Overall, these results suggest that arm motor planning and control are tuned with respect to gravitational information issued from joint torque, which presumably enhances arm position sense and activates internal models optimally adapted to the gravitoinertial environment.

Simulated microgravity: critical review on the use of random positioning machines for mammalian cell culture.

PubMed

Wuest, Simon L; Richard, Stéphane; Kopp, Sascha; Grimm, Daniela; Egli, Marcel

2015-01-01

Random Positioning Machines (RPMs) have been used since many years as a ground-based model to simulate microgravity. In this review we discuss several aspects of the RPM. Recent technological development has expanded the operative range of the RPM substantially. New possibilities of live cell imaging and partial gravity simulations, for example, are of particular interest. For obtaining valuable and reliable results from RPM experiments, the appropriate use of the RPM is of utmost importance. The simulation of microgravity requires that the RPM's rotation is faster than the biological process under study, but not so fast that undesired side effects appear. It remains a legitimate question, however, whether the RPM can accurately and reliably simulate microgravity conditions comparable to real microgravity in space. We attempt to answer this question by mathematically analyzing the forces working on the samples while they are mounted on the operating RPM and by comparing data obtained under real microgravity in space and simulated microgravity on the RPM. In conclusion and after taking the mentioned constraints into consideration, we are convinced that simulated microgravity experiments on the RPM are a valid alternative for conducting examinations on the influence of the force of gravity in a fast and straightforward approach.

Simulated Microgravity: Critical Review on the Use of Random Positioning Machines for Mammalian Cell Culture

PubMed Central

Wuest, Simon L.; Richard, Stéphane; Kopp, Sascha

2015-01-01

Random Positioning Machines (RPMs) have been used since many years as a ground-based model to simulate microgravity. In this review we discuss several aspects of the RPM. Recent technological development has expanded the operative range of the RPM substantially. New possibilities of live cell imaging and partial gravity simulations, for example, are of particular interest. For obtaining valuable and reliable results from RPM experiments, the appropriate use of the RPM is of utmost importance. The simulation of microgravity requires that the RPM's rotation is faster than the biological process under study, but not so fast that undesired side effects appear. It remains a legitimate question, however, whether the RPM can accurately and reliably simulate microgravity conditions comparable to real microgravity in space. We attempt to answer this question by mathematically analyzing the forces working on the samples while they are mounted on the operating RPM and by comparing data obtained under real microgravity in space and simulated microgravity on the RPM. In conclusion and after taking the mentioned constraints into consideration, we are convinced that simulated microgravity experiments on the RPM are a valid alternative for conducting examinations on the influence of the force of gravity in a fast and straightforward approach. PMID:25649075

Ground Based Studies of Gas-Liquid Flows in Microgravity Using Learjet Trajectories

NASA Technical Reports Server (NTRS)

Bousman, W. S.; Dukler, A. E.

1994-01-01

A 1.27 cm diameter two phase gas-liquid flow experiment has been developed with the NASA Lewis Research Center to study two-phase flows in microgravity. The experiment allows for the measurement of void fraction, pressure drop, film thickness and bubble and wave velocities as well as for high speed photography. Three liquids were used to study the effects of liquid viscosity and surface tension, and flow pattern maps are presented for each. The experimental results are used to develop mechanistically based models to predict void fraction, bubble velocity, pressure drop and flow pattern transitions in microgravity.

Effect of modeled microgravity on UV-C-induced interplant communication of Arabidopsis thaliana.

PubMed

Wang, Ting; Xu, Wei; Li, Huasheng; Deng, Chenguang; Zhao, Hui; Wu, Yuejin; Liu, Min; Wu, Lijun; Lu, Jinying; Bian, Po

2017-12-01

Controlled ecological life support systems (CELSS) will be an important feature of long-duration space missions of which higher plants are one of the indispensable components. Because of its pivotal role in enabling plants to cope with environmental stress, interplant communication might have important implications for the ecological stability of such CELSS. However, the manifestations of interplant communication in microgravity conditions have yet to be fully elucidated. To address this, a well-established Arabidopsis thaliana co-culture experimental system, in which UV-C-induced airborne interplant communication is evaluated by the alleviation of transcriptional gene silencing (TGS) in bystander plants, was placed in microgravity modeled by a two-dimensional rotating clinostat. Compared with plants under normal gravity, TGS alleviation in bystander plants was inhibited in microgravity. Moreover, TGS alleviation was also prevented when plants of the pgm-1 line, which are impaired in gravity sensing, were used in either the UV-C-irradiated or bystander group. In addition to the specific TGS-loci, interplant communication-shaped genome-wide DNA methylation in bystander plants was altered under microgravity conditions. These results indicate that interplant communications might be modified in microgravity. Time course analysis showed that microgravity interfered with both the production of communicative signals in UV-C-irradiated plants and the induction of epigenetic responses in bystander plants. This was further confirmed by the experimental finding that microgravity also prevented the response of bystander plants to exogenous methyl jasmonate (JA) and methyl salicylate (SA), two well-known airborne signaling molecules, and down-regulated JA and SA biosynthesis in UV-C-irradiated plants. Copyright © 2017 Elsevier B.V. All rights reserved.

Proteomic Analysis of Rat Hippocampus under Simulated Microgravity

NASA Astrophysics Data System (ADS)

Wang, Yun; Li, Yujuan; Zhang, Yongqian; Liu, Yahui; Deng, Yulin

It has been found that microgravity may lead to impairments in cognitive functions performed by CNS. However, the exact mechanism of effects of microgravity on the learning and memory function in animal nervous system is not elucidated yet. Brain function is mainly mediated by membrane proteins and their dysfunction causes degeneration of the learning and memory. To induce simulated microgravity, the rat tail suspension model was established. Comparative O (18) labeling quantitative proteomic strategy was applied to detect the differentially expressed proteins in rat brain hippocampus. The proteins in membrane fraction from rat hippocampus were digested by trypsin and then the peptides were separated by off-gel for the first dimension with 24 wells device encompassing the pH range of 3 - 10. An off-gel fraction was subjected into LC-ESI-QTOF in triplicate. Preliminary results showed that nearly 77% of the peptides identified were specific to one fraction. 676 proteins were identified among which 108 proteins were found differentially expressed under simulated microgravity. Using the KOBAS server, many enriched pathways, such as metabolic pathway, synaptic vesicle cycle, endocytosis, calcium signaling pathway, and SNAREs pathway were identified. Furthermore, it has been found that neurotransmitter released by Ca (2+) -triggered synaptic vesicles fusion may play key role in neural function. Rab 3A might inhibit the membrane fusion and neurotransmitter release. The protein alteration of the synaptic vesicle cycle may further explain the effects of microgravity on learning and memory function in rats. Key words: Microgravity; proteomics; synaptic vesicle; O (18) ({}) -labeling

Effects of microgravity on epidermal development in the rat

NASA Technical Reports Server (NTRS)

Hoath, Steven B.

1995-01-01

The overall goal of this project was to investigate the effects of prolonged weightlessness on the development of the skin in the fetal and newborn rat. Specifically, we used the NASA microgravitational rat model to test the following hypotheses: (1) Exposure of the pregnant rat to microscopy during late gestation will diminish the transport of calcium across the placenta from the mother to the fetus leading to decreases in total epidermal and dermal calcium content; (2) Microgravity will lead to slowing of body growth and diminish the rate of formation of the outermost layer of the epidermis and the stratum corneum; and (3) Microgravity will lead to formation of a stratum corneum with decreased DC electrical resistance and increased permeability to tritiated water.

Oxygen and Fuel Jet Diffusion Flame Studies in Microgravity Motivated by Spacecraft Oxygen Storage Fire Safety

NASA Technical Reports Server (NTRS)

Sunderland, P. B.; Yuan, Z.-G.; Krishnan, S. S.; Abshire, J. M.; Gore, J. P.

2003-01-01

Owing to the absence of past work involving flames similar to the Mir fire namely oxygen-enhanced, inverse gas-jet diffusion flames in microgravity the objectives of this work are as follows: 1. Observe the effects of enhanced oxygen conditions on laminar jet diffusion flames with ethane fuel. 2. Consider both earth gravity and microgravity. 3. Examine both normal and inverse flames. 4. Compare the measured flame lengths and widths with calibrated predictions of several flame shape models. This study expands on the work of Hwang and Gore which emphasized radiative emissions from oxygen-enhanced inverse flames in earth gravity, and Sunderland et al. which emphasized the shapes of normal and inverse oxygen-enhanced gas-jet diffusion flames in microgravity.

Development of life sciences equipment for microgravity and hypergravity simulation

NASA Technical Reports Server (NTRS)

Mulenburg, G. M.; Evans, J.; Vasques, M.; Gundo, D. P.; Griffith, J. B.; Harper, J.; Skundberg, T.

1994-01-01

The mission of the Life Science Division at the NASA Ames Research Center is to investigate the effects of gravity on living systems in the spectrum from cells to humans. The range of these investigations is from microgravity, as experienced in space, to Earth's gravity, and hypergravity. Exposure to microgravity causes many physiological changes in humans and other mammals including a headward shift of body fluids, atrophy of muscles - especially the large muscles of the legs - and changes in bone and mineral metabolism. The high cost and limited opportunity for research experiments in space create a need to perform ground based simulation experiments on Earth. Models that simulate microgravity are used to help identify and quantify these changes, to investigate the mechanisms causing these changes and, in some cases, to develop countermeasures.

Signaling in Human and Murine Lymphocytes in Microgravity: Parallels and Contrasts

NASA Technical Reports Server (NTRS)

Neal, Pellis; Alamelu, Sundaresan; Kulkarni, A. D.; Yamauchi, K.

2006-01-01

Immune function in space undergoes dramatic changes, some of which are detrimental to lymphocyte function. These changes may lead to significant immune suppression. Studies with human lymphocytes both in space flight and with ground-based models (NASA in vitro ground-based microgravity analog) indicate that T cell activation is inhibited in microgravity. Other lymphocyte functions, such as locomotion, are also inhibited. There is about an 80 percent homology in the immune response of mice to that of humans. A murine model was investigated because of its ability to parallel some microgravity using hind limb suspension. In in vivo antiorthostatically (AOS)-suspended mice, T cell activation is greatly suppressed, with the majority of activation related cytokines being inhibited. PHA activation in lymphocytes derived from AOS mice (in vivo ground-based microgravity analog) is also suppressed. Calcium ionophore studies in human lymphocytes exposed to modeled microgravity indicate that the calcium pathways are probably unaffected in microgravity. IP3 (inositol triphosphate) receptor expression in both human and mouse lymphocytes cultured in modeled microgravity indicate no suppression of calcium signaling. In the human system, microgravity seems to inhibit signaling cascades either at the level of, or up-stream of, Protein Kinase C (PKC). In particular, a membrane event, such as phospholipase C gamma 1 activity in human lymphocytes is affected, with its direct upstream effector, LAT, being deficiently expressed. In the mouse pathway, LAT is undiminished while another critical intermediate, SLP-76, is diminished significantly. This study identifies critical stages in the human and mouse immune systems and in lymphocytes as a function of microgravity.

Suppression of Antigen-Specific Lymphocyte Activation in Simulated Microgravity

NASA Technical Reports Server (NTRS)

Cooper, David; Pride, Michael W.; Brown, Eric L.; Risin, Diana; Pellis, Neal R.

1999-01-01

Various parameters of immune suppression are observed in astronauts during and after spaceflight, and in isolated immune cells in true and simulated microgravity. Specifically, polyclonal activation of T cells is severely suppressed in true and simulated microgravity. These recent findings with various polyclonal activators suggests a suppression of oligoclonal lymphocyte activation in microgravity. We utilized rotating wall vessel (RWV) bioreactors that simulate aspects of microgravity for cell cultures to analyze three models of antigen-specific activation. A mixed-lymphocyte reaction (MLR), as a model for a primary immune response; a tetanus toxoid (TT) response and a B. burgdorferi (Bb) response, as models of a secondary immune response, were all suppressed in the RWV bioreactor. Our findings confirm that the suppression of activation observed with polyclonal models also encompasses oligoclonal antigen-specific activation.

Gravitational Effects on Signal Transduction

NASA Technical Reports Server (NTRS)

Sytkowski, Arthur J.

1999-01-01

The purpose of this study was to investigate in ground-based experiments, the effect of microgravity on in vitro erythroid differentiation triggered by the hematopoietic growth factor erythropoietin (Epo) and to begin to determine whether this is associated with the anemia of space flight. We chose to use a model cell culture system with which we have had a long and successful experience. These cells, designated Rauscher murine erythroleukemia, grow independently in suspension culture. We first compared the growth rate of Rauscher cells under conditions of simulated microgravity with that of cells grown at 1XG in standard tissue culture flasks. Therefore, since there were fewer cells in the RWV at each specified time, glucose consumption per cell was increased in simulated microgravity. We next began to study the effect of simulated microgravity on erythropoietin induced differentiation of these cells. In another experiment, we allow the cells to grown in flasks or in the RWV for 24 hours prior to the addition of Epo. We initiated studies of c-myb, a proto-oncogene the down-regulation of which is necessary for erythroid differentiation. These preliminary results suggest that simulated microgravity interferes with the signal to c-myb. This may be part of the mechanism that blocks differentiation. A flight experiment is planned within the next 18- 24 months.

Effect of Oxygen Enrichment in Propane Laminar Diffusion Flames under Microgravity and Earth Gravity Conditions

NASA Astrophysics Data System (ADS)

Bhatia, Pramod; Singh, Ravinder

2017-06-01

Diffusion flames are the most common type of flame which we see in our daily life such as candle flame and match-stick flame. Also, they are the most used flames in practical combustion system such as industrial burner (coal fired, gas fired or oil fired), diesel engines, gas turbines, and solid fuel rockets. In the present study, steady-state global chemistry calculations for 24 different flames were performed using an axisymmetric computational fluid dynamics code (UNICORN). Computation involved simulations of inverse and normal diffusion flames of propane in earth and microgravity condition with varying oxidizer compositions (21, 30, 50, 100 % O2, by mole, in N2). 2 cases were compared with the experimental result for validating the computational model. These flames were stabilized on a 5.5 mm diameter burner with 10 mm of burner length. The effect of oxygen enrichment and variation in gravity (earth gravity and microgravity) on shape and size of diffusion flames, flame temperature, flame velocity have been studied from the computational result obtained. Oxygen enrichment resulted in significant increase in flame temperature for both types of diffusion flames. Also, oxygen enrichment and gravity variation have significant effect on the flame configuration of normal diffusion flames in comparison with inverse diffusion flames. Microgravity normal diffusion flames are spherical in shape and much wider in comparison to earth gravity normal diffusion flames. In inverse diffusion flames, microgravity flames were wider than earth gravity flames. However, microgravity inverse flames were not spherical in shape.

Simulated microgravity influenced the expression of DNA damage repair genes

NASA Astrophysics Data System (ADS)

Zhang, Meng; Sun, Yeqing; Jiawei, Liu; Wang, Ting

2016-07-01

Ionizing radiation and microgravity were considered to be the most important stress factors of space environmental the respective study of the biological effects of the radiation and microgravity carried out earlier, but the interaction of the effects of radiation with microgravity started later, and due to difference of the materials and methods the result of this experiment were not consistent. To further investigate the influence of microgravity on the expression of the radiation damage repair genes, the seed of Arabidopsis (Col) and its gravity-insensitive mutant (PIN2) were exposed to 0.1Gy of the dose of energetic carbon-ion beam radiation (LET = 30KeV / μm), and the germinated seed were than fixed in the 3D random positioning apparatus immediately for a 10-day simulated microgravity. By measuring the deflection angle of root tip and the changes of the expression of Ku70 and RAD51 protein, we investigated the impact of microgravity effect on radiation damage repair systems. The results shown that radiation, microgravity and microgravity with radiation could increase the angle of the root of the Col significantly, but no obvious effect on PIN2 type. The radiation could increase the expression of Ku70 significantly in both Col and PIN2, microgravity does not affect the expression, but the microgravity with radiation could decrease the expression of Ku70. This result shown that the microgravity could influence the radiation damage repair systems in molecular level. Moreover, our findings were important to understand the molecular mechanism of the impact of microgravity effect on radiation damage repair systems in vivo.

Crucible de-wetting during bridgman growth of semiconductors in microgravity

NASA Astrophysics Data System (ADS)

Duffar, T.; Paret-Harter, I.; Dusserre, P.

1990-02-01

After a literature survey and observations made during a space experiment, the phenomenon of crucible de-wetting by the crystal during Bridgman solidification in microgravity is explained by a model involving composite wetting of the crucible by the liquid, crystal angle of growth and interface advance. A ground experiment was run in order to validate this model which also explains why a crystal detaches from the crucible surface when a sand blasted crucible is used in Bridgman solidification on the ground. It is shown that de-wetting leads to enhanced quality of the crystal produced and that capillary-induced convection effects are not to be feared in this case. Consequently, it is highly advisable to use rough-surface crucibles for crystal growth both in microgravity and on the ground.

Comparative effectiveness of a clinostat and a slow-turning lateral vessel at mimicking the ultrastructural effects of microgravity in plant cells

NASA Technical Reports Server (NTRS)

Moore, R.

1990-01-01

The object of this research was to determine how effectively the actions of a clinostat and a fluid-filled, slow-turning lateral vessel (STLV) mimic the ultrastructural effects of microgravity in plant cells. We accomplished this by qualitatively and quantitatively comparing the ultrastructures of cells grown on clinostats and in an STLV with those of cells grown at 1 g and in microgravity aboard the Space Shuttle Columbia. Columella cells of Brassica perviridis seedlings grown in microgravity and in an STLV have similar structures. Both contain significantly more lipid bodies, less starch, and fewer dictyosomes than columella cells of seedlings grown at 1 g. Cells of seedlings grown on clinostats have significantly different ultrastructures from those grown in microgravity or in an STLV, indicating that clinostats do not mimic microgravity at the ultrastructural level. The similar structures of columella cells of seedlings grown in an STLV and in microgravity suggest that an STLV effectively mimics microgravity at the ultrastructural level.

Single and compound effects of radiation and microgravity responses in Caenorhabditis elegans

NASA Astrophysics Data System (ADS)

Wang, Wei; Sun, Yeqing; Xu, Dan; Yang, Jun; Luo, Yajing

2016-07-01

Space radiation and microgravity are main factors of spaceflight which could cause effects on organism. However, studies on the combined effects of microgravity and radiation have had conflicting results. For further elucidate the single factor effects of radiation or microgravity and the compound factor effects of them, the wild-type strain (Bristol N2) and muscle repair defective strain (dys-1) of Caenorhabditis elegansin dauer larvae were treated by ground simulated radiation in different doses (0.2Gy,2Gy) and/or 16.5-day simulated microgravity. The locomotory capacity assay and proteomic analysis were processed after the recovery of dauer larvae to adult. Locomotory capacity assay showed that the N2 nematodes were susceptible to simulated microgravity while dys-1 nematodes were susceptible to simulation radiation especially in high dose radiation (2Gy). The compound factor of microgravity and radiation has different influences to different strains. Proteomic results indicated that a wide range but different biological processes were involved in responding to radiation and/or microgravity.

Modeled Microgravity Inhibits Apoptosis in Peripheral Blood Lymphocytes

NASA Technical Reports Server (NTRS)

Risin, Diana; Pellis, Neal R.

2000-01-01

Microgravity interferes with numerous lymphocyte functions (expression of cell surface molecules, locomotion, polyclonal and antigen-specific activation, and the protein kinase C activity in signal transduction). The latter suggests that gravity may also affect programmed cell death (PCD) in lymphocyte populations. To test this hypothesis, we investigated spontaneous, activation- and radiation-induced PCD in peripheral blood mononuclear cells (PBMC) exposed to modeled microgravity using a rotating cell culture system. The results showed significant inhibition of radiation- and activation-induced apoptosis in modeled microgravity and provide insights into the potential mechanisms of this phenomenon.

Changes in multifidus and abdominal muscle size in response to microgravity: possible implications for low back pain research.

PubMed

Hides, J A; Lambrecht, G; Stanton, W R; Damann, V

2016-05-01

In microgravity, muscle atrophy occurs in the intrinsic muscles of the spine, with changes also observed in the abdominal muscles. Exercises are undertaken on the International Space Station and on Earth following space flight to remediate these effects. Similar effects have been seen on Earth in prolonged bed rest studies and in people with low back pain (LBP). The aim of this case report was to examine the effects of microgravity, exercise in microgravity and post-flight rehabilitation on the size of the multifidus and antero-lateral abdominal muscles. Ultrasound imaging was used to assess size of the multifidus, transversus abdominis and internal oblique muscles at four time points: pre-flight and after daily rehabilitation on day one (R + 1), day 8 (R + 8) and day 14 (R + 14) after return to Earth (following 6 months in microgravity). Exercises in microgravity maintained multifidus size at L2-L4, however, after spaceflight, size of the multifidus muscle at L5 was reduced, size of the internal oblique muscle was increased and size of transversus abdominis was reduced. Rehabilitation post-space flight resulted in hypertrophy of the multifidus muscle to pre-mission size at the L5 vertebral level and restoration of antero-lateral abdominal muscle size. Exercise in space can prevent loss of spinal intrinsic muscle size. For the multifidus muscles, effectiveness varied at different levels of the spine. Post-mission rehabilitation targeting specific motor control restored muscle balance between the antero-lateral abdominal and multifidus muscles, similar to results from intervention trials for people with LBP. A limitation of the current investigation is that only one astronaut was studied, however, the microgravity model could be valuable as predictable effects on trunk muscles can be induced and interventions evaluated. Level of Evidence Case series.

Macromolecular crystallization in microgravity generated by a superconducting magnet.

PubMed

Wakayama, N I; Yin, D C; Harata, K; Kiyoshi, T; Fujiwara, M; Tanimoto, Y

2006-09-01

About 30% of the protein crystals grown in space yield better X-ray diffraction data than the best crystals grown on the earth. The microgravity environments provided by the application of an upward magnetic force constitute excellent candidates for simulating the microgravity conditions in space. Here, we describe a method to control effective gravity and formation of protein crystals in various levels of effective gravity. Since 2002, the stable and long-time durable microgravity generated by a convenient type of superconducting magnet has been available for protein crystal growth. For the first time, protein crystals, orthorhombic lysozyme, were grown at microgravity on the earth, and it was proved that this microgravity improved the crystal quality effectively and reproducibly. The present method always accompanies a strong magnetic field, and the magnetic field itself seems to improve crystal quality. Microgravity is not always effective for improving crystal quality. When we applied this microgravity to the formation of cubic porcine insulin and tetragonal lysozyme crystals, we observed no dependence of effective gravity on crystal quality. Thus, this kind of test will be useful for selecting promising proteins prior to the space experiments. Finally, the microgravity generated by the magnet is compared with that in space, considering the cost, the quality of microgravity, experimental convenience, etc., and the future use of this microgravity for macromolecular crystal growth is discussed.

Space Shuttle Projects

NASA Image and Video Library

1994-07-01

In this photograph, astronaut Carl Walz performs the Performance Assessment Workstation (PAWS) experiment at the flight deck of the Space Shuttle Orbiter Columbia during the STS-65 mission. Present day astronauts are subject to a variety of stresses during spaceflight. These include microgravity, physical isolation, confinement, lack of privacy, fatigue, and changing work/rest cycles. The purpose of this experiment is to determine the effects of microgravity upon thinking skills critical to the success of operational tasks in space. The principle objective is to distinguish between the effects of microgravity on specific information-processing skills affecting performance and those of fatigue caused by long work periods. To measure these skills, the investigators use a set of computerized performance tests called the Performance Assessment Workstation, which is based on current theoretical models of human performance. The tests were selected by analyzing tasks related to space missions and their hypothesized sensitivity to microgravity. Multiple subjective measures of cumulative fatigue and changing mood states are also included for interpreting performance data.

Microgravity Effects on Microbiology In Space Laboratories

NASA Technical Reports Server (NTRS)

Nelson, Emily S.; Juergensmeyer, Elizabeth; Juergensmeyer, Margaret

2000-01-01

Here we present a review of the effects of residual acceleration on microorganisms in space Laboratories. Residual acceleration in the microgravity environment is frequently ignored by microbiologists, although their experiments may be as sensitive to this acceleration as those designed by materials scientists and fluid physicists. Furthermore, analysis to date has been largely empirical and/or based on very simple theoretical models. As a result, the responses of single cells to the space environment are widely assumed to be taking place in "pure" microgravity. These responses vary widely and are not well understood. Some of this variation may be due to the range of microgravity conditions experience by organisms. In the future, as we move from visiting orbital environments to living and working there, we will undoubtedly bring microorganisms with us. It is also quite likely that the first extraterrestrial life we encounter will be single-celled organisms. Therefore, we would like to present a summary of the current knowledge base, and to challenge the space community to develop new approaches in understanding this important field.

STS-65 Mission Onboard Photograph

NASA Technical Reports Server (NTRS)

1994-01-01

In this photograph, astronaut Carl Walz performs the Performance Assessment Workstation (PAWS) experiment at the flight deck of the Space Shuttle Orbiter Columbia during the STS-65 mission. Present day astronauts are subject to a variety of stresses during spaceflight. These include microgravity, physical isolation, confinement, lack of privacy, fatigue, and changing work/rest cycles. The purpose of this experiment is to determine the effects of microgravity upon thinking skills critical to the success of operational tasks in space. The principle objective is to distinguish between the effects of microgravity on specific information-processing skills affecting performance and those of fatigue caused by long work periods. To measure these skills, the investigators use a set of computerized performance tests called the Performance Assessment Workstation, which is based on current theoretical models of human performance. The tests were selected by analyzing tasks related to space missions and their hypothesized sensitivity to microgravity. Multiple subjective measures of cumulative fatigue and changing mood states are also included for interpreting performance data.

Effects of a simulated microgravity model on cell structure and function in rat testis and epididymis

NASA Technical Reports Server (NTRS)

Hadley, Jill A.; Hall, Joseph C.; O'Brien, Ami; Ball, Richard

1992-01-01

The effect of simulated microgravity on the structure and function of the testis and epididymis cells was investigated in rats subjected to 7 days of tail suspension. Results of a histological examination revealed presence of disorganized seminiferous tubules and accumulation of large multinucleated cells and spermatids in the lumen of the epididymis. In addition, decreases in the content of testis protein and in testosterone levels in the testis, the interstitial fluid, and the epididymis were observed.

Microgravity Effects on the Early Events of Biological Nitrogen Fixation in Medicago Truncatula: Results from the SyNRGE Experiment

NASA Technical Reports Server (NTRS)

Stutte, Gary W.; Roberts, Michael

2012-01-01

SyNRGE (Symbiotic Nodulation in a Reduced Gravity Environment) was a sortie mission on STS-135 in the Biological Research in Canisters (BRIC) hardware to study the effect of microgravity on a plant-microbe symbiosis resulting in biological nitrogen fixation. Medicago truncatula, a model species for th legume family, was inoculated with its bacterial symbiont, Sinorhizobium meliloti, to observe early biomolecular events associated with infection and nodulation in Petri Dish Fixation Units (PDFU's).

Life sciences and space research XXIV(1) - Gravitational biology; Proceedings of Symposia 10 and 13 of the Topical Meeting of the Interdisciplinary Scientific Commission F (Meetings F1 and F2) of the COSPAR 28th Plenary Meeting, The Hague, Netherlands, June 25-July 6, 1990

NASA Technical Reports Server (NTRS)

Young, R. S. (Editor); Cogoli, A. (Editor); Planel, H. (Editor); Ubbels, G. A. (Editor); Sievers, A. (Editor); Oser, H. (Editor); Horneck, G. (Editor); Wagner, H. (Editor)

1992-01-01

Topics presented include an introduction to theories and models of biological response to gravity, gravity effects on biological systems, the function of calcium in plant graviperception, developmental biology on unmanned spacecraft, and the effect of microgravity on the development of plant protoplasts flown on Biocosmos 9. Also presented are the mechanism by which an asymmetric distribution of plant growth hormone is attained, the perception of gravity by plants, an animal research facility for Space Station Freedom, the long-term effects of microgravity and possible countermeasures, and an experimental system for determining the influence of microgravity on B lymphocyte activation and cell fusion.

The Distinctive Sensitivity to Microgravity of Immune Cell Subpopulations

NASA Astrophysics Data System (ADS)

Chen, Hui; Luo, Haiying; Liu, Jing; Wang, Peng; Dong, Dandan; Shang, Peng; Zhao, Yong

2015-11-01

Immune dysfunction in astronauts is well documented after spaceflights. Microgravity is one of the key factors directly suppressing the function of immune system. However, it is unclear which subpopulations of immune cells including innate and adaptive immune cells are more sensitive to microgravity We herein investigated the direct effects of modeled microgravity (MMg) on different immune cells in vitro. Mouse splenocytes, thymocytes and bone marrow cells were exposed to MMg for 16 hrs. The survival and the phenotypes of different subsets of immune cells including CD4+T cells, CD8+T cells, CD4+Foxp3+ regulatory T cells (Treg), B cells, monocytes/macrophages, dendritic cells (DCs), natural killer cells (NK) were determined by flow cytometry. After splenocytes were cultured under MMg for 16h, the cell frequency and total numbers of monocytes, macrophages and CD4+Foxp3+T cells were significantly decreased more than 70 %. MMg significantly decreased the cell numbers of CD8+ T cells, B cells and neutrophils in splenocytes. The cell numbers of CD4+T cells and NK cells were unchanged significantly when splenocytes were cultured under MMg compared with controls. However, MMg significantly increased the ratio of mature neutrophils to immature neutrophils in bone marrow and the cell number of DCs in splenocytes. Based on the cell survival ability, monocytes, macrophages and CD4+Foxp3+Treg cells are most sensitive to microgravity; CD4+T cells and NK cells are resistant to microgravity; CD8+T cells and neutrophils are impacted by short term microgravity exposure. Microgravity promoted the maturation of neutrophils and development of DCs in vitro. The present studies offered new insights on the direct effects of MMg on the survival and homeostasis of immune cell subsets.

Fruit_Flies_in_Microgravity

NASA Image and Video Library

2017-05-25

Scientists study how astronauts are affected by microgravity, but with a relatively small number of human subjects available to them, they often turn to model organisms for research. Model organisms are living organisms that have a genetic makeup that is relatively well-documented and understood, and is similar to human systems. Fruit flies are reliable model organisms because their systems closely resemble that of larger organisms. They have the benefit of being small in size, well understood, and reproduce quickly so many generations can be studied in a short amount of time. Some of the things we can study using fruit flies are how microgravity affects the immune system. Will the muscle cells of the heart lose strength in microgravity? Are reproduction, lifespan and the aging process affected by microgravity? Do changes in gravity affect the basic metabolic rate and metabolism of living systems? Fruit flies offer a manageable way to study living systems in microgravity. Learn more about other model organisms and how they are being used for microgravity research, and keep up with all the science being conducted aboard your orbiting laboratory by visiting ISS Research Overview on nasa.gov http://www.twitter.com/ISS_Research

Vortex/Flame Interactions in Microgravity Pulsed Jet Diffusion Flames

NASA Technical Reports Server (NTRS)

Bahadori, M. Y.; Hegde, U.; Stocker, D. P.

1999-01-01

The problem of vortex/flame interaction is of fundamental importance to turbulent combustion. These interactions have been studied in normal gravity. It was found that due to the interactions between the imposed disturbances and buoyancy induced instabilities, several overall length scales dominated the flame. The problem of multiple scales does not exist in microgravity for a pulsed laminar flame, since there are no buoyancy induced instabilities. The absence of buoyant convection therefore provides an environment to study the role of vortices interacting with flames in a controlled manner. There are strong similarities between imposed and naturally occurring perturbations, since both can be described by the same spatial instability theory. Hence, imposing a harmonic disturbance on a microgravity laminar flame creates effects similar to those occurring naturally in transitional/turbulent diffusion flames observed in microgravity. In this study, controlled, large-scale, axisymmetric vortices are imposed on a microgravity laminar diffusion flame. The experimental results and predictions from a numerical model of transient jet diffusion flames are presented and the characteristics of pulsed flame are described.

Investigation of the Influence of Microgravity on Transport Mechanism in a Virtual Spaceflight Chamber: A Flight Definition Program

NASA Technical Reports Server (NTRS)

Trolinger, James D.; Rangel, Roger; Witherow, William; Rogers, Jan; Lal, Ravindra B.

1999-01-01

A need exists for understanding precisely how particles move and interact in a fluid in the absence of gravity. Such understanding is required, for example, for modeling and predicting crystal growth in space where crystals grow from solution around nucleation sites as well as for any study of particles or bubbles in liquids or in experiments where particles are used as tracers for mapping microconvection. We have produced an exact solution to the general equation of motion of particles at extremely low Reynolds number in microgravity that covers a wide range of interesting conditions. We have also developed diagnostic tools and experimental techniques to test the validity of the general equation . This program, which started in May, 1998, will produce the flight definition for an experiment in a microgravity environment of space to validate the theoretical model. We will design an experiment with the help of the theoretical model that is optimized for testing the model, measuring g, g-jitter, and other microgravity phenomena. This paper describes the goals, rational, and approach for the flight definition program. The first objective of this research is to understand the physics of particle interactions with fluids and other particles in low Reynolds number flows in microgravity. Secondary objectives are to (1) observe and quantify g-jitter effects and microconvection on particles in fluids, (2) validate an exact solution to the general equation of motion of a particle in a fluid, and (3) to characterize the ability of isolation tables to isolate experiments containing particle in liquids. The objectives will be achieved by recording a large number of holograms of particle fields in microgravity under controlled conditions, extracting the precise three-dimensional position of all of the particles as a function of time and examining the effects of all parameters on the motion of the particles. The feasibility for achieving these results has already been established in the ongoing ground-based NRA, which led to the "virtual spaceflight chamber" concept.

Modeling of two-phase flow in membranes and porous media in microgravity as applied to plant irrigation in space

NASA Technical Reports Server (NTRS)

Scovazzo, P.; Illangasekare, T. H.; Hoehn, A.; Todd, P.

2001-01-01

In traditional applications in soil physics it is convention to scale porous media properties, such as hydraulic conductivity, soil water diffusivity, and capillary head, with the gravitational acceleration. In addition, the Richards equation for water flux in partially saturated porous media also contains a gravity term. With the plans to develop plant habitats in space, such as in the International Space Station, it becomes necessary to evaluate these properties and this equation under conditions of microgravitational acceleration. This article develops models for microgravity steady state two-phase flow, as found in irrigation systems, that addresses critical design issues. Conventional dimensionless groups in two-phase mathematical models are scaled with gravity, which must be assigned a value of zero for microgravity modeling. The use of these conventional solutions in microgravity, therefore, is not possible. This article therefore introduces new dimensionless groups for two-phase models. The microgravity models introduced here determined that in addition to porous media properties, important design factors for microgravity systems include applied water potential and the ratio of inner to outer radii for cylindrical and spherical porous media systems.

Low-shear modeled microgravity: a global environmental regulatory signal affecting bacterial gene expression, physiology, and pathogenesis

NASA Technical Reports Server (NTRS)

Nickerson, Cheryl A.; Ott, C. Mark; Wilson, James W.; Ramamurthy, Rajee; LeBlanc, Carly L.; Honer zu Bentrup, Kerstin; Hammond, Timothy; Pierson, Duane L.

2003-01-01

Bacteria inhabit an impressive variety of ecological niches and must adapt constantly to changing environmental conditions. While numerous environmental signals have been examined for their effect on bacteria, the effects of mechanical forces such as shear stress and gravity have only been investigated to a limited extent. However, several important studies have demonstrated a key role for the environmental signals of low shear and/or microgravity in the regulation of bacterial gene expression, physiology, and pathogenesis [Chem. Rec. 1 (2001) 333; Appl. Microbiol. Biotechnol. 54 (2000) 33; Appl. Environ. Microbiol. 63 (1997) 4090; J. Ind. Microbiol. 18 (1997) 22; Curr. Microbiol. 34(4) (1997) 199; Appl. Microbiol. Biotechnol. 56(3-4) (2001) 384; Infect Immun. 68(6) (2000) 3147; Cell 109(7) (2002) 913; Appl. Environ. Microbiol. 68(11) (2002) 5408; Proc. Natl. Acad. Sci. U. S. A. 99(21) (2002) 13807]. The response of bacteria to these environmental signals, which are similar to those encountered during prokaryotic life cycles, may provide insight into bacterial adaptations to physiologically relevant conditions. This review focuses on the current and potential future research trends aimed at understanding the effect of the mechanical forces of low shear and microgravity analogues on different bacterial parameters. In addition, this review also discusses the use of microgravity technology to generate physiologically relevant human tissue models for research in bacterial pathogenesis.

Effect of low shear modeled microgravity on phenotypic and central chitin metabolism in the filamentous fungi Aspergillus niger and Penicillium chrysogenum.

PubMed

Sathishkumar, Yesupatham; Velmurugan, Natarajan; Lee, Hyun Mi; Rajagopal, Kalyanaraman; Im, Chan Ki; Lee, Yang Soo

2014-08-01

Phenotypic and genotypic changes in Aspergillus niger and Penicillium chrysogenum, spore forming filamentous fungi, with respect to central chitin metabolism were studied under low shear modeled microgravity, normal gravity and static conditions. Low shear modeled microgravity (LSMMG) response showed a similar spore germination rate with normal gravity and static conditions. Interestingly, high ratio of multiple germ tube formation of A. niger in LSMMG condition was observed. Confocal laser scanning microscopy images of calcofluor flurophore stained A. niger and P. chrysogenum showed no significant variations between different conditions tested. Transmission electron microscopy images revealed number of mitochondria increased in P. chrysogenum in low shear modeled microgravity condition but no stress related-woronin bodies in fungal hyphae were observed. To gain additional insight into the cell wall integrity under different conditions, transcription level of a key gene involved in cell wall integrity gfaA, encoding the glutamine: fructose-6-phosphate amidotransferase enzyme, was evaluated using qRT-PCR. The transcription level showed no variation among different conditions. Overall, the results collectively indicate that the LSMMG has shown no significant stress on spore germination, mycelial growth, cell wall integrity of potentially pathogenic fungi, A. niger and P. chrysogenum.

Mutualism in a Reduced Gravity Environment (MuRGE)

NASA Technical Reports Server (NTRS)

Patel, Karishma K.

2010-01-01

MuRGE (Mutualism in a Reduced Gravity Environment) is a NASA flight-research experiment to investigate the microgravity effects associated with cell-cell communication and beneficial microbe-host interactions using a plant-fungal model system. This investigation will use a clinostat, an instrument that slowly rotates the plants to negate the effects of gravitational pull on plant growth (gravitropism) and development, to simulate microgravity. I will be using the endophytic fungus Piriformospora indica (Pi) and the model plant species Arabidopsis thaliana (At). P. indica has been shown to colonize roots of various plant species, including A. thaliana, and to increase plant growth and resistance to stress. The fungus has the ability to grow from spores or in axenic cultures without the presence of a host. P. indica spores and P. indica extract will be used to inoculate Arabidopsis seeds germinated on a clinostat in order to determine if simulated microgravity affects the interaction between the fungus and its plant host.

[Mutualism in a Reduced Gravity Environment (MuRGE)

NASA Technical Reports Server (NTRS)

Patel, Karishma

2010-01-01

MuRGE (Mutualism in a Reduced Gravity Environment) is a NASA flight-research experiment to investigate the microgravity effects associated with cell-cell communication and beneficial microbe-host interactions using a plant-fungal model system. This investigation will use a clinostat, an instrument that slowly rotates the plants to negate the effects of gravitational pull on plant growth (gravitropism) and development, to simulate microgravity. I will be using the endophytic fungus Piriformospora indica (Pi) and the model plant species Arabidopsis thaliana (At). P. indica has been shown to colonize roots of various plant species, including A. thaliana, and to increase plant growth and resistance to stress. The fungus has the ability to grow from spores or in axenic cultures without the presence of a host. P. indica spores and P. indica extract will be used to inoculate Arabidopsis seeds germinated on a clinostat in order to determine if simulated microgravity affects the interaction between the fungus and its plant host.

Analysis of biological effects in human endothelial cells after stimulated microgravity

NASA Astrophysics Data System (ADS)

Min, Zhang; Sun, Yeqing; Xu, Dan

Space environment is characterized by strong radiation, ultra-high vacuum, weak magnetic field and microgravity. Among them, microgravity (10-4-10-6g) in space is different from gravity (1g) on earth, possibly causing visual disorders, muscle alterations, bone loss and dysfunction of cardiovascular systems. To study about microgravity environment, the most advanced rotary cell culture system (RCCS-1) was used to do stimulated microgravity (SMG) experiments in the ground. Up to now, most of studies focus on the biological effects under stimulated microgravity, but it is less known about the cellular response after stimulated microgravity. In the present study, we explored the subsequent effects of stimulated microgravity on human endothelial cells (HUVEC-C) after these cells were cultured on RCCS-1 for 48 hours. We co-cultured HUVEC-C cells with Hillex-microcarriers in 60-mm culture dishes for 24h, followed by transferring them to RCCS-1 so that cells remain to be the state of SMG. In parallel, HUVEC-C cells were co-cultured with microcarriers in the ground condition. We found that stimulated microgravity induced cytoskeleton remodeling, cell cycle G2/M arrest and cellular senescence, consistent with previous reports. To study the subsequent effects of stimulated microgravity, we make cells detach from microcarriers and observed various effects including cell growth, cell adhesion, cytoskeleton, cell cycle, apoptosis and senescence. The results showed that those cells undergoing stimulated microgravity appeared obvious growth inhibition, a transition from the decrease in cell adhesion ability and cytoskeleton remodeling within 24h to induction of apoptosis and senescence-like phenotype in the later time with slight changes in cell cycle. Analysis of protein expression in western blot demonstrated that apoptosis-related protein PTEN was up-regulated on the time-dependent pattern after stimulated microgravity, indicating that PTEN-PI3K-Akt pathway might play an important role in apoptosis. Our study suggests that stimulated microgravity has the subsequent biological effects of HUVEC-C, providing new insight of understanding the global effect of microgravity on cellular response in human endothelial cells.

Numerical simulation of gender differences in a long-term microgravity exposure

NASA Astrophysics Data System (ADS)

Perez-Poch, Antoni

The objective of this work is to analyse and simulate gender differences when individuals are exposed to long-term microgravity. Risk probability of a health impairment which may put in jeopardy a long-term mission is also evaluated. Computer simulations are becoming a promising research line of work, as physiological models become more and more sophisticated and reliable. Technological advances in state-of-the-art hardware technology and software allow nowadays for better and more accurate simulations of complex phenomena, such as the response of the human cardiovascular system to long-term exposure to microgravity. Experimental data for long-term missions are difficult to achieve and reproduce, therefore the predictions of computer simulations are of a major importance in this field. Our approach is based on a previous model developed and implemented in our laboratory (NELME: Numerical Evaluation of Long-term Microgravity Effects). The software simulates the behaviour of the cardiovascular system and different human organs, has a modular architecture, and allows to introduce perturbations such as physical exercise or countermeasures. The implementation is based on a complex electricallike model of this control system, using inexpensive software development frameworks, and has been tested and validated with the available experimental data. Gender differences have been implemented for this specific work, as an adjustment of a number of parameters that are included in the model. Women versus men physiological differences have been therefore taken into account, based upon estimations from the physiology bibliography. A number of simulations have been carried out for long-term exposure to microgravity. Gravity varying from Earth-based to zero, and time exposure are the two main variables involved in the construction of results, including responses to patterns of physical aerobical exercise, and also thermal stress simulating an extra-vehicular activity. Results show that significant differences appear between men and women physiological response after long-term exposure (more than three months) to microgravity. Risk evaluation for every gender, and specific risk thresholds are provided. Initial results are compatible with the existing data, and provide unique information regarding different patterns of microgravity exposure. We conclude that computer-based models such us NELME are a promising line of work to predict health risks in long-term missions. More experimental work is needed to adjust some parameters of the model. This work may be seen as another contribution to a better understanding of the underlying processes involved for both women in man adaptation to long-term microgravity.

Developmental effects of simulated microgravity on zebrafish, (Danio rerio)

NASA Astrophysics Data System (ADS)

Stoyek, Matthew; Edsall, Sara; Franz-Odendaal, Tamara; Smith, Frank; Croll, Roger

Zebrafish are widely used model vertebrates in research and recently this species has been used to study the effects of microgravity on fundamental biological processes. In this study we used a NASA-designed rotating wall vessel (RWV) to investigate the effects of simulated microgravity (SMG) on zebrafish development up to 14 days post fertilization (dpf). At developmental stages beyond the 3-4 somite stage we found SMG-exposed embryos reached key developmental stag-ing points more rapidly than fish raised within a non-rotating vessel. By the 21 somite stage, both groups were again synchronized in their developmental staging. However, SMG-exposed embryos eventually exhibited a delay in hatching time compared to controls. Otolith and to-tal body size were observed to be greater in larvae raised in SMG. In addition, pigmentation patterns in SMG exposed fish differed, with larger and differentially aggregated melanocytes . Heart development was slowed in SMG exposed fish, but no change in nervous system de-velopment was detected. Ongoing research will focus on differences in heart and respiration rates. Finally, by developing a method to extend the duration of SMG exposure, we found the swimming behaviour of SMG-exposed animals was altered with time in the RWV. Initially SMG-exposed animals swam in the direction of RWV rotation (5-9dpf) but older (9+dpf) fish swam against rotation and demonstrated righting behaviour with each rotation. These results suggest that vestibular reflexes may develop normally and be maintained in animals exposed to SMG. Together, our data provide insights into how zebrafish may develop when flown in space, permitting better formulation of experiments to test mechanisms by which microgravity may affect ontogeny of this model organism. Keywords: microgravity, zebrafish, growth, development

Rotaing Systems Used as Microgravity Simulators for Studies of Cartilage Differentiation

NASA Technical Reports Server (NTRS)

Duke, Pauline Jackie; Montufar-Solis, Dina

1998-01-01

Just as Studies of abnormal chondrogenesis produced by mutation or teratogen add to our understanding of the normal chondrogenic process, studying chondrogenesis in space may assist in 1 g studies of chondrogenic defects. Opportunities to study cartilage differentiation in space, however, are limited, so systems have been developed which can be used at 1 g to simulate microgravity. One model used to mimic effects of microgravity is the clinostat a rotating system which converts gravity from a vector quantity to a scalar quantity. In slow rotating clitiostat systems, cells are attached to a substrate as at 1 g, and rotated with the plane of the culture perpendicular to the gravitational field. Another rotating system used as a microgravity simulator is the Slow Turning Lateral Vessel (STLV) which uses a rotating cylindrical vessel, completely filled with medium to culture cells in suspension without subjecting them to damaging shear forces. Embronic limb cells cultured in the slow rotating clinostat, the STLV, and in space exhibit changes in chondrogenesis related to the stage at which the cells are exposed. Clinorotation decreases the number of nodules in micromass cultures, showing an effect on the condensation process. In micromass cultures flown in space, condensation occurred preflight, so the primary effect of microgravity exposure was on matrix production. In chondrocytes in the STLV, as in growth plates of spaceflown rats, hypertrophy was decreased. Future clinostat and spaceflight experiments will examine the effect on adhesive molecules and on cytoskeletal organization because of their involvement in the processes that are affected. The mechanisms by which micro-gravity alters phenotype modulation, matrix production and aggregation, and chondrocyte hypertrophy after the cartilage phenotype is established must also be elucidated. The mechanisms resulting in cartilage defects are to a large extent unknown, and microgravitv may provide a way to identify them.

Finite Element Modeling of the Posterior Eye in Microgravity

NASA Technical Reports Server (NTRS)

Feola, Andrew; Raykin, Julia; Mulugeta, Lealem; Gleason, Rudolph; Myers, Jerry G.; Nelson, Emily S.; Samuels, Brian; Ethier, C. Ross

2015-01-01

Microgravity experienced during spaceflight affects astronauts in various ways, including weakened muscles and loss of bone density. Recently, visual impairment and intracranial pressure (VIIP) syndrome has become a major concern for space missions lasting longer than 30 days. Astronauts suffering from VIIP syndrome have changes in ocular anatomical and visual impairment that persist after returning to earth. It is hypothesized that a cephalad fluid shift in microgravity may increase the intracranial pressure (ICP), which leads to an altered biomechanical environment of the posterior globe and optic nerve sheath (ONS).Currently, there is a lack of knowledge of how elevated ICP may lead to vision impairment and connective tissue changes in VIIP. Our goal was to develop a finite element model to simulate the acute effects of elevated ICP on the posterior eye and optic nerve sheath. We used a finite element (FE) analysis approach to understand the response of the lamina cribrosa and optic nerve to the elevations in ICP thought to occur in microgravity and to identify which tissue components have the greatest impact on strain experienced by optic nerve head tissues.

The effect of acute microgravity on mechanically-induced membrane damage and membrane-membrane fusion events

NASA Technical Reports Server (NTRS)

Clarke, M. S.; Vanderburg, C. R.; Feeback, D. L.; McIntire, L. V. (Principal Investigator)

2001-01-01

Although it is unclear how a living cell senses gravitational forces there is no doubt that perturbation of the gravitational environment results in profound alterations in cellular function. In the present study, we have focused our attention on how acute microgravity exposure during parabolic flight affects the skeletal muscle cell plasma membrane (i.e. sarcolemma), with specific reference to a mechanically-reactive signaling mechanism known as mechanically-induced membrane disruption or "wounding". Both membrane rupture and membrane resealing events mediated by membrane-membrane fusion characterize this response. We here present experimental evidence that acute microgravity exposure can inhibit membrane-membrane fusion events essential for the resealing of sarcolemmal wounds in individual human myoblasts. Additional evidence to support this contention comes from experimental studies that demonstrate acute microgravity exposure also inhibits secretagogue-stimulated intracellular vesicle fusion with the plasma membrane in HL-60 cells. Based on our own observations and those of other investigators in a variety of ground-based models of membrane wounding and membrane-membrane fusion, we suggest that the disruption in the membrane resealing process observed during acute microgravity is consistent with a microgravity-induced decrease in membrane order.

The Effect of Acute Microgravity on Mechanically-Induced Membrane Damage and Membrane-Membrane Fusion Events

NASA Technical Reports Server (NTRS)

Clarke, Mark, S. F.; Vanderburg, Charles R.; Feedback, Daniel L.

2001-01-01

Although it is unclear how a living cell senses gravitational forces there is no doubt that perturbation of the gravitational environment results in profound alterations in cellular function. In the present study, we have focused our attention on how acute microgravity exposure during parabolic flight affects the skeletal muscle cell plasma membrane (i.e. sarcolemma), with specific reference to a mechanically-reactive signaling mechanism known as mechanically-induced membrane disruption or "wounding". This response is characterized by both membrane rupture and membrane resealing events mediated by membrane-membrane fusion. We here present experimental evidence that acute microgravity exposure can inhibit membrane-membrane fusion events essential for the resealing of sarcolemmal wounds in individual human myoblasts. Additional evidence to support this contention comes from experimental studies that demonstrate acute microgravity exposure also inhibits secretagogue-stimulated intracellular vesicle fusion with the plasma membrane in HL-60 cells. Based on our own observations and those of other investigators in a variety of ground-based models of membrane wounding and membrane-membrane fusion, we suggest that the disruption in the membrane resealing process observed during acute microgravity is consistent with a microgravity-induced decrease in membrane order.

The Prospective Function of Curcumin Against the Negative Effects of Microgravity

NASA Astrophysics Data System (ADS)

Lewis, A.; Johnson, P.; Jejelowo, O. A.; Sodipe, A.; Shishodia, S.

2010-04-01

Microgravity has several deleterious effects on cells. These cells may exhibit an up-regulation or down-regulation of their gene expression. We are investigating the effects of the phytochemical curcumin on microgravity-induced deleterious effects.

Design and testing of a unique randomized gravity, continuous flow bioreactor

NASA Technical Reports Server (NTRS)

Lassiter, Carroll B.

1993-01-01

A rotating, null gravity simulator, or Couette bioreactor was successfully used for the culture of mammalian cells in a simulated microgravity environment. Two limited studies using Lipomyces starkeyi and Streptomyces clavuligerus were also conducted under conditions of simulated weightlessness. Although these studies with microorganisms showed promising preliminary results, oxygen limitations presented significant limitations in studying the biochemical and cultural characteristics of these cell types. Microbial cell systems such as bacteria and yeast promise significant potential as investigative models to study the effects of microgravity on membrane transport, as well as substrate induction of inactive enzyme systems. Additionally, the smaller size of the microorganisms should further reduce the gravity induced oscillatory particle motion and thereby improve the microgravity simulation on earth. Focus is on the unique conceptual design, and subsequent development of a rotating bioreactor that is compatible with the culture and investigation of microgravity effects on microbial systems. The new reactor design will allow testing of highly aerobic cell types under simulated microgravity conditions. The described reactor affords a mechanism for investigating the long term effects of reduced gravity on cellular respiration, membrane transfer, ion exchange, and substrate conversions. It offers the capability of dynamically altering nutrients, oxygenation, pH, carbon dioxide, and substrate concentration without disturbing the microgravity simulation, or Couette flow, of the reactor. All progeny of the original cell inoculum may be acclimated to the simulated microgravity in the absence of a substrate or nutrient. The reactor has the promise of allowing scientists to probe the long term effects of weightlessness on cell interactions in plants, bacteria, yeast, and fungi. The reactor is designed to have a flow field growth chamber with uniform shear stress, yet transfer high concentrations of oxygen into the culture medium. The system described allows for continuous, on line sampling for production of product without disturbing fluid and particle dynamics in the reaction chamber. It provides for the introduction of substrate, or control substances after cell adaptation to simulated microgravity has been accomplished. The reactor system provides for the nondisruptive, continuous flow replacement of nutrient and removal of product. On line monitoring and control of growth conditions such as pH and nutrient status are provided. A rotating distribution valve allows cessation of growth chamber rotation, thereby preserving the simulated microgravity conditions over longer periods of time.

Immune suppression of human lymphoid tissues and cells in rotating suspension culture and onboard the International Space Station

PubMed Central

Fitzgerald, Wendy; Chen, Silvia; Walz, Carl; Zimmerberg, Joshua; Margolis, Leonid

2013-01-01

The immune responses of human lymphoid tissue explants or cells isolated from this tissue were studied quantitatively under normal gravity and microgravity. Microgravity was either modeled by solid body suspension in a rotating, oxygenated culture vessel or was actually achieved on the International Space Station (ISS). Our experiments demonstrate that tissues or cells challenged by recall antigen or by polyclonal activator in modeled microgravity lose all their ability to produce antibodies and cytokines and to increase their metabolic activity. In contrast, if the cells were challenged before being exposed to modeled microgravity suspension culture, they maintained their responses. Similarly, in microgravity in the ISS, lymphoid cells did not respond to antigenic or polyclonal challenge, whereas cells challenged prior to the space flight maintained their antibody and cytokine responses in space. Thus, immune activation of cells of lymphoid tissue is severely blunted both in modeled and true microgravity. This suggests that suspension culture via solid body rotation is sufficient to induce the changes in cellular physiology seen in true microgravity. This phenomenon may reflect immune dysfunction observed in astronauts during space flights. If so, the ex vivo system described above can be used to understand cellular and molecular mechanisms of this dysfunction. PMID:19609626

On the role of numerical simulations in studies of reduced gravity-induced physiological effects in humans. Results from NELME.

NASA Astrophysics Data System (ADS)

Perez-Poch, Antoni

Computer simulations are becoming a promising research line of work, as physiological models become more and more sophisticated and reliable. Technological advances in state-of-the-art hardware technology and software allow nowadays for better and more accurate simulations of complex phenomena, such as the response of the human cardiovascular system to long-term exposure to microgravity. Experimental data for long-term missions are difficult to achieve and reproduce, therefore the predictions of computer simulations are of a major importance in this field. Our approach is based on a previous model developed and implemented in our laboratory (NELME: Numercial Evaluation of Long-term Microgravity Effects). The software simulates the behaviour of the cardiovascular system and different human organs, has a modular archi-tecture, and allows to introduce perturbations such as physical exercise or countermeasures. The implementation is based on a complex electrical-like model of this control system, using inexpensive development frameworks, and has been tested and validated with the available experimental data. The objective of this work is to analyse and simulate long-term effects and gender differences when individuals are exposed to long-term microgravity. Risk probability of a health impairement which may put in jeopardy a long-term mission is also evaluated. . Gender differences have been implemented for this specific work, as an adjustment of a number of parameters that are included in the model. Women versus men physiological differences have been therefore taken into account, based upon estimations from the physiology bibliography. A number of simulations have been carried out for long-term exposure to microgravity. Gravity varying continuosly from Earth-based to zero, and time exposure are the two main variables involved in the construction of results, including responses to patterns of physical aerobic ex-ercise and thermal stress simulating an extra-vehicular activity. Results show that significant differences appear between men and women physiological response after long-term exposure (more than three months) to microgravity. Risk evaluation for every gender, and specific risk thresholds are provided. Different scenarios like a long-term mission to Moon or Mars are evaluated, including countermeasures such as aerobic exercise. Initial results are compatible with the existing data, and provide useful insights regarding different patterns of microgravity exposure. We conclude that computer-based models such us NELME are a promising line of work to predict health risks in long-term missions.

Molecular and Cellular Characterization of Space Flight Effects on Microvascular Endothelial Cell Function - PreparatoryWork for the SFEF Project

NASA Astrophysics Data System (ADS)

Balsamo, Michele; Barravecchia, Ivana; Mariotti, Sara; Merenda, Alessandra; De Cesari, Chiara; Vukich, Marco; Angeloni, Debora

2014-12-01

Exposure to microgravity during space flight (SF) of variable length induces suffering of the endothelium (the cells lining all blood vessels), mostly responsible for health problems found in astronauts and animals returning from space. Of interest to pre-nosological medicine, the effects of microgravity on astronauts are strikingly similar to the consequences of sedentary life, senescence and degenerative diseases on Earth, although SF effects are accelerated and reversible. Thus, microgravity is a significant novel model for better understanding of common pathologies. A comprehensive cell and molecular biology study is needed in order to explain pathophysiological findings after SFs. This project will study the effects of microgravity and cosmic radiation on endothelial cells (ECs) cultured on the International Space Station through analysis of 1) cell transcriptome, 2) DNA methylome, 3) DNA damage and cell senescence, 4) variations in cell cycle and cell morphology. This project has been selected by the European Space Agency and the Italian Space Agency and is presently in preparation. The ground study presented here was performed to determine the biological and engineering requirements that will allow us to retrieve suitable samples after culturing, fixing and storing ECs in space. We expect to identify molecular pathways activated by space microgravity in microvascular ECs, which may shed light on pathogenic molecular mechanisms responsible for endothelial suffering shared by astronauts and individuals affected with aging, degenerative and sedentary life-associated pathologies on Earth.

Responses of Haloarchaea to Simulated Microgravity

NASA Astrophysics Data System (ADS)

Dornmayr-Pfaffenhuemer, Marion; Legat, Andrea; Schwimbersky, Karin; Fendrihan, Sergiu; Stan-Lotter, Helga

2011-04-01

Various effects of microgravity on prokaryotes have been recognized in recent years, with the focus on studies of pathogenic bacteria. No archaea have been investigated yet with respect to their responses to microgravity. For exposure experiments on spacecrafts or on the International Space Station, halophilic archaea (haloarchaea) are usually embedded in halite, where they accumulate in fluid inclusions. In a liquid environment, these cells will experience microgravity in space, which might influence their viability and survival. Two haloarchaeal strains, Haloferax mediterranei and Halococcus dombrowskii, were grown in simulated microgravity (SMG) with the rotary cell culture system (RCCS, Synthecon). Initially, salt precipitation and detachment of the porous aeration membranes in the RCCS were observed, but they were avoided in the remainder of the experiment by using disposable instead of reusable vessels. Several effects were detected, which were ascribed to growth in SMG: Hfx. mediterranei's resistance to the antibiotics bacitracin, erythromycin, and rifampicin increased markedly; differences in pigmentation and whole cell protein composition (proteome) of both strains were noted; cell aggregation of Hcc. dombrowskii was notably reduced. The results suggest profound effects of SMG on haloarchaeal physiology and cellular processes, some of which were easily observable and measurable. This is the first report of archaeal responses to SMG. The molecular mechanisms of the effects induced by SMG on prokaryotes are largely unknown; haloarchaea could be used as nonpathogenic model systems for their elucidation and in addition could provide information about survival during lithopanspermia (interplanetary transport of microbes inside meteorites).

Immune Response in Microgravity: Genetic Basis and Countermeasure Development Implications

NASA Technical Reports Server (NTRS)

Risin, Diana; Ward, Nancy E.; Risin, Semyon A.; Pellis, Neal R.

2006-01-01

Impairment of the immunity in astronauts and cosmonauts even in shortterm flights is a recognized risk. Longterm orbital space missions and anticipated interplanetary flights increase the concern for more pronounced effects on the immune system with potential clinical consequences. Studies in true and modeled microgravity (MG) have demonstrated that MG directly affects numerous lymphocyte functions. The purpose of this study was to screen for genes involved in lymphocytes response to modeled microgravity (MMG) that could explain the functional and structural changes observed earlier. The microgravity-induced changes in gene expression were analyzed by microarray DNA chip technology. CD3and IL2activated Tcells were cultured in 1g (static) and modeled microgravity (NASA Rotating Wall Vessel bioreactor) conditions for 24 hours. Total RNA was extracted using the RNeasy isolation kit (Qiagen, Valencia, CA). Microarray experiments were performed utilizing Affymetrix Gene Chips (U133A), allowing testing for 18,400 human genes. To decrease the biological variation and aid in detecting microgravity-associated changes, experiments were performed in triplicate using cells obtained from three different donors. Exposure to modeled microgravity resulted in alteration of 89 genes, 10 of which were upregulated and 79 down-regulated. Altered genes were categorized by their function, structural role and by association with metabolic and regulatory pathways. A large proportion was found to be involved in fundamental cellular processes: signal transduction, DNA repair, apoptosis, and multiple metabolic pathways. There was a group of genes directly related to immune and inflammatory responses (IL7R, granulysin, proteasome activator subunit 2, peroxiredoxin 4, HLADRA, lymphocyte antigen 75, IL18R and DOCK2 genes). Among these genes only one (IL7R) was upregulated, the rest were downregulated. The upregulation of the IL7 receptor gene was confirmed by RT PCR. Three genes with altered expression were identified in the apoptosis related group (Granzyme B, APO2 ligand and Beta3endonexin). All of them were downregulated. Gene expression changes in MG might appear pivotal in identifying potential molecular targets for countermeasure development. (Supported by NRA OLMSA02 and NSCORT NAG54072 grants).

Analytical Model For Fluid Dynamics In A Microgravity Environment

NASA Technical Reports Server (NTRS)

Naumann, Robert J.

1995-01-01

Report presents analytical approximation methodology for providing coupled fluid-flow, heat, and mass-transfer equations in microgravity environment. Experimental engineering estimates accurate to within factor of 2 made quickly and easily, eliminating need for time-consuming and costly numerical modeling. Any proposed experiment reviewed to see how it would perform in microgravity environment. Model applied in commercial setting for preliminary design of low-Grashoff/Rayleigh-number experiments.

An Experimental and Computational Study on Soot Formation in a Coflow Jet Flame Under Microgravity and Normal Gravity

NASA Technical Reports Server (NTRS)

Ma, Bin; Cao, Su; Giassi, Davide; Stocker, Dennis P.; Takahashi, Fumiaki; Bennett, Beth Anne V.; Smooke, Mitchell D.; Long, Marshall B.

2014-01-01

Upon the completion of the Structure and Liftoff in Combustion Experiment (SLICE) in March 2012, a comprehensive and unique set of microgravity coflow diffusion flame data was obtained. This data covers a range of conditions from weak flames near extinction to strong, highly sooting flames, and enabled the study of gravitational effects on phenomena such as liftoff, blowout and soot formation. The microgravity experiment was carried out in the Microgravity Science Glovebox (MSG) on board the International Space Station (ISS), while the normal gravity experiment was performed at Yale utilizing a copy of the flight hardware. Computational simulations of microgravity and normal gravity flames were also carried out to facilitate understanding of the experimental observations. This paper focuses on the different sooting behaviors of CH4 coflow jet flames in microgravity and normal gravity. The unique set of data serves as an excellent test case for developing more accurate computational models.Experimentally, the flame shape and size, lift-off height, and soot temperature were determined from line-of-sight flame emission images taken with a color digital camera. Soot volume fraction was determined by performing an absolute light calibration using the incandescence from a flame-heated thermocouple. Computationally, the MC-Smooth vorticity-velocity formulation was employed to describe the chemically reacting flow, and the soot evolution was modeled by the sectional aerosol equations. The governing equations and boundary conditions were discretized on an axisymmetric computational domain by finite differences, and the resulting system of fully coupled, highly nonlinear equations was solved by a damped, modified Newtons method. The microgravity sooting flames were found to have lower soot temperatures and higher volume fraction than their normal gravity counterparts. The soot distribution tends to shift from the centerline of the flame to the wings from normal gravity to microgravity.

Development of microgravity, full body functional reach envelope using 3-D computer graphic models and virtual reality technology

NASA Technical Reports Server (NTRS)

Lindsey, Patricia F.

1994-01-01

In microgravity conditions mobility is greatly enhanced and body stability is difficult to achieve. Because of these difficulties, optimum placement and accessibility of objects and controls can be critical to required tasks on board shuttle flights or on the proposed space station. Anthropometric measurement of the maximum reach of occupants of a microgravity environment provide knowledge about maximum functional placement for tasking situations. Calculations for a full body, functional reach envelope for microgravity environments are imperative. To this end, three dimensional computer modeled human figures, providing a method of anthropometric measurement, were used to locate the data points that define the full body, functional reach envelope. Virtual reality technology was utilized to enable an occupant of the microgravity environment to experience movement within the reach envelope while immersed in a simulated microgravity environment.

Effect of IR Laser on Myoblasts: Prospects of Application for Counteracting Microgravity-Induced Muscle Atrophy

NASA Astrophysics Data System (ADS)

Monici, Monica; Cialdai, Francesca; Romano, Giovanni; Corsetto, Paola Antonia; Rizzo, Angela Maria; Caselli, Anna; Ranaldi, Francesco

2013-02-01

Microgravity-induced muscle atrophy is a problem of utmost importance for the impact it may have on the health and performance of astronauts. Therefore, appropriate countermeasures are needed to prevent disuse atrophy and favour muscle recovery. Muscle atrophy is characterized by loss of muscle mass and strength, and a shift in substrate utilization from fat to glucose, that leads to a reduced metabolic efficiency and enhanced fatigability. Laser therapy is already used in physical medicine and rehabilitation to accelerate muscle recovery and in sports medicine to prevent damages produced by metabolic disturbances and inflammatory reactions after heavy exercise. The aim of the research we present was to get insights on possible benefits deriving from the application of an advanced infrared laser system to counteract deficits of muscle energy metabolism and stimulate the recovery of the hypotrophic tissue. The source used was a Multiwave Locked System (MLS) laser, which combines continuous and pulsed emissions at 808 nm and 905 nm, respectively. We studied the effect of MLS treatment on morphology and energy metabolism of C2C12 cells, a widely accepted myoblast model, previously exposed to microgravity conditions modelled by a Random Positioning Machine. The MLS laser treatment was able to restore basal levels of serine/threonine protein phosphatase activity and to counteract cytoskeletal alterations and increase in glycolytic enzymes activity that occurred following the exposure to modelled microgravity. In conclusion, the results provide interesting insights for the application of infrared laser in the treatment of muscle atrophy.

The role of nucleotides in augmentation of lymphocyte locomotion: Adaptional countermeasure development in microgravity analog environments

NASA Astrophysics Data System (ADS)

Sundaresan, Alamelu; Kulkarni, Anil D.; Yamauchi, Keiko; Pellis, Neal R.

2006-09-01

Space travel and long-term space residence such as envisaged in the exploration era implicates burdens on the immune system. An optimal immune response is required to countered and with-stand exposure to pathogens. Countermeasure development is an important avenue in space research especially for long-term space exploration. Microgravity exposure causes detrimental effects in lymphocyte functions which may impair immune response. Impaired lymphocyte function can be remedied by bypassing cell membrane events. This is done by using compounds such as Phorbol Myristate Acetate (PMA). Since activation in mouse splenocytes was augmented using nucleotides, it was essential to observe their effects on human lymphocyte locomotion. A nucleotide/nucleoside (NT/NT) mixture from Otsuka Pharmaceuticals (Naruto, Japan) was used at recommended doses. In lymphocytes cultured in modeled microgravity, the NT/NT mixture used orchestrated locomotion recovery by more than 87%, similar to the response documented with PMA in lymphocytes. Both 12µM and 120µM doses worked similarly. These are preliminary results leading to the possible use of the NT/NT mixture to mitigate immune suppression in micro-gravity. More studies in this direction are required to delineate the role of NT/NT on the immune response in microgravity.

Blunt trauma and operative care in microgravity: a review of microgravity physiology and surgical investigations with implications for critical care and operative treatment in space.

PubMed

Kirkpatrick, A W; Campbell, M R; Novinkov, O L; Goncharov, I B; Kovachevich, I V

1997-05-01

The assembly of the International Space Station in a low earth orbit will soon become a reality. The National Aeronautics and Space Administration envisions inhabited lunar bases and staffed missions to Mars in the future. Increasing numbers of astronauts, construction of high-mass structures, increased extra-vehicular activity, and prolonged if not prohibitive medical evacuation times to earth underscore the need to address requirements for trauma care in nonterrestrial environments. A search was carried out to review the relevant literature in the MEDLINE and SPACELINE databases. All related Technical, Corporate, and Flight Test Reports in the KRUG Life Sciences corporate library were also reviewed. Bibliographies of all articles were then reviewed from these papers to identify additional pertinent literature. Senior Russian investigators reviewed the Russian literature and translated Russian publications when appropriate. Personal communication and discussion with active microgravity investigators and ongoing microgravity research supplemented published reports. A large volume of data exist to document the multiple detrimental physiologic effects of microgravity exposure on human physiology. Organs systems such as cardiovascular, neurohumoral, immune, hematopoetic, and musculoskeletal systems may be particularly affected. These physiologic changes suggest an impaired ability to withstand major systemic trauma. Observational data also suggest adverse changes in numerous aspects of response to wounding and injury, and in areas such as the behavior of hemorrhage, microbiologic flora, and wound healing. In addition to an increased volume of ongoing and anticipated basic science research in microgravity physiology, preliminary studies of clinical diagnosis and therapy have been carried out in microgravity and microgravity laboratories. The feasibility of a wide range of ancillary critical care techniques has been verified in the parabolic flight model of microgravity. Although Russian investigators first performed laparotomies on rabbits in parabolic flight in 1967, only recently have American investigators demonstrated the reproducible feasibility of open and endoscopic surgical procedures under general anesthetic in animal models in a microgravity environment. With appropriate instrumentation and personnel, the majority of resuscitative and surgical interventions required to stabilize a severely injured astronaut are feasible in a microgravity environment. Onboard limitations in mass, volume, and power that are ever present in any spacecraft design will limit the realistic capabilities of the medical system. Standard proved and tested trauma and operative management protocols will constitute the basis for extra-terrestrial care. Surgeons should familiarize themselves with the microgravity environment and remain active in planning trauma care for the continued exploration of space.

Development of neuronal and sensorimotor systems in the absence of gravity: Neurobiological research on four soyuz taxi flights to the international space station

NASA Astrophysics Data System (ADS)

Horn, Eberhard R.; Dournon, Christian; Frippiat, Jean-Pol; Marco, Roberto; Böser, Sybille; Kirschnick, Uta

2007-09-01

Neurobiological experiments on 4 animal species (Xenopus laevis, Pleurodeles waltl, Drosophila melanogaster, Acheta domesticus) were performed to study effects of microgravity on development and aging of neuronal, sensory and motor systems. Animal models were selected according to their suitability to answer questions concerning μg-effects on neuroanatomy, neuronal activity, and behaviour. The studies were performed on the Soyuz Taxi flights Andromède, Cervantes, Eneide and LDM-TMA8/TMA7. Observations from these flights include: (1) In tadpoles and cricket larvae, morphological features of sensory cells and neurons are rarely affected by microgravity. (2) In crickets, in-flight fertilization was successful; after landing, flight larvae hatched earlier than ground reared siblings. (3) In crickets, proliferation of peptidergic neurons and their projection patterns within the nervous system were not affected by microgravity. (4) During aging, the impact of microgravity on peptidergic neurons of male Drosophila was limited to the size of cell body. (5) In Xenopus, neurophysiological features of the spinal motor system during fictive swimming were partially modified. (6) In Xenopus tadpoles, the vestibuloocular reflex was affected in an age-related manner. Modifications were also related to the occurrence of a tail lordosis induced by microgravity. It is concluded that adaptation to microgravity during development and aging is mainly based on physiological mechanisms within the central nervous system while structural modifications of the sensory and neuronal system contribute less.

Advances in engineered microorganisms for improving metabolic conversion via microgravity effects.

PubMed

Huangfu, Jie; Zhang, Genlin; Li, Jun; Li, Chun

2015-01-01

As an extreme and unique environment, microgravity has significant effects on microbial cellular processes, such as cell growth, gene expression, natural pathways and biotechnological products. Application of microgravity effects to identify the regulatory elements in reengineering microbial hosts will draw much more attention in further research. In this commentary, we discuss the microgravity effects in engineered microorganisms for improving metabolic conversion, including cell growth kinetics, antimicrobial susceptibility, resistance to stresses, secondary metabolites production, recombinant protein production and enzyme activity, as well as gene expression changes. Application of microgravity effects in engineered microorganisms could provide valuable platform for innovative approaches in bioprocessing technology to largely improve the metabolic conversion efficacy of biopharmaceutical products.

Clinical models of cardiovascular regulation after weightlessness

NASA Technical Reports Server (NTRS)

Robertson, D.; Jacob, G.; Ertl, A.; Shannon, J.; Mosqueda-Garcia, R.; Robertson, R. M.; Biaggioni, I.

1996-01-01

After several days in microgravity, return to earth is attended by alterations in cardiovascular function. The mechanisms underlying these effects are inadequately understood. Three clinical disorders of autonomic function represent possible models of this abnormal cardiovascular function after spaceflight. They are pure autonomic failure, baroreflex failure, and orthostatic intolerance. In pure autonomic failure, virtually complete loss of sympathetic and parasympathetic function occurs along with profound and immediate orthostatic hypotension. In baroreflex failure, various degrees of debuffering of blood pressure occur. In acute and complete baroreflex failure, there is usually severe hypertension and tachycardia, while with less complete and more chronic baroreflex impairment, orthostatic abnormalities may be more apparent. In orthostatic intolerance, blood pressure fall is minor, but orthostatic symptoms are prominent and tachycardia frequently occurs. Only careful autonomic studies of human subjects in the microgravity environment will permit us to determine which of these models most closely reflects the pathophysiology brought on by a period of time in the microgravity environment.

Simulated microgravity facilitates cell migration and neuroprotection after bone marrow stromal cell transplantation in spinal cord injury

PubMed Central

2013-01-01

Introduction Recently, cell-based therapy has gained significant attention for the treatment of central nervous system diseases. Although bone marrow stromal cells (BMSCs) are considered to have good engraftment potential, challenges due to in vitro culturing, such as a decline in their functional potency, have been reported. Here, we investigated the efficacy of rat BMSCs (rBMSCs) cultured under simulated microgravity conditions, for transplantation into a rat model of spinal cord injury (SCI). Methods rBMSCs were cultured under two different conditions: standard gravity (1G) and simulated microgravity attained by using the 3D-clinostat. After 7 days of culture, the rBMSCs were analyzed morphologically, with RT-PCR and immunostaining, and were used for grafting. Adult rats were used for constructing SCI models by using a weight-dropping method and were grouped into three experimental groups for comparison. rBMSCs cultured under 1 g and simulated microgravity were transplanted intravenously immediately after SCI. We evaluated the hindlimb functional improvement for 3 weeks. Tissue repair after SCI was examined by calculating the cavity area ratio and immunohistochemistry. Results rBMSCs cultured under simulated microgravity expressed Oct-4 and CXCR4, in contrast to those cultured under 1 g conditions. Therefore, rBMSCs cultured under simulated microgravity were considered to be in an undifferentiated state and thus to possess high migration ability. After transplantation, grafted rBMSCs cultured under microgravity exhibited greater survival at the periphery of the lesion, and the motor functions of the rats that received these grafts improved significantly compared with the rats that received rBMSCs cultured in 1 g. In addition, rBMSCs cultured under microgravity were thought to have greater trophic effects on reestablishment and survival of host spinal neural tissues because cavity formations were reduced, and apoptosis-inhibiting factor expression was high at the periphery of the SCI lesion. Conclusions Here we show that transplantation of rBMSCs cultured under simulated microgravity facilitates functional recovery from SCI rather than those cultured under 1 g conditions. PMID:23548163

Binding of alpha-fetoprotein by immobilized monoclonal antibodies during episodes of zero-gravity obtained by parabolic flight

NASA Technical Reports Server (NTRS)

Spooner, Brian S.; Guikema, James A.; Barnes, Grady

1990-01-01

Alpha-fetoprotein (AFP), a single-chain polypeptide which is synthesized by the liver and yolk sac of the human fetus, provided a model ligand for assessing the effects of microgravity on ligand binding to surface-immobilized model receptor molecules. Monoclonal antibodies, used as receptors for AFP, were immobilized by covalent attachment to latex microparticles. Zero gravity environment was obtained by parabolic flight aboard NASA 930, a modified KC-135 aircraft. Buring the onset of an episode of zero gravity, ligand and receptor were mixed. Timed incubation (20 s) was terminated by centrifugation, the supernatant removed, and microparticies were assessed for bound AFP by immunochemical methods. The extent of binding was not influenced by microgravity, when compared with 1-G controls, which suggests that aberrant cellular activities observed in microgravity are not the simple expression of altered macromolecular interactions.

Frequency-Weighting Filter Selection, for H2 Control of Microgravity Isolation Systems: A Consideration of the "Implicit Frequency Weighting" Problem

NASA Technical Reports Server (NTRS)

Hampton, Roy David; Whorton, Mark S.

1999-01-01

Many space-science experiments need an active isolation system to provide them with the requisite microgravity environment. The isolation systems planned for use with the International Space Station (ISS) have been appropriately modeled using relative position, relative velocity, and acceleration states. In theory, frequency-weighting design filters can be applied to these state-space models, in order to develop optimal H2 or mixed-norm controllers with desired stability and performance characteristics. In practice, however, since there is a kinematic relationship among the various states, any frequency weighting applied to one state will implicitly weight other states. These implicit frequency-weighting effects must be considered, for intelligent frequency-weighting filter assignment. This paper suggests a rational approach to the assignment of frequency-weighting design filters, in the presence of the kinematic coupling among states that exists in the microgravity vibration isolation problem.

Preparation for microgravity: The role of the microgravity materials science laboratory

NASA Technical Reports Server (NTRS)

Johnston, J. Christopher; Rosenthal, Bruce N.; Meyer, Maryjo B.; Glasgow, Thomas K.

1988-01-01

A laboratory dedicated to ground based materials processing in preparation for space flight was established at the NASA Lewis Research Center. Experiments are performed to delineate the effects of gravity on processes of both scientific and commercial interest. Processes are modeled physically and mathematically. Transport model systems are used where possible to visually track convection, settling, crystal growth, phase separation, agglomeration, vapor transport, diffusive flow, and polymers reactions. The laboratory contains apparatus which functionally duplicates apparatus available for flight experiments and other pieces instrumented specifically to allow process characterization. Materials addressed include metals, alloys, salts, glasses, ceramics, and polymers. The Microgravity Materials Science Laboratory is staffed by engineers and technicians from a variety of disciplines and is open to users from industry and academia as well as the government. Examples will be given of the laboratory apparatus typical experiments and results.

Enzyme Kinetics in Microgravity

NASA Astrophysics Data System (ADS)

Liu, C. C.; Licata, V. J.

2010-04-01

The kinetics of some enzymes have been found to be enhanced by the microgravity environment. This is a relatively small effect, but is sufficient to have physiological effects and to impact pharmaceutical therapy in microgravity.

Current Results and Proposed Activities in Microgravity Fluid Dynamics

NASA Technical Reports Server (NTRS)

Polezhaev, V. I.

1996-01-01

The Institute for Problems in Mechanics' Laboratory work in mathematical and physical modelling of fluid mechanics develops models, methods, and software for analysis of fluid flow, instability analysis, direct numerical modelling and semi-empirical models of turbulence, as well as experimental research and verification of these models and their applications in technological fluid dynamics, microgravity fluid mechanics, geophysics, and a number of engineering problems. This paper presents an overview of the results in microgravity fluid dynamics research during the last two years. Nonlinear problems of weakly compressible and compressible fluid flows are discussed.

Comparison of hindlimb unloading and partial weight suspension models for spaceflight-type condition induced effects on white blood cells

NASA Astrophysics Data System (ADS)

Wilson, Jolaine M.; Krigsfeld, Gabriel S.; Sanzari, Jenine K.; Wagner, Erika B.; Mick, Rosemarie; Kennedy, Ann R.

2012-01-01

Animal models are frequently used to assist in the determination of the long- and short-term effects of space flight. The space environment, including microgravity, can impact many physiological and immunological system parameters. It has been found that ground based models of microgravity produce changes in white blood cell counts, which negatively affects immunologic function. As part of the Center of Acute Radiation Research (CARR), we compared the acute effects on white blood cell parameters induced by the more traditionally used animal model of hindlimb unloading (HU) with a recently developed reduced weightbearing analog known as partial weight suspension (PWS). Female ICR mice were either hindlimb unloaded or placed in the PWS system at 16% quadrupedal weightbearing for 4 h, 1, 2, 7 or 10 days, at which point complete blood counts were obtained. Control animals (jacketed and non-jacketed) were exposed to identical conditions without reduced weightbearing. Results indicate that significant changes in total white blood cell (WBC), neutrophil, lymphocyte, monocyte and eosinophil counts were observed within the first 2 days of exposure to each system. These differences in blood cell counts normalized by day 7 in both systems. The results of these studies indicate that there are some statistically significant changes observed in the blood cell counts for animals exposed to both the PWS and HU simulated microgravity systems.

Combustion of Unconfined Droplet Clusters in Microgravity

NASA Technical Reports Server (NTRS)

Ruff, G. A.; Liu, S.

2001-01-01

Combustion experiments using arrays of droplets seek to provide a link between single droplet combustion phenomena and the behavior of complex spray combustion systems. Both single droplet and droplet array studies have been conducted in microgravity to better isolate the droplet interaction phenomena and eliminate or reduce the confounding effects of buoyancy-induced convection. In most experiments involving droplet arrays, the droplets are supported on fibers to keep them stationary and close together before the combustion event. The presence of the fiber, however, disturbs the combustion process by introducing a source of heat transfer and asymmetry into the configuration. As the number of drops in a droplet array increases, supporting the drops on fibers becomes less practical because of the cumulative effect of the fibers on the combustion process. To eliminate the effect of the fiber, several researchers have conducted microgravity experiments using unsupported droplets. Jackson and Avedisian investigated single, unsupported drops while Nomura et al. studied droplet clouds formed by a condensation technique. The overall objective of this research is to extend the study of unsupported drops by investigating the combustion of well-characterized drop clusters in a microgravity environment. Direct experimental observations and measurements of the combustion of droplet clusters would fill a large gap in our current understanding of droplet and spray combustion and provide unique experimental data for the verification and improvement of spray combustion models. In this work, the formation of drop clusters is precisely controlled using an acoustic levitation system so that dilute, as well as dense clusters can be created and stabilized before combustion in microgravity is begun. This paper describes the design and performance of the 1-g experimental apparatus, some preliminary 1-g results, and plans for testing in microgravity.

Non-invasive water-table imaging with joint DC-resistivity/microgravity/hydrologic-model inversion

NASA Astrophysics Data System (ADS)

Kennedy, J.; Macy, J. P.

2017-12-01

The depth of the water table, and fluctuations thereof, is a primary concern in hydrology. In riparian areas, the water table controls when and where vegetation grows. Fluctuations in the water table depth indicate changes in aquifer storage and variation in ET, and may also be responsible for the transport and degradation of contaminants. In the latter case, installation of monitoring wells is problematic because of the potential to create preferential flow pathways. We present a novel method for non-invasive water table monitoring using combined DC resistivity and repeat microgravity data. Resistivity profiles provide spatial resolution, but a quantifiable relation between resistivity changes and aquifer-storage changes depends on a petrophysical relation (typically, Archie's Law), with additional parameters and therefore uncertainty. Conversely, repeat microgravity data provide a direct, quantifiable measurement of aquifer-storage change but lack depth resolution. We show how these two geophysical measurements, together with an unsaturated-zone flow model (Hydrogeosphere), effectively constrain the water table position and help identify groundwater-flow model parameters. A demonstration of the method is made using field data collected during the historic 2014 pulse flow in the Colorado River Delta, which shows that geophysical data can effectively constrain a coupled surface-water/groundwater model used to simulate the potential for riparian vegetation germination and recruitment.

Gramicidin S production by Bacillus brevis in simulated microgravity

NASA Technical Reports Server (NTRS)

Fang, A.; Pierson, D. L.; Mishra, S. K.; Koenig, D. W.; Demain, A. L.

1997-01-01

In a continuing study of microbial secondary metabolism in simulated microgravity, we have examined gramicidin S (GS) production by Bacillus brevis strain Nagano in NASA High Aspect Rotating Vessels (HARVs), which are designed to simulate some aspects of microgravity. Growth and GS production were found to occur under simulated microgravity. When performance under simulated microgravity was compared with that under normal gravity conditions in the bioreactors, GS production was found to be unaffected by simulated microgravity. The repressive effect of glycerol in flask fermentations was not observed in the HARV. Thus the negative effect of glycerol on specific GS formation is dependent on shear and/or vessel geometry, not gravity.

The Use of Microgravity Simulators for Space Research

NASA Technical Reports Server (NTRS)

Zhang, Ye; Richards, Stephanie E.; Richards, Jeffrey T.; Levine, Howard G.

2016-01-01

The spaceflight environment is known to influence biological processes ranging from stimulation of cellular metabolism to possible impacts on cellular damage repair, suppression of immune functions, and bone loss in astronauts. Microgravity is one of the most significant stress factors experienced by living organisms during spaceflight, and therefore, understanding cellular responses to altered gravity at the physiological and molecular level is critical for expanding our knowledge of life in space. Since opportunities to conduct experiments in space are scarce, various microgravity simulators and analogues have been widely used in space biology ground studies. Even though simulated microgravity conditions have produced some, but not all of the biological effects observed in the true microgravity environment, they provide test beds that are effective, affordable, and readily available to facilitate microgravity research. Kennedy Space Center (KSC) provides ground microgravity simulator support to offer a variety of microgravity simulators and platforms for Space Biology investigators. Assistance will be provided by both KSC and external experts in molecular biology, microgravity simulation, and engineering. Comparisons between the physical differences in microgravity simulators, examples of experiments using the simulators, and scientific questions regarding the use of microgravity simulators will be discussed.

Effect of Residual Noncondensables on Pressurization and Pressure Control of a Zero-Boil-Off Tank in Microgravity

NASA Technical Reports Server (NTRS)

Kassemi, Mohammad; Hylton, Sonya; Kartizova, Olga

2013-01-01

The Zero-Boil-Off Tank (ZBOT) Experiment is a small-scale experiment that uses a transparent ventless Dewar and a transparent simulant phase-change fluid to study sealed tank pressurization and pressure control with applications to on-surface and in-orbit storage of propellant cryogens. The experiment will be carried out under microgravity conditions aboard the International Space Station in the 2014 timeframe. This paper presents preliminary results from ZBOT's ground-based research that focuses on the effects of residual noncondensable gases in the ullage on both pressurization and pressure reduction trends in the sealed Dewar. Tank pressurization is accomplished through heating of the test cell wall in the wetted and un-wetted regions simultaneously or separately. Pressure control is established through mixing and destratification of the bulk liquid using a temperature controlled forced jet flow with different degrees of liquid jet subcooling. A Two-Dimensional axisymmetric two-phase CFD model for tank pressurization and pressure control is also presented. Numerical prediction of the model are compared to experimental 1g results to both validate the model and also indicate the effect of the noncondensable gas on evolution of pressure and temperature distributions in the ullage during pressurization and pressure control. Microgravity simulations case studies are also performed using the validated model to underscore and delineate the profound effect of the noncondensables on condensation rates and interfacial temperature distributions with serious implications for tank pressure control in reduced gravity.

Utilizing Controlled Vibrations in a Microgravity Environment to Understand and Promote Microstructural Homogeneity During Floating-Zone Crystal Growth

NASA Technical Reports Server (NTRS)

Grugel, Richard N.

1999-01-01

It has been demonstrated in floating-zone configurations utilizing silicone oil and nitrate salts that mechanically induced vibration effectively minimizes detrimental, gravity independent, thermocapillary flow. The processing parameters leading to crystal improvement and aspects of the on-going modeling effort are discussed. Plans for applying the crystal growth technique to commercially relevant materials, e.g., silicon, as well as the value of processing in a microgravity environment are presented.

Shear History Extensional Rheology Experiment II (SHERE II) Microgravity Rheology with Non-Newtonian Polymeric Fluids

NASA Technical Reports Server (NTRS)

Jaishankar, Aditya; Haward, Simon; Hall, Nancy Rabel; Magee, Kevin; McKinley, Gareth

2012-01-01

The primary objective of SHERE II is to study the effect of torsional preshear on the subsequent extensional behavior of filled viscoelastic suspensions. Microgravity environment eliminates gravitational sagging that makes Earth-based experiments of extensional rheology challenging. Experiments may serve as an idealized model system to study the properties of lunar regolith-polymeric binder based construction materials. Filled polymeric suspensions are ubiquitous in foods, cosmetics, detergents, biomedical materials, etc.

Depression, mood state, and back pain during microgravity simulated by bed rest

NASA Technical Reports Server (NTRS)

Styf, J. R.; Hutchinson, K.; Carlsson, S. G.; Hargens, A. R.

2001-01-01

OBJECTIVE: The objective of this study was to develop a ground-based model for spinal adaptation to microgravity and to study the effects of spinal adaptation on depression, mood state, and pain intensity. METHODS: We investigated back pain, mood state, and depression in six subjects, all of whom were exposed to microgravity, simulated by two forms of bed rest, for 3 days. One form consisted of bed rest with 6 degrees of head-down tilt and balanced traction, and the other consisted of horizontal bed rest. Subjects had a 2-week period of recovery between the studies. The effects of bed rest on pain intensity in the lower back, depression, and mood state were investigated. RESULTS: Subjects experienced significantly more intense lower back pain, lower hemisphere abdominal pain, headache, and leg pain during head-down tilt bed rest. They had higher scores on the Beck Depression Inventory (ie, were more depressed) and significantly lower scores on the activity scale of the Bond-Lader questionnaire. CONCLUSIONS: Bed rest with 6 degrees of head-down tilt may be a better experimental model than horizontal bed rest for inducing the pain and psychosomatic reactions experienced in microgravity. Head-down tilt with balanced traction may be a useful method to induce low back pain, mood changes, and altered self-rated activity level in bed rest studies.

Loss of signal transduction and inhibition of lymphocyte locomotion in a ground-based model of microgravity

NASA Technical Reports Server (NTRS)

Sundaresan, Alamelu; Risin, Diana; Pellis, Neal R.; McIntire, L. V. (Principal Investigator)

2002-01-01

Inflammatory adherence to, and locomotion through the interstitium is an important component of the immune response. Conditions such as microgravity and modeled microgravity (MMG) severely inhibit lymphocyte locomotion in vitro through gelled type I collagen. We used the NASA rotating wall vessel bioreactor or slow-turning lateral vessel as a prototype for MMG in ground-based experiments. Previous experiments from our laboratory revealed that when lymphocytes (human peripheral blood mononuclear cells [PBMCs]) were first activated with phytohemaglutinin followed by exposure to MMG, locomotory capacity was not affected. In the present study, MMG inhibits lymphocyte locomotion in a manner similar to that observed in microgravity. Phorbol myristate acetate (PMA) treatment of PBMCs restored lost locomotory capacity by a maximum of 87%. Augmentation of cellular calcium flux with ionomycin had no restorative effect. Treatment of lymphocytes with mitomycin C prior to exposure to MMG, followed by PMA, restored locomotion to the same extent as when nonmitomycin C-treated lymphocytes were exposed to MMG (80-87%), suggesting that deoxyribonucleic acid replication is not essential for the restoration of locomotion. Thus, direct activation of protein kinase C (PKC) with PMA was effective in restoring locomotion in MMG comparable to the normal levels seen in Ig cultures. Therefore, in MMG, lymphocyte calcium signaling pathways were functional, with defects occurring at either the level of PKC or upstream of PKC.

Microgravity induces inhibition of osteoblastic differentiation and mineralization through abrogating primary cilia.

PubMed

Shi, Wengui; Xie, Yanfang; He, Jinpeng; Zhou, Jian; Gao, Yuhai; Wei, Wenjun; Ding, Nan; Ma, Huiping; Xian, Cory J; Chen, Keming; Wang, Jufang

2017-05-12

It is well documented that microgravity in space environment leads to bone loss in astronauts. These physiological changes have also been validated by human and animal studies and modeled in cell-based analogs. However, the underlying mechanisms are elusive. In the current study, we identified a novel phenomenon that primary cilia (key sensors and functioning organelles) of rat calvarial osteoblasts (ROBs) gradually shrank and disappeared almost completely after exposure to simulated microgravity generated by a random positioning machine (RPM). Along with the abrogation of primary cilia, the differentiation, maturation and mineralization of ROBs were inhibited. We also found that the disappearance of primary cilia was prevented by treating ROBs with cytochalasin D, but not with LiCl or dynein light chain Tctex-type 1 (Dynlt1) siRNA. The repression of the differentiation, maturation and mineralization of ROBs was effectively offset by cytochalasin D treatment in microgravity conditions. Blocking ciliogenesis using intraflagellar transport protein 88 (IFT88) siRNA knockdown inhibited the ability of cytochalasin D to counteract this reduction of osteogenesis. These results indicate that the abrogation of primary cilia may be responsible for the microgravity's inhibition on osteogenesis. Reconstruction of primary cilia may become a potential strategy against bone loss induced by microgravity.

Protein Kinases Possibly Mediate Hypergravity-Induced Changes in F-Actin Expression by Endothelial Cells

NASA Technical Reports Server (NTRS)

Love, Felisha D.; Melhado, Caroline D.; Bosah, Francis N.; Harris-Hooker, Sandra A.; Sanford, Gary L.

1998-01-01

Basic cellular functions such as electrolyte concentration, cell growth rate, glucose utilization, bone formation, response to growth stimulation, and exocytosis are modified in microgravity. These studies indicate that microgravity affects a number of physiological systems and included in this are cell signaling mechanisms. Rijken and coworkers performed growth factor studies that showed PKC signaling and actin microfilament organization appears to be sensitive to microgravity, suggesting that the inhibition of signal transduction by microgravity may be related to alterations in actin microfilament organization. However, similar studies have not been done for vascular cells. Vascular endothelial cells play critical roles in providing nutrients to organ and tissues and in wound repair. The major deterrent to ground-based microgravity studies is that it is impossible to achieved true microgravity for longer than a few minutes on earth. Hence, it has not been possible to conduct prolonged microgravity studies except for two models that simulate certain aspects of microgravity. However, hypergravity is quite easily achieved. Several researchers have shown that hypergravity will increase the proliferation of several different cell lines while decreasing cell motility and slowing liver regeneration following partial hepatectomy, These studies indicate the hypergravity also alters the behavior of most cells. Several investigators have shown that hypergravity affects the activation of several protein kinases (PKs) in cells. In this study, we investigated whether hypergravity alters the expression of f-actin by bovine aortic endothelial cells (BAECs) and the role of PK's (calmodulin 11 dependent, PKA and PKC) as mediators of these effects.

Numerical Simulation of cardiovascular deconditioning in different reduced gravity exposure scenarios. Parabolic flight validation.

NASA Astrophysics Data System (ADS)

Perez-Poch, Antoni; Gonzalez, Daniel

Numerical models and simulations are an emerging area of research in human physiology. As complex numerical models are available, along with high-speed computing technologies, it is possible to produce more accurate predictions of the long-term effects of reduced gravity on the human body. NELME (Numerical Emulation of Long-Term Microgravity Effects) has been developed as an electrical-like control system model of the pysiological changes that may arise when gravity changes are applied to the cardiovascular system. Validation of the model has been carried out in parabolic flights at UPC BarcelonaTech Platform. A number of parabolas of up to 8 seconds were performed at Sabadell Airport with an aerobatic single-engine CAP10B plane capable of performing such maneuvres. Heart rate, arterial pressure, and gravity data was collected and compared to the output obtained from the model in order to optimize its parameters. The model is then able to perform simulations for long-term periods of exposure to microgravity, and then the risk for a major malfunction is evaluated. Vascular resistance is known to be impaired during a long-term mission. This effects are not fully understood, and the model is capable of providing a continuous thread of simulated scenarios, while varying gravity in a nearly-continuous way. Aerobic exercise as countermeasure has been simulated as a periodic perturbation into the simulated physiological system. Results are discussed in terms of the validaty and reliability of the outcomes from the model, that have been found compatible with the available data in the literature. Different gender sensitivities to microgravity exposure are discussed. Also thermal stress along with exercise, as it happens in the case of Extravehicular activity is smulated. Results show that vascular resistance is significantly impared (p<0,05) at gravity levels less than 0,4g, when exposed for a period of time longer than 16 days. This degree of impairement is comparable with that resulting from a microgravity exposure. These results suggest that long-term activities on the surface of Mars may have a greater impact on the cardiovascular health than previously thought.

Numerical simulation of aerobic exercise as a countermeasure in human spaceflight

NASA Astrophysics Data System (ADS)

Perez-Poch, Antoni

The objective of this work is to analyse the efficacy of long-term regular exercise on relevant cardiovascular parameters when the human body is also exposed to microgravity. Computer simulations are an important tool which may be used to predict and analyse these possible effects, and compare them with in-flight experiments. We based our study on a electrical-like computer model (NELME: Numerical Evaluation of Long-term Microgravity Effects) which was developed in our laboratory and validated with the available data, focusing on the cardiovascu-lar parameters affected by changes in gravity exposure. NELME is based on an electrical-like control system model of the physiological changes, that are known to take place when grav-ity changes are applied. The computer implementation has a modular architecture. Hence, different output parameters, potential effects, organs and countermeasures can be easily imple-mented and evaluated. We added to the previous cardiovascular system module a perturbation module to evaluate the effect of regular exercise on the output parameters previously studied. Therefore, we simulated a well-known countermeasure with different protocols of exercising, as a pattern of input electric-like perturbations on the basic module. Different scenarios have been numerically simulated for both men and women, in different patterns of microgravity, reduced gravity and time exposure. Also EVAs were simulated as perturbations to the system. Results show slight differences in gender, with more risk reduction for women than for men after following an aerobic exercise pattern during a simulated mission. Also, risk reduction of a cardiovascular malfunction is evaluated, with a ceiling effect found in all scenarios. A turning point in vascular resistance for a long-term exposure of microgravity below 0.4g has been found of particular interest. In conclusion, we show that computer simulations are a valuable tool to analyse different effects of long-term microgravity exposure on the human body. Potential countermeasures such as physical exercise can also be evaluated as an induced perturbation into the system. Relevant results are compatible with existing data, and are of valuable interest as an assessment of the efficacy of aerobic exercise as a countermeasure in future missions to Mars.

Microgravity as a novel environmental signal affecting Salmonella enterica serovar Typhimurium virulence

NASA Technical Reports Server (NTRS)

Nickerson, C. A.; Ott, C. M.; Mister, S. J.; Morrow, B. J.; Burns-Keliher, L.; Pierson, D. L.

2000-01-01

The effects of spaceflight on the infectious disease process have only been studied at the level of the host immune response and indicate a blunting of the immune mechanism in humans and animals. Accordingly, it is necessary to assess potential changes in microbial virulence associated with spaceflight which may impact the probability of in-flight infectious disease. In this study, we investigated the effect of altered gravitational vectors on Salmonella virulence in mice. Salmonella enterica serovar Typhimurium grown under modeled microgravity (MMG) were more virulent and were recovered in higher numbers from the murine spleen and liver following oral infection compared to organisms grown under normal gravity. Furthermore, MMG-grown salmonellae were more resistant to acid stress and macrophage killing and exhibited significant differences in protein synthesis than did normal-gravity-grown cells. Our results indicate that the environment created by simulated microgravity represents a novel environmental regulatory factor of Salmonella virulence.

Parametric Investigation of Liquid Jets in Low Gravity

NASA Technical Reports Server (NTRS)

Chato, David J.

2005-01-01

An axisymmetric phase field model is developed and used to model surface tension forces on liquid jets in microgravity. The previous work in this area is reviewed and a baseline drop tower experiment selected for model comparison. This paper uses the model to parametrically investigate the influence of key parameters on the geysers formed by jets in microgravity. Investigation of the contact angle showed the expected trend of increasing contact angle increasing geyser height. Investigation of the tank radius showed some interesting effects and demonstrated the zone of free surface deformation is quite large. Variation of the surface tension with a laminar jet showed clearly the evolution of free surface shape with Weber number. It predicted a breakthrough Weber number of 1.

Manifestation of the shape-memory effect in polyetherurethane cellular plastics, fabric composites, and sandwich structures under microgravity

NASA Astrophysics Data System (ADS)

Babaevskii, P. G.; Kozlov, N. A.; Agapov, I. G.; Reznichenko, G. M.; Churilo, N. V.; Churilo, I. V.

2016-09-01

The results of experiments that were performed to test the feasibility of creating sandwich structures (consisting of thin-layer sheaths of polymer composites and a cellular polymer core) with the shapememory effect as models of the transformable components of space structures have been given. The data obtained indicate that samples of sandwich structures under microgravity conditions on board the International Space Station have recovered their shape to almost the same degree as under terrestrial conditions, which makes it possible to recommend them for creating components of transformable space structures on their basis.

Numerical Investigation of Microgravity Tank Pressure Rise Due to Boiling

NASA Technical Reports Server (NTRS)

Hylton, Sonya; Ibrahim, Mounir; Kartuzova, Olga; Kassemi, Mohammad

2015-01-01

The ability to control self-pressurization in cryogenic storage tanks is essential for NASAs long-term space exploration missions. Predictions of the tank pressure rise in Space are needed in order to inform the microgravity design and optimization process. Due to the fact that natural convection is very weak in microgravity, heat leaks into the tank can create superheated regions in the liquid. The superheated regions can instigate microgravity boiling, giving rise to pressure spikes during self-pressurization. In this work, a CFD model is developed to predict the magnitude and duration of the microgravity pressure spikes. The model uses the Schrage equation to calculate the mass transfer, with a different accommodation coefficient for evaporation at the interface, condensation at the interface, and boiling in the bulk liquid. The implicit VOF model was used to account for the moving interface, with bounded second order time discretization. Validation of the models predictions was carried out using microgravity data from the Tank Pressure Control Experiment, which flew aboard the Space Shuttle Mission STS-52. Although this experiment was meant to study pressurization and pressure control, it underwent boiling during several tests. The pressure rise predicted by the CFD model compared well with the experimental data. The ZBOT microgravity experiment is scheduled to fly on February 2016 aboard the ISS. The CFD model was also used to perform simulations for setting parametric limits for the Zero-Boil-Off Tank (ZBOT) Experiments Test Matrix in an attempt to avoid boiling in the majority of the test runs that are aimed to study pressure increase rates during self-pressurization. *Supported in part by NASA ISS Physical Sciences Research Program, NASA HQ, USA

The effects of simulated microgravity on cultured chicken embryonic chondrocytes

NASA Astrophysics Data System (ADS)

Zhang, X.; Li, X. B.; Yang, S. Z.; Li, S. G.; Jiang, P. D.; Lin, Z. H.

2003-10-01

Using the cultured chicken embryonic chondrocytes as a model, the effects of simulated microgravity on the microtubular system of the cellular skeleton, extracellular matrix, alkaline phosphatase activity, intracellular free calcium concentration and mitochondrial ATP synthase activity with its oligomycin inhibition rate were studied with a clinostat. The microtubular content was measured by a flow cytometer. The decrease of microtubular content showed the impairment of the cellular skeleton system. Observation on the extracellualr matrix by the scanning electron microscopy showed that it decreased significantly after rotating, and the fibers in the extracellular matrix were more tiny and disorderly than that of the control group. It can be concluded that the simulated microgravity can affect the secreting and assembly of the extracellular matrix. In contrast to the control, there was a time course decrease in alkaline phosphatase activity of chondrocytes, a marker of matrix mineralization. Meanwhile a significant drop in the intracellular calcium concentration happened at the beginning of rotation. These results indicate that simulated microgravity can suppress matrix calcification of cultured chondrocytes, and intracellular free calcium may be involved in the regulation of matrix calcification as the second signal transmitter. No significant changes happened in the mitochondrial ATP synthase activity and its oligomycin inhibition rate. Perhaps the energy metabolism wasn't affected by the simulated microgravity. The possible mechanisms about them were discussed.

JSC Human Life Sciences Project

NASA Technical Reports Server (NTRS)

1998-01-01

This section of the Life and Microgravity Spacelab (LMS) publication includes articles entitled: (1) E029 - Magnetic Resonance Imaging after Exposure to Microgravity; (2) E030 - Extended Studies of Pulmonary Function in Weightlessness; (3) E074 - Direct Measurement of the Initial Bone Response to Spaceflight in Humans; (4) E401 - The Effects of Microgravity on Skeletal Muscle Contractile Properties; (5) E407 - Effects of Microgravity on the Biochemical and Bioenergetic Characteristics of Human Skeletal Muscle; (6) E410 - Torso Rotation Experiment; (7) E920 - Effect of Weightlessness on Human Single Muscle Fiber Function; (8) E948 - Human Sleep, Circadian Rhythms and Performance in Space; (9) E963 - Microgravity Effects on Standardized Cognitive Performance Measures; and (10) E971 - Measurement of Energy Expenditures During Spaceflight Using the Doubly Labeled Water Method

The Water-Mist Fire Suppression Experiment (Mist): Preliminary Results From The STS-107 Mission

NASA Technical Reports Server (NTRS)

Abbud-Madrid, Angel; McKinnon, J. Thomas; Amon, Francine; Gokoglu, Suleyman

2003-01-01

An investigation of the effect of water mists on premixed flame propagation has been conducted onboard the Space Shuttle to take advantage of the prolonged microgravity environment to study the effect of uniformly distributed clouds of polydisperse water mists on the speed and shape of propagating propane-air premixed flames. The suspension of a quiescent and uniform water mist cloud was confirmed during the microgravity tests. Preliminary results show good agreement with trends obtained by the numerical predictions of a computational model that uses a hybrid Eulerian-Lagrangian formulation to simulate the two-phase, flame/mist interaction. Effective flame suppression is observed at progressively higher water loadings and smaller water droplet sizes. Other unusual flame behavior, such as flame front breakup and pulsating flames, is still under investigation. The promising results from the microgravity tests will be used to assess the feasibility of using water mists as fire suppressants on Earth and on spacecraft.

Quantitative EEG and its Correlation with Cardiovascular, Cognition and mood State: an Integrated Study in Simulated Microgravity

NASA Astrophysics Data System (ADS)

Zhang, Jianyuan; Hu, Bin; Chen, Wenjuan; Moore, Philip; Xu, Tingting; Dong, Qunxi; Liu, Zhenyu; Luo, Yuejia; Chen, Shanguang

2014-12-01

The focus of the study is the estimation of the effects of microgravity on the central nervous activity and its underlying influencing mechanisms. To validate the microgravity-induced physiological and psychological effects on EEG, quantitative EEG features, cardiovascular indicators, mood state, and cognitive performances data collection was achieved during a 45 day period using a -6°head-down bed rest (HDBR) integrated approach. The results demonstrated significant differences in EEG data, as an increased Theta wave, a decreased Beta wave and a reduced complexity of brain, accompanied with an increased heart rate and pulse rate, decreased positive emotion, and degraded emotion conflict monitoring performance. The canonical correlation analysis (CCA) based cardiovascular and cognitive related EEG model showed the cardiovascular effect on EEG mainly affected bilateral temporal region and the cognitive effect impacted parietal-occipital and frontal regions. The results obtained in the study support the use of an approach which combines a multi-factor influential mechanism hypothesis. The changes in the EEG data may be influenced by both cardiovascular and cognitive effects.

Simulating Bone Loss in Microgravity Using Mathematical Formulations of Bone Remodeling

NASA Technical Reports Server (NTRS)

Pennline, James A.

2009-01-01

Most mathematical models of bone remodeling are used to simulate a specific bone disease, by disrupting the steady state or balance in the normal remodeling process, and to simulate a therapeutic strategy. In this work, the ability of a mathematical model of bone remodeling to simulate bone loss as a function of time under the conditions of microgravity is investigated. The model is formed by combining a previously developed set of biochemical, cellular dynamics, and mechanical stimulus equations in the literature with two newly proposed equations; one governing the rate of change of the area of cortical bone tissue in a cross section of a cylindrical section of bone and one governing the rate of change of calcium in the bone fluid. The mechanical stimulus comes from a simple model of stress due to a compressive force on a cylindrical section of bone which can be reduced to zero to mimic the effects of skeletal unloading in microgravity. The complete set of equations formed is a system of first order ordinary differential equations. The results of selected simulations are displayed and discussed. Limitations and deficiencies of the model are also discussed as well as suggestions for further research.

The Use of Microgravity Simulators for Space Research

NASA Technical Reports Server (NTRS)

Zhang, Ye; Richards, Stephanie E.; Wade, Randall I.; Richards, Jeffrey T.; Fritsche, Ralph F.; Levine, Howard G.

2016-01-01

The spaceflight environment is known to influence biological processes ranging from stimulation of cellular metabolism to possible impacts on cellular damage repair, suppression of immune functions, and bone loss in astronauts. Microgravity is one of the most significant stress factors experienced by living organisms during spaceflight, and therefore, understanding cellular responses to altered gravity at the physiological and molecular level is critical for expanding our knowledge of life in space. Since opportunities to conduct experiments in space are scarce, various microgravity simulators and analogues have been widely used in space biology ground studies. Even though simulated microgravity conditions have produced some, but not all of the biological effects observed in the true microgravity environment, they provide test beds that are effective, affordable, and readily available to facilitate microgravity research. A Micro-g Simulator Center is being developed at Kennedy Space Center (KSC) to offer a variety of microgravity simulators and platforms for Space Biology investigators. Assistance will be provided by both KSC and external experts in molecular biology, microgravity simulation, and engineering. Comparisons between the physical differences in microgravity simulators, examples of experiments using the simulators, and scientific questions regarding the use of microgravity simulators will be discussed.

A Test of Macromolecular Crystallization in Microgravity: Large, Well-Ordered Insulin Crystals

NASA Technical Reports Server (NTRS)

Borgstahl, Gloria E. O.; Vahedi-Faridi, Ardeschir; Lovelace, Jeff; Bellamy, Henry D.; Snell, Edward H.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

Crystals of insulin grown in microgravity on space shuttle mission STS-95 were extremely well-ordered and unusually large (many > 2 mm). The physical characteristics of six microgravity and six earth-grown crystals were examined by X-ray analysis employing superfine f slicing and unfocused synchrotron radiation. This experimental setup allowed hundreds of reflections to be precisely examined for each crystal in a short period of time. The microgravity crystals were on average 34 times larger, had 7 times lower mosaicity, had 54 times higher reflection peak heights and diffracted to significantly higher resolution than their earth grown counterparts. A single mosaic domain model could account for reflections in microgravity crystals whereas reflections from earth crystals required a model with multiple mosaic domains. This statistically significant and unbiased characterization indicates that the microgravity environment was useful for the improvement of crystal growth and resultant diffraction quality in insulin crystals and may be similarly useful for macromolecular crystals in general.

Development of a Simulation Capability for the Space Station Active Rack Isolation System

NASA Technical Reports Server (NTRS)

Johnson, Terry L.; Tolson, Robert H.

1998-01-01

To realize quality microgravity science on the International Space Station, many microgravity facilities will utilize the Active Rack Isolation System (ARIS). Simulation capabilities for ARIS will be needed to predict the microgravity environment. This paper discusses the development of a simulation model for use in predicting the performance of the ARIS in attenuating disturbances with frequency content between 0.01 Hz and 10 Hz. The derivation of the model utilizes an energy-based approach. The complete simulation includes the dynamic model of the ISPR integrated with the model for the ARIS controller so that the entire closed-loop system is simulated. Preliminary performance predictions are made for the ARIS in attenuating both off-board disturbances as well as disturbances from hardware mounted onboard the microgravity facility. These predictions suggest that the ARIS does eliminate resonant behavior detrimental to microgravity experimentation. A limited comparison is made between the simulation predictions of ARIS attenuation of off-board disturbances and results from the ARIS flight test. These comparisons show promise, but further tuning of the simulation is needed.

Mechanism of platelet functional changes and effects of anti-platelet agents on in vivo hemostasis under different gravity conditions.

PubMed

Li, Suping; Shi, Quanwei; Liu, Guanglei; Zhang, Weilin; Wang, Zhicheng; Wang, Yuedan; Dai, Kesheng

2010-05-01

Serious thrombotic and hemorrhagic problems or even fatalities evoked by either microgravity or hypergravity occur commonly in the world. We recently reported that platelet functions are inhibited in microgravity environments and activated under high-G conditions, which reveals the pathogenesis for gravity change-related hemorrhagic and thrombotic diseases. However, the mechanisms of platelet functional variations under different gravity conditions remain unclear. In this study we show that the amount of filamin A coimmunoprecipitated with GPIbalpha was enhanced in platelets exposed to modeled microgravity and, in contrast, was reduced in 8 G-exposed platelets. Hypergravity induced actin filament formation and redistribution, whereas actin filaments were reduced in platelets treated with modeled microgravity. Furthermore, intracellular Ca2+ levels were elevated by hypergravity. Pretreatment of platelets with the cell-permeable Ca2+ chelator BAPTA-AM had no effect on cytoskeleton reorganization induced by hypergravity but significantly reduced platelet aggregation induced by ristocetin/hypergravity. Two anti-platelet agents, aspirin and tirofiban, effectively reversed the shortened tail bleeding time and reduced the death rate of mice exposed to hypergravity. Furthermore, the increased P-selectin surface expression was obviously reduced in platelets from mice treated with aspirin/hypergravity compared with those from mice treated with hypergravity alone. These data suggest that the actin cytoskeleton reorganization and intracellular Ca2+ level play key roles in the regulation of platelet functions in different gravitational environments. The results with anti-platelet agents not only further confirm the activation of platelets in vivo but also suggest a therapeutic potential for hypergravity-induced thrombotic diseases.

Embryogenesis and organogenesis of Carausius morosus under spaceflight conditions.

PubMed

Bucker, H; Facius, R; Horneck, G; Reitz, G; Graul, E H; Berger, H; Hoffken, H; Ruther, W; Heinrich, W; Beaujean, R; Enge, W

1986-01-01

The influence of cosmic radiation and/or microgravity on insect development was studied during the 7 day German Spacelab Mission D1. Eggs of Carausius morosus of five stages differing in sensitivity to radiation and in capacity to regeneration were allowed to continue their development in the BIORACK 22 degrees C incubator, either at microgravity conditions or on the 1 g reference centrifuge. Using the Biostack concept--eggs in monolayers were sandwiched between visual track detectors--and the 1 g reference centrifuge, we were able to separate radiation effects from microgravity effects and also from combined effects of these two factors in space. After retrieval, hatching rates, growth kinetics and anomaly frequencies were determined in the different test samples. The early stages of development turned out to be highly sensitive to single hits of cosmic ray particles as well as to the temporary exposure to microgravity during their development. In some cases, the combined action of radiation and microgravity even amplified the effects exerted by the single parameters of space. Hits by single HZE particles caused early effects, such as body anomalies, as well as late effects, such as retarded growth after hatching. Microgravity exposure lead to a reduced hatching rate. A synergistic action of HZE particle hits and microgravity was established in the unexpectedly high frequency of anomal larvae. However, it cannot be excluded, that cosmic background radiation or low LET HZE particles are also causally involved in damage observed in the microgravity samples.

Response of Human Prostate Cancer Cells to Mitoxantrone Treatment in Simulated Microgravity Environment

NASA Technical Reports Server (NTRS)

Zhang, Ye; Edwards, Christopher; Wu, Honglu

2011-01-01

This study explores the changes in growth of human prostate cancer cells (LNCaP) and their response to the treatment of antineoplastic agent, mitoxantrone, under the simulated microgravity condition. In comparison to static 1g, microgravity and simulated microgravity have been shown to alter global gene expression patterns and protein levels in various cultured cell models or animals. However, very little is known about the effect of altered gravity on the responses of cells to drugs, especially chemotherapy drugs. To test the hypothesis that zero gravity would result in altered regulation of cells in response to antineoplastic agents, we cultured LNCaP cells for 96 hr either in a High Aspect Ratio Vessel (HARV) bioreactor at the rotating condition to model microgravity in space or in the static condition as a control. 24 hr after the culture started, mitoxantrone was introduced to the cells at a final concentration of 1 M. The mitoxantrone treatment lasted 72 hr and then the cells were collected for various measurements. Compared to static 1g controls, the cells cultured in the simulated microgravity environment did not show significant differences in cell viability, growth rate, or cell cycle distribution. However, in response to mitoxantrone (1uM), a significant proportion of bioreactor cultured cells (30%) was arrested at G2 phase and a significant number of these cells were apoptotic in comparison to their static controls. The expressions of 84 oxidative stress related genes were analyzed using Qiagen PCR array to identify the possible mechanism underlying the altered responses of bioreactor culture cells to mitoxantrone. Nine out of 84 genes showed higher expression at four hour post mitoxantrone treatment in cells cultured at rotating condition compared to those at static. Taken together, the results reported here indicate that simulated microgravity may alter the responses of LNCaP cells to mitoxantrone treatment. The alteration of oxidative stress pathways in cells cultured under simulated microgravity conditions may be one of the mechanisms to cause such changes of sensitivity of LNCaP cells to mitoxantrone treatment.

The Scorpion An ideal animal model to study long-term microgravity effects on circadian rhythms

NASA Astrophysics Data System (ADS)

Riewe, Pascal C.; Horn, Eberhard R.

2000-01-01

The temporal pattern of light and darkness is basic for the coordination of circadian rhythms and establishment of homoeostasis. The 24th frequency of zeitgebers is probably a function of the Earth's rotation. The only way to eliminate its influence on organisms is to study their behavior in space because the reduced day length during orbiting the Earth might disrupt synchronizing mechanisms based on the 24th rhythm. The stability of microgravity induced disturbances of synchronization as well as the extent of adaptation of different physiological processes to this novel environment can only be studied during long-term exposures to microgravity, i.e., on the International Space Station. Biological studies within the long-term domain on ISS demand the use of experimental models which can be exposed to automatic handling of measurements and which need less or no nutritional care. Scorpions offer these features. We describe a fully automatic recording device for the simultaneous collection of data regarding the sensorimotor system and homoeostatic mechanisms. In particular, we record sensitivity changes of the eyes, motor activity and heart beat and/or respiratory activity. The advantage of the scorpion model is supported by the fact that data can be recorded preflight, inflight and postflight from the same animal. With this animal model, basic insights will be obtained about the de-coupling of circadian rhythms of multiple oscillators and their adaptation to the entraining zeitgeber periodicity during exposure to microgravity for at least three biological parameters recorded simultaneously. .

Treatment of Radix Dipsaci extract prevents long bone loss induced by modeled microgravity in hindlimb unloading rats.

PubMed

Niu, Yinbo; Li, Chenrui; Pan, Yalei; Li, Yuhua; Kong, Xianghe; Wang, Shuo; Zhai, YuanKun; Wu, Xianglong; Fan, Wutu; Mei, Qibing

2015-01-01

Radix Dipsaci is a kidney tonifying herbal medicine with a long history of safe use for treatment of bone fractures and joint diseases in China. Previous studies have shown that Radix Dipsaci extract (RDE) could prevent bone loss in ovariectomized rats. This study investigates the effect of RDE against bone loss induced by simulated microgravity. A hindlimb unloading rat model was established to determine the effect of RDE on bone mineral density and bone microarchitecture. Twenty-four male Sprague-Dawley rats were divided into four groups (n = 6 per group): control (CON), hindlimb unloading with vehicle (HLU), hindlimb unloading treated with alendronate (HLU-ALN, 2.0 mg/kg/d), and hindlimb unloading treated with RDE (HLU-RDE, 500 mg/kg/d). RDE or ALN was administrated orally for 4 weeks. Treatment with RDE had a positive effect on mechanical strength, BMD, BMC, bone turnover markers, and the changes in urinary calcium and phosphorus excretion. MicroCT analysis showed that RDE significantly prevented the reduction of the bone volume fraction, connectivity density, trabecular number, thickness, tissue mineral density, and tissue mineral content as well as improved the trabecular separation and structure model index. RDE was demonstrated to prevent the loss of bone mass induced by HLU treatment, which suggests the potential application of RDE in the treatment of microgravity-induced bone loss.

Regeneration of eye tissues is modulated by altered levels of gravity at 1g, 2g, and in microgravity during spaceflight

NASA Astrophysics Data System (ADS)

Grigoryan, Eleonora; Almeida, Eduardo; Mitashov, Victor

The pursuit of human space exploration requires detailed knowledge of microgravity-related changes in fundamental biological processes, and their effects on health. Normal regeneration of organs and tissues is one such fundamental process that allows maintenance of vitality and function of living organisms. Animal models of tissue regeneration include the newt (Pleurodeles waltl, Urodela) eye, which has been extensively used by our team in Russian Bion and Foton microgravity experiments since 1985, and in recent NASA 2.5 meter diameter centrifuge hypergravity experiments. In total, these experiments allow us to draw several broad conclusions: Newt lens regeneration is significantly altered in microgravity and hypergravity relative to 1g controls. Lenses formed in microgravity are larger and more developed than those regenerated in 1g controls; Microgravity alterations of lens regeneration can persist after spaceflight, and continue to affect repeated removal and regeneration of the lens after return to 1g; Microgravity increases the numbers of early stage regenerative proliferating BrdU-labeled cells in dorsal iris progenitors and in the lens regenerate. Regeneration under hypergravity conditions at 2g inhibits lens regeneration, and often causes retinal detachment. Molecular mechanisms regulating lens regeneration rate include FGF2 signaling, (a key pathway for eye tissue development and regeneration), and an expression of stress-related proteins - HSPs. In conclusion, regeneration of lens and other eye tissues in the newt is sensitive to, and regulated by the level of gravity mechanotransduction and developmental signaling pathways, with microgravity favoring stem cell progenitor proliferation, and gravity at 1g promoting terminal differentiation, while hypergravity at 2g often causes damage of delicate regenerating tissues.

Microgravity nucleation and particle coagulation experiments support

NASA Technical Reports Server (NTRS)

Lilleleht, L. U.; Lass, T. J.

1987-01-01

A hollow sphere model is developed to predict the range of supersaturation ratio values for refractory metal vapors in a proposed experimental nucleation apparatus. Since the experiments are to be carried out in a microgravity environment, the model neglects the effects of convection and assumes that the only transfer of vapors through an inert gas atmosphere is by conduction and molecular diffusion. A consistent set of physical properties data is assembled for the various candidate metals and inert ambient gases expected to be used in the nucleation experiments. Transient partial pressure profiles are computed for the diffusing refractory species for two possible temperature distributions. The supersaturation ratio values from both candidate temperature profiles are compared with previously obtained experimetnal data on a silver-hydrogen system. The model is used to simulate the diffusion of magnesium vapor through argon and other inert gas atmospheres over ranges of initial and boundary conditions. These results identify different combinations of design and operating parameters which are liekly to produce supersaturation ratio values high enough to induce homogeneous nucleation in the apparatus being designed for the microgravity nucleation experiments.

The adaptation of Escherichia coli cells grown in simulated microgravity for an extended period is both phenotypic and genomic.

PubMed

Tirumalai, Madhan R; Karouia, Fathi; Tran, Quyen; Stepanov, Victor G; Bruce, Rebekah J; Ott, C Mark; Pierson, Duane L; Fox, George E

2017-01-01

Microorganisms impact spaceflight in a variety of ways. They play a positive role in biological systems, such as waste water treatment but can be problematic through buildups of biofilms that can affect advanced life support. Of special concern is the possibility that during extended missions, the microgravity environment will provide positive selection for undesirable genomic changes. Such changes could affect microbial antibiotic sensitivity and possibly pathogenicity. To evaluate this possibility, Escherichia coli (lac plus) cells were grown for over 1000 generations on Luria Broth medium under low-shear modeled microgravity conditions in a high aspect rotating vessel. This is the first study of its kind to grow bacteria for multiple generations over an extended period under low-shear modeled microgravity. Comparisons were made to a non-adaptive control strain using growth competitions. After 1000 generations, the final low-shear modeled microgravity-adapted strain readily outcompeted the unadapted lac minus strain. A portion of this advantage was maintained when the low-shear modeled microgravity strain was first grown in a shake flask environment for 10, 20, or 30 generations of growth. Genomic sequencing of the 1000 generation strain revealed 16 mutations. Of the five changes affecting codons, none were neutral. It is not clear how significant these mutations are as individual changes or as a group. It is concluded that part of the long-term adaptation to low-shear modeled microgravity is likely genomic. The strain was monitored for acquisition of antibiotic resistance by VITEK analysis throughout the adaptation period. Despite the evidence of genomic adaptation, resistance to a variety of antibiotics was never observed.

Opposed-Flow Flame Spread over Thin Solid Fuels in a Narrow Channel under Different Gravity

NASA Astrophysics Data System (ADS)

Zhang, Xia; Yu, Yong; Wan, Shixin; Wei, Minggang; Hu, Wen-Rui

Flame spread over solid surface is critical in combustion science due to its importance in fire safety in both ground and manned spacecraft. Eliminating potential fuels from materials is the basic method to protect spacecraft from fire. The criterion of material screening is its flamma-bility [1]. Since gas flow speed has strong effect on flame spread, the combustion behaviors of materials in normal and microgravity will be different due to their different natural convec-tion. To evaluate the flammability of materials used in the manned spacecraft, tests should be performed under microgravity. Nevertheless, the cost is high, so apparatus to simulate mi-crogravity combustion under normal gravity was developed. The narrow channel is such an apparatus in which the buoyant flow is restricted effectively [2, 3]. The experimental results of the horizontal narrow channel are consistent qualitatively with those of Mir Space Station. Quantitatively, there still are obvious differences. However, the effect of the channel size on flame spread has only attracted little attention, in which concurrent-flow flame spread over thin solid in microgravity is numerically studied[4], while the similarity of flame spread in different gravity is still an open question. In addition, the flame spread experiments under microgravity are generally carried out in large wind tunnels without considering the effects of the tunnel size [5]. Actually, the materials are always used in finite space. Therefore, the flammability given by experiments using large wind tunnels will not correctly predict the flammability of materials in the real environment. In the present paper, the effect of the channel size on opposed-flow flame spread over thin solid fuels in both normal and microgravity was investigated and compared. In the horizontal narrow channel, the flame spread rate increased before decreased as forced flow speed increased. In low speed gas flows, flame spread appeared the same trend as that in microgravity. This showed that the horizontal narrow channel can restrict natural convection effectively. In the vertical narrow channel, flame spread became slower as the forced gas flow speed increased. In low speed gas flows, flame spread was not near quench limit. Instead, the spread rate got its maximum value. This was entirely different from the result of microgravity and showed that the vertical narrow channel can not restrict natural convection. For the horizontal narrow channel, when the channel height lowered to 1 cm (The Grashof number was 149 using the half height as a characteristic length), the natural convection was restricted. For vertical narrow channel, a lower height was needed to restrict natural convection. References 1. NASA Technical Standard, "Flammability, Odor, Offgassing, and Compatibility Require-ments and Test Procedures for Materials in Environments That Support Combustion", NASA STD-6001, 1998. 2. Ivanov, A. V., Balashov, Ye. V., Andreeva, T. V., and et al., "Experimental Verification of Material Flammability in Space", NASA CR-1999-209405, 1999. 3. Melikhov, A. S., Bolodyan, I. A., Potyakin, V. I., and et al., "The study of polymer material combustion in simulated microgravity by physical modeling method", In: Sacksteder K, ed, "Fifth Int Microgravity Comb Workshop", NASA CP-1999-208917, 1999, 361. 4. T'ien, J. S., Shih, H.-Y., Jiang, C.-B., and et al., "Mechanisms of flame spread and smol-der wave propagation", In: Ross, H. D., ed, "Microgravity Combustion: Fire in Free Fall", Academic Press, 2001. 299. 5. Olson, S. L., Comb Sci Tech, 76, 233, 1991.

Effects of spaceflight and simulated microgravity on microbial growth and secondary metabolism.

PubMed

Huang, Bing; Li, Dian-Geng; Huang, Ying; Liu, Chang-Ting

2018-05-14

Spaceflight and ground-based microgravity analog experiments have suggested that microgravity can affect microbial growth and metabolism. Although the effects of microgravity and its analogs on microorganisms have been studied for more than 50 years, plausible conflicting and diverse results have frequently been reported in different experiments, especially regarding microbial growth and secondary metabolism. Until now, only the responses of a few typical microbes to microgravity have been investigated; systematic studies of the genetic and phenotypic responses of these microorganisms to microgravity in space are still insufficient due to technological and logistical hurdles. The use of different test strains and secondary metabolites in these studies appears to have caused diverse and conflicting results. Moreover, subtle changes in the extracellular microenvironments around microbial cells play a key role in the diverse responses of microbial growth and secondary metabolisms. Therefore, "indirect" effects represent a reasonable pathway to explain the occurrence of these phenomena in microorganisms. This review summarizes current knowledge on the changes in microbial growth and secondary metabolism in response to spaceflight and its analogs and discusses the diverse and conflicting results. In addition, recommendations are given for future studies on the effects of microgravity in space on microbial growth and secondary metabolism.

Microgravity

NASA Image and Video Library

2004-04-15

Protein isolated from hen egg-white and functions as a bacteriostatic enzyme by degrading bacterial cell walls. First enzyme ever characterized by protein crystallography. It is used as an excellent model system for better understanding parameters involved in microgravity experiments with data from laboratory experiments to study the equilibrium rate of hanging drop experiments in microgravity.

Equations of Motion for the g-LIMIT Microgravity Vibration Isolation System

NASA Technical Reports Server (NTRS)

Kim, Y. K.; Whorton, M. S.

2001-01-01

A desirable microgravity environment for experimental science payloads may require an active vibration isolation control system. A vibration isolation system named g-LIMIT (GLovebox Integrated Microgravity Isolation Technology) is being developed by NASA Marshall Space Flight Center to support microgravity science experiments using the microgravity science glovebox. In this technical memorandum, the full six-degree-of-freedom nonlinear equations of motion for g-LIMIT are derived. Although the motivation for this model development is control design and analysis of g-LIMIT, the equations are derived for a general configuration and may be used for other isolation systems as well.

Effect of Microgravity on Mammalian Lymphocytes

NASA Technical Reports Server (NTRS)

Banerjee, H.; Blackshear, M.; Mahaffey, K.; Knight, C.; Khan, A. A.; Delucas, L.

2004-01-01

The effect of microgravity on mammalian system is an important and interesting topic for scientific investigation, since NASA s objective is to send manned flights to planets like Mars and eventual human colonization.The Astronauts will be exposed to microgravity environment for a long duration of time during these flights.Our objective of research is to conduct in vitro studies for the effect of microgravity on mammalian immune system.We did our preliminary investigations by exposing mammalian lymphocytes to a microgravity simulator cell bioreactor designed by NASA and manufactured at Synthecon Inc (USA).Our initial results showed no significant change in cytokine expression in these cells for a time period of forty eight hours exposure.Our future experiments will involve exposure for a longer period of time.

Crustaceans as a model for microgravity-induced muscle atrophy

NASA Astrophysics Data System (ADS)

Mykles, D. L.

Atrophy of skeletal muscles is a serious problem in a microgravity environment. It is hypothesized that the unloading of postural muscles, which no longer must resist gravity force, causes an accelerated breakdown of contractile proteins, resulting in a reduction in muscle mass and strength. A crustacean model using the land crab, Gecarcinus lateralis, to assess the effects of spaceflight on protein metabolism is presented. The model is compared to a developmentally-regulated atrophy in which a premolt reduction in muscle mass allows the withdrawal of the large claws at molt. The biochemical mechanisms underlying protein breakdown involves both Ca^2+-dependent and multicatalytic proteolytic enzymes. Crustacean claw muscle can be used to determine the interactions between shortening and unloading at the molecular level.

Crustaceans as a model for microgravity-induced muscle atrophy

NASA Technical Reports Server (NTRS)

Mykles, D. L.

1996-01-01

Atrophy of skeletal muscles is a serious problem in a microgravity environment. It is hypothesized that the unloading of postural muscles, which no longer must resist gravity force, causes an accelerated breakdown of contractile proteins, resulting in reduction in muscle mass and strength. A crustacean model using the land crab, Gecarcinus lateralis, to assess the effects of spaceflight on protein meatabolism is presented. The model is compared to a developmentally-regulated atrophy in which a premolt reduction in muscle mass allows the withdrawal of the large claws at molt. The biochemical mechanisms underlying protein breakdown involves both Ca2(+) -dependent and multicatalytic proteolytic enzymes. Crustacean claw muscle can be used to determine the interactions between shortening and unloading at the molecular level.

Models and molecular approaches to assessing the effects of the microgravity environment on vertebrate development

NASA Technical Reports Server (NTRS)

Wolgemuth, D. J.; Murashov, A. K.

1995-01-01

The extent to which gravity, and especially the lack thereof, can affect normal development in higher organisms is poorly understood. Underlying this question is the assumption that normal development depends on the embryo's ability to maintain a programmed temporal and spatial coordination of morphogenetic events. There are several reports documenting the apparently normal development of several vertebrate species, including mammals, under conditions of exposure to space flight during various periods of the development process. Evidence to the contrary also exists and it is therefore likely that some alterations in morphology do occur in a microgravity environment. Although subsequent development may appear overtly normal, more subtle abnormalities result. In all studies, the evaluation is restricted by the few numbers of specimens that can be examined and the relatively insensitive techniques for assessing potentially subtle effects. In the present discussion, we summarize some observations of mammalian development made in microgravity and consider which stages might be expected to be differentially sensitive to altered gravity conditions. While we emphasize mammalian development, we discuss the suitability of another model system for examining such effects in a cross-species context. Furthermore, we consider recent developments in our understanding of the molecular genetic program regulating embryogenesis that could serve as markers for assessing perturbations of development.

Nucleate pool boiling in subcooled liquid under microgravity: Results of TEXUS experimental investigations

NASA Astrophysics Data System (ADS)

Zell, M.; Straub, J.; Weinzierl, A.

1984-12-01

Experiments on subcooled nucleate pool boiling in microgravity were carried out to separate gravity driven effects on heat transfer within the boiling process. A ballistic trajectory by sounding rocket flight (TEXUS 5 and 10) achieved a gravity level of a/g = 0.0001 for 360 sec. For determination of geometrical effects on heat transport two different experimental configurations (platinum wire and flat plate) were employed. Boiling curves and bubble dynamics recorded by cinematography lead to gravity independent modelling of the boiling phenomena. The results ensure the applicability and high efficiency of nucleate pool boiling for heat exchangers in space laboratories.

Virtual Reality Simulation of the Effects of Microgravity in Gastrointestinal Physiology

NASA Technical Reports Server (NTRS)

Compadre, Cesar M.

1998-01-01

The ultimate goal of this research is to create an anatomically accurate three-dimensional (3D) simulation model of the effects of microgravity in gastrointestinal physiology and to explore the role that such changes may have in the pharmacokinetics of drugs given to the space crews for prevention or therapy. To accomplish this goal the specific aims of this research are: 1) To generate a complete 3-D reconstructions of the human GastroIntestinal (GI) tract of the male and female Visible Humans. 2) To develop and implement time-dependent computer algorithms to simulate the GI motility using the above 3-D reconstruction.

Effects of Simulated Microgravity on the Expression Profile of Microrna in Human Lymphoblastoid Cells

NASA Astrophysics Data System (ADS)

Zhang, Ye; Wu, Honglu; Ramesh, Govindarajan; Rohde, Larry; Story, Michael; Mangala, Lingegowda

2012-07-01

EFFECTS OF SIMULATED MICROGRAVITY ON THE EXPRESSION PROFILE OF MICRORNA IN HUMAN LYMPHOBLASTOID CELLS Lingegowda S. Mangala1,2, Ye Zhang1,3, Zhenhua He2, Kamal Emami1, Govindarajan T. Ramesh4, Michael Story 5, Larry H. Rohde2, and Honglu Wu1 1 NASA Johnson Space Center, Houston, Texas, USA 2 University of Houston Clear Lake, Houston, Texas, USA 3 Wyle Integrated Science and Engineering Group, Houston, Texas, USA 4 Norfolk State University, Norfolk, VA, USA 5 University of Texas, Southwestern Medical Center, Dallas, Texas, USA This study explores the changes in expression of microRNA (miRNA) and related genes under simulated microgravity conditions. In comparison to static 1g, microgravity has been shown to alter global gene expression patterns and protein levels in cultured cells or animals. miRNA has recently emerged as an important regulator of gene expression, possibly regulating as many as one-third of all human genes. However, very little is known about the effect of altered gravity on miRNA expression. To test the hypothesis that the miRNA expression profile would be altered in zero gravity resulting in altered regulation of gene expression leading to metabolic or functional changes in cells, we cultured TK6 human lymphoblastoid cells in a High Aspect Ratio Vessel (HARV; bioreactor) for 72 h either in the rotating condition to model microgravity in space or in the static condition as a control. Expression of several miRNA was changed significantly in the simulated microgravity condition including miR-150, miR-34a, miR-423-5p, miR-22 and miR-141, miR-618 and miR-222. To confirm whether this altered miRNA expression correlates with gene expression and functional changes of the cells, we performed DNA microarray and validated the related genes using q-RT PCR. Network and pathway analysis of gene and miRNA expression profiles indicates that the regulation of cell communication and catalytic activities, as well as pathways involved in immune response_IL-15 signaling and NGF mediated NF-kB activation were significantly altered under the simulated microgravity condition.

Payload vibration isolation in a microgravity environment

NASA Technical Reports Server (NTRS)

Alexander, Richard M.

1990-01-01

Many in-space research experiments require the microgravity environment attainable near the center of mass of the Space Station. Disturbances to the structure surrounding an experiment may lead to vibration levels that will degrade the microgravity environment and undermine the experiment's validity. In-flight disturbances will include vibration transmission from nearby equipment and excitation from crew activity. Isolation of these vibration-sensitive experiments is required. Analytical and experimental work accomplished to develop a payload (experiment) isolation system for use in space is described. The isolation scheme allows the payload to float freely within a prescribed boundary while being kept centered with forces generated by small jets of air. The vibration criterion was a maximum payload acceleration of 10 micro-g's (9.81x10(exp -5)m/s(exp 2), independent of frequency. An experimental setup, composed of a cart supported by air bearings on a flat granite slab, was designed and constructed to simulate the microgravity environment in the horizontal plane. Experimental results demonstrate that the air jet control system can effectively manage payload oscillatory response. An analytical model was developed and verified by comparing predicted and measured payload response. The mathematical model, which includes payload dynamics, control logic, and air jet forces, is used to investigate payload response to disturbances likely to be present in the Space Station.

Secondary metabolism in simulated microgravity: beta-lactam production by Streptomyces clavuligerus

NASA Technical Reports Server (NTRS)

Fang, A.; Pierson, D. L.; Mishra, S. K.; Koenig, D. W.; Demain, A. L.

1997-01-01

Rotating bioreactors designed at NASA's Johnson Space Center were used to simulate a microgravity environment in which to study secondary metabolism. The system examined was beta-lactam antibiotic production by Streptomyces clavuligerus. Both growth and beta-lactam production occurred in simulated microgravity. Stimulatory effects of phosphate and L-lysine, previously detected in normal gravity, also occurred in simulated microgravity. The degree of beta-lactam antibiotic production was markedly inhibited by simulated microgravity.

Effects of simulated microgravity on the expression of presynaptic proteins distorting the GABA/glutamate equilibrium--A proteomics approach.

PubMed

Wang, Yun; Iqbal, Javed; Liu, Yahui; Su, Rui; Lu, Song; Peng, Guang; Zhang, Yongqian; Qing, Hong; Deng, Yulin

2015-11-01

Microgravity may cause cognition-related changes in the animal nervous system due to the resulting uneven flow of fluids in the body. These changes may restrict the long-term stay of humans in space for various purposes. In this study, a rat tail suspension model (30°) was used to explore the effects of 21 days of prolonged simulated microgravity (SM) on the expression of proteins involved in cognitive functions in the rat hippocampus. SM decreased the content of γ-aminobutyric acid (GABA) and increased the content of glutamate (Glu) in the rat hippocampus. A comparative (18)O-labeled quantitative proteomics strategy was applied to detect the differential expression of synaptic proteins under SM. Fifty-three proteins were found to be differentially expressed under SM. Microgravity induces difficulty in the formation of the SNARE complex due to the down-regulation of vesicle-associated membrane protein 3(VAMP3) and syntaxin-1A. Synaptic vesicle recycling may also be affected due to the dysregulation of syntaxin-binding protein 5 (tomosyn), rab3A and its effector rim2. Both processes are disturbed, indicating that presynaptic proteins mediate a GABA/Glu imbalance under SM. These findings provide clues for understanding the mechanism of the GABA/Glu equilibrium in the hippocampus induced by microgravity in space and represent steps toward safe space travel. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of Simulated Microgravity Environments Induced by Diamagnetic Levitation of Plant Cell Suspension Cultures

NASA Astrophysics Data System (ADS)

Kamal, Khaled Y.; Herranz, Raúl; van Loon, Jack J. W. A.; Christianen, Peter C. M.; Medina, F. Javier

2016-06-01

Ground-Based Facilities (GBF) are essetial tools to understand the physical and biological effects of the absence of gravity and they are necessary to prepare and complement space experiments. It has been shown previously that a real microgravity environment induces the dissociation of cell proliferation from cell growth in seedling root meristems, which are limited populations of proliferating cells. Plant cell cultures are large and homogeneous populations of proliferating cells, so that they are a convenient model to study the effects of altered gravity on cellular mechanisms regulating cell proliferation and associated cell growth. Cell suspension cultures of the Arabidopsis thaliana cell line MM2d were exposed to four altered gravity and magnetic field environments in a magnetic levitation facility for 3 hours, including two simulated microgravity and Mars-like gravity levels obtained with different magnetic field intensities. Samples were processed either by quick freezing, to be used in flow cytometry for cell cycle studies, or by chemical fixation for microscopy techniques to measure parameters of the nucleolus. Although the trend of the results was the same as those obtained in real microgravity on meristems (increased cell proliferation and decreased cell growth), we provide a technical discussion in the context of validation of proper conditions to achieve true cell levitation inside a levitating droplet. We conclude that the use of magnetic levitation as a simulated microgravity GBF for cell suspension cultures is not recommended.

Modeled microgravity suppressed invasion and migration of human glioblastoma U87 cells through downregulating store-operated calcium entry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Zi-xuan; Rao, Wei; Wang, Huan

Glioblastoma is the most common brain tumor and is characterized with robust invasion and migration potential resulting in poor prognosis. Previous investigations have demonstrated that modeled microgravity (MMG) could decline the cell proliferation and attenuate the metastasis potential in several cell lines. In this study, we studied the effects of MMG on the invasion and migration potentials of glioblastoma in human glioblastoma U87 cells. We found that MMG stimulation significantly attenuated the invasion and migration potentials, decreased thapsigargin (TG) induced store-operated calcium entry (SOCE) and downregulated the expression of Orai1 in U87 cells. Inhibition of SOCE by 2-APB or stromalmore » interaction molecule 1 (STIM1) downregulation both mimicked the effects of MMG on the invasion and migration potentials in U87 cells. Furthermore, upregulation of Orai1 significantly weakened the effects of MMG on the invasion and migration potentials in U87 cells. Therefore, these findings indicated that MMG stimulation inhibited the invasion and migration potentials of U87 cells by downregulating the expression of Orai1 and sequentially decreasing the SOCE, suggesting that MMG might be a new potential therapeutic strategy in glioblastoma treatment in the future. - Highlights: • Modeled microgravity (MMG) suppressed migration and invasion in U87 cells. • MMG downregulated the SOCE and the expression of Orai1. • SOCE inhibition mimicked the effects of MMG on migration and invasion potentials. • Restoration of SOCE diminished the effects of MMG on migration and invasion.« less

Regulation of hematopoiesis in rats exposed to antiorthostatic, hypokinetic/hypodynamia. I - Model description

NASA Technical Reports Server (NTRS)

Dunn, C. D. R.; Johnson, P. C.; Lange, R. D.; Perez, L.; Nessel, R.

1985-01-01

The effect of a 7-day suspension in a jacket and harness with 20-deg head-down tilt on body weight, food and water consumption, and hematological parameters is investigated experimentally in male Sprague-Dawley rats weighing 150-175 g. The results are presented in graphs and compared with those for unsuspended controls and with published data on rats and humans exposed to microgravity in space flight. Suspended rats are found to have reduced red-blood-cell mass, erythropoiesis, plasma volume (leading to temporarily increased hematocrit), body weight, and food and water consumption; rightward-shifted oxyhemoglobin-dissociation curves; and unchanged platelet count, leucocyte count or PHA reactivity, and red-blood-cell shape distribution. Since many of these effects are also seen in space flight, the present experimental model is considered a promising technique for simulating the hematopoietic effects of microgravity at 1 g.

Modeled Microgravity Affects Fibroblast Functions Related to Wound Healing

NASA Astrophysics Data System (ADS)

Cialdai, Francesca; Vignali, Leonardo; Morbidelli, Lucia; Colciago, Alessandra; Celotti, Fabio; Santi, Alice; Caselli, Anna; Cirri, Paolo; Monici, Monica

2017-02-01

Wound healing is crucial for the survival of an organism. Therefore, in the perspective of space exploration missions, it is important to understand if and how microgravity conditions affect the behavior of the cell populations involved in wound healing and the evolution of the process. Since fibroblasts are the major players in tissue repair, this study was focused on the behavior of fibroblasts in microgravity conditions, modeled by a RCCS. Cell cytoskeleton was studied by immunofluorescence microscopy, the ability to migrate was assessed by microchemotaxis and scratch assay, and the expression of markers of fibroblast activation, angiogenesis, and inflammation was assessed by western blot. Results revealed that after cell exposure to modeled microgravity conditions, a thorough rearrangement of microtubules occurred and α-SMA bundles were replaced by a tight network of faulty and disorganized filaments. Exposure to modeled microgravity induced a decrease in α-SMA and E-CAD expressions. Also, the expression of the pro-angiogenic protein VEGF decreased, while that of the inflammatory signal COX-2 increased. Fibroblast ability to adhere, migrate, and respond to chemoattractants (PRP), closely related to cytoskeleton integrity and membrane junctions, was significantly impaired. Nevertheless, PRP was able to partially restore fibroblast migration.

Improved Crystal Quality by Detached Solidification in Microgravity

NASA Technical Reports Server (NTRS)

Regel, Liya L.; Wilcox, William R.

1999-01-01

Directional solidification in microgravity has often led to ingots that grew with little or no contact with the ampoule wall. When this occurred, crystallographic perfection was usually greatly improved -- often by several orders of magnitude. Unfortunately, until recently the true mechanisms underlying detached solidification were unknown. As a consequence, flight experiments yielded erratic results. Within the past four years, we have developed a new theoretical model that explains many of the flight results. This model gives rise to predictions of the conditions required to yield detached solidification, both in microgravity and on earth. A discussion of models of detachment, the meniscus models and results of theoretical modeling, and future plans are presented.

Effect of Microgravity on Mammalian Lymphocytes

NASA Technical Reports Server (NTRS)

Banerjee, H.; Blackshear, M.; Mahaffey, K.; Khan, A. A.; Delucas, L.

2004-01-01

The effect of microgravity on mammalian system is an important and interesting topic for scientific investigation, since NASA s objective is to send manned flights to planets like Mars and eventual human colonization. The Astronauts will be exposed to microgravity environment for a long duration of time during these flights. Our objective of research is to conduct in vitro studies for the effect of microgravity on mammalian immune system and nervous system. We did our preliminary investigations by exposing mammalian lymphocytes and astrocyte cells to a microgravity simulator cell bioreactor designed by NASA and manufactured at Synthecon, Inc. (USA).Our initial results showed no significant change in cytokine expression in these cells up to a time period of 120 hours exposure. Our future experiments will involve exposure for a longer period of time.

Materials Research in Microgravity 2012

NASA Technical Reports Server (NTRS)

Hyers, R. (Editor); Bojarevis, V. (Editor); Downey, J.; Henein, H. (Editor); Matson, D.; Seidel, A. (Editor); Voss, D. (Editor); SanSoucie, M. (Compiler)

2012-01-01

Reducing gravitational effects such as thermal and solutal buoyancy enables investigation of a large range of different phenomena in materials science. The Symposium on Materials Research in Microgravity involved 6 sessions composed of 39 presentations and 14 posters with contributions from more than 14 countries. The sessions concentrated on four different categories of topics related to ongoing reduced-gravity research. Highlights from this symposium will be featured in the September 2012 issue of JOM. The TMS Materials Processing and Manufacturing Division, Process Technology and Modeling Committee and Solidification Committee sponsored the symposium.

NASA/ASEE Summer Faculty Fellowship Program, 1990, Volume 1

NASA Technical Reports Server (NTRS)

Bannerot, Richard B. (Editor); Goldstein, Stanley H. (Editor)

1990-01-01

The 1990 Johnson Space Center (JSC) NASA/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by the University of Houston-University Park and JSC. A compilation of the final reports on the research projects are presented. The topics covered include: the Space Station; the Space Shuttle; exobiology; cell biology; culture techniques; control systems design; laser induced fluorescence; spacecraft reliability analysis; reduced gravity; biotechnology; microgravity applications; regenerative life support systems; imaging techniques; cardiovascular system; physiological effects; extravehicular mobility units; mathematical models; bioreactors; computerized simulation; microgravity simulation; and dynamic structural analysis.

The influence of gravity on the process of development of animal systems

NASA Technical Reports Server (NTRS)

Malacinski, G. M.; Neff, A. W.

1984-01-01

The development of animal systems is described in terms of a series of overlapping phases: pattern specification; differentiation; growth; and aging. The extent to which altered (micro) gravity (g) affects those phases is briefly reviewed for several animal systems. As a model, amphibian egg/early embryo is described. Recent data derived from clinostat protocols indicates that microgravity simulation alters early pattern specification (dorsal/ventral polarity) but does not adversely influence subsequent morphogenesis. Possible explanations for the absence of catastrophic microgravity effects on amphibian embryogenesis are discussed.

Real Time Quantitative 3-D Imaging of Diffusion Flame Species

NASA Technical Reports Server (NTRS)

Kane, Daniel J.; Silver, Joel A.

1997-01-01

A low-gravity environment, in space or ground-based facilities such as drop towers, provides a unique setting for study of combustion mechanisms. Understanding the physical phenomena controlling the ignition and spread of flames in microgravity has importance for space safety as well as better characterization of dynamical and chemical combustion processes which are normally masked by buoyancy and other gravity-related effects. Even the use of so-called 'limiting cases' or the construction of 1-D or 2-D models and experiments fail to make the analysis of combustion simultaneously simple and accurate. Ideally, to bridge the gap between chemistry and fluid mechanics in microgravity combustion, species concentrations and temperature profiles are needed throughout the flame. However, restrictions associated with performing measurements in reduced gravity, especially size and weight considerations, have generally limited microgravity combustion studies to the capture of flame emissions on film or video laser Schlieren imaging and (intrusive) temperature measurements using thermocouples. Given the development of detailed theoretical models, more sophisticated studies are needed to provide the kind of quantitative data necessary to characterize the properties of microgravity combustion processes as well as provide accurate feedback to improve the predictive capabilities of the computational models. While there have been a myriad of fluid mechanical visualization studies in microgravity combustion, little experimental work has been completed to obtain reactant and product concentrations within a microgravity flame. This is largely due to the fact that traditional sampling methods (quenching microprobes using GC and/or mass spec analysis) are too heavy, slow, and cumbersome for microgravity experiments. Non-intrusive optical spectroscopic techniques have - up until now - also required excessively bulky, power hungry equipment. However, with the advent of near-IR diode lasers, the possibility now exists to obtain reactant and product concentrations and temperatures non-intrusively in microgravity combustion studies. Over the past ten years, Southwest Sciences has focused its research on the high sensitivity, quantitative detection of gas phase species using diode lasers. Our research approach combines three innovations in an experimental system resulting in a new capability for nonintrusive measurement of major combustion species. FM spectroscopy or high frequency Wavelength Modulation Spectroscopy (WMS) have recently been applied to sensitive absorption measurements at Southwest Sciences and in other laboratories using GaAlAs or InGaAsP diode lasers in the visible or near-infrared as well as lead-salt lasers in the mid-infrared spectral region. Because these lasers exhibit essentially no source noise at the high detection frequencies employed with this technique, the achievement of sensitivity approaching the detector shot noise limit is possible.

Stress, and pathogen response gene expression in modeled microgravity

NASA Technical Reports Server (NTRS)

Sundaresan, Alamelu; Pellis, Neal R.

2006-01-01

Purpose: Immune suppression in microgravity has been well documented. With the advent of human exploration and long-term space travel, the immune system of the astronaut must be optimally maintained. It is important to investigate the expression patterns of cytokine genes, because they are directly related to immune response. Heat shock proteins (HSPs), also called stress proteins, are a group of proteins that are present in the cells of every life form. These proteins are induced when a cell responds to stressors such as heat, cold and oxygen deprivation. Microgravity is another stressor that may regulate HSPs. Heat shock proteins trigger immune response through activities that occur both inside the cell (intracellular) and outside the cell (extracellular). Knowledge about these two gene groups could lead to establishment of a blueprint of the immune response and adaptation-related genes in the microgravity environment. Methods: Human peripheral blood cells were cultured in 1g (T flask) and modeled microgravity (MMG, rotating-wall vessel) for 24 and 72 hours. Cell samples were collected and subjected to gene array analysis using the Affymetrix HG_U95 array. Data was collected and subjected to a two-way analysis of variance. The genes related to immune and stress responses were analyzed. Results and Conclusions: HSP70 was up-regulated by more than two fold in microgravity culture, while HSP90 was significantly down-regulated. HSP70 is not typically expressed in all kinds of cells, but it is expressed at high levels in stress conditions. HSP70 participates in translation, protein translocation, proteolysis and protein folding, suppressing aggregation and reactivating denatured proteins. Increased serum HSP70 levels correlate with a better outcome for heat-stroke or severe trauma patients. At the same time, elevated serum levels of HSP70 have been detected in patients with peripheral or renal vascular disease. HSP90 has been identified in the cytosol, nucleus and endoplasmic reticulum, and exists in many tissue types. HSP90 associates with actin filaments in certain conditions and aids cell motility. The down-regulation of HSP90 could lead to deleterious effects in the lymphocytes, thereby contributing to suppressed immune function in microgravity. Interleukins such as IL 1 alpha, IL11 receptor chain alpha, IL7R, and IL4R were significantly down regulated in modeled microgravity. Further analysis of the genes involved in immune response at the protein level may provide a basis for prophylactic and countermeasure strategies to augment the human immune system for space exploration.

Influence of Low-Shear Modeled Microgravity on Heat Resistance, Membrane Fatty Acid Composition, and Heat Stress-Related Gene Expression in Escherichia coli O157:H7 ATCC 35150, ATCC 43889, ATCC 43890, and ATCC 43895.

PubMed

Kim, H W; Rhee, M S

2016-05-15

We previously showed that modeled microgravity conditions alter the physiological characteristics of Escherichia coli O157:H7. To examine how microgravity conditions affect bacterial heat stress responses, D values, membrane fatty acid composition, and heat stress-related gene expression (clpB, dnaK, grpE, groES, htpG, htpX, ibpB, and rpoH), E. coli O157:H7 ATCC 35150, ATCC 43889, ATCC 43890, and ATCC 43895 were cultured under two different conditions: low-shear modeled microgravity (LSMMG, an analog of spaceflight conditions) and normal gravity (NG, Earth-like conditions). When 24-h cultures were heated to 55°C, cells cultured under LSMMG conditions showed reduced survival compared with cells cultured under NG conditions at all time points (P < 0.05). D values of all tested strains were lower after LSMMG culture than after NG culture. Fourteen of 37 fatty acids examined were present in the bacterial membrane: nine saturated fatty acids (SFA) and five unsaturated fatty acids (USFA). The USFA/SFA ratio, a measure of membrane fluidity, was higher under LSMMG conditions than under NG conditions. Compared with control cells grown under NG conditions, cells cultured under LSMMG conditions showed downregulation of eight heat stress-related genes (average, -1.9- to -3.7-fold). The results of this study indicate that in a simulated space environment, heat resistance of E. coli O157:H7 decreased, and this might be due to the synergistic effects of the increases in membrane fluidity and downregulated relevant heat stress genes. Microgravity is a major factor that represents the environmental conditions in space. Since infectious diseases are difficult to deal with in a space environment, comprehensive studies on the behavior of pathogenic bacteria under microgravity conditions are warranted. This study reports the changes in heat stress resistance of E. coli O157:H7, the severe foodborne pathogen, under conditions that mimic microgravity. The results provide scientific clues for further understanding of the bacterial response under the simulated microgravity conditions. It will contribute not only to the improvement of scientific knowledge in the academic fields but also ultimately to the development of a prevention strategy for bacterial disease in the space environment. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Ground based ISS payload microgravity disturbance assessments.

PubMed

McNelis, Anne M; Heese, John A; Samorezov, Sergey; Moss, Larry A; Just, Marcus L

2005-01-01

In order to verify that the International Space Station (ISS) payload facility racks do not disturb the microgravity environment of neighboring facility racks and that the facility science operations are not compromised, a testing and analytical verification process must be followed. Currently no facility racks have taken this process from start to finish. The authors are participants in implementing this process for the NASA Glenn Research Center (GRC) Fluids and Combustion Facility (FCF). To address the testing part of the verification process, the Microgravity Emissions Laboratory (MEL) was developed at GRC. The MEL is a 6 degree of freedom inertial measurement system capable of characterizing inertial response forces (emissions) of components, sub-rack payloads, or rack-level payloads down to 10(-7) g's. The inertial force output data, generated from the steady state or transient operations of the test articles, are utilized in analytical simulations to predict the on-orbit vibratory environment at specific science or rack interface locations. Once the facility payload rack and disturbers are properly modeled an assessment can be made as to whether required microgravity levels are achieved. The modeling is utilized to develop microgravity predictions which lead to the development of microgravity sensitive ISS experiment operations once on-orbit. The on-orbit measurements will be verified by use of the NASA GRC Space Acceleration Measurement System (SAMS). The major topics to be addressed in this paper are: (1) Microgravity Requirements, (2) Microgravity Disturbers, (3) MEL Testing, (4) Disturbance Control, (5) Microgravity Control Process, and (6) On-Orbit Predictions and Verification. Published by Elsevier Ltd.

Using a time lapse microgravity model for mapping seawater intrusion around Semarang

DOE Office of Scientific and Technical Information (OSTI.GOV)

Supriyadi,, E-mail: supriyadi@mail.unnes.ac.id; Khumaedi; Yusuf, M.

A modeling of time-lapse microgravity anomaly due to sea water intrusion has been conducted. It used field data of aquifer cross section, aquifer thickness and lithology of research area. Those data were then processed using Grav3D and Surfer. Modeling results indicated that the intrusion of sea water resulting in a time-lapse microgravity anomalies of 0.12 to 0.18 mGal, at soil layer density of 0.15 g/cm{sup 3} to 0.3 g/cm{sup 3} and at depth of 30 to 100 m. These imply that the areas experiencing seawater intrusion were Tanjung Mas, SPBE Bandarharjo, Brass, Old Market Boom and Johar as the microgravity measured there weremore » in the range of 0.12 to 0.18 mGal and the density contrast were at 0.15 g/cm{sup 3} to 0.28 g/cm{sup 3}. Areas that experienced fluid reduction were Puri Anjasmoro, Kenconowungu and Puspowarno with microgravity changes from -0.06 mGal to -0.18 mGal.« less

Ground-Based Gas-Liquid Flow Research in Microgravity Conditions: State of Knowledge

NASA Technical Reports Server (NTRS)

McQuillen, J.; Colin, C.; Fabre, J.

1999-01-01

During the last decade, ground-based microgravity facilities have been utilized in order to obtain predictions for spacecraft system designers and further the fundamental understanding of two-phase flow. Although flow regime, pressure drop and heat transfer coefficient data has been obtained for straight tubes and a limited number of fittings, measurements of the void fraction, film thickness, wall shear stress, local velocity and void information are also required in order to develop general mechanistic models that can be utilized to ascertain the effects of fluid properties, tube geometry and acceleration levels. A review of this research is presented and includes both empirical data and mechanistic models of the flow behavior.

Finite Element Analysis of Osteocytes Mechanosensitivity Under Simulated Microgravity

NASA Astrophysics Data System (ADS)

Yang, Xiao; Sun, Lian-Wen; Du, Cheng-Fei; Wu, Xin-Tong; Fan, Yu-Bo

2018-04-01

It was found that the mechanosensitivity of osteocytes could be altered under simulated microgravity. However, how the mechanical stimuli as the biomechanical origins cause the bioresponse in osteocytes under microgravity is unclear yet. Computational studies may help us to explore the mechanical deformation changes of osteocytes under microgravity. Here in this paper, we intend to use the computational simulation to investigate the mechanical behavior of osteocytes under simulated microgravity. In order to obtain the shape information of osteocytes, the biological experiment was conducted under simulated microgravity prior to the numerical simulation The cells were rotated by a clinostat for 6 hours or 5 days and fixed, the cytoskeleton and the nucleus were immunofluorescence stained and scanned, and the cell shape and the fluorescent intensity were measured from fluorescent images to get the dimension information of osteocytes The 3D finite element (FE) cell models were then established based on the scanned image stacks. Several components such as the actin cortex, the cytoplasm, the nucleus, the cytoskeleton of F-actin and microtubules were considered in the model. The cell models in both 6 hours and 5 days groups were then imposed by three magnitudes (0.5, 10 and 15 Pa) of simulating fluid shear stress, with cell total displacement and the internal discrete components deformation calculated. The results showed that under the simulated microgravity: (1) the nuclear area and height statistically significantly increased, which made the ratio of membrane-cortex height to nucleus height statistically significantly decreased; (2) the fluid shear stress-induced maximum displacements and average displacements in the whole cell decreased, with the deformation decreasing amplitude was largest when exposed to 1.5Pa of fluid shear stress; (3) the fluid shear stress-induced deformation of cell membrane-cortex and cytoskeleton decreased, while the fluid shear stress-induced deformation of nucleus increased. The results suggested the mechanical behavior of whole osteocyte cell body was suppressed by simulated microgravity, and this decrement was enlarged with either the increasing amplitude of fluid shear stress or the duration of simulated microgravity. What's more, the mechanical behavior of membrane-cortex and cytoskeleton was suppressed by the simulated microgravity, which indicated the mechanotransduction process in the cell body may be further inhibited. On the contrary, the cell nucleus deformation increased under simulated microgravity, which may be related to either the decreased amount of cytoskeleton or the increased volume occupied proportion of nucleus in whole cell under the simulated microgravity. The numerical results supported our previous biological experiments, and showed particularly affected cellular components under the simulated microgravity. The computational study here may help us to better understand the mechanism of mechanosensitivity changes in osteocytes under simulated microgravity, and further to explore the mechanism of the bone loss in space flight.

Microgravity Disturbance Predictions in the Combustion Integrated Rack

NASA Astrophysics Data System (ADS)

Just, M.; Grodsinsky, Carlos M.

2002-01-01

This paper will focus on the approach used to characterize microgravity disturbances in the Combustion Integrated Rack (CIR), currently scheduled for launch to the International Space Station (ISS) in 2005. Microgravity experiments contained within the CIR are extremely sensitive to vibratory and transient disturbances originating on-board and off-board the rack. Therefore, several techniques are implemented to isolate the critical science locations from external vibration. A combined testing and analysis approach is utilized to predict the resulting microgravity levels at the critical science location. The major topics to be addressed are: 1) CIR Vibration Isolation Approaches, 2) Disturbance Sources and Characterization, 3) Microgravity Predictive Modeling, 4) Science Microgravity Requirements, 6) Microgravity Control, and 7) On-Orbit Disturbance Measurement. The CIR is using the Passive Rack Isolation System (PaRIS) to isolate the rack from offboard rack disturbances. By utilizing this system, CIR is connected to the U.S. Lab module structure by either 13 or 14 umbilical lines and 8 spring / damper isolators. Some on-board CIR disturbers are locally isolated by grommets or wire ropes. CIR's environmental and science on board support equipment such as air circulation fans, pumps, water flow, air flow, solenoid valves, and computer hard drives cause disturbances within the rack. These disturbers along with the rack structure must be characterized to predict whether the on-orbit vibration levels during experimentation exceed the specified science microgravity vibration level requirements. Both vibratory and transient disturbance conditions are addressed. Disturbance levels/analytical inputs are obtained for each individual disturber in a "free floating" condition in the Glenn Research Center (GRC) Microgravity Emissions Lab (MEL). Flight spare hardware is tested on an Orbital Replacement Unit (ORU) basis. Based on test and analysis, maximum disturbance level allocations are developed for each ORU. The worst-case disturbances are input into an on-orbit analytical dynamic model of the rack. These models include both NASTRAN and MATLAB Simulink models , which include eigenvector and frequency inputs of the rack rigid body modes, the rack umbilical modes, and the racks' structural modes. The disturbance areas and science locations need to be modeled accurately to give valid predictions. The analytically determined microgravity vibration levels are compared to the CIR science requirements contained in the FCF Science Requirements Envelope Document (SRED). The predicted levels will be compared with the on-orbit measurements provided by the Space Acceleration Measurement System (SAMS) sensor, which is to be mounted on the CIR optics bench.

Effect of Oenothera odorata Root Extract on Microgravity and Disuse-Induced Muscle Atrophy

PubMed Central

Lee, Yong-Hyeon; Seo, Dong-Hyun; Park, Ji-Hyung; Kabayama, Kazuya; Opitz, Joerg; Lee, Kwang Ho; Kim, Han-Sung; Kim, Tack-Joong

2015-01-01

Muscle atrophy, a reduction of muscle mass, strength, and volume, results from reduced muscle use and plays a key role in various muscular diseases. In the microgravity environment of space especially, muscle atrophy is induced by muscle inactivity. Exposure to microgravity induces muscle atrophy through several biological effects, including associations with reactive oxygen species (ROS). This study used 3D-clinostat to investigate muscle atrophy caused by oxidative stress in vitro, and sciatic denervation was used to investigate muscle atrophy in vivo. We assessed the effect of Oenothera odorata root extract (EVP) on muscle atrophy. EVP helped recover cell viability in C2C12 myoblasts exposed to microgravity for 24 h and delayed muscle atrophy in sciatic denervated mice. However, the expressions of HSP70, SOD1, and ceramide in microgravity-exposed C2C12 myoblasts and in sciatic denervated mice were either decreased or completely inhibited. These results suggested that EVP can be expected to have a positive effect on muscle atrophy by disuse and microgravity. In addition, EVP helped characterize the antioxidant function in muscle atrophy. PMID:25945103

Effect of Oenothera odorata Root Extract on Microgravity and Disuse-Induced Muscle Atrophy.

PubMed

Lee, Yong-Hyeon; Seo, Dong-Hyun; Park, Ji-Hyung; Kabayama, Kazuya; Opitz, Joerg; Lee, Kwang Ho; Kim, Han-Sung; Kim, Tack-Joong

2015-01-01

Muscle atrophy, a reduction of muscle mass, strength, and volume, results from reduced muscle use and plays a key role in various muscular diseases. In the microgravity environment of space especially, muscle atrophy is induced by muscle inactivity. Exposure to microgravity induces muscle atrophy through several biological effects, including associations with reactive oxygen species (ROS). This study used 3D-clinostat to investigate muscle atrophy caused by oxidative stress in vitro, and sciatic denervation was used to investigate muscle atrophy in vivo. We assessed the effect of Oenothera odorata root extract (EVP) on muscle atrophy. EVP helped recover cell viability in C2C12 myoblasts exposed to microgravity for 24 h and delayed muscle atrophy in sciatic denervated mice. However, the expressions of HSP70, SOD1, and ceramide in microgravity-exposed C2C12 myoblasts and in sciatic denervated mice were either decreased or completely inhibited. These results suggested that EVP can be expected to have a positive effect on muscle atrophy by disuse and microgravity. In addition, EVP helped characterize the antioxidant function in muscle atrophy.

Prediction of renal crystalline size distributions in space using a PBE analytic model. 1. Effect of microgravity-induced biochemical alterations.

PubMed

Kassemi, Mohammad; Thompson, David

2016-09-01

An analytical Population Balance Equation model is developed and used to assess the risk of critical renal stone formation for astronauts during future space missions. The model uses the renal biochemical profile of the subject as input and predicts the steady-state size distribution of the nucleating, growing, and agglomerating calcium oxalate crystals during their transit through the kidney. The model is verified through comparison with published results of several crystallization experiments. Numerical results indicate that the model is successful in clearly distinguishing between 1-G normal and 1-G recurrent stone-former subjects based solely on their published 24-h urine biochemical profiles. Numerical case studies further show that the predicted renal calculi size distribution for a microgravity astronaut is closer to that of a recurrent stone former on Earth rather than to a normal subject in 1 G. This interestingly implies that the increase in renal stone risk level in microgravity is relatively more significant for a normal person than a stone former. However, numerical predictions still underscore that the stone-former subject carries by far the highest absolute risk of critical stone formation during space travel. Copyright © 2016 the American Physiological Society.

Effects of simulated microgravity on otoliths growth and microstructure of Larval Zebrafish, Danio rerio

NASA Astrophysics Data System (ADS)

Li, Xiaoyan; Wang, Gaohong; Liu, Yongding

2012-07-01

Otolith is the vestibular endorgan that takes part in gravitational signal initiation. Environmental change can leave mark on otolith microstructure. In this study, we use zebrafish from embryo stage of 10hpf to middle larval stage of 12dpf to investigate the effect of microgravity on otolith development. It was found that otoliths size of microgravity group was larger than the control before 6dpf, but after that both groups kept nearly the same size. Surface scanning of otolith morphology with SEM showed that otolith of microgravity group were much smoother than the control. After etching with HCl, we found both groups formed daily increments, but microgravity group lack clear check marks in some special developmental stage. Widths between increments were wider, and granule shape was much sharper in microgravity group. Analysis of crystal orientation disclosed the increments of microgravity group formed irregularly. The surface etched with PKb also exhibited different granule size and orientation: the granules in the control had nearly the same size and direction, while the particles in microgravity were smaller and orientated differently along the translucent ring. The organic leftover were also found between layers in microgravity group. These results suggest that microgravity can affect otolith development, the component and structural mode of inorganic and organic parts change with different gravitation environment, which may be involved in orientation adjustment of SMS (Space Movement Sickness).

Effects of Solar Particle Event-Like Proton Radiation and/or Simulated Microgravity on Circulating Mouse Blood Cells.

PubMed

Romero-Weaver, Ana L; Lin, Liyong; Carabe-Fernandez, Alejandro; Kennedy, Ann R

2014-08-01

Astronauts traveling in space missions outside of low Earth orbit will be exposed for longer times to a microgravity environment. In addition, the increased travel time involved in exploration class missions will result in an increased risk of exposure to significant doses of solar particle event (SPE) radiation. Both conditions could significantly affect the number of circulating blood cells. Therefore, it is critical to determine the combined effects of exposure to both microgravity and SPE radiation. The purpose of the present study was to assess these risks by evaluating the effects of SPE-like proton radiation and/or microgravity, as simulated with the hindlimb unloading (HU) system, on circulating blood cells using mouse as a model system. The results indicate that exposure to HU alone caused minimal or no significant changes in mouse circulating blood cell numbers. The exposure of mice to SPE-like proton radiation with or without HU treatment caused a significant decrease in the number of circulating lymphocytes, granulocytes and platelets. The reduced numbers of circulating lymphocytes, granulocytes, and platelets, resulting from the SPE-like proton radiation exposure, with or without HU treatment, in mice suggest that astronauts participating in exploration class missions may be at greater risk of developing infections and thrombotic diseases; thus, countermeasures may be necessary for these biological endpoints.

Materials science research in microgravity

NASA Technical Reports Server (NTRS)

Perepezko, John H.

1992-01-01

There are several important attributes of an extended duration microgravity environment that offer a new dimension in the control of the microstructure, processing, and properties of materials. First, when gravitational effects are minimized, buoyancy driven convection flows are also minimized. The flows due to density differences, brought about either by composition or temperature gradients will then be reduced or eliminated to permit a more precise control of the temperature and the composition of a melt which is critical in achieving high quality crystal growth of electronic materials or alloy structures. Secondly, body force effects such as sedimentation, hydrostatic pressure, and deformation are similarly reduced. These effects may interfere with attempts to produce uniformly dispersed or aligned second phases during melt solidification. Thirdly, operating in a microgravity environment will facilitate the containerless processing of melts to eliminate the limitations of containment for reactive melts. The noncontacting forces such as those developed from electromagnet, electrostatic, or acoustic fields can be used to position samples. With this mode of operation, contamination can be minimized to enable the study of reactive melts and to eliminate extraneous crystal nucleation so that novel crystalline structures and new glass compositions may be produced. In order to take advantage of the microgravity environment for materials research, it has become clear that reliable processing models based on a sound ground based experimental experience and an established thermophysical property data base are essential.

Acoustic Flame Suppression Mechanics in a Microgravity Environment

NASA Astrophysics Data System (ADS)

Beisner, Eryn; Wiggins, Nathanial David; Yue, Kwok-Bun; Rosales, Miguel; Penny, Jeremy; Lockridge, Jarrett; Page, Ryan; Smith, Alexander; Guerrero, Leslie

2015-06-01

The following paper deals with acoustic flame suppression mechanics in a microgravity environment with measurements taken from an Arduino-based sensor system and validation of the technique. A Zippo lighter is ignited in microgravity and then displaced from the base of the flame and suppressed using surface interactions with single tone acoustic waves to extinguished the flame. The analysis of data collected shows that the acoustic flame suppression measurementtechniques are effective to finding qualitative differences in extinguishing in microgravity and normal gravity. Further, the results suggest that the suppression may be more effective in a microgravity environment than in a normal (1g) environment and may be a viable method of extinguishing fires during space flight.

Combined Effects of Simulated Microgravity and Radiation Exposure on Osteoclast Cell Fusion.

PubMed

Shanmugarajan, Srinivasan; Zhang, Ye; Moreno-Villanueva, Maria; Clanton, Ryan; Rohde, Larry H; Ramesh, Govindarajan T; Sibonga, Jean D; Wu, Honglu

2017-11-18

The loss of bone mass and alteration in bone physiology during space flight are one of the major health risks for astronauts. Although the lack of weight bearing in microgravity is considered a risk factor for bone loss and possible osteoporosis, organisms living in space are also exposed to cosmic radiation and other environmental stress factors. As such, it is still unclear as to whether and by how much radiation exposure contributes to bone loss during space travel, and whether the effects of microgravity and radiation exposure are additive or synergistic. Bone is continuously renewed through the resorption of old bone by osteoclast cells and the formation of new bone by osteoblast cells. In this study, we investigated the combined effects of microgravity and radiation by evaluating the maturation of a hematopoietic cell line to mature osteoclasts. RAW 264.7 monocyte/macrophage cells were cultured in rotating wall vessels that simulate microgravity on the ground. Cells under static 1g or simulated microgravity were exposed to γ rays of varying doses, and then cultured in receptor activator of nuclear factor-κB ligand (RANKL) for the formation of osteoclast giant multinucleated cells (GMCs) and for gene expression analysis. Results of the study showed that radiation alone at doses as low as 0.1 Gy may stimulate osteoclast cell fusion as assessed by GMCs and the expression of signature genes such as tartrate resistant acid phosphatase ( Trap ) and dendritic cell-specific transmembrane protein ( Dcstamp ). However, osteoclast cell fusion decreased for doses greater than 0.5 Gy. In comparison to radiation exposure, simulated microgravity induced higher levels of cell fusion, and the effects of these two environmental factors appeared additive. Interestingly, the microgravity effect on osteoclast stimulatory transmembrane protein ( Ocstamp ) and Dcstamp expressions was significantly higher than the radiation effect, suggesting that radiation may not increase the synthesis of adhesion molecules as much as microgravity.

Planarians Sense Simulated Microgravity and Hypergravity

PubMed Central

Adell, Teresa; Saló, Emili; van Loon, Jack J. W. A.

2014-01-01

Planarians are flatworms, which belong to the phylum Platyhelminthes. They have been a classical subject of study due to their amazing regenerative ability, which relies on the existence of adult totipotent stem cells. Nowadays they are an emerging model system in the field of developmental, regenerative, and stem cell biology. In this study we analyze the effect of a simulated microgravity and a hypergravity environment during the process of planarian regeneration and embryogenesis. We demonstrate that simulated microgravity by means of the random positioning machine (RPM) set at a speed of 60 °/s but not at 10 °/s produces the dead of planarians. Under hypergravity of 3 g and 4 g in a large diameter centrifuge (LDC) planarians can regenerate missing tissues, although a decrease in the proliferation rate is observed. Under 8 g hypergravity small planarian fragments are not able to regenerate. Moreover, we found an effect of gravity alterations in the rate of planarian scission, which is its asexual mode of reproduction. No apparent effects of altered gravity were found during the embryonic development. PMID:25309918

Planarians sense simulated microgravity and hypergravity.

PubMed

Adell, Teresa; Saló, Emili; van Loon, Jack J W A; Auletta, Gennaro

2014-01-01

Planarians are flatworms, which belong to the phylum Platyhelminthes. They have been a classical subject of study due to their amazing regenerative ability, which relies on the existence of adult totipotent stem cells. Nowadays they are an emerging model system in the field of developmental, regenerative, and stem cell biology. In this study we analyze the effect of a simulated microgravity and a hypergravity environment during the process of planarian regeneration and embryogenesis. We demonstrate that simulated microgravity by means of the random positioning machine (RPM) set at a speed of 60 °/s but not at 10 °/s produces the dead of planarians. Under hypergravity of 3 g and 4 g in a large diameter centrifuge (LDC) planarians can regenerate missing tissues, although a decrease in the proliferation rate is observed. Under 8 g hypergravity small planarian fragments are not able to regenerate. Moreover, we found an effect of gravity alterations in the rate of planarian scission, which is its asexual mode of reproduction. No apparent effects of altered gravity were found during the embryonic development.

Our experience in the evaluation of the thermal comfort during the space flight and in the simulated space environment

NASA Astrophysics Data System (ADS)

Novák, Ludvik

The paper presents the results of the mathematical modelling the effects of hypogravity on the heat output by the spontaneous convection. The theoretical considerations were completed by the experiments "HEAT EXCHANGE 1" performed on the biosatellite "KOSMOS 936". In the second experiment "HEAT EXCHANGE 2" acomplished on the board of the space laboratory "SALYUT 6" was studied the effect of the microgravity on the thermal state of a man during the space flight. Direct measurement in weightlessness prowed the capacity of the developed electric dynamic katathermometer to check directly the effect of the microgravity on the heat output by the spontaneous convection. The role of the heat partition impairment's in man as by the microgravity, so by the inadequate forced convection are clearly expressed in changes of the skin temperature and the subjective feeling of the cosmonaut's thermal comfort. The experimental extension of the elaborated methods for the flexible adjustment of the thermal environment to the actual physiological needs of man and suggestions for the further investigation are outlined.

Microgravity Effects on Chronoamperometric Ammonia Oxidation Reaction at Platinum Nanoparticles on Modified Mesoporous Carbon Supports

NASA Astrophysics Data System (ADS)

Poventud-Estrada, Carlos M.; Acevedo, Raúl; Morales, Camila; Betancourt, Luis; Diaz, Diana C.; Rodriguez, Manuel A.; Larios, Eduardo; José-Yacaman, Miguel; Nicolau, Eduardo; Flynn, Michael; Cabrera, Carlos R.

2017-10-01

The effect of microgravity on the electrochemical oxidation of ammonia at platinum nanoparticles supported on modified mesoporous carbons (MPC) with three different pore diameters (64, 100, and 137 Å) was studied via the chronoamperometric technique in a half-cell. The catalysts were prepared by a H2 reductive process of PtCl6^{4-} in presence of the mesoporous carbon support materials. A microgravity environment was obtained with an average gravity of less than 0.02 g created aboard an airplane performing parabolic maneuvers. Results show the chronoamperommetry of the ammonia oxidation reaction in 1.0 M NH4OH at 0.60 V vs. RHE under microgravity conditions. The current density, in all three catalysts, decreased while in microgravity conditions when compared to ground based experiments. Under microgravity, all three catalysts yielded a decrease in ammonia oxidation reaction current density between 25 to 63% versus terrestrial experimental results, in time scales between 1 and 15 s. The Pt catalyst prepared with mesoporous carbon of 137 Å porous showed the smallest changes, between 25 to 48%. Nanostructuring catalyst materials have an effect on the level of current density decrease under microgravity conditions.

Increased Arginine and Ornithine Flux in Islets of Langerhans Cultured in a Microgravity Model System

NASA Technical Reports Server (NTRS)

Tobin, B. W.; Sams, C. F.; Smith, S. M.

2000-01-01

Microgravity is associated with alterations in protein metabolism of both muscle and bone. That pancreas-derived insulin is essential to the normal maintenance of body protein balance is well known. The importance of altered endocrine pancreas function in microgravity is not yet established. We proposed to examine the influence of a microgravity model system, the High Aspect Ratio Vessel (HARV) upon islets of Langerhans from Wistar Furth rats. Islets were cultured in the HARV for 48 hr in Medium-199 and contrasted to static control islets (PLATE). Nitrogenous compounds elaborated into the media (micromoles/ml) were analyzed at 0 and 48 hr of culture and compared to PLATE with a 2-way ANOVA (HARV vs Hour).

The Effect of Microgravity on the Smallest Space Travelers: Bacterial Physiology and Virulence on Earth and in Microgravity

NASA Technical Reports Server (NTRS)

Pyle, Barry; Vasques, Marilyn; Aquilina, Rudy (Technical Monitor)

2002-01-01

Since the first human flights outside of Earth's gravity, crew health and well-being have been major concerns. Exposure to microgravity during spaceflight is known to affect the human immune response, possibly making the crew members more vulnerable to infectious disease. In addition, biological experiments previously flown in space have shown that bacteria grow faster in microgravity than they do on Earth. The ability of certain antibiotics to control bacterial infections may also differ greatly in microgravity. It is therefore critical to understand how spaceflight and microgravity affect bacterial virulence, which is their ability to cause disease. By utilizing spaceflight hardware provided by the European Space Agency (ESA), Dr. Barry Pyle and his team at Montana State University, Bozeman, will be performing an experiment to study the effects of microgravity on the virulence of a common soil and water bacterium, Pseudomonas aeruginosa. Importantly, these bacteria have been detected in the water supplies of previous Space Shuttle flights. The experiment will examine the effects of microgravity exposure on bacterial growth and on the bacterium's ability to form a toxin called Exotoxin A. Another goal is to evaluate the effects of microgravity on the physiology of the bacteria by analyzing their ability to respire (produce energy), by studying the condition of the plasma membrane surrounding the cell, and by determining if specific enzymes remain active. Proteins produced by the bacteria will also be assayed to see if the normal functions of the bacteria are affected. In the context of human life support in spaceflight, the results of this experiment will offer guidance in providing the highest possible water quality for the Shuttle in order to limit the risk of infection to human occupants and to minimize water system and spacecraft deterioration.

Spacelab J: Microgravity and life sciences

NASA Technical Reports Server (NTRS)

1992-01-01

Spacelab J is a joint venture between NASA and the National Space Development Agency of Japan (NASDA). Using a Spacelab pressurized long module, 43 experiments will be performed in the areas of microgravity and life sciences. These experiments benefit from the microgravity environment available on an orbiting Shuttle. Removed from the effects of gravity, scientists will seek to observe processes and phenomena impossible to study on Earth, to develop new and more uniform mixtures, to study the effects of microgravity and the space environment on living organisms, and to explore the suitability of microgravity for certain types of research. Mission planning and an overview of the experiments to be performed are presented. Orbital research appears to hold many advantages for microgravity science investigations, which on this mission include electronic materials, metals and alloys, glasses and ceramics, fluid dynamics and transport phenomena, and biotechnology. Gravity-induced effects are eliminated in microgravity. This allows the investigations on Spacelab J to help scientists develop a better understanding of how these gravity-induced phenomena affect both processing and products on Earth and to observe subtle phenomena that are masked in gravity. The data and samples from these investigations will not only allow scientists to better understand the materials but also will lead to improvements in the methods used in future experiments. Life sciences research will collect data on human adaptation to the microgravity environment, investigate ways of assisting astronauts to readapt to normal gravity, explore the effects of microgravity and radiation on living organisms, and gather data on the fertilization and development of organisms in the absence of gravity. This research will improve crew comfort and safety on future missions while helping scientists to further understand the human body.

The Question of Impurities in Macromolecule Crystal Quality Improvement in Microgravity

NASA Technical Reports Server (NTRS)

Judge, Russell A.; Snell, Edward H.; Pusey, Marc L.; Sportiello, Michael G.; Todd, Paul; Bellamy, Henry; Borgstahl, Gloria E.; Pokros, Matthew; Cassanto, John M.

2000-01-01

While macromolecule impurities may affect crystal size and morphology the over-riding question is how do macromolecule impurities effect crystal X-ray quality and diffraction resolution. In the case of chicken egg white lysozyme previous researchers have reported that crystals grown in the presence of ovalbumin, ovotransferrin, and turkey egg white lysozyme show no difference in diffraction resolution compared to those grown in pure solutions. One impurity however, a naturally occurring lysozyme dimer, does negatively impact the X-ray crystal properties. For this impurity it has been reported that crystal quality improvement in microgravity may be due to improved impurity partitioning during crystallization. In this study we have examined the incorporation of the dimer into lysozyme crystals, both on the ground and in microgravity experiments, and have performed detailed X-ray analysis of the crystals using a new technique for finely probing the mosaicity of the crystal at the Stanford Synchrotron Radiation Laboratory. Dimer partitioning was not significantly different in microgravity compared to the ground based experiments, although it is significantly better than that previously reported in microgravity. Mosaicity analysis of pure crystals, 1422 indexed reflections (microgravity) and 752 indexed reflections (ground), gave average results of 0.0066 and 0.0092 degrees (FWHM) respectively. The microgravity crystals also provided an increased signal to noise. Dimer incorporation increased the average mosaicity in microgravity but not on the ground. However, dimer incorporation did greatly reduce the resolution limit in both ground and microgravity grown crystals. The data is being treated anisotropically to explore these effects. These results indicate that impurity effects in microgravity are complex and that the conditions or techniques employed may greatly affect the role of impurities.

Free and membrane-bound calcium in microgravity and microgravity effects at the membrane level

NASA Astrophysics Data System (ADS)

Belyavskaya, N. A.

The changes of [Ca^2+]_i controlled is known to play a key regulatory role in numerous cellular processes especially associated with membranes. Previous studies from our laboratory have demonstrated an increase in calcium level in root cells of pea seedlings grown aboard orbital station ``Salyut 6'' /1/. These results: 1) indicate that observed Ca^2+-binding sites of membranes also consist in proteins and phospholipids; 2) suggest that such effects of space flight in membrane Ca-binding might be due to the enhancement of Ca^2+ influx through membranes. In model presented, I propose that Ca^2+-activated channels in plasma membrane in response to microgravity allow the movement of Ca^2+ into the root cells, causing a rise in cytoplasmic free Ca^2+ levels. The latter, in its turn, may induce the inhibition of a Ca^2+ efflux by Ca^2+-activated ATPases and through a Ca^2+/H^+ antiport. It is possible that increased cytosolic levels of Ca^2+ ions have stimulated hydrolysis and turnover of phosphatidylinositols, with a consequent elevation of cytosolic [Ca^2+]_i. Plant cell can response to such a Ca^2+ rise by an enhancement of membranous Ca^2+-binding activities to rescue thus a cell from an abundance of a cytotoxin. A Ca^2+-induced phase separation of membranous lipids assists to appear the structure nonstable zones with high energy level at the boundary of microdomains which are rich by some phospholipid components; there is mixing of molecules of the membranes contacted in these zones, the first stage of membranous fusion, which was found in plants exposed to microgravity. These results support the hypothesis that a target for microgravity effect is the flux mechanism of Ca^2+ to plant cell.

Research on liquid sloshing performance in vane type tank under microgravity

NASA Astrophysics Data System (ADS)

Hu, Q.; Li, Y.; Liu, J. T.; Liang, J. Q.

2016-05-01

Propellant management device (PMD) in vane type tank mainly comprises of vane type structure parts, whose performance of restraining liquid sloshing should satisfy spacecraft requirements of high stabilization and fast orbital maneuver. Aiming at liquid sloshing performance in vane type tank under microgravity environment, gas-liquid flow model based on the volume of fluid (VOF) method was put forward, and via numerical simulation liquid sloshing performances of vane type PMD with anti-sloshing baffles and without anti-sloshing baffles in microgravity were analyzed and compared. Simulation results reveal that liquid sloshing performance of vane type PMD with anti-sloshing baffles is markedly superior vane type PMD without anti-sloshing baffles and the baffles make liquid surface become stable fast. Then by comparing between results of microgravity experiments and results of numerical simulations, they are very similar. According to present research, vane type PMD with antisloshing baffles has better effects on restraining liquid sloshing and is able to restrain observably propellant sloshing in tanks in order to satisfy spacecraft requirements of high stabilization and fast orbital maneuver.

The Microgravity Demonstrator

NASA Technical Reports Server (NTRS)

Rogers, Melissa J. B.; Wargo, Michael J.

1999-01-01

The Demonstrator is a tool to create microgravity conditions in your classroom. A series of demonstrations is used to provide a dramatically visual, physical connection between free-fall and microgravity conditions and to understand why various types of experiments are performed under microgravity conditions. A wealth of back-round material on free-fall, microgravity, and micro-gravity sciences is available in two educational documents available through the NASA Teacher Resource Centers: Microgravity-Activity Guide for Science, Mathematics, and Technology Education, and The Mathematics of Microgravity. The remainder of this manual is divided into five sections. The first explains how to put the Microgravity Demonstrator together. The next section introduces the individual demonstrations and discusses the underlying physical science concepts. Following that are detailed steps for conducting each demonstration to make your use of the Demonstrator most effective. Next are some ideas on how to make your own Microgravity Demonstrator. The last section is a tips and troubleshooting guide for video connections and operations. If you have one of the NASA Microgravity Demonstrators, this entire manual should be useful. If you have a copy of the Microgravity Demonstrator Videotape and would like to use that as a teaching tool, the Demonstrations and Scientific Background section of this manual will give you insight into the science areas studied in microgravity.

PI Microgravity Services Role for International Space Station Operations

NASA Technical Reports Server (NTRS)

DeLombard, Richard

1998-01-01

During the ISS era, the NASA Lewis Research Center's Principal Investigator Microgravity Services (PIMS) project will provide to principal investigators (PIs) microgravity environment information and characterization of the accelerations to which their experiments were exposed during on orbit operations. PIMS supports PIs by providing them with microgravity environment information for experiment vehicles, carriers, and locations within the vehicle. This is done to assist the PI with their effort to evaluate the effect of acceleration on their experiments. Furthermore, PIMS responsibilities are to support the investigators in the area of acceleration data analysis and interpretation, and provide the Microgravity science community with a microgravity environment characterization of selected experiment carriers and vehicles. Also, PIMS provides expertise in the areas of microgravity experiment requirements, vibration isolation, and the implementation of requirements for different spacecraft to the microgravity community and other NASA programs.

The effect of simulated microgravity on bacteria from the mir space station

NASA Astrophysics Data System (ADS)

Baker, Paul W.; Leff, Laura

2004-03-01

The effects of simulated microgravity on two bacterial isolates, Sphingobacterium thalpophilium and Ralstonia pickettii (formerly Burkholderia pickettii), originally recovered from water systems aboard the Mir space station were examined. These bacteria were inoculated into water, high and low concentrations of nutrient broth and subjected to simulated microgravity conditions. S. thalpophilium (which was motile and had flagella) showed no significant differences between simulated microgravity and the normal gravity control regardless of the method of enumeration and medium. In contrast, for R. pickettii (that was non-motile and lacked flagella), there were significantly higher numbers in high nutrient broth under simulated microgravity compared to normal gravity. Conversely, when R. pikkettii was inoculated into water (i.e., starvation conditions) significantly lower numbers were found under simulated microgravity compared to normal gravity. Responses to microgravity depended on the strain used (e.g., the motile strain exhibited no response to microgravity, while the non-motile strain did), the method of enumeration, and the nutrient concentration of the medium. Under oligotrophic conditions, non-motile cells may remain in geostationary orbit and deplete nutrients in their vicinity, while in high nutrient medium, resources surrounding the cell may be sufficient so that high growth is observed until nutrients becoming limiting.

The effect of simulated microgravity on bacteria from the Mir space station.

PubMed

Baker, Paul W; Leff, Laura

2004-01-01

The effects of simulated microgravity on two bacterial isolates, Sphingobacterium thalpophilium and Ralstonia pickettii (formerly Burkholderia pickettii), originally recovered from water systems aboard the Mir space station were examined. These bacteria were inoculated into water, high and low concentrations of nutrient broth and subjected to simulated microgravity conditions. S. thalpophilium (which was motile and had flagella) showed no significant differences between simulated microgravity and the normal gravity control regardless of the method of enumeration and medium. In contrast, for R. pickettii (that was non-motile and lacked flagella), there were significantly higher numbers in high nutrient broth under simulated microgravity compared to normal gravity. Conversely, when R. pikkettii was inoculated into water (i.e., starvation conditions) significantly lower numbers were found under simulated microgravity compared to normal gravity. Responses to microgravity depended on the strain used (e.g., the motile strain exhibited no response to microgravity, while the non-motile strain did), the method of enumeration, and the nutrient concentration of the medium. Under oligotrophic conditions, non-motile cells may remain in geostationary orbit and deplete nutrients in their vicinity, while in high nutrient medium, resources surrounding the cell may be sufficient so that high growth is observed until nutrients becoming limiting.

The effect of simulated microgravity on bacteria from the Mir space station

NASA Technical Reports Server (NTRS)

Baker, Paul W.; Leff, Laura

2004-01-01

The effects of simulated microgravity on two bacterial isolates, Sphingobacterium thalpophilium and Ralstonia pickettii (formerly Burkholderia pickettii), originally recovered from water systems aboard the Mir space station were examined. These bacteria were inoculated into water, high and low concentrations of nutrient broth and subjected to simulated microgravity conditions. S. thalpophilium (which was motile and had flagella) showed no significant differences between simulated microgravity and the normal gravity control regardless of the method of enumeration and medium. In contrast, for R. pickettii (that was non-motile and lacked flagella), there were significantly higher numbers in high nutrient broth under simulated microgravity compared to normal gravity. Conversely, when R. pikkettii was inoculated into water (i.e., starvation conditions) significantly lower numbers were found under simulated microgravity compared to normal gravity. Responses to microgravity depended on the strain used (e.g., the motile strain exhibited no response to microgravity, while the non-motile strain did), the method of enumeration, and the nutrient concentration of the medium. Under oligotrophic conditions, non-motile cells may remain in geostationary orbit and deplete nutrients in their vicinity, while in high nutrient medium, resources surrounding the cell may be sufficient so that high growth is observed until nutrients becoming limiting.

Investigating the Effect of Impurities on Macromolecule Crystal Growth in Microgravity

NASA Technical Reports Server (NTRS)

Snell, Edward H.; Judge, Russell A.; Crawford, Lisa; Forsythe, Elizabeth L.; Pusey, Marc L.; Sportiello, Michael; Todd, Paul; Bellamy, Henry; Lovelace, Jeff; Cassanto, John M.;

The lung in space.

PubMed

Prisk, G Kim

2005-09-01

The lung is exquisitely sensitive to gravity, which induces gradients in ventilation, blood flow, and gas exchange. Studies of lungs in microgravity provide a means of elucidating the effects of gravity. They suggest a mechanism by which gravity serves to match ventilation to perfusion, making for a more efficient lung than anticipated. Despite predictions, lungs do not become edematous, and there is no disruption to, gas exchange in microgravity. Sleep disturbances in microgravity are not a result of respiratory-related events; obstructive sleep apnea is caused principally by the gravitational effects on the upper airways. In microgravity, lungs may be at greater risk to the effects of inhaled aerosols.

The lung in space

NASA Technical Reports Server (NTRS)

Prisk, G. Kim

2005-01-01

The lung is exquisitely sensitive to gravity, which induces gradients in ventilation, blood flow, and gas exchange. Studies of lungs in microgravity provide a means of elucidating the effects of gravity. They suggest a mechanism by which gravity serves to match ventilation to perfusion, making for a more efficient lung than anticipated. Despite predictions, lungs do not become edematous, and there is no disruption to, gas exchange in microgravity. Sleep disturbances in microgravity are not a result of respiratory-related events; obstructive sleep apnea is caused principally by the gravitational effects on the upper airways. In microgravity, lungs may be at greater risk to the effects of inhaled aerosols.

Time-dependent computational studies of flames in microgravity

NASA Technical Reports Server (NTRS)

Oran, Elaine S.; Kailasanath, K.

1989-01-01

The research performed at the Center for Reactive Flow and Dynamical Systems in the Laboratory for Computational Physics and Fluid Dynamics, at the Naval Research Laboratory, in support of the NASA Microgravity Science and Applications Program is described. The primary focus was on investigating fundamental questions concerning the propagation and extinction of premixed flames in Earth gravity and in microgravity environments. The approach was to use detailed time-dependent, multispecies, numerical models as tools to simulate flames in different gravity environments. The models include a detailed chemical kinetics mechanism consisting of elementary reactions among the eight reactive species involved in hydrogen combustion, coupled to algorithms for convection, thermal conduction, viscosity, molecular and thermal diffusion, and external forces. The external force, gravity, can be put in any direction relative to flame propagation and can have a range of values. A combination of one-dimensional and two-dimensional simulations was used to investigate the effects of curvature and dilution on ignition and propagation of flames, to help resolve fundamental questions on the existence of flammability limits when there are no external losses or buoyancy forces in the system, to understand the mechanism leading to cellular instability, and to study the effects of gravity on the transition to cellular structure. A flame in a microgravity environment can be extinguished without external losses, and the mechanism leading to cellular structure is not preferential diffusion but a thermo-diffusive instability. The simulations have also lead to a better understanding of the interactions between buoyancy forces and the processes leading to thermo-diffusive instability.

Disrupted resting-state functional architecture of the brain after 45-day simulated microgravity

PubMed Central

Zhou, Yuan; Wang, Yun; Rao, Li-Lin; Liang, Zhu-Yuan; Chen, Xiao-Ping; Zheng, Dang; Tan, Cheng; Tian, Zhi-Qiang; Wang, Chun-Hui; Bai, Yan-Qiang; Chen, Shan-Guang; Li, Shu

2014-01-01

Long-term spaceflight induces both physiological and psychological changes in astronauts. To understand the neural mechanisms underlying these physiological and psychological changes, it is critical to investigate the effects of microgravity on the functional architecture of the brain. In this study, we used resting-state functional MRI (rs-fMRI) to study whether the functional architecture of the brain is altered after 45 days of −6° head-down tilt (HDT) bed rest, which is a reliable model for the simulation of microgravity. Sixteen healthy male volunteers underwent rs-fMRI scans before and after 45 days of −6° HDT bed rest. Specifically, we used a commonly employed graph-based measure of network organization, i.e., degree centrality (DC), to perform a full-brain exploration of the regions that were influenced by simulated microgravity. We subsequently examined the functional connectivities of these regions using a seed-based resting-state functional connectivity (RSFC) analysis. We found decreased DC in two regions, the left anterior insula (aINS) and the anterior part of the middle cingulate cortex (MCC; also called the dorsal anterior cingulate cortex in many studies), in the male volunteers after 45 days of −6° HDT bed rest. Furthermore, seed-based RSFC analyses revealed that a functional network anchored in the aINS and MCC was particularly influenced by simulated microgravity. These results provide evidence that simulated microgravity alters the resting-state functional architecture of the brains of males and suggest that the processing of salience information, which is primarily subserved by the aINS–MCC functional network, is particularly influenced by spaceflight. The current findings provide a new perspective for understanding the relationships between microgravity, cognitive function, autonomic neural function, and central neural activity. PMID:24926242

RWPV bioreactor mass transport: earth-based and in microgravity

NASA Technical Reports Server (NTRS)

Begley, Cynthia M.; Kleis, Stanley J.

2002-01-01

Mass transport and mixing of perfused scalar quantities in the NASA Rotating Wall Perfused Vessel bioreactor are studied using numerical models of the flow field and scalar concentration field. Operating conditions typical of both microgravity and ground-based cell cultures are studied to determine the expected vessel performance for both flight and ground-based control experiments. Results are presented for the transport of oxygen with cell densities and consumption rates typical of colon cancer cells cultured in the RWPV. The transport and mixing characteristics are first investigated with a step change in the perfusion inlet concentration by computing the time histories of the time to exceed 10% inlet concentration. The effects of a uniform cell utilization rate are then investigated with time histories of the outlet concentration, volume average concentration, and volume fraction starved. It is found that the operating conditions used in microgravity produce results that are quite different then those for ground-based conditions. Mixing times for microgravity conditions are significantly shorter than those for ground-based operation. Increasing the differential rotation rates (microgravity) increases the mixing and transport, while increasing the mean rotation rate (ground-based) suppresses both. Increasing perfusion rates enhances mass transport for both microgravity and ground-based cases, however, for the present range of operating conditions, above 5-10 cc/min there are diminishing returns as much of the inlet fluid is transported directly to the perfusion exit. The results show that exit concentration is not a good indicator of the concentration distributions in the vessel. In microgravity conditions, the NASA RWPV bioreactor with the viscous pump has been shown to provide an environment that is well mixed. Even when operated near the theoretical minimum perfusion rates, only a small fraction of the volume provides less than the required oxygen levels. 2002 Wiley Periodicals, Inc.

RWPV bioreactor mass transport: earth-based and in microgravity.

PubMed

Begley, Cynthia M; Kleis, Stanley J

2002-11-20

Mass transport and mixing of perfused scalar quantities in the NASA Rotating Wall Perfused Vessel bioreactor are studied using numerical models of the flow field and scalar concentration field. Operating conditions typical of both microgravity and ground-based cell cultures are studied to determine the expected vessel performance for both flight and ground-based control experiments. Results are presented for the transport of oxygen with cell densities and consumption rates typical of colon cancer cells cultured in the RWPV. The transport and mixing characteristics are first investigated with a step change in the perfusion inlet concentration by computing the time histories of the time to exceed 10% inlet concentration. The effects of a uniform cell utilization rate are then investigated with time histories of the outlet concentration, volume average concentration, and volume fraction starved. It is found that the operating conditions used in microgravity produce results that are quite different then those for ground-based conditions. Mixing times for microgravity conditions are significantly shorter than those for ground-based operation. Increasing the differential rotation rates (microgravity) increases the mixing and transport, while increasing the mean rotation rate (ground-based) suppresses both. Increasing perfusion rates enhances mass transport for both microgravity and ground-based cases, however, for the present range of operating conditions, above 5-10 cc/min there are diminishing returns as much of the inlet fluid is transported directly to the perfusion exit. The results show that exit concentration is not a good indicator of the concentration distributions in the vessel. In microgravity conditions, the NASA RWPV bioreactor with the viscous pump has been shown to provide an environment that is well mixed. Even when operated near the theoretical minimum perfusion rates, only a small fraction of the volume provides less than the required oxygen levels. 2002 Wiley Periodicals, Inc.

Trabecular bone adaptation to low-magnitude high-frequency loading in microgravity.

PubMed

Torcasio, Antonia; Jähn, Katharina; Van Guyse, Maarten; Spaepen, Pieter; Tami, Andrea E; Vander Sloten, Jos; Stoddart, Martin J; van Lenthe, G Harry

2014-01-01

Exposure to microgravity causes loss of lower body bone mass in some astronauts. Low-magnitude high-frequency loading can stimulate bone formation on earth. Here we hypothesized that low-magnitude high-frequency loading will also stimulate bone formation under microgravity conditions. Two groups of six bovine cancellous bone explants were cultured at microgravity on a Russian Foton-M3 spacecraft and were either loaded dynamically using a sinusoidal curve or experienced only a static load. Comparable reference groups were investigated at normal gravity. Bone structure was assessed by histology, and mechanical competence was quantified using μCT and FE modelling; bone remodelling was assessed by fluorescent labelling and secreted bone turnover markers. Statistical analyses on morphometric parameters and apparent stiffness did not reveal significant differences between the treatment groups. The release of bone formation marker from the groups cultured at normal gravity increased significantly from the first to the second week of the experiment by 90.4% and 82.5% in response to static and dynamic loading, respectively. Bone resorption markers decreased significantly for the groups cultured at microgravity by 7.5% and 8.0% in response to static and dynamic loading, respectively. We found low strain magnitudes to drive bone turnover when applied at high frequency, and this to be valid at normal as well as at microgravity. In conclusion, we found the effect of mechanical loading on trabecular bone to be regulated mainly by an increase of bone formation at normal gravity and by a decrease in bone resorption at microgravity. Additional studies with extended experimental time and increased samples number appear necessary for a further understanding of the anabolic potential of dynamic loading on bone quality and mechanical competence.

Characteristics of Non-Premixed Turbulent Flames in Microgravity

NASA Technical Reports Server (NTRS)

Hegde, U.; Yuan, Z. G.; Stocker, D. P.; Bahadori, M. Y.

2001-01-01

This project is concerned with the characteristics of turbulent hydrocarbon (primarily propane) gas-jet diffusion flames in microgravity. A microgravity environment provides the opportunity to study the structure of turbulent diffusion flames under momentum-dominated conditions (large Froude number) at moderate Reynolds number which is a combination not achievable in normal gravity. This paper summarizes progress made since the last workshop. Primarily, the features of flame radiation from microgravity turbulent jet diffusion flames in a reduced gravity environment are described. Tests were conducted for non-premixed, nitrogen diluted propane flames burning in quiescent air in the NASA Glenn 5.18 Second Zero Gravity Facility. Measured flame radiation from wedge-shaped, axial slices of the flame are compared for microgravity and normal gravity flames. Results from numerical computations of the flame using a k-e model for the turbulence are also presented to show the effects of flame radiation on the thermal field. Flame radiation is an important quantity that is impacted by buoyancy as has been shown in previous studies by the authors and also by Urban et al. It was found that jet diffusion flames burning under microgravity conditions have significantly higher radiative loss (about five to seven times higher) compared to their normal gravity counterparts because of larger flame size in microgravity and larger convective heat loss fraction from the flame in normal gravity. These studies, however, were confined to laminar flames. For the case of turbulent flames, the flame radiation is a function of time and both the time-averaged and time-dependent components are of interest. In this paper, attention is focused primarily on the time-averaged level of the radiation but the turbulent structure of the flame is also assessed from considerations of the radiation power spectra.

A Systems Biology Analysis Unfolds the Molecular Pathways and Networks of Two Proteobacteria in Spaceflight and Simulated Microgravity Conditions.

PubMed

Roy, Raktim; Shilpa, P Phani; Bagh, Sangram

2016-09-01

Bacteria are important organisms for space missions due to their increased pathogenesis in microgravity that poses risks to the health of astronauts and for projected synthetic biology applications at the space station. We understand little about the effect, at the molecular systems level, of microgravity on bacteria, despite their significant incidence. In this study, we proposed a systems biology pipeline and performed an analysis on published gene expression data sets from multiple seminal studies on Pseudomonas aeruginosa and Salmonella enterica serovar Typhimurium under spaceflight and simulated microgravity conditions. By applying gene set enrichment analysis on the global gene expression data, we directly identified a large number of new, statistically significant cellular and metabolic pathways involved in response to microgravity. Alteration of metabolic pathways in microgravity has rarely been reported before, whereas in this analysis metabolic pathways are prevalent. Several of those pathways were found to be common across studies and species, indicating a common cellular response in microgravity. We clustered genes based on their expression patterns using consensus non-negative matrix factorization. The genes from different mathematically stable clusters showed protein-protein association networks with distinct biological functions, suggesting the plausible functional or regulatory network motifs in response to microgravity. The newly identified pathways and networks showed connection with increased survival of pathogens within macrophages, virulence, and antibiotic resistance in microgravity. Our work establishes a systems biology pipeline and provides an integrated insight into the effect of microgravity at the molecular systems level. Systems biology-Microgravity-Pathways and networks-Bacteria. Astrobiology 16, 677-689.

Unsteady numerical simulations of the stability and dynamics of flames

NASA Technical Reports Server (NTRS)

Kailasanath, K.; Patnaik, G.; Oran, E. S.

1995-01-01

In this report we describe the research performed at the Naval Research Laboratory in support of the NASA Microgravity Science and Applications Program over the past three years (from Feb. 1992) with emphasis on the work performed since the last microgravity combustion workshop. The primary objective of our research is to develop an understanding of the differences in the structure, stability, dynamics and extinction of flames in earth gravity and in microgravity environments. Numerical simulations, in which the various physical and chemical processes can be independently controlled, can significantly advance our understanding of these differences. Therefore, our approach is to use detailed time-dependent, multi-dimensional, multispecies numerical models to perform carefully designed computational experiments. The basic issues we have addressed, a general description of the numerical approach, and a summary of the results are described in this report. More detailed discussions are available in the papers published which are referenced herein. Some of the basic issues we have addressed recently are (1) the relative importance of wall losses and gravity on the extinguishment of downward-propagating flames; (2) the role of hydrodynamic instabilities in the formation of cellular flames; (3) effects of gravity on burner-stabilized flames, and (4) effects of radiative losses and chemical-kinetics on flames near flammability limits. We have also expanded our efforts to include hydrocarbon flames in addition to hydrogen flames and to perform simulations in support of other on-going efforts in the microgravity combustion sciences program. Modeling hydrocarbon flames typically involves a larger number of species and a much larger number of reactions when compared to hydrogen. In addition, more complex radiation models may also be needed. In order to efficiently compute such complex flames recent developments in parallel computing have been utilized to develop a state-of-the-art parallel flame code. This is discussed below in some detail after a brief discussion of the numerical models.

[The problem of artificial gravity: the present status and possible approaches].

PubMed

Kotovskaia, A R

2008-01-01

The author reviews the Russian and international literature on the potentialities of artificial gravity in extended piloted space flights, especially in view of the declared initiatives to set forth on exploration missions in the first part of this century. Physical deconditioning and loss of tolerance to the gravitational loads consistently have their effects on cosmonauts despite the large assortment of in-flight preventive procedures. Effectiveness of artificial gravity generated by the short-arm centrifuge (SAC) has been assessed in experiments simulating the physiological consequences of microgravity by immersion or HDT, and flown aboard the dedicated satellites. It is emphasized that all the data indiscriminately indicate effectiveness of SAC as a preventive and therapeutic instrument alleviating the negative effects of modeled microgravity. Open issues and research objectives are presented.

A Theoretical Investigation of Oxidation Efficiency of a Volatile Removal Assembly Reactor Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Guo, Boyun

2005-01-01

Volatile Removal Assembly (VRA) is a subsystem of the Closed Environment Life Support System (CELSS) installed in the International Space Station. It is used for removing contaminants (volatile organics) in the wastewater produced by the space station crews. The major contaminants are formic acid, ethanol, and propylene glycol. The VRA contains a slim packbed reactor (3.5 cm diameter and four 28 cm long tubes in series) to perform catalyst oxidation of wastewater at elevated pressure and temperature under microgravity conditions. In the reactor, the contaminants are burned with oxygen gas (O2) to form water and carbon dioxide (CO2) that dissolves in the water stream. Optimal design of the reactor requires a thorough understanding about how the reactor performs under microgravity conditions. The objective of this study was to develop a mathematical model to interpret experimental data obtained from normal and microgravity conditions, and to predict the performance of VRA reactor under microgravity conditions. Catalyst oxidation kinetics and the total oxygen-water contact area control the efficiency of catalyst oxidation for mass transfer, which depends on oxygen gas holdup and distribution in the reactor. The process involves bubbly flow in porous media with chemical reactions in microgravity environment. This presents a unique problem in fluid dynamics that has not been studied. Guo et al. (2004) developed a mathematical model that predicts oxygen holdup in the VRA reactor. No mathematical model has been found in the literature that can be used to predict the efficiency of catalyst oxidation under microgravity conditions.

Mechanisms of Cardiopulmonary Adaptation to Microgravity. Part 1

NASA Technical Reports Server (NTRS)

1997-01-01

Session TA1 includes short reports covering: (1) Indices of Baroreceptor Reflex Sensitivity: The Use in Rehabilitation Medicine and Space Cardiology; (2) +Gz and +Gx Tolerance of Healthy Persons of Non-Flying Trades at Primary Selection of the Centrifuge; (3) Effect of Dry Immersion on Calf Blood Supply During Sustained Contraction and Upright Exercise in Man; (4) Cardiovascular and Valsalva Responses during Parabolic flight; (5) An Analysis of the Cardiovascular Responses under Hyper- and Hypo-Gravity Environments using a Mathematical model; (6) Effect of Very Gradual Onset Rate +Gz Exposures on the Cardiovascular System; and (7) NASA Specialized Center of Research and Training (NSCORT) in Integrated Physiology: Mechanisms of Physiological Adaptations to Microgravity.

Comparative Analysis of Thaumatin Crystals Grown on Earth and in Microgravity. Experiment 23

NASA Technical Reports Server (NTRS)

Ng, Joseph D.; Lorber, Bernard; Giege, Richard; Koszelak, Stanley; Day, John; Greenwood, Aaron; McPherson, Alexander

1998-01-01

The protein thaumatin was studied as a model macromolecule for crystallization in microgravity environment experiments conducted on two U.S. Space Shuttle missions (second United States Microgravity Laboratory (USML-2) and Life and Microgravity Spacelab (LMS)). In this investigation we evaluated and compared the quality of space- and Earth-grown thaumatin crystals using x-ray diffraction analysis and characterized them according to crystal size, diffraction resolution limit, and mosaicity. Two different approaches for growing thaumatin crystals in the microgravity environment, dialysis and liquid-liquid diffusion, were employed as a joint experiment by our two investigative teams. Thaumatin crystals grown under a microgravity environment were generally larger in volume with fewer total crystals. They diffracted to significantly higher resolution and with improved diffraction properties as judged by relative Wilson plots. The mosaicity for space-grown crystals was significantly less than for those grown on Earth. Increasing concentrations of protein in the crystallization chambers under microgravity lead to larger crystals. The data presented here lend further support to the idea that protein crystals of improved quality can be obtained in a microgravity environment.

A Systems Biology Analysis Unfolds the Molecular Pathways and Networks of Two Proteobacteria in Spaceflight and Simulated Microgravity Conditions

NASA Astrophysics Data System (ADS)

Roy, Raktim; Phani Shilpa, P.; Bagh, Sangram

2016-09-01

Bacteria are important organisms for space missions due to their increased pathogenesis in microgravity that poses risks to the health of astronauts and for projected synthetic biology applications at the space station. We understand little about the effect, at the molecular systems level, of microgravity on bacteria, despite their significant incidence. In this study, we proposed a systems biology pipeline and performed an analysis on published gene expression data sets from multiple seminal studies on Pseudomonas aeruginosa and Salmonella enterica serovar Typhimurium under spaceflight and simulated microgravity conditions. By applying gene set enrichment analysis on the global gene expression data, we directly identified a large number of new, statistically significant cellular and metabolic pathways involved in response to microgravity. Alteration of metabolic pathways in microgravity has rarely been reported before, whereas in this analysis metabolic pathways are prevalent. Several of those pathways were found to be common across studies and species, indicating a common cellular response in microgravity. We clustered genes based on their expression patterns using consensus non-negative matrix factorization. The genes from different mathematically stable clusters showed protein-protein association networks with distinct biological functions, suggesting the plausible functional or regulatory network motifs in response to microgravity. The newly identified pathways and networks showed connection with increased survival of pathogens within macrophages, virulence, and antibiotic resistance in microgravity. Our work establishes a systems biology pipeline and provides an integrated insight into the effect of microgravity at the molecular systems level.

Exercise training - Blood pressure responses in subjects adapted to microgravity

NASA Technical Reports Server (NTRS)

Convertino, Victor A.

1991-01-01

Conventional endurance exercise training that involves daily workouts of 1-2 hr duration during exposure to microgravity has not proven completely effective in ameliorating postexposure orthostatic hypotension. Single bouts of intense exercise have been shown to increase plasma volume and baroreflex sensitivity in ambulatory subjects through 24 hr postexercise and to reverse decrements in maximal oxygen uptake and syncopal episodes following exposure to simulated microgravity. These physiological adaptations to acute intense exercise were opposite to those observed following exposure to microgravity. These results suggest that the 'exercise training' stimulus used to prevent orthostatic hypotension induced by microgravity may be specific and should be redefined to include single bouts of maximal exercise which may provide an acute effective countermeasure against postflight hypotension.

Modeled microgravity inhibits apoptosis in peripheral blood lymphocytes

NASA Technical Reports Server (NTRS)

Risin, D.; Pellis, N. R.; McIntire, L. V. (Principal Investigator)

2001-01-01

Microgravity interferes with numerous lymphocyte functions (expression of cell surface molecules, locomotion, polyclonal and antigen-specific activation, and the protein kinase C activity in signal transduction). The latter suggests that gravity may also affect programmed cell death (PCD) in lymphocyte populations. To test this hypothesis, we investigated spontaneous, activation- and radiation-induced PCD in peripheral blood mononuclear cells exposed to modeled microgravity (MMG) using a rotating cell culture system. The results showed significant inhibition of radiation- and activation-induced apoptosis in MMG and provide insights into the potential mechanisms of this phenomenon.

Electrically Driven Liquid Film Boiling Experiment

NASA Technical Reports Server (NTRS)

Didion, Jeffrey R.

2016-01-01

This presentation presents the science background and ground based results that form the basis of the Electrically Driven Liquid Film Boiling Experiment. This is an ISS experiment that is manifested for 2021. Objective: Characterize the effects of gravity on the interaction of electric and flow fields in the presence of phase change specifically pertaining to: a) The effects of microgravity on the electrically generated two-phase flow. b) The effects of microgravity on electrically driven liquid film boiling (includes extreme heat fluxes). Electro-wetting of the boiling section will repel the bubbles away from the heated surface in microgravity environment. Relevance/Impact: Provides phenomenological foundation for the development of electric field based two-phase thermal management systems leveraging EHD, permitting optimization of heat transfer surface area to volume ratios as well as achievement of high heat transfer coefficients thus resulting in system mass and volume savings. EHD replaces buoyancy or flow driven bubble removal from heated surface. Development Approach: Conduct preliminary experiments in low gravity and ground-based facilities to refine technique and obtain preliminary data for model development. ISS environment required to characterize electro-wetting effect on nucleate boiling and CHF in the absence of gravity. Will operate in the FIR - designed for autonomous operation.

Fluid mechanics phenomena in microgravity; ASME Winter Annual Meeting, Anaheim, CA, Nov. 8-13, 1992

NASA Technical Reports Server (NTRS)

Siginer, Dennis A. (Editor); Weislogel, Mark M. (Editor)

1992-01-01

This paper is the first in a series of symposia presenting research activity in microgravity fluid mechanics. General topics addressed include two-phase flow and transport phenomena, thermo-capillary flow, and interfacial stability. Papers present mathmatical models of fluid dynamics in the microgravity environment. Applications suggested include space manufacturing and storage of liquids in low gravity.

Combined Effects of Microgravity, Radiation and Psychological Stress on Immune System Cells

NASA Technical Reports Server (NTRS)

Moreno-Villanueva, Maria

2017-01-01

The aim of this project was to investigate the combined effects of microgravity, radiation and psychological stress on DNA damage response. In order to mimic the combined conditions of space environment and psychological stress, cells were stimulated with isoproterenol (an epinephrine analogue compound) and exposed to radiation in a bioreactor that simulates microgravity conditions on the ground.

Microgravity effects on 'postural' muscle activity patterns

NASA Technical Reports Server (NTRS)

Layne, Charles S.; Spooner, Brian S.

1994-01-01

Changes in neuromuscular activation patterns associated with movements made in microgravity can contribute to muscular atrophy. Using electromyography (EMG) to monitor 'postural' muscles, it was found that free floating arm flexions made in microgravity were not always preceded by neuromuscular activation patterns normally observed during movements made in unit gravity. Additionally, manipulation of foot sensory input during microgravity arm flexion impacted upon anticipatory postural muscle activation.

The effect of space and parabolic flight on macrophage hematopoiesis and function

NASA Technical Reports Server (NTRS)

Armstrong, J. W.; Gerren, R. A.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

1995-01-01

We used weak electric fields to monitor macrophage spreading in microgravity. Using this technique, we demonstrated that bone marrow-derived macrophages responded to microgravity within 8 s. We also showed that microgravity differentially altered two processes associated with bone marrow-derived macrophage development. Spaceflight enhanced cellular proliferation and inhibited differentiation. These data indicate that the space/microgravity environment significantly affects macrophages.

Prolonged head-down tilt exposure reduces maximal cutaneous vasodilator and sweating capacity in humans

NASA Technical Reports Server (NTRS)

Crandall, C. G.; Shibasaki, M.; Wilson, T. E.; Cui, J.; Levine, B. D.

2003-01-01

Cutaneous vasodilation and sweat rate are reduced during a thermal challenge after simulated and actual microgravity exposure. The effects of microgravity exposure on cutaneous vasodilator capacity and on sweat gland function are unknown. The purpose of this study was to test the hypothesis that simulated microgravity exposure, using the 6 degrees head-down tilt (HDT) bed rest model, reduces maximal forearm cutaneous vascular conductance (FVC) and sweat gland function and that exercise during HDT preserves these responses. To test these hypotheses, 20 subjects were exposed to 14 days of strict HDT bed rest. Twelve of those subjects exercised (supine cycle ergometry) at 75% of pre-bed rest heart rate maximum for 90 min/day throughout HDT bed rest. Before and after HDT bed rest, maximal FVC was measured, via plethysmography, by heating the entire forearm to 42 degrees C for 45 min. Sweat gland function was assessed by administering 1 x 10(-6) to 2 M acetylcholine (9 doses) via intradermal microdialysis while simultaneously monitoring sweat rate over the microdialysis membranes. In the nonexercise group, maximal FVC and maximal stimulated sweat rate were significantly reduced after HDT bed rest. In contrast, these responses were unchanged in the exercise group. These data suggest that 14 days of simulated microgravity exposure, using the HDT bed rest model, reduces cutaneous vasodilator and sweating capacity, whereas aerobic exercise training during HDT bed rest preserves these responses.

3D Simulation: Microgravity Environments and Applications

NASA Technical Reports Server (NTRS)

Hunter, Steve L.; Dischinger, Charles; Estes, Samantha; Parker, Nelson C. (Technical Monitor)

2001-01-01

Most, if not all, 3-D and Virtual Reality (VR) software programs are designed for one-G gravity applications. Space environments simulations require gravity effects of one one-thousandth to one one-million of that of the Earth's surface (10(exp -3) - 10(exp -6) G), thus one must be able to generate simulations that replicate those microgravity effects upon simulated astronauts. Unfortunately, the software programs utilized by the National Aeronautical and Space Administration does not have the ability to readily neutralize the one-G gravity effect. This pre-programmed situation causes the engineer or analysis difficulty during micro-gravity simulations. Therefore, microgravity simulations require special techniques or additional code in order to apply the power of 3D graphic simulation to space related applications. This paper discusses the problem and possible solutions to allow microgravity 3-D/VR simulations to be completed successfully without program code modifications.

Enzyme catalysis in microgravity: steady-state kinetic analysis of the isocitrate lyase reaction.

PubMed

Ranaldi, Francesco; Vanni, Paolo; Giachetti, Eugenio

2003-01-21

Two decades of research in microgravity have shown that certain biochemical processes can be altered by weightlessness. Approximately 10 years ago, our team, supported by the European Space Agency (ESA) and the Agenzia Spaziale Italiana, started the Effect of Microgravity on Enzyme Catalysis project to test the possibility that the microgravity effect observed at cellular level could be mediated by enzyme reactions. An experiment to study the cleavage reaction catalyzed by isocitrate lyase was flown on the sounding rocket MASER 7, and we found that the kinetic parameters were not altered by microgravity. During the 28th ESA parabolic flight campaign, we had the opportunity to replicate the MASER 7 experiment and to perform a complete steady-state analysis of the isocitrate lyase reaction. This study showed that both in microgravity and in standard g controls the enzyme reaction obeyed the same kinetic mechanism and none of the kinetic parameters, nor the equilibrium constant of the overall reaction were altered. Our results contrast with those of a similar experiment, which was performed during the same parabolic flight campaign, and showed that microgravity increased the affinity of lipoxygenase-1 for linoleic acid. The hypotheses suggested to explain this change effect of the latter were here tested by computer simulation, and appeared to be inconsistent with the experimental outcome.

Principal Investigator Microgravity Services Role in ISS Acceleration Data Distribution

NASA Technical Reports Server (NTRS)

McPherson, Kevin

1999-01-01

Measurement of the microgravity acceleration environment on the International Space Station will be accomplished by two accelerometer systems. The Microgravity Acceleration Measurement System will record the quasi-steady microgravity environment, including the influences of aerodynamic drag, vehicle rotation, and venting effects. Measurement of the vibratory/transient regime comprised of vehicle, crew, and equipment disturbances will be accomplished by the Space Acceleration Measurement System-II. Due to the dynamic nature of the microgravity environment and its potential to influence sensitive experiments, Principal Investigators require distribution of microgravity acceleration in a timely and straightforward fashion. In addition to this timely distribution of the data, long term access to International Space Station microgravity environment acceleration data is required. The NASA Glenn Research Center's Principal Investigator Microgravity Services project will provide the means for real-time and post experiment distribution of microgravity acceleration data to microgravity science Principal Investigators. Real-time distribution of microgravity environment acceleration data will be accomplished via the World Wide Web. Data packets from the Microgravity Acceleration Measurement System and the Space Acceleration Measurement System-II will be routed from onboard the International Space Station to the NASA Glenn Research Center's Telescience Support Center. Principal Investigator Microgravity Services' ground support equipment located at the Telescience Support Center will be capable of generating a standard suite of acceleration data displays, including various time domain and frequency domain options. These data displays will be updated in real-time and will periodically update images available via the Principal Investigator Microgravity Services web page.

Renal Function of Rats in Response to 37 Days of Head-Down Tilt

NASA Technical Reports Server (NTRS)

Wang, Tommy J.; Wade, Charles E.; Dalton, Bonnie P. (Technical Monitor)

2001-01-01

Spaceflight induces changes in human renal function, suggesting similar changes may occur in rats. Since rats continue to be the prime mammalian model for study in space, the effects of chronic microgravity on rat renal function should be clarified. Acute studies in rats using the ground-based microgravity simulation model, head-down tilt (HDT), have shown increases in glomerular filtration rate (GFR), electrolyte excretion, and a diuresis. However, long term effects of HDT have not been studied extensively. This study was performed to elucidate rat renal function following long-term simulated microgravity. Chronic exposure to HDT will cause an increase in GFR and electrolyte excretion in rats, similar to acute exposures, and lead to a decrease in the fractional excretion of filtered electrolytes. Experimental animals (HDT, n=10) were tail-suspended for 37 days and renal function compared to ambulatory controls (AMB, n=10). On day 37 of HDT, GFR, osmolal clearance, and electrolyte excretion were decreased, while plasma osmolality and free water clearance were increased. Urine output remained similar between groups. The fractional excretion of the filtered electrolytes was unchanged except for a decrease in the percentage of filtered calcium excreted. Chronic exposure to HDT results in decreased GFR and electrolyte excretion, but the fractional excretion of filtered electrolytes remained primarily unaffected.

Microgravity

NASA Image and Video Library

1997-04-01

Apfel's excellent match: This series of photos shows a water drop containing a surfactant (Triton-100) as it experiences a complete cycle of superoscillation on U.S. Microgravity Lab-2 (USML-2; October 1995). The time in seconds appears under the photos. The figures above the photos are the oscillation shapes predicted by a numerical model. The time shown with the predictions is nondimensional. Robert Apfel (Yale University) used the Drop Physics Module on USML-2 to explore the effect of surfactants on liquid drops. Apfel's research of surfactants may contribute to improvements in a variety of industrial processes, including oil recovery and environmental cleanup.

Microgravity

NASA Image and Video Library

2001-01-24

Experiments with colloidal solutions of plastic microspheres suspended in a liquid serve as models of how molecules interact and form crystals. For the Dynamics of Colloidal Disorder-Order Transition (CDOT) experiment, Paul Chaikin of Princeton University has identified effects that are attributable to Earth's gravity and demonstrated that experiments are needed in the microgravity of orbit. Space experiments have produced unexpected dendritic (snowflake-like) structures. To date, the largest hard sphere crystal grown is a 3 mm single crystal grown at the cool end of a ground sample. At least two more additional flight experiments are plarned aboard the International Space Station. This image is from a video downlink.

How effectively does a clinostat mimic the ultrastructural effects of microgravity on plant cells?

NASA Technical Reports Server (NTRS)

Moore, R.

1990-01-01

Columella cells of seedlings of Zea mays L. cv. Bear Hybrid grown in the microgravity of orbital flight allocate significantly larger relative-volumes to hyaloplasm and lipid bodies, and significantly smaller relative-volumes to dictyosomes, plastids, and starch than do columella cells of seedlings grown at 1 g. The ultrastructure of columella cells of seedlings grown at 1 g and on a rotating clinostat is not significantly different. However, the ultrastructure of cells exposed to these treatments differs significantly from that of seedlings grown in microgravity. These results indicate that the actions of a rotating clinostat do not mimic the ultrastructural effects of microgravity in columella cells of Z. mays.

Microgravity Effects on Plant Boundary Layers

NASA Technical Reports Server (NTRS)

Stutte, Gary; Monje, Oscar

2005-01-01

The goal of these series of experiment was to determine the effects of microgravity conditions on the developmental boundary layers in roots and leaves and to determine the effects of air flow on boundary layer development. It is hypothesized that microgravity induces larger boundary layers around plant organs because of the absence of buoyancy-driven convection. These larger boundary layers may affect normal metabolic function because they may reduce the fluxes of heat and metabolically active gases (e.g., oxygen, water vapor, and carbon dioxide. These experiments are to test whether there is a change in boundary layer associated with microgravity, quantify the change if it exists, and determine influence of air velocity on boundary layer thickness under different gravity conditions.

ISS-Experiments of Columnar-to-Equiaxed Transition in Solidification Processing

NASA Technical Reports Server (NTRS)

Sturz, Laszlo; Zimmermann, Gerhard; Gandin, Charles, Andre; Billia, Bernard; Magelinck, Nathalie; Nguyen-Thi, Henry; Browne, David John; Mirihanage, Wajira U.; Voss, Daniela; Beckermann, Christoph;

Gas-Liquid Packed Bed Reactors in Microgravity

NASA Technical Reports Server (NTRS)

Balakotaiah, Vemuri; Motil, Brian J.; McCready, Mark J.; Kamotani, Yasuhiro

2004-01-01

Flow regime and pressure drop data was obtained and analyzed. Pulse flow exists at lower liquid flow rates in 0-g compared to 1-g. 1-g flow regime maps do not apply in microgravity. Pressure drop is higher in microgravity (enhanced interfacial effects).

Development of an Autonomous, Dual Chamber Bioreactor for the Growth of 3-Dimensional Epithelial-Stromal Tissues in Microgravity

NASA Technical Reports Server (NTRS)

Patel, Zarana S.; Wettergreen, Matthew A.; Huff, Janice L.

2014-01-01

We are developing a novel, autonomous bioreactor that can provide for the growth and maintenance in microgravity of 3-D organotypic epithelial-stromal cultures that require an air-liquid interface. These complex 3-D tissue models accurately represent the morphological features, differentiation markers, and growth characteristics observed in normal human epithelial tissues, including the skin, esophagus, lung, breast, pancreas, and colon. However, because of their precise and complex culture requirements, including that of an air-liquid interface, these 3-D models have yet to be utilized for life sciences research aboard the International Space Station. The development of a bioreactor for these cultures will provide the capability to perform biological research on the ISS using these realistic, tissue-like human epithelial-stromal cell models and will contribute significantly to advances in fundamental space biology research on questions regarding microgravity effects on normal tissue development, aging, cancer, and other disease processes. It will also allow for the study of how combined stressors, such as microgravity with radiation and nutritional deficiencies, affect multiple biological processes and will provide a platform for conducting countermeasure investigations on the ISS without the use of animal models. The technology will be autonomous and consist of a cell culture chamber that provides for air-liquid, liquid-liquid, and liquid-air exchanges within the chambers while maintaining the growth and development of the biological samples. The bioreactor will support multiple tissue types and its modular design will provide for incorporation of add-on capabilities such as microfluidics drug delivery, media sampling, and in situ biomarker analysis. Preliminary flight testing of the hardware will be conducted on a parabolic platform through NASA's Flight Opportunities Program.

Drosophila melanogaster (fruit fly) locomotion during a sounding rocket flight

NASA Astrophysics Data System (ADS)

Miller, Mark S.; Keller, Tony S.

2008-05-01

The locomotor activity of young Drosophila melanogaster (fruit fly) was studied during a Nike-Orion sounding rocket flight, which included a short-duration microgravity exposure. An infrared monitoring system was used to determine the activity level, instantaneous velocity, and continuous velocity of 240 (120 male, 120 female) fruit flies. Individual flies were placed in chambers that limit their motion to walking. Chambers were oriented both vertically and horizontally with respect to the rocket's longitudinal axis. Significant changes in Drosophila locomotion patterns were observed throughout the sounding rocket flight, including launch, microgravity exposure, payload re-entry, and after ocean impact. During the microgravity portion of the flight (3.8 min), large increases in all locomotion measurements for both sexes were observed, with some measurements doubling compared to pad (1 G) data. Initial effects of microgravity were probably delayed due to large accelerations from the payload despining immediately before entering microgravity. The results indicate that short-duration microgravity exposure has a large effect on locomotor activity for both males and females, at least for a short period of time. The locomotion increases may explain the increased male aging observed during long-duration exposure to microgravity. Studies focusing on long-duration microgravity exposure are needed to confirm these findings, and the relationship of increased aging and locomotion.

Swimming kinematics and respiratory behaviour of Xenopus laevis larvae raised in altered gravity.

PubMed

Fejtek, M; Souza, K; Neff, A; Wassersug, R

1998-06-01

We examined the respiratory behaviours and swimming kinematics of Xenopus laevis tadpoles hatched in microgravity (Space Shuttle), simulated microgravity (clinostat) and hypergravity (3 g centrifuge). All observations were made in the normal 1 g environment. Previous research has shown that X. laevis raised in microgravity exhibit abnormalities in their lungs and vestibular system upon return to 1 g. The tadpoles raised in true microgravity exhibited a significantly lower tailbeat frequency than onboard 1 g centrifuge controls on the day of landing (day0), but this behaviour normalized within 9 days. The two groups did not differ significantly in buccal pumping rates. Altered buoyancy in the space-flight microgravity tadpoles was indicated by an increased swimming angle on the day after landing (day1). Tadpoles raised in simulated microgravity differed to a greater extent in swimming behaviours from their 1 g controls. The tadpoles raised in hypergravity showed no substantive effects on the development of swimming or respiratory behaviours, except swimming angle. Together, these results show that microgravity has a transient effect on the development of locomotion in X. laevis tadpoles, most notably on swimming angle, indicative of stunted lung development. On the basis of the behaviours we studied, there is no indication of neuromuscular retardation in amphibians associated with embryogenesis in microgravity.

Swimming kinematics and respiratory behaviour of Xenopus laevis larvae raised in altered gravity

NASA Technical Reports Server (NTRS)

Fejtek, M.; Souza, K.; Neff, A.; Wassersug, R.

1998-01-01

We examined the respiratory behaviours and swimming kinematics of Xenopus laevis tadpoles hatched in microgravity (Space Shuttle), simulated microgravity (clinostat) and hypergravity (3 g centrifuge). All observations were made in the normal 1 g environment. Previous research has shown that X. laevis raised in microgravity exhibit abnormalities in their lungs and vestibular system upon return to 1 g. The tadpoles raised in true microgravity exhibited a significantly lower tailbeat frequency than onboard 1 g centrifuge controls on the day of landing (day0), but this behaviour normalized within 9 days. The two groups did not differ significantly in buccal pumping rates. Altered buoyancy in the space-flight microgravity tadpoles was indicated by an increased swimming angle on the day after landing (day1). Tadpoles raised in simulated microgravity differed to a greater extent in swimming behaviours from their 1 g controls. The tadpoles raised in hypergravity showed no substantive effects on the development of swimming or respiratory behaviours, except swimming angle. Together, these results show that microgravity has a transient effect on the development of locomotion in X. laevis tadpoles, most notably on swimming angle, indicative of stunted lung development. On the basis of the behaviours we studied, there is no indication of neuromuscular retardation in amphibians associated with embryogenesis in microgravity.

Simulated microgravity induces an inflammatory response in the common carotid artery of rats.

PubMed

Liu, Huan; Wang, Zhong-Chao; Yue, Yuan; Yu, Jin-Wen; Cai, Yue; Bai, Yun-Gang; Zhang, Hai-Jun; Bao, Jun-Xiang; Ren, Xin-Ling; Xie, Man-Jiang; Ma, Jin

2014-08-01

Post-spaceflight orthostatic intolerance is one of the most important adverse effects after exposure to space microgravity, and there are still no effective countermeasures. It has been considered that arterial remodeling may play an important role in the occurrence of post-spaceflight orthostatic intolerance, but the cellular mechanisms remain unknown. In this study, we investigated whether an inflammatory response exists in the common carotid artery of rats exposed to simulated microgravity. For this, Sprague-Dawley rats were subjected to 4 weeks of hindlimb unweighting to simulate microgravity. The expression levels of the adhesion molecules E-selectin and vascular cell adhesion molecule-1 (VCAM-1), and the cytokine monocyte chemoattractant protein-1 (MCP-1) in the common carotid artery of simulated microgravity rats were evaluated by immunohistochemical staining, quantitative RT-PCR, and Western blot analyses. The recruitment of monocytes in the common carotid artery of rats exposed to simulated microgravity was investigated by en face immunofluorescence staining and monocyte binding assays. Our results provided convincing evidence that there is an inflammatory response in the common carotid artery of rats exposed to simulated microgravity. Our work suggests that the inflammatory response may be a novel cellular mechanism that is responsible for the arterial remodeling that occurs during exposure to microgravity.

Solidification Using the Baffle in Sealed Ampoules

NASA Technical Reports Server (NTRS)

Ostrogorsky, A.; Marin, C.; Churilov, A.; Volz, M. P.; Bonner, W. A.; Spivey, R. A.; Smith, G.

2003-01-01

Solidification Using a Baffle in Sealed Ampoules (SUBSA) is the first investigation conducted in the Microgravity Science Glovebox (MSG) Facility at the International Space Station (ISS) Alpha. In July, August and September of 2002, 8 single crystals of InSb, doped with Te and Zn, were directionally solidified in microgravity. Ground based tests, related numerical modeling and images of the growth process obtained in microgravity are presented.

Modeled microgravity and hindlimb unloading sensitize osteoclast precursors to RANKL mediated osteoclastogenesis

PubMed Central

Saxena, Ritu; Pan, George; Dohm, Erik D.; McDonald, Jay M.

2010-01-01

Mechanical forces are essential to maintain skeletal integrity, and microgravity exposure leads to bone loss. The underlying molecular mechanisms leading to the changes in osteoblasts and osteoclast differentiation and function remain be to fully elucidated. Due to the infrequency of spaceflights and payload constraints, establishing in vitro and in vivo systems that mimic microgravity conditions becomes necessary. We have established a simulated microgravity (modeled microgravity, MMG) system to study the changes induced in osteoclast precursors. We observed that MMG, on its own was unable to induce osteoclastogenesis of osteoclast precursors, however, 24h of MMG activates osteoclastogenesis-related signaling molecules ERK, p38, PLCγ2, and NFATc1. RANKL (and/or M-CSF) stimulation for 3-4 days in gravity of cells that had been exposed to MMG for 24h, enhanced the formation of very large TRAP positive multinucleated (>30 nuclei) osteoclasts accompanied by an upregulation of osteoclast marker genes- TRAP and cathepsin K. To validate the in vitro system, we established the hindlimb unloading system using BALB/c mice and observed a decrease in BMD of femurs and a loss of 3D microstructure of both cortical and trabecular bone as determined by microCT. There was a marked stimulation of osteoclastogenesis as determined by the total number of TRAP positive multinucleated osteoclasts formed and also an increase in RANKL stimulated osteoclastogenesis from precursors removed from the tibias of mice after 28 days of hindlimb unloading. Contrary to earlier reported findings, we did not observe any histomorphometrical changes in the bone formation parameters. Thus, the above observations indicate that microgravity sensitizes osteoclast precursors for increased differentiation. The in vitro model system described here is potentially a valid system for testing drugs for preventing microgravity induced bone loss by targeting the molecular events occurring in microgravity-induced enhanced osteoclastogenesis. PMID:20589403

Early use of Space Station Freedom for NASA's Microgravity Science and Applications Program

NASA Technical Reports Server (NTRS)

Rhome, Robert C.; O'Malley, Terence F.

1992-01-01

The paper describes microgravity science opportunities inherent to the restructured Space Station and presents a synopsis of the scientific utilization plan for the first two years of ground-tended operations. In the ground-tended utilization mode the Space Station is a large free-flyer providing a continuous microgravity environment unmatched by any other platform within any existing U.S. program. It is pointed out that the importance of this period of early Space Station mixed-mode utilization between crew-tended and ground-tended approaches is of such magnitude that Station-based microgravity science experiments many become benchmarks to the disciplines involved. The traffic model that is currently being pursued is designed to maximize this opportunity for the U.S. microgravity science community.

Microgravity Effects on Yersinia Pestis Virulence

NASA Astrophysics Data System (ADS)

Lawal, A.; Abogunde, O.; Jejelowo, O.; Rosenzweig, J.-A.

2010-04-01

Microgravity effects on Yersinia pestis proliferation, cold growth, and type three secretion system function were evaluated in macrophage cell infections, HeLa cell infections, and cold growth plate assays.

Early Renal Changes in 45° Hdt Rats

NASA Astrophysics Data System (ADS)

R. Pettis, Chris; Drake, Matt; Witten, Mark L.; Truitt, Jill; Braun, Eldon; Lindberg, Kim; McNeil, George; Hall, Jack N.

Background: Both microgravity and simulated microgravity models, such as the 45HDT (45 ∘ head-down tilt), cause a redistribution of body fluids indicating a possible adaptive process to the microgravity stressor. Understanding the physiological processes that occur in microgravity is a first step to developing countermeasures to stop its harmful effects, i.e., (edema, motion sickness) during long-term space flights. Hypothesis: Because of the kidneys' functional role in the regulation of fluid volume in the body, it plays a key role in the body's adaptation to microgravity. Methods: Rats were injected intramuscularly with a radioactive tracer and then lightly anesthetized in order to facilitate their placement in the 45HDT position. They were then placed in the 45HDT position using a specially designed ramp (45HDT group) or prone position (control group) for an experimental time period of 1 h. During this period, the 99mTc-DTPA (technetium-labeled diethylenepentaacetate, MW=492 amu, physical half-life of 6.02 h) radioactive tracer clearance rate was determined by measuring gamma counts per minute. The kidneys were then fixed and sectioned for electron microscopy. A point counting method was used to quantitate intracellular spaces of the kidney proximal tubules. Results: 45HDT animals show a significantly ( p=0.0001) increased area in the interstitial space of the proximal tubules. Conclusions: There are significant changes in the kidneys during a 1 h exposure to a simulated microgravity environment that consist primarily of anatomical alterations in the kidney proximal tubules. The kidneys also appear to respond differently to the initial periods of head-down tilt.

Numerical Modeling of Ocular Dysfunction in Space

NASA Technical Reports Server (NTRS)

Nelson, Emily S.; Mulugeta, Lealem; Vera, J.; Myers, J. G.; Raykin, J.; Feola, A. J.; Gleason, R.; Samuels, B.; Ethier, C. R.

2014-01-01

Upon introduction to microgravity, the near-loss of hydrostatic pressure causes a marked cephalic (headward) shift of fluid in an astronaut's body. The fluid shift, along with other factors of spaceflight, induces a cascade of interdependent physiological responses which occur at varying time scales. Long-duration missions carry an increased risk for the development of the Visual Impairment and Intracranial Pressure (VIIP) syndrome, a spectrum of ophthalmic changes including posterior globe flattening, choroidal folds, distension of the optic nerve sheath, kinking of the optic nerve and potentially permanent degradation of visual function. In the cases of VIIP found to date, the initial onset of symptoms occurred after several weeks to several months of spaceflight, by which time the gross bodily fluid distribution is well established. We are developing a suite of numerical models to simulate the effects of fluid shift on the cardiovascular, central nervous and ocular systems. These models calculate the modified mean volumes, flow rates and pressures that are characteristic of the altered quasi-homeostatic state in microgravity, including intracranial and intraocular pressures. The results of the lumped models provide initial and boundary data to a 3D finite element biomechanics simulation of the globe, optic nerve head and retrobulbar subarachnoid space. The integrated set of models will be used to investigate the evolution of the biomechanical stress state in the ocular tissues due to long-term exposure to microgravity.

Exposure to microgravity for 30 days onboard Bion M1 caused muscle atrophy and impaired regeneration in murine femoral Quadriceps

NASA Astrophysics Data System (ADS)

Radugina, E. A.; Almeida, E. A. C.; Blaber, E.; Poplinskaya, V. A.; Markitantova, Y. V.; Grigoryan, E. N.

2018-02-01

Mechanical unloading in microgravity during spaceflight is known to cause muscular atrophy, changes in muscle fiber composition, gene expression, and reduction in regenerative muscle growth. Although some limited data exists for long-term effects of microgravity in human muscle, these processes have mostly been studied in rodents for short periods of time. Here we report on how long-term (30-day long) mechanical unloading in microgravity affects murine muscles of the femoral Quadriceps group. To conduct these studies we used muscle tissue from 6 microgravity mice, in comparison to habitat (7), and vivarium (14) ground control mice from the NASA Biospecimen Sharing Program conducted in collaboration with the Institute for Biomedical Problems of the Russian Academy of Sciences, during the Russian Bion M1 biosatellite mission in 2013. Muscle histomorphology from microgravity specimens showed signs of extensive atrophy and regenerative hypoplasia relative to ground controls. Specifically, we observed a two-fold decrease in the number of myonuclei, compared to vivarium and ground controls, and central location of myonuclei, low density of myofibers in the tissue, and of myofibrils within a fiber, as well as fragmentation and swelling of myofibers. Despite obvious atrophy, muscle regeneration nevertheless appeared to have continued after 30 days in microgravity as evidenced by thin and short newly formed myofibers. Many of them, however, showed evidence of apoptotic cells and myofibril degradation, suggesting that long-term unloading in microgravity may affect late stages of myofiber differentiation. Ground asynchronous and vivarium control animals demonstrated normal, well-developed tissue structure with sufficient blood and nerve supply and evidence of regenerative formation of new myofibers free of apoptotic nuclei. Regenerative activity of satellite cells in muscles was observed both in microgravity and ground control groups, using Pax7 and Myogenin immunolocalization, as well as Myogenin expression analysis. In addition, we have detected positive nuclear immunolocalization of c-Jun and c-Myc proteins indicating their sensitivity to changes in gravitational loading in a given model. In summary, long-term spaceflight in microgravity caused significant atrophy and degeneration of the femoral Quadriceps muscle group, and it may interfere with muscle regenerative processes by inducing apoptosis in newly-formed myofibrils during their differentiation phase.

Estimating the center of mass of a free-floating body in microgravity.

PubMed

Lejeune, L; Casellato, C; Pattyn, N; Neyt, X; Migeotte, P-F

2013-01-01

This paper addresses the issue of estimating the position of the center of mass (CoM) of a free-floating object of unknown mass distribution in microgravity using a stereoscopic imaging system. The method presented here is applied to an object of known mass distribution for validation purposes. In the context of a study of 3-dimensional ballistocardiography in microgravity, and the elaboration of a physical model of the cardiovascular adaptation to weightlessness, the hypothesis that the fluid shift towards the head of astronauts induces a significant shift of their CoM needs to be tested. The experiments were conducted during the 57th parabolic flight campaign of the European Space Agency (ESA). At the beginning of the microgravity phase, the object was given an initial translational and rotational velocity. A 3D point cloud corresponding to the object was then generated, to which a motion-based method inspired by rigid body physics was applied. Through simulations, the effects of the centroid-to-CoM distance and the number of frames of the sequence are investigated. In experimental conditions, considering the important residual accelerations of the airplane during the microgravity phases, CoM estimation errors (16 to 76 mm) were consistent with simulations. Overall, our results suggest that the method has a good potential for its later generalization to a free-floating human body in a weightless environment.

Development of the Gecko (Pachydactylus turneri) Animal Model during Foton M-2 to Study Comparative Effects of Microgravity in Terrestrial and Aquatic Organisms

NASA Technical Reports Server (NTRS)

Almeida, E. A.; Roden, C.; Phillips, J. A.; Globus, R. K.; Searby, N.; Vercoutere, W.; Morey-Holton, E.; Gulimova, V.; Saveliev, S.; Tairbekov, M.;

The Biophysics Microgravity Initiative

NASA Technical Reports Server (NTRS)

Gorti, S.

2016-01-01

Biophysical microgravity research on the International Space Station using biological materials has been ongoing for several decades. The well-documented substantive effects of long duration microgravity include the facilitation of the assembly of biological macromolecules into large structures, e.g., formation of large protein crystals under micro-gravity. NASA is invested not only in understanding the possible physical mechanisms of crystal growth, but also promoting two flight investigations to determine the influence of µ-gravity on protein crystal quality. In addition to crystal growth, flight investigations to determine the effects of shear on nucleation and subsequent formation of complex structures (e.g., crystals, fibrils, etc.) are also supported. It is now considered that long duration microgravity research aboard the ISS could also make possible the formation of large complex biological and biomimetic materials. Investigations of various materials undergoing complex structure formation in microgravity will not only strengthen NASA science programs, but may also provide invaluable insight towards the construction of large complex tissues, organs, or biomimetic materials on Earth.

Mineralization and growth of cultured embryonic skeletal tissue in microgravity

NASA Technical Reports Server (NTRS)

Klement, B. J.; Spooner, B. S.

1999-01-01

Microgravity provides a unique environment in which to study normal and pathological phenomenon. Very few studies have been done to examine the effects of microgravity on developing skeletal tissue such as growth plate formation and maintenance, elongation of bone primordia, or the mineralization of growth plate cartilage. Embryonic mouse premetatarsal triads were cultured on three space shuttle flights to study cartilage growth, differentiation, and mineralization, in a microgravity environment. The premetatarsal triads that were cultured in microgravity all formed cartilage rods and grew in length. However, the premetatarsal cartilage rods cultured in microgravity grew less in length than the ground control cartilage rods. Terminal chondrocyte differentiation also occurred during culture in microgravity, as well as in the ground controls, and the matrix around the hypertrophied chondrocytes was capable of mineralizing in both groups. The same percentage of premetatarsals mineralized in the microgravity cultures as mineralized in the ground control cultures. In addition, the sizes of the mineralized areas between the two groups were very similar. However, the amount of 45Ca incorporated into the mineralized areas was significantly lower in the microgravity cultures, suggesting that the composition or density of the mineralized regions was compromised in microgravity. There was no significant difference in the amount of 45Ca liberated from prelabeled explants in microgravity or in the ground controls.

Microgravity, stem cells, and embryonic development: challenges and opportunities for 3D tissue generation

NASA Astrophysics Data System (ADS)

Andreazzoli, Massimiliano; Angeloni, Debora; Broccoli, Vania; Demontis, Gian C.

2017-04-01

Space is a challenging environment for the human body, due to the combined effects of reduced gravity (microgravity) and cosmic radiation. Known effects of microgravity range from the blood redistribution that affects the cardiovascular system and the eye to muscle wasting, bone loss, anemia and immune depression. About cosmic radiation, the shielding provided by the spaceship hull is far less efficient than that afforded at ground level by the combined effects of the Earth atmosphere and magnetic field. The eye and its nervous layer (the retina) are affected by both microgravity and heavy ions exposure. Considering the importance of sight for long-term manned flights, visual research aimed at devising measures to protect the eye from environmental conditions of the outer space represents a special challenge to meet. In this review we focus on the impact of microgravity on embryonic development, discussing the roles of mechanical forces in the context of the neutral buoyancy the embryo experiences in the womb. At variance with its adverse effects on the adult human body, simulated microgravity may provide a unique tool for understanding the biomechanical events involved in the development and assembly in vitro of three-dimensional (3D) ocular tissues. Prospective benefits are the development of novel safety measures to protect the human eye from cosmic radiation in microgravity during long-term manned spaceflights in the outer space, as well as the generation of human 3D-retinas with its supporting structures to develop innovative and effective therapeutic options for degenerative eye diseases.

Combined Exposure to Simulated Microgravity and Acute or Chronic Radiation Reduces Neuronal Network Integrity and Survival

PubMed Central

Quintens, Roel; Samari, Nada; de Saint-Georges, Louis; van Oostveldt, Patrick; Baatout, Sarah; Benotmane, Mohammed Abderrafi

2016-01-01

During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. However, most earth-based studies on the potential health risks of space conditions have investigated the effects of these two conditions separately. This study aimed at assessing the combined effect of radiation exposure and microgravity on neuronal morphology and survival in vitro. In particular, we investigated the effects of simulated microgravity after acute (X-rays) or during chronic (Californium-252) exposure to ionizing radiation using mouse mature neuron cultures. Acute exposure to low (0.1 Gy) doses of X-rays caused a delay in neurite outgrowth and a reduction in soma size, while only the high dose impaired neuronal survival. Of interest, the strongest effect on neuronal morphology and survival was evident in cells exposed to microgravity and in particular in cells exposed to both microgravity and radiation. Removal of neurons from simulated microgravity for a period of 24 h was not sufficient to recover neurite length, whereas the soma size showed a clear re-adaptation to normal ground conditions. Genome-wide gene expression analysis confirmed a modulation of genes involved in neurite extension, cell survival and synaptic communication, suggesting that these changes might be responsible for the observed morphological effects. In general, the observed synergistic changes in neuronal network integrity and cell survival induced by simulated space conditions might help to better evaluate the astronaut's health risks and underline the importance of investigating the central nervous system and long-term cognition during and after a space flight. PMID:27203085

Effects of Spaceflight on the Attachment of Muscle to the Tibia, Fibula and Calcaneus

NASA Technical Reports Server (NTRS)

Johnson, R. B.; Tsao, A. K.; St.John, K. R.; Betcher, R. A.; Tucci, M. A.; Parsell, D. E.; Dai, X.; Zardiackas, L. D.; Benghuzzi, H. A.

1999-01-01

Microgravity significantly reduces transmission of ground-reaction forces to bones, promoting atrophy. There is little information available concerning the effects of microgravity on bones at sites where anti-gravity muscles are attached (tendon-bone junctions). This study evaluates the effects of microgravity on the origin and insertion sites of anti-gravity muscles on the rat tibia, fibula and calcaneus. Changes in the strength of those tendon-bone junctions could predispose the animal to injury following spaceflight.

An Overview of the Thermal Challenges of Designing Microgravity Furnaces

NASA Technical Reports Server (NTRS)

Westra, Douglas G.

2001-01-01

Marshall Space Flight Center is involved in a wide variety of microgravity projects that require furnaces, with hot zone temperatures ranging from 300 C to 2300 C, requirements for gradient processing and rapid quench, and both semi-conductor and metal materials. On these types of projects, the thermal engineer is a key player in the design process. Microgravity furnaces present unique challenges to the thermal designer. One challenge is designing a sample containment assembly that achieves dual containment, yet allows a high radial heat flux. Another challenge is providing a high axial gradient but a very low radial gradient. These furnaces also present unique challenges to the thermal analyst. First, there are several orders of magnitude difference in the size of the thermal 'conductors' between various parts of the model. A second challenge is providing high fidelity in the sample model, and connecting the sample with the rest of the furnace model, yet maintaining some sanity in the number of total nodes in the model. The purpose of this paper is to present an overview of the challenges involved in designing and analyzing microgravity furnaces and how some of these challenges have been overcome. The thermal analysis tools presently used to analyze microgravity furnaces and will be listed. Challenges for the future and a description of future analysis tools will be given.

Does vector-free gravity simulate microgravity? Functional and morphologic attributes of clinorotated nerve and muscle grown in cell culture

NASA Technical Reports Server (NTRS)

Gruener, Raphael; Hoeger, Glenn

1988-01-01

Cocultured Xenopus neurons and myocytes were subjected to nonvectorial gravity by clinostat rotation to determine the effects of microgravity on cell development and communications. Observed effects included increases in the myocyte and its nuclear area, fragmentation of nucleoli, the appearance of neuritic aneurysms, decreased growth in the presence of trophic factors, and decreased yolk utilization. These effects were most notable at 1-10 rpm and depended on the onset and duration of rotation. It is found that, in microgravity, cell differentiation is altered by interference with cytoskeleton-related mechanisms. It is suggested that the alteration of the distribution of acetylcholine receptor aggregates on myocytes which occurs might indicate that microgravity affects brain development.

Experimental Program to Stimulate Competitive Research (EPSCoR)

NASA Technical Reports Server (NTRS)

Dingerson, Michael R.

1997-01-01

Report includes: (1) CLUSTER: "Studies in Macromolecular Behavior in Microgravity Environment": The Role of Protein Oligomers in Protein Crystallization; Phase Separation Phenomena in Microgravity; Traveling Front Polymerizations; Investigating Mechanisms Affecting Phase Transition Response and Changes in Thermal Transport Properties in ER-Fluids under Normal and Microgravity Conditions. (2) CLUSTER: "Computational/Parallel Processing Studies": Flows in Local Chemical Equilibrium; A Computational Method for Solving Very Large Problems; Modeling of Cavitating Flows.

Microgravity

NASA Image and Video Library

1996-01-25

Dan Carter and Charles Sisk center a Lysozyme Protein crystal grown aboard the USML-2 shuttle mission. Protein isolated from hen egg-white and functions as a bacteriostatic enzyme by degrading bacterial cell walls. First enzyme ever characterized by protein crystallography. It is used as an excellent model system for better understanding parameters involved in microgravity crystal growth experiments. The goal is to compare kinetic data from microgravity experiments with data from laboratory experiments to study the equilibrium.

Calbindins decreased after space flight

NASA Technical Reports Server (NTRS)

Sergeev, I. N.; Rhoten, W. B.; Carney, M. D.

1996-01-01

Exposure of the body to microgravity during space flight causes a series of well-documented changes in Ca2+ metabolism, yet the cellular and molecular mechanisms leading to these changes are poorly understood. Calbindins, vitamin D-dependent Ca2+ binding proteins, are believed to have a significant role in maintaining cellular Ca2+ homeostasis. In this study, we used biochemical and immunocytochemical approaches to analyze the expression of calbindin-D28k and calbindin-D9k in kidneys, small intestine, and pancreas of rats flown for 9 d aboard the space shuttle. The effects of microgravity on calbindins in rats from space were compared with synchronous Animal Enclosure Module controls, modeled weightlessness animals (tail suspension), and their controls. Exposure to microgravity resulted in a significant and sustained decrease in calbindin-D28k content in the kidney and calbindin-D9k in the small intestine of flight animals, as measured by enzyme-linked immunosorbent assay (ELISA). Modeled weightlessness animals exhibited a similar decrease in calbindins by ELISA. Immunocytochemistry (ICC) in combination with quantitative computer image analysis was used to measure in situ the expression of calbindins in the kidney and the small intestine, and the expression of insulin in pancreas. There was a large decrease of immunoreactivity in renal distal tubular cell-associated calbindin-D28k and in intestinal absorptive cell-associated calbindin-D9k of space flight and modeled weightlessness animals compared with matched controls. No consistent difference in pancreatic insulin immunoreactivity between space flight, modeled weightlessness, and controls was observed. Regression analysis of results obtained by quantitative ICC and ELISA for space flight, modeled weightlessness animals, and their controls demonstrated a significant correlation. These findings after a short-term exposure to microgravity or modeled weightlessness suggest that a decreased expression of calbindins may contribute to the disorders of Ca2+ metabolism induced by space flight.

The German ISS-Experiment Cellular Responses to Radiation in Space (CERASP): The Effects of Single and Combined Space Flight Conditions on Mammalian Cells

NASA Astrophysics Data System (ADS)

Baumstark-Khan, C.; Hellweg, C. E.; Arenz, A.

The combined action of ionizing radiation and microgravity will continue to influence future space missions with special risks for astronauts on the Moon surface or for long duration missions to Mars Previous space flight experiments have reported additive neither sensitization nor protection as well as synergistic increased radiation effect under microgravity interactions of radiation and microgravity in different cell systems Although a direct effect of microgravity on enzymatic mechanisms can be excluded on thermo dynamical reasons modifications of cellular repair can not be excluded as such processes are under the control of cellular signal transduction systems which are controlled by environmental parameters presumably also by gravity DNA repair studies in space on bacteria yeast cells and human fibroblasts which were irradiated before flight gave contradictory results from inhibition of repair by microgravity to enhancement whereas others did not detect any influence of microgravity on repair At the Radiation Biology Department of the German Aerospace Center DLR recombinant bacterial and mammalian cell systems were developed as reporters for cellular signal transduction modulation by genotoxic environmental conditions The space experiment CERASP Cellular Responses to Radiation in Space to be performed at the International Space Station ISS will make use of such reporter cell lines thereby supplying basic information on the cellular response to radiation applied in microgravity One of the biological endpoints will be survival

Comparison of Carbon Dioxide and Helium as Fire Extinguishing Agents for Spacecraft

NASA Technical Reports Server (NTRS)

Gokoglu, Suleyman; Son, Youngjin; Ronney, Paul D.

2004-01-01

The effects of radiation heat transfer in microgravity compared to convection heat transfer in earth gravity for opposed-flow (downward) over thermally-thick fuel using low density foam fuel were investigated. Microgravity experiments on flame spread over thermally-thick fuels were conducted using foam fuels to obtain low density and thermal conductivity, and thus large flame spread rate compared to dense fuels such as PMMA. And thereby valid microgravity results were obtained even in 2.2 second drop-tower experiments not to mention for the longer duration tests in Zero Gravity Facility. Contrast to the conventional understanding, it was found that steady flame spread can occur over thick fuels in quiescent microgravity environments, especially when radiatively-active diluent gases such as CO2 were employed. This is proposed to result from radiative heat transfer from the flame to the fuel surface, which could lead to steady spread even when the amount of the heat transfer via conduction from the flame to the fuel bed is negligible. Radiative effects are more significant at microgravity conditions because the flame is thicker and thus the volume of radiating combustion products is larger as well. These results suggested that helium may be a better inert or extinguishment agent on both a mass and a mole bases at microgravity even though CO2 is much better on a mole bases at earth gravity, and these are relevant to studies of fire safety in manned spacecraft, particularly the International Space Station that uses CO2 fire extinguishers. CO2 may not be as effective as an extinguishing agent at microgravity as it is at earth gravity in some conditions because of the differences in spread mechanisms between the two cases. In particular, the difference between conduction-dominated heat transport to the fuel bed at earth gravity and radiation-dominated heat transport at microgravity indicates that radiatively-inert diluent such as helium could be preferable in microgravity applications. Helium may be a superior fire suppression agent at microgravity on several bases. First, helium is more effective than CO2 on a mole basis (thus pressure times storage volume basis) at microgravity, meaning that the size and weight of storage bottles would be smaller for the same fire-fighting capability. Second; helium is much more effective on a mass basis (by about 11 times) at microgravity. Third; helium has no physiological activity, unlike CO2 that affects human respiration. Fourth, as compared to N2 or CO2, is not very soluble in water and thus has fewer tendencies to cause bloodstream bubble formation following rapid spacecraft cabin depressurization.

Alkylating agent (MNU)-induced mutation in space environment

NASA Astrophysics Data System (ADS)

Ohnishi, T.; Takahashi, A.; Ohnishi, K.; Takahashi, S.; Masukawa, M.; Sekikawa, K.; Amano, T.; Nakano, T.; Nagaoka, S.

2001-01-01

In recent years, some contradictory data about the effects of microgravity on radiation-induced biological responses in space experiments have been reported. We prepared a damaged template DNA produced with an alkylating agent (N-methyl-N-nitroso urea; MNU) to measure incorrect base-incorporation during DNA replication in microgravity. We examined whether mutation frequency is affected by microgravity during DNA replication for a DNA template damaged by an alkylating agent. Using an in vitro enzymatic reaction system, DNA synthesis by Taq polymerase or polymerase III was done during a US space shuttle mission (Discovery, STS-91). After the flight, DNA replication and mutation frequencies were measured. We found that there was almost no effect of microgravity on DNA replication and mutation frequency. It is suggested that microgravity might not affect at the stage of substrate incorporation in induced-mutation frequency.

Performance analysis of no-vent fill process for liquid hydrogen tank in terrestrial and on-orbit environments

NASA Astrophysics Data System (ADS)

Wang, Lei; Li, Yanzhong; Zhang, Feini; Ma, Yuan

2015-12-01

Two finite difference computer models, aiming at the process predictions of no-vent fill in normal gravity and microgravity environments respectively, are developed to investigate the filling performance in a liquid hydrogen (LH2) tank. In the normal gravity case model, the tank/fluid system is divided into five control volume including ullage, bulk liquid, gas-liquid interface, ullage-adjacent wall, and liquid-adjacent wall. In the microgravity case model, vapor-liquid thermal equilibrium state is maintained throughout the process, and only two nodes representing fluid and wall regions are applied. To capture the liquid-wall heat transfer accurately, a series of heat transfer mechanisms are considered and modeled successively, including film boiling, transition boiling, nucleate boiling and liquid natural convection. The two models are validated by comparing their prediction with experimental data, which shows good agreement. Then the two models are used to investigate the performance of no-vent fill in different conditions and several conclusions are obtained. It shows that in the normal gravity environment the no-vent fill experiences a continuous pressure rise during the whole process and the maximum pressure occurs at the end of the operation, while the maximum pressure of the microgravity case occurs at the beginning stage of the process. Moreover, it seems that increasing inlet mass flux has an apparent influence on the pressure evolution of no-vent fill process in normal gravity but a little influence in microgravity. The larger initial wall temperature brings about more significant liquid evaporation during the filling operation, and then causes higher pressure evolution, no matter the filling process occurs under normal gravity or microgravity conditions. Reducing inlet liquid temperature can improve the filling performance in normal gravity, but cannot significantly reduce the maximum pressure in microgravity. The presented work benefits the understanding of the no-vent fill performance and may guide the design of on-orbit no-vent fill system.

Microgravity as a biological tool to examine host-pathogen interactions and to guide development of therapeutics and preventatives that target pathogenic bacteria.

PubMed

Higginson, Ellen E; Galen, James E; Levine, Myron M; Tennant, Sharon M

2016-11-01

Space exploration programs have long been interested in the effects of spaceflight on biology. This research is important not only in its relevance to future deep space exploration, but also because it has allowed investigators to ask questions about how gravity impacts cell behavior here on Earth. In the 1980s, scientists designed and built the first rotating wall vessel, capable of mimicking the low shear environment found in space. This vessel has since been used to investigate growth of both microorganisms and human tissue cells in low shear modeled microgravity conditions. Bacterial behavior has been shown to be altered both in space and under simulated microgravity conditions. In some cases, bacteria appear attenuated, whereas in others virulence is enhanced. This has consequences not only for manned spaceflight, but poses larger questions about the ability of bacteria to sense the world around them. By using the microgravity environment as a tool, we can exploit this phenomenon in the search for new therapeutics and preventatives against pathogenic bacteria for use both in space and on Earth. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Microgravity ignition experiment

NASA Technical Reports Server (NTRS)

Motevalli, Vahid; Elliott, William; Garrant, Keith; Marcotte, Ryan

1992-01-01

The purpose of this project is to develop a flight-ready apparatus of the microgravity ignition experiment for the GASCAN 2 program. The microgravity ignition experiment is designed to study how a microgravity environment affects the time to ignition of a sample of alpha-cellulose paper. A microgravity environment will result in a decrease in the heat transferred from the sample due to a lack of convection currents, which would decrease time to ignition. A lack of convection current would also cause the oxygen supply at the sample not to be renewed, which could delay or even prevent ignition. When this experiment is conducted aboard GASCAN 2, the dominant result of the lack of ignition will be determined. The experiment consists of four canisters containing four thermocouples and a sensor to detect ignition of the paper sample. This year the interior of the canister was redesigned and a mathematical model of the heat transfer around the sample was developed. This heat transfer model predicts an ignition time of approximately 5.5 seconds if the decrease of heat loss from the sample is the dominant factor of the lack of convection currents.

Development of the dynamic motion simulator of 3D micro-gravity with a combined passive/active suspension system

NASA Technical Reports Server (NTRS)

Yoshida, Kazuya; Hirose, Shigeo; Ogawa, Tadashi

1994-01-01

The establishment of those in-orbit operations like 'Rendez-Vous/Docking' and 'Manipulator Berthing' with the assistance of robotics or autonomous control technology, is essential for the near future space programs. In order to study the control methods, develop the flight models, and verify how the system works, we need a tool or a testbed which enables us to simulate mechanically the micro-gravity environment. There have been many attempts to develop the micro-gravity testbeds, but once the simulation goes into the docking and berthing operation that involves mechanical contacts among multi bodies, the requirement becomes critical. A group at the Tokyo Institute of Technology has proposed a method that can simulate the 3D micro-gravity producing a smooth response to the impact phenomena with relatively simple apparatus. Recently the group carried out basic experiments successfully using a prototype hardware model of the testbed. This paper will present our idea of the 3D micro-gravity simulator and report the results of our initial experiments.

Effects of Simulated Microgravity on Otolith Growth of Larval Zebrafish using a Rotating-Wall Vessel: Appropriate Rotation Speed and Fish Developmental Stage

NASA Astrophysics Data System (ADS)

Li, Xiaoyan; Anken, Ralf; Liu, Liyue; Wang, Gaohong; Liu, Yongding

2017-02-01

Stimulus dependence is a general feature of developing animal sensory systems. In this respect, it has extensively been shown earlier that fish inner ear otoliths can act as test masses as their growth is strongly affected by altered gravity such as hypergravity obtained using centrifuges, by (real) microgravity achieved during spaceflight or by simulated microgravity using a ground-based facility. Since flight opportunities are scarce, ground-based simulators of microgravity, using a wide variety of physical principles, have been developed to overcome this shortcoming. Not all of them, however, are equally well suited to provide functional weightlessness from the perspective of the biosystem under evaluation. Therefore, the range of applicability of a particular simulator has to be extensively tested. Earlier, we have shown that a Rotating-Wall Vessel (RWV) can be used to provide simulated microgravity for developing Zebrafish regarding the effect of rotation on otolith development. In the present study, we wanted to find the most effective speed of rotation and identify the appropriate developmental stage of Zebrafish, where effects are the largest, in order to provide a methodological basis for future in-depth analyses dedicated to the physiological processes underlying otolith growth at altered gravity. Last not least, we compared data on the effect of simulated microgravity on the size versus the weight of otoliths, since the size usually is measured in related studies due to convenience, but the weight more accurately approximates the physical capacity of an otolith. Maintaining embryos at 10 hours post fertilization for three days in the RWV, we found that 15 revolutions per minute (rpm) yielded the strongest effects on otolith growth. Maintenance of Zebrafish staged at 10 hpf, 1 day post fertilization (dpf), 4 dpf, 7 dpf and 14 dpf for three days at 15 rpm resulted in the most prominent effects in 7 dpf larvae. Weighing versus measuring the size of otoliths yielded basically similar results, but the data gained by weighing were more distinct. Overall, our results clearly support the concept that the environmental gravity vector regulates fish otolith growth in terms of the pendulum model of otolith test masses, and that wall vessel rotation is a valuable means to provide functional weightlessness from the perspective of developing Zebrafish. We recommend that Zebrafish embryos staged 7 dpf (or possibly slightly elder) are rotated at 15 rpm in a Rotating-Wall Vessel as used in the present study for further experiments designed to elucidate the mechanisms underlying (altered gravity affected) otolith growth.

Investigation of the Influence of Microgravity on Transport Mechanisms in a Virtual Spaceflight Chamber: A Ground Based Program

NASA Technical Reports Server (NTRS)

Trolinger, James D.; Rangel, Roger; Witherow, William; Rogers, Jan; Lal, Ravindra B.

1999-01-01

In January 1992, the IML-1 FES experiment produced a set of classic experimental data and a 40 hour holographic "movie" of an ensemble of spheres in a fluid in microgravity. Because the data are in the form of holograms, we can study the three-dimensional distribution of particles with unprecedented detail by a variety of methods and for a wide variety of interests. The possession of the holographic movie is tantamount to having a complex experiment in space while working in an easily accessible laboratory on earth. The movie contains a vast amount of useful data, including residual g, g-jitter, convection and transport data, and particle fluid interaction data. The information content in the movie is so great that we have scarcely begun to tap into the data that is actually available in the more than 1000 holograms, each containing as much as 1000 megabytes of information. This ground-based project is exploiting this data and the concept of holographic storage of spaceflight data to provide an understanding of the effects of microgravity in materials processing. This paper provides the foundation, objectives, and status of the ground based project. The primary objective of this project is to advance the understanding of microgravity effects on crystal growth, convection in materials processing in the space environment, and complex transport phenomena at low Reynolds numbers. This objective is being achieved both experimentally and theoretically. Experiments are making use of existing holographic data recorded during the IML- I spaceflight. A parallel theoretical effort is providing the models for understanding the particle fields and their physics in the microgravity environment.

Glucocorticoid: A potential role in microgravity-induced bone loss

NASA Astrophysics Data System (ADS)

Yang, Jiancheng; Yang, Zhouqi; Li, Wenbin; Xue, Yanru; Xu, Huiyun; Li, Jingbao; Shang, Peng

2017-11-01

Exposure of animals and humans to conditions of microgravity, including actual spaceflight and simulated microgravity, results in numerous negative alterations to bone structure and mechanical properties. Although there are abundant researches on bone loss in microgravity, the explicit mechanism is not completely understood. At present, it is widely accepted that the absence of mechanical stimulus plays a predominant role in bone homeostasis disorders in conditions of weightlessness. However, aside from mechanical unloading, nonmechanical factors such as various hormones, cytokines, dietary nutrition, etc. are important as well in microgravity induced bone loss. The stress-induced increase in endogenous glucocorticoid (GC) levels is inevitable in microgravity environments. Moreover, it is well known that GCs have a detrimental effect to bone health at excess concentrations. Therefore, GC plays a potential role in microgravity-induced bone loss. This review summarizeds several studies and their prospective solutions to this hypothesis.

Long-Duration Spaceflight During the Bion-M1 Spaceflight Experiment Resulted in Significant Bone Loss in the Femoral Head and Alterations in Stem Cell Differentiation Potential in Male Mice

NASA Astrophysics Data System (ADS)

Blaber, Elizabeth; Almeida, Eduardo; Grigoryan, Eleonora; Globus, Ruth

Scientific understanding of the effects of microgravity on mammalian physiology has been limited to short duration spaceflight experiments (10-15 days). As long duration and inter-planetary missions are being initiated, there is a great need to understand the long-term effects of spaceflight on various physiological processes, including stem cell-based tissue regeneration. Bion-M1, for the first time, enabled the possibility of studying the effects of 30-days of microgravity exposure on a mouse model with sufficient sample size to enable statistical analysis. In this experiment, we hypothesized that microgravity negatively impacts stem cell based tissue regeneration, such as bone remodeling and regeneration from hematopoietic and mesenchymal precursors, thereby resulting in tissue degeneration in mice exposed to spaceflight. To test this hypothesis we collected the pelvis and proximal femur from space-flown mice and asynchronous ground controls and analyzed bone and bone marrow using techniques including Microcomputed Tomography (MicroCT), and in-vitro differentiation and differentiating cell motility assays. To determine the effects of 30-days spaceflight on bone tissue mass, we used MicroCT to analyze the trabecular bone of the femoral head and the cortical bone of the femoral neck and mid-shaft. We found that spaceflight caused a 45% decrease in bone volume ratio, a 17% decrease in trabecular thickness, a 25% decrease in trabecular number, and a 17% increase in trabecular spacing of trabecular bone. Furthermore, structural model index and trabecular pattern factor were increased by 32% and 82% respectively indicating that 30-days spaceflight resulted not only in a large loss of trabecular bone but also in a decrease of bone strength indicators. Analysis of the femoral neck cortical bone showed an increase in marrow area and cortical porosity indicating an overall widening of the femoral neck. Interestingly, no significant alterations were found in the cortical bone of the femoral mid-shaft. To determine the regenerative potential of osteoblasts derived from mesenchymal stem cells flown in microgravity we conducted post-flight in-vitro osteoblastogenesis and mineralized nodule formation assays. We found an increase in post-flight differentiation and mineralization of microgravity-flown osteogenic cells, suggesting an accumulation of precursor cells that fail to fully differentiate in space, and then resume vigorous osteogenesis upon reloading at 1g. Overall, these preliminary results indicate that exposure to 30-days spaceflight causes significant trabecular bone loss in the femoral head, a decrease in trabecular bone strength indicators, and compensatory widening of the femoral neck. These results, coupled with diminished regenerative potential of bone marrow stem cells during mechanical unloading in microgravity, have potentially serious implications for bone health and fracture risk during long-duration spaceflight.

Altered TNF-Alpha, Glucose, Insulin and Amino Acids in Islets Langerhans Cultured in a Microgravity Model System

NASA Technical Reports Server (NTRS)

Tobin, Brian W.; Leeper-Woodford, Sandra K.; Hashemi, Brian B.; Smith, Scott M.; Sams, Clarence F.

2001-01-01

The present studies were designed to determine effects of a microgravity model system upon lipopolysaccharide (LPS) stimulated tumor necrosis factor alpha (TNF-alpha) activity and indices of insulin and fuel homeostasis of pancreatic islets of Langerhans. Islets (1726+/-1 17,150 u IEU) from Wistar Furth rats were treated as: 1) HARV (High Aspect Ratio Vessel cell culture) , 2) HARV plus LPS, 3) static culture, 4) static culture plus LPS. TNF-alpha (L929 cytotoxicity assay) was significantly increased in LPS-induced HARV and static cultures, yet the increase was more pronounced in the static culture group (p<0.05). A decrease in insulin concentration was demonstrated in the LPS stimulated HARV culture (p<0.05). We observed a greater glucose concentration and increased disappearance of arginine in islets cultured in HARVs. While nitrogenous compound analysis indicated a ubiquitous reliance upon glutamine in all experimental groups, arginine was converted to ornithine at a two-fold greater rate in the islets cultured in the HARV microgravity model system (p<0.05). These studies demonstrate alterations in LPS induced TNF-alpha production of pancreatic islets of Langerhans, favoring a lesser TNF activity in the HARV. These alterations in fuel homeostasis may be promulgated by gravity averaged cell culture methods or by three dimensional cell assembly.

Adrenomedullin is a key Protein Mediating Rotary Cell Culture System that Induces the Effects of Simulated Microgravity on Human Breast Cancer Cells

NASA Astrophysics Data System (ADS)

Chen, Li; Yang, Xi; Cui, Xiang; Jiang, Minmin; Gui, Yu; Zhang, Yanni; Luo, Xiangdong

2015-11-01

Microgravity or simulated microgravity promotes stem cell proliferation and inhibits differentiation. But, researchers have not yet been able to understand the underlying mechanism through which microgravity or simulated microgravity brings about stem cell proliferation and inhibition of differentiation. In this study, we investigated the effect of simulated microgravity (SMG) on MDA-MB-231 and MCF-7 human breast cancer cells using rotary cell culture system (RCCS). SMG induced a significant accumulation of these cancer cells in S phase of the cell cycle. But, compared with the static group, there was no effect on the overall growth rate of cells in the RCCS group. Furthermore, the expression of cyclin D1 was inhibited in the RCCS group, indicating that RCCS induced cell cycle arrest. In addition, RCCS also induced glycolytic metabolism by increasing the expression of adrenomedullin (ADM), but not HIF1 a. The addition of ADM further enhanced the effects of SMG, which was induced by RCCS. But, the addition of adrenomedullin antagonist (AMA) reversed these effects of SMG. Finally, our results proved that RCCS, which induced cells cycle arrest of breast cancer cells, enhanced glycolysis and upregulated the expression of ADM. But, this did not lead to an increase in hypoxia-inducible factor-1 a (HIF1 a) expression. Thus, we have uncovered a new mechanism for understanding the Warburg effect in breast cancer cells, this mechanism is not the same as hypoxia induced glycolysis.

Length Scale and Gravity Effects on Microgravity Boiling Heat Transfer

NASA Technical Reports Server (NTRS)

Kim, Jungho; McQuillen, John; Balombin, Joe

2002-01-01

Boiling is a complex phenomenon where hydrodynamics, heat transfer, mass transfer, and interfacial phenomena are tightly interwoven. An understanding of boiling and critical heat flux in microgravity environments is of importance to space based hardware and processes such as heat exchange, cryogenic fuel storage and transportation, electronic cooling, and material processing due to the large amounts of heat that can be removed with relatively little increase in temperature. Although research in this area has been performed in the past four decades, the mechanisms by which heat is removed from surfaces in microgravity are still unclear. In earth gravity, buoyancy is an important parameter that affects boiling heat transfer through the rate at which bubbles are removed from the surface. A simple model describing the bubble departure size based on a quasistatic force balance between buoyancy and surface tension is given by the Fritz [I] relation: Bo(exp 1/2) = 0.0208 theta where Bo is the ratio between buoyancy and surface tension forces. For small, rapidly growing bubbles, inertia associated with the induced liquid motion can also cause bubble departure. In microgravity, the magnitude of effects related to natural convection and buoyancy are small and physical mechanisms normally masked by natural convection in earth gravity such as Marangoni convection can substantially influence the boiling and vapor bubble dynamics. CHF (critical heat transfer) is also substantially affected by microgravity. In 1 g environments, Bo has been used as a correlating parameter for CHF. Zuber's CHF model for an infinite horizontal surface assumes that vapor columns formed by the merger of bubbles become unstable due to a Helmholtz instability blocking the supply of liquid to the surface. The jets are spaced lambda(sub D) apart, where lambda(sub D) = 2pi square root of 3[(sigma)/(g(rho(sub l) - rho(sub v)](exp 1/2) = 2pi square root of 3 L Bo(exp -1/2) = square root of 3 lambda(sub c) and is the wavelength that amplifies most rapidly. The critical wavelength, lambda(sub c), is the wavelength below which a vapor layer underneath a liquid layer is stable. For heaters with Bo smaller than about 3 (heaters smaller than lambda(sub D)), the above model is not applicable, and surface tension effects dominate. Bubble coalescence is thought to be the mechanism for CHF under these conditions. Small Bo can result by decreasing the size of a heater in earth gravity, or by operating a large heater in a lower gravity environment. In the microgravity of space, even large heaters can have low Bo, and models based on Helmholtz instability should not be applicable. The macrolayer model of Haramura and Katto is dimensionally equivalent to Zuber's model and has the same dependence on gravity, so it should not be applicable as well. The goal of this work is to determine how boiling heat transfer mechanisms in a low-g environment are altered from those at higher gravity levels. Boiling data using a microheater array was obtained under gravity environments ranging from 1.8 g to 0.02 g with heater sizes ranging from 2.7 mm to 1 mm. The boiling behavior for 2.7 mm at 0.02 g looked quite similar to boiling on the 1 mm heater at 1 g-the formation of a large primary bubble surrounded by smaller satellite bubbles was observed under both conditions. The similarity suggests that for heaters smaller than some fraction of I(sub c), coalescence and surface tension dominate boiling heat transfer. It also suggests that microgravity boiling can be studied by studying boiling on very small heaters.

Microgravity and immunity: Changes in lymphocyte gene expression.

NASA Astrophysics Data System (ADS)

Risin, D.; Ward, N. E.; Risin, S. A.; Pellis, N. R.

Earlier studies had shown that modeled and true microgravity MG cause multiple direct effects on human lymphocytes MG inhibits lymphocyte locomotion suppresses polyclonal and antigen-specific activation affects signal transduction mechanisms as well as activation-induced apoptosis In this study we assessed changes in gene expression associated with lymphocyte exposure to microgravity in an attempt to identify microgravity-sensitive genes MGSG in general and specifically those genes that might be responsible for the functional and structural changes observed earlier Two sets of experiments targeting different goals were conducted In the first set T-lymphocytes from normal donors were activated with anti-CD3 and IL2 and then cultured in 1g static and modeled MG MMG conditions Rotating Wall Vessel bioreactor for 24 hours This setting allowed searching for MGSG by comparison of gene expression patterns in zero and 1 g gravity In the second set - activated T-cells after culturing for 24 hours in 1g and MMG were exposed three hours before harvesting to a secondary activation stimulus PHA thus triggering the apoptotic pathway Total RNA was extracted using the RNeasy isolation kit Qiagen Valencia CA Affymetrix Gene Chips U133A allowing testing for 18 400 human genes were used for microarray analysis The experiments were performed in triplicates with T-cells obtained from different blood donors to minimize the possible input of biological variation in gene expression and discriminate changes that are associated with the

Control of the Onboard Microgravity Environment and Extension of the Service Life of the Long-Term Space Station

NASA Astrophysics Data System (ADS)

Titov, V. A.

2018-03-01

The problem of control of the on-board microgravity environment in order to extend the service life of the long-term space station has been discussed. Software developed for the ISS and the results of identifying dynamic models and external impacts based on telemetry data have been presented. Proposals for controlling the onboard microgravity environment for future long-term space stations have been formulated.

Proteomic Analysis of Mouse Hypothalamus under Simulated Microgravity

PubMed Central

Sarkar, Poonam; Sarkar, Shubhashish; Ramesh, Vani; Kim, Helen; Barnes, Stephen; Kulkarni, Anil; Hall, Joseph C.; Wilson, Bobby L.; Thomas, Renard L.; Pellis, Neal R.

2009-01-01

Exposure to altered microgravity during space travel induces changes in the brain and these are reflected in many of the physical behavior seen in the astronauts. The vulnerability of the brain to microgravity stress has been reviewed and reported. Identifying microgravity-induced changes in the brain proteome may aid in understanding the impact of the microgravity environment on brain function. In our previous study we have reported changes in specific proteins under simulated microgravity in the hippocampus using proteomics approach. In the present study the profiling of the hypothalamus region in the brain was studied as a step towards exploring the effect of microgravity in this region of the brain. Hypothalamus is the critical region in the brain that strictly controls the pituitary gland that in turn is responsible for the secretion of important hormones. Here we report a 2-dimensional gel electrophoretic analysis of the mouse hypothalamus in response to simulated microgravity. Lowered glutathione and differences in abundance expression of seven proteins were detected in the hypothalamus of mice exposed to microgravity. These changes included decreased superoxide dismutase-2 (SOD-2) and increased malate dehydrogenase and peroxiredoxin-6, reflecting reduction of the antioxidant system in the hypothalamus. Taken together the results reported here indicate that oxidative imbalance occurred in the hypothalamus in response to simulated microgravity. PMID:18473167

Fluid Dynamics and Solidification of Molten Solder Droplets Impacting on a Substrate in Microgravity

NASA Technical Reports Server (NTRS)

Poulikakos, Dimos; Megaridis, Constantine M.; Vedha-Nayagam, M.

1996-01-01

This program investigates the fluid dynamics and simultaneous solidification of molten solder droplets impacting on a flat substrate. The problem of interest is directly relevant to the printing of microscopic solder droplets in surface mounting of microelectronic devices. The study consists of a theoretical and an experimental component. The theoretical work uses axisymmetric Navier-Stokes models based on finite element techniques. The experimental work is performed in microgravity to allow for the use of larger solder droplets that make feasible the performance of accurate measurements while maintaining similitude of the relevant fluid dynamics groups (Re, We) and keeping the effect of gravity negligible.

The immune system in space and microgravity

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald

2002-01-01

Space flight and models that created conditions similar to those that occur during space flight have been shown to affect a variety of immunological responses. These have primarily been cell-mediated immune responses including leukocyte proliferation, cytokine production, and leukocyte subset distribution. The mechanisms and biomedical consequences of these changes remain to be established. Among the possible causes of space flight-induced alterations in immune responses are exposure to microgravity, exposure to stress, exposure to radiation, and many more as yet undetermined causes. This review chronicles the known effects of space flight on the immune system and explores the possible role of stress in contributing to these changes.

Modeling of Blood Lead Levels in Astronauts Exposed to Lead from Microgravity-Accelerated Bone Loss

NASA Technical Reports Server (NTRS)

Garcia, H.; James, J.; Tsuji, J.

2014-01-01

Human exposure to lead has been associated with toxicity to multiple organ systems. Studies of various population groups with relatively low blood lead concentrations (<10 µg/dL) have indicated associations of blood lead level with lower cognitive test scores in children, later onset of puberty in girls, and increased blood pressure and cardiovascular mortality rates in adults. Cognitive effects are considered by regulatory agencies to be the most sensitive endpoint at low doses. Although 95% of the body burden of lead is stored in the bones, the adverse effects of lead correlate with the concentration of lead in the blood better than with that in the bones. NASA has found that prolonged exposure to microgravity during spaceflight results in a significant loss of bone minerals, the extent of which varies from individual to individual and from bone to bone, but generally averages about 0.5% per month. During such bone loss, lead that had been stored in bones would be released along with calcium. The effects on the concentration of lead in the blood (PbB) of various concentrations of lead in drinking water (PbW) and of lead released from bones due to accelerated osteoporosis in microgravity, as well as changes in exposure to environmental lead before, during, and after spaceflight were evaluated using a physiologically based pharmacokinetic (PBPK) model that incorporated exposure to environmental lead both on earth and in flight and included temporarily increased rates of osteoporosis during spaceflight.

Evaluation of conditions necessary for successful bioprocessing of gray water in a microgravity environment

NASA Astrophysics Data System (ADS)

Urban, James E.; Supra, Laura; MacKnight, Allen

2000-01-01

A unique combination of researchers are investigating biological and engineering aspects of a biological wastewater treatment system which could effectively function to treat gray water in a microgravity environment such as that on the International Space Station and human-occupied interplanetary spacecraft. As part of the effort, 23 bacterial strains have been isolated from a bioprocessor operating at unit gravity and various strain combinations have been tested in microgravity for survivability and reduction of total organic carbon in ersatz gray water. All tested strains survive equally well in microgravity and unit gravity and each is capable of reducing TOC in microgravity. While the results reported are encouraging, they also reveal that current testing procedures and equipment are inadequate for fully evaluating bioprocessing in microgravity. .

BIM LAU-PE: Seedlings in Microgravity

NASA Astrophysics Data System (ADS)

Gass, S.; Pennese, R.; Chapuis, D.; Dainesi, P.; Nebuloni, S.; Garcia, M.; Oriol, A.

2015-09-01

The effect of gravity on plant roots is an intensive subject of research. Sounding rockets represent a costeffective platform to study this effect under microgravity conditions. As part of the upcoming MASER 13 sounding rocket campaign, two experiments on Arabidopsis thaliana seedlings have been devised: GRAMAT and SPARC. These experiments are aimed at studying (1) the genes that are specifically switched on or off during microgravity, and (2) the position of auxin-transporting proteins during microgravity. To perform these experiments, RUAG Space Switzerland site of Nyon, in collaboration with the Swedish Space Corporation (SSC) and the University of Freiburg, has developed the BIM LAU-PE (Biolology In Microgravity Late Access Unit Plant Experiment). In the following an overview of the BIM LAU-PE design is presented, highlighting specific module design features and verifications performed. A particular emphasis is placed on the parabolic flight experiments, including results of the micro-g injection system validation.

Macromolecule Crystal Quality Improvement in Microgravity: The Role of Impurities

NASA Technical Reports Server (NTRS)

Judge, Russell A.; Snell, Edward H.; Pusey, Marc L.; Sportiello, Michael G.; Todd, Paul; Bellamy, Henry; Borgstahl, Gloria E.; Pokros, Matt; Cassanto, John M.

2000-01-01

While macromolecule impurities may affect crystal size and morphology the over-riding question is; "How do macromolecule impurities effect crystal X-ray quality and diffraction resolution?" In the case of chicken egg white lysozyme, crystals can be grown in the presence of a number of impurities without affecting diffraction resolution. One impurity however, the lysozyme dimer, does negatively impact the X-ray crystal properties. Crystal quality improvement as a result of better partitioning of this impurity during crystallization in microgravity has been reported'. In our recent experimental work dimer partitioning was found to be not significantly different between the two environments. Mosaicity analysis of pure crystals showed a reduced mosaicity and increased signal to noise for the microgravity grown crystals. Dimer incorporation however, did greatly reduce the resolution limit in both ground and microgravity grown crystals. These results indicate that impurity effects in microgravity are complex and may rely on the conditions or techniques employed.

Phase Distribution Phenomena for Simulated Microgravity Conditions: Experimental Work

NASA Technical Reports Server (NTRS)

Singhal, Maneesh; Bonetto, Fabian J.; Lahey, R. T., Jr.

1996-01-01

This report summarizes the work accomplished at Rensselaer to study phase distribution phenomenon under simulated microgravity conditions. Our group at Rensselaer has been able to develop sophisticated analytical models to predict phase distribution in two-phase flows under a variety of conditions. These models are based on physics and data obtained from carefully controlled experiments that are being conducted here. These experiments also serve to verify the models developed.

Phase Distribution Phenomena for Simulated Microgravity Conditions: Experimental Work

NASA Technical Reports Server (NTRS)

Singhal, Maneesh; Bonetto, Fabian J.; Lahey, R. T., Jr.

1996-01-01

This report summarizes the work accomplished at Rensselaer to study phase distribution phenomenon under simulated microgravity conditions. Our group at Rensselaer has been able to develop sophisticated analytical models to predict phase distribution in two-phase flows under variety of conditions. These models are based on physics and data obtained from carefully controlled experiments that are being conducted here. These experiments also serve to verify the models developed.

Creating Simulated Microgravity Patient Models

NASA Technical Reports Server (NTRS)

Hurst, Victor; Doerr, Harold K.; Bacal, Kira

2004-01-01

The Medical Operational Support Team (MOST) has been tasked by the Space and Life Sciences Directorate (SLSD) at the NASA Johnson Space Center (JSC) to integrate medical simulation into 1) medical training for ground and flight crews and into 2) evaluations of medical procedures and equipment for the International Space Station (ISS). To do this, the MOST requires patient models that represent the physiological changes observed during spaceflight. Despite the presence of physiological data collected during spaceflight, there is no defined set of parameters that illustrate or mimic a 'space normal' patient. Methods: The MOST culled space-relevant medical literature and data from clinical studies performed in microgravity environments. The areas of focus for data collection were in the fields of cardiovascular, respiratory and renal physiology. Results: The MOST developed evidence-based patient models that mimic the physiology believed to be induced by human exposure to a microgravity environment. These models have been integrated into space-relevant scenarios using a human patient simulator and ISS medical resources. Discussion: Despite the lack of a set of physiological parameters representing 'space normal,' the MOST developed space-relevant patient models that mimic microgravity-induced changes in terrestrial physiology. These models are used in clinical scenarios that will medically train flight surgeons, biomedical flight controllers (biomedical engineers; BME) and, eventually, astronaut-crew medical officers (CMO).

An innovative approach to the development of a portable unit for analytical flame characterization in a microgravity environment

NASA Technical Reports Server (NTRS)

Dubinskiy, Mark A.; Kamal, Mohammed M.; Misra, Prabhaker

1995-01-01

The availability of manned laboratory facilities in space offers wonderful opportunities and challenges in microgravity combustion science and technology. In turn, the fundamentals of microgravity combustion science can be studied via spectroscopic characterization of free radicals generated in flames. The laser-induced fluorescence (LIF) technique is a noninvasive method of considerable utility in combustion physics and chemistry suitable for monitoring not only specific species and their kinetics, but it is also important for imaging of flames. This makes LIF one of the most important tools for microgravity combustion science. Flame characterization under microgravity conditions using LIF is expected to be more informative than other methods aimed at searching for effects like pumping phenomenon that can be modeled via ground level experiments. A primary goal of our work consisted in working out an innovative approach to devising an LIF-based analytical unit suitable for in-space flame characterization. It was decided to follow two approaches in tandem: (1) use the existing laboratory (non-portable) equipment and determine the optimal set of parameters for flames that can be used as analytical criteria for flame characterization under microgravity conditions; and (2) use state-of-the-art developments in laser technology and concentrate some effort in devising a layout for the portable analytical equipment. This paper presents an up-to-date summary of the results of our experiments aimed at the creation of the portable device for combustion studies in a microgravity environment, which is based on a portable UV tunable solid-state laser for excitation of free radicals normally present in flames in detectable amounts. A systematic approach has allowed us to make a convenient choice of species under investigation, as well as the proper tunable laser system, and also enabled us to carry out LIF experiments on free radicals using a solid-state laser tunable in the UV.

Nineteenth International Microgravity Measurements Group Meeting

NASA Technical Reports Server (NTRS)

DeLombard, Richard (Compiler)

2000-01-01

The Microgravity Measurements Group meetings provide a forum for an exchange of information and ideas about various aspects of microgravity acceleration research in international microgravity research programs. These meetings are sponsored by the PI Microgravity Services (PIMS) project at the NASA Glenn Research Center. The 19th MGMG meeting was held 11-13 July 2000 at the Sheraton Airport Hotel in Cleveland, Ohio. The 44 attendees represented NASA, other space agencies, universities, and commercial companies; 8 of the attendees were international representatives from Japan, Italy, Canada, Russia, and Germany. Twenty-seven presentations were made on a variety of microgravity environment topics including the International Space Station (ISS), acceleration measurement and analysis results, science effects from microgravity accelerations, vibration isolation, free flyer satellites, ground testing, vehicle characterization, and microgravity outreach and education. The meeting participants also toured three microgravity-related facilities at the NASA Glenn Research Center. Contained within the minutes is the conference agenda, which indicates each speaker, the title of their presentation, and the actual time of their presentation. The minutes also include the charts for each presentation, which indicate the authors' name(s) and affiliation. In some cases, a separate written report was submitted and has been Included here

Interphase Chromosome Conformation and Chromatin-Chromatin Interactions in Human Epithelial Cells Cultured Under Different Gravity Conditions

NASA Technical Reports Server (NTRS)

Zhang, Ye; Wong, Michael; Hada, Megumi; Wu, Honglu

2015-01-01

Microgravity has been shown to alter global gene expression patterns and protein levels both in cultured cells and animal models. It has been suggested that the packaging of chromatin fibers in the interphase nucleus is closely related to genome function, and the changes in transcriptional activity are tightly correlated with changes in chromatin folding. This study explores the changes of chromatin conformation and chromatin-chromatin interactions in the simulated microgravity environment, and investigates their correlation to the expression of genes located at different regions of the chromosome. To investigate the folding of chromatin in interphase under various culture conditions, human epithelial cells, fibroblasts, and lymphocytes were fixed in the G1 phase. Interphase chromosomes were hybridized with a multicolor banding in situ hybridization (mBAND) probe for chromosome 3 which distinguishes six regions of the chromosome as separate colors. After images were captured with a laser scanning confocal microscope, the 3-dimensional structure of interphase chromosome 3 was reconstructed at multi-mega base pair scale. In order to determine the effects of microgravity on chromosome conformation and orientation, measures such as distance between homologous pairs, relative orientation of chromosome arms about a shared midpoint, and orientation of arms within individual chromosomes were all considered as potentially impacted by simulated microgravity conditions. The studies revealed non-random folding of chromatin in interphase, and suggested an association of interphase chromatin folding with radiation-induced chromosome aberration hotspots. Interestingly, the distributions of genes with expression changes over chromosome 3 in cells cultured under microgravity environment are apparently clustered on specific loci and chromosomes. This data provides important insights into how mammalian cells respond to microgravity at molecular level.

Analysis of gene expression during parabolic flights reveals distinct early gravity responses in Arabidopsis roots.

PubMed

Aubry-Hivet, D; Nziengui, H; Rapp, K; Oliveira, O; Paponov, I A; Li, Y; Hauslage, J; Vagt, N; Braun, M; Ditengou, F A; Dovzhenko, A; Palme, K

2014-01-01

Plant roots are among most intensively studied biological systems in gravity research. Altered gravity induces asymmetric cell growth leading to root bending. Differential distribution of the phytohormone auxin underlies root responses to gravity, being coordinated by auxin efflux transporters from the PIN family. The objective of this study was to compare early transcriptomic changes in roots of Arabidopsis thaliana wild type, and pin2 and pin3 mutants under parabolic flight conditions and to correlate these changes to auxin distribution. Parabolic flights allow comparison of transient 1-g, hypergravity and microgravity effects in living organisms in parallel. We found common and mutation-related genes differentially expressed in response to transient microgravity phases. Gene ontology analysis of common genes revealed lipid metabolism, response to stress factors and light categories as primarily involved in response to transient microgravity phases, suggesting that fundamental reorganisation of metabolic pathways functions upstream of a further signal mediating hormonal network. Gene expression changes in roots lacking the columella-located PIN3 were stronger than in those deprived of the epidermis and cortex cell-specific PIN2. Moreover, repetitive exposure to microgravity/hypergravity and gravity/hypergravity flight phases induced an up-regulation of auxin responsive genes in wild type and pin2 roots, but not in pin3 roots, suggesting a critical function of PIN3 in mediating auxin fluxes in response to transient microgravity phases. Our study provides important insights towards understanding signal transduction processes in transient microgravity conditions by combining for the first time the parabolic flight platform with the transcriptome analysis of different genetic mutants in the model plant, Arabidopsis. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Wireless Drop Tower for Microgravity Demonstrations. Educational Brief.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

Microgravity-the absence or reduction of some of the effects of gravity-is an important attribute of free-fall. In microgravity (often incorrectly called zero-g), water no longer flows "downhill" and neither do smoke or steam bubbles rise. This changes a number of chemical and physical activities. Experiments in combustion, fluid behavior,…

Spinal Elongation and its Effects on Seated Height in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Rajulu, Sudhakar; Young, Karen

2009-01-01

Objectives: 1. To collect spinal elongation induced seated height data for subjects exposed to microgravity environments. 2. To provide information relating to the seated height rate of change over time for astronauts subjected to microgravity. We will collect: Seated Height measurement (ground & flight) and digital still photograph (ground and flight).

Microgravity Environment Description Handbook

NASA Technical Reports Server (NTRS)

DeLombard, Richard; McPherson, Kevin; Hrovat, Kenneth; Moskowitz, Milton; Rogers, Melissa J. B.; Reckart, Timothy

1997-01-01

The Microgravity Measurement and Analysis Project (MMAP) at the NASA Lewis Research Center (LeRC) manages the Space Acceleration Measurement System (SAMS) and the Orbital Acceleration Research Experiment (OARE) instruments to measure the microgravity environment on orbiting space laboratories. These laboratories include the Spacelab payloads on the shuttle, the SPACEHAB module on the shuttle, the middeck area of the shuttle, and Russia's Mir space station. Experiments are performed in these laboratories to investigate scientific principles in the near-absence of gravity. The microgravity environment desired for most experiments would have zero acceleration across all frequency bands or a true weightless condition. This is not possible due to the nature of spaceflight where there are numerous factors which introduce accelerations to the environment. This handbook presents an overview of the major microgravity environment disturbances of these laboratories. These disturbances are characterized by their source (where known), their magnitude, frequency and duration, and their effect on the microgravity environment. Each disturbance is characterized on a single page for ease in understanding the effect of a particular disturbance. The handbook also contains a brief description of each laboratory.

Behavior of stem cells under outer-space microgravity and ground-based microgravity simulation.

PubMed

Zhang, Cui; Li, Liang; Chen, Jianling; Wang, Jinfu

2015-06-01

With rapid development of space engineering, research on life sciences in space is being conducted extensively, especially cellular and molecular studies on space medicine. Stem cells, undifferentiated cells that can differentiate into specialized cells, are considered a key resource for regenerative medicine. Research on stem cells under conditions of microgravity during a space flight or a ground-based simulation has generated several excellent findings. To help readers understand the effects of outer space and ground-based simulation conditions on stem cells, we reviewed recent studies on the effects of microgravity (as an obvious environmental factor in space) on morphology, proliferation, migration, and differentiation of stem cells. © 2015 International Federation for Cell Biology.

The impact of simulated microgravity on purinergic signaling in an endothelial and smooth muscle cell co-culture model

NASA Astrophysics Data System (ADS)

Zhang, Yu; Hemmersbach, Ruth; Lau, Patrick; Pansky, Andreas; Kassack, Matthias; Tobiasch, Edda

Astronauts suffer from cardiovascular deconditioning when they are exposed to microgravity conditions during space missions. Thus, current research focuses on the identification of the underlying mechanism also with respect to therapy and countermeasures. Endothelial cells (ECs) and smooth muscle cells (SMCs) play a key role in a variety of vascular functions. Gene expression, cytoskeleton morphology and apoptosis in both, ECs and SMCs, have shown alterations under simulated and real microgravity condition. However, all these data were observed during single culturing of either ECs or SMCs under microgravity conditions, which is different from the in vivo situation. Purinergic 2 (P2) receptors bind extracellular nucleotides and can regulate the vascular tone and vascular cell proliferation, migration and apoptosis. In this study primary ECs and SMCs were obtained from bovine aorta and characterized using specific markers. Here we show for the first time that the P2-receptor expressions pattern in ECs and in SMCs is altered after 24h in simulated microgravity. Specific receptors are down- or up-regulated on the gene and protein level. In addition the supernatant of ECs during culture was used as conditioned medium for SMCs and vice visa to investigate the influence of either cell type on the other. ECs and SMCs secret cytokines which induce pathogenic proliferation and an altered migration behavior under simulated microgravity conditions. Interestingly, co-culturing with condition medium could compensate this change. In detail, P2X7 was down-regulated in ECs after 24h clinorotation but recovered to the 1 g level when cultured with conditioned medium from SMCs collected under normal gravity. In conclusion, our data indicate that the paracrine effect between ECs and SMCs is an important regulator of cell behavior, also under altered gravity conditions. P2-receptor gene and protein expression were altered during microgravity. Since several P2-receptor artificial ligands are already established as drugs, P2-receptors might be a reasonable candidate for drug development for astronaut treatment of vascular deconditioning in the future. Keywords: simulated microgravity, purinergic signaling, endothelial cells, smooth muscle cells, co-culture, clinostat

Toward Understanding Pore Formation And Mobility During Controlled Directional Solidification In A Microgravity Environment Investigation (PFMI)

NASA Technical Reports Server (NTRS)

Grugel, R. N.; Anilkumar, A.; Luz, P.; Jeter, L.; Volz, M. P.; Spivey, R.; Smith, G. A.; Curreri, Peter A. (Technical Monitor)

2002-01-01

The generation and inclusion of detrimental porosity, e.g., "pipes" and "rattails" can occur during controlled directional solidification processing. The origin of these defects is generally attributed to gas evolution and entrapment during solidification of the melt. On Earth, owing to buoyancy, an initiated bubble can rapidly rise through the liquid melt and "pop" at the surface; this is obviously not ensured in a low gravity or microgravity environment. Clearly, porosity generation and inclusion is detrimental to conducting any meaningful solidification-science studies in microgravity. Thus it is essential that model experiments be conducted in microgravity, to understand the details of the generation and mobility of porosity, so that methods can be found to eliminate it. In hindsight, this is particularly relevant given the results of the previous directional solidification experiments conducted in Space. The current International Space Station (ISS) Microgravity Science Glovebox (MSG) investigation addresses the central issue of porosity formation and mobility during controlled directional solidification processing in microgravity. The study will be done using a transparent metal-analogue material, succinonitrile (SCN) and succinonitrile-water "alloys", so that direct observation and recording of pore generation and mobility can be made during the experiments. Succinonitrile is particularly well suited for the proposed investigation because it is transparent, it solidifies in a manner analogous to most metals, it has a convenient melting point, its material properties are well characterized and, it has been successfully used in previous microgravity experiments. The PFMI experiment will be launched on the UF-2, STS-111 flight. Highlighting the porosity development problem in metal alloys during microgravity processing, the poster will describe: (i) the intent of the proposed experiments, (ii) the theoretical rationale behind using SCN as the study material for porosity generation and migration and, (iii) the experimental protocol for the investigation of the effects of the processing parameters. Photographs of the flight experimental hardware, and the novel sample ampoule, will be exhibited. The experimental apparatus will be described in detail and a summary of the scientific objectives will be presented.

Toward Understanding Pore Formation and Mobility during Controlled Directional Solidification in a Microgravity Environment Investigation (PFMI)

NASA Technical Reports Server (NTRS)

Grugel, Richard N.; Anilkumar, A. V.; Luz, Paul; Jeter, Linda; Volz, Martin P.; Spivey, Reggie; Smith, G.

2003-01-01

The generation and inclusion of detrimental porosity, e.g., pipes and rattails can occur during controlled directional solidification processing. The origin of these defects is generally attributed to gas evolution and entrapment during solidification of the melt. On Earth, owing to buoyancy, an initiated bubble can rapidly rise through the liquid melt and pop at the surface; this is obviously not ensured in a low gravity or microgravity environment. Clearly, porosity generation and inclusion is detrimental to conducting any meaningful solidification-science studies in microgravity. Thus it is essential that model experiments be conducted in microgravity, to understand the details of the generation and mobility of porosity, so that methods can be found to eliminate it. In hindsight, this is particularly relevant given the results of the previous directional solidification experiments conducted in Space. The current International Space Station (ISS) Microgravity Science Glovebox (MSG) investigation addresses the central issue of porosity formation and mobility during controlled directional solidification processing in microgravity. The study will be done using a transparent metal-analogue material, succinonitrile (SCN) and succinonitrile-water 'alloys', so that direct observation and recording of pore generation and mobility can be made during the experiments. Succinonitrile is particularly well suited for the proposed investigation because it is transparent, it solidifies in a manner analogous to most metals, it has a convenient melting point, its material properties are well characterized and, it has been successfully used in previous microgravity experiments. The PFMI experiment will be launched on the UF-2, STS-111 flight. Highlighting the porosity development problem in metal alloys during microgravity processing, the poster will describe: (i) the intent of the proposed experiments, (ii) the theoretical rationale behind using SCN as the study material for porosity generation and migration and, (iii) the experimental protocol for the investigation of the effects of the processing parameters. Photographs of the flight experimental hardware, and the novel sample ampoule, will be exhibited. The experimental apparatus will be described in detail and a summary of the scientific objectives will be presented.

Effect of microgravity simulation using 3D clinostat on cavendish banana (Musa acuminata AAA Group) ripening process

NASA Astrophysics Data System (ADS)

Dwivany, Fenny Martha; Esyanti, Rizkita R.; Prapaisie, Adeline; Puspa Kirana, Listya; Latief, Chunaeni; Ginaldi, Ari

2016-11-01

The objective of the research was to determine the effect of microgravity simulation by 3D clinostat on Cavendish banana (Musa acuminata AAA group) ripening process. In this study, physical, physiological changes as well as genes expression were analysed. The result showed that in microgravity simulation condition ripening process in banana was delayed and the MaACOl, MaACSl and MaACS5 gene expression were affected.

Effects and possible mechanisms of simulated-microgravity on zebrafish embryonic cell

NASA Astrophysics Data System (ADS)

Hang, Xiaoming; Sun, Yeqing; Wu, Di; Li, Yixiao; Wang, Ruonan

2016-07-01

Cellular level studies are helpful for revealing the underlying mechanisms of microgravity effects on living organisms. Many cell types, ranging from bacteria to mammalian cells, are sensitive to the microgravity environment. In this study, zebrafish embryonic cells (ZF4) were exposed to simulated-microgravity (SMG) for different times to investigate the effects and possible mechanisms of microgravity on fibroblasts. A significant arrest in G2/M phase was detected in ZF4 cells after 24 or 48 hour of SMG exposure, respectively. The mRNA levels of G2/M phase regulators cyclinB1 and cdc2 were significantly decreased, while wee1 was significantly increased. Additionally, CEP135, a core centrosome protein throughout the cell cycle, seems to play a key role in modulating this effect. Quantitative analysis showed that cep135 expression was significantly increased, while CEP135 protein expression level was significantly decreased two times after SMG. Further investigation demonstrated the transfection of dre-miR-22a, a miRNA for targeting cep135, also induced G2/M arrest in ZF4 cells. These results suggest that SMG induced G2/M arrest in ZF4 cells may due to the regulation of dre-miR-22a and its target cep135. Key Words: Simulated-microgravity; zebrafish embryonic cell; G2/M arrest; molecular mechanism

Flame spread over thick polymethylmethacrylate samples in a simulated and actual microgravity environment

NASA Astrophysics Data System (ADS)

Shah, Tirthesh Jayesh

The NASA Burning and Suppression of Solids-II (BASS II) experiment examines the combustion of different solid materials and material geometries in microgravity. While flames in microgravity are driven by diffusion and weak advection due to crew movements and ventilation, the current NASA spacecraft material selection test method (NASA-STD- 6001 Test 1) is driven by buoyant forces as gravity is present. The overall goal of this project is to understand the burning of intermediate and thick fuels in microgravity, and devise a normal gravity test to apply to future materials. Clear cast polymethylmethacrylate (PMMA) samples 10 cm long by 1 or 2 cm wide with thicknesses ranging from 1-5 mm were investigated. PMMA is the ideal choice since it is widely used and we know its stoichiometric chemistry. Tests included both one sided and two sided burns. Samples are ignited by heating a wire behind the sample. The samples are burned in a flow duct within the Microgravity Science Glovebox (MSG) on the International Space Station (ISS) to ensure true microgravity conditions. The experiment takes place in opposed flow with varying Oxygen concentrations and flow velocities. Flames are recorded on two cameras and later tracked to determine spread rate. Currently we are modeling combustion of PMMA using Fire Dynamics Simulator (FDS 5.5.3) and Smokeview. The entire modelling for BASS-II is done in DNS mode because of the laminar conditions and small domain. In DNS mode the Navier Stokes equations are solved without the Turbulence model. The model employs the same test sample and MSG geometry as the experiment; but in 2D. The experimental data gave upstream velocity at several points using an anemometer. A flow profile for the inlet velocity is obtained using Matlab and input into the model. The flame spread rates obtained after tracking are then compared with the experimental data and the results follow the trends but the spread rates are higher.

Effects of simulated microgravity on Streptococcus mutans physiology and biofilm structure.

PubMed

Cheng, Xingqun; Xu, Xin; Chen, Jing; Zhou, Xuedong; Cheng, Lei; Li, Mingyun; Li, Jiyao; Wang, Renke; Jia, Wenxiang; Li, Yu-Qing

2014-10-01

Long-term spaceflights will eventually become an inevitable occurrence. Previous studies have indicated that oral infectious diseases, including dental caries, were more prevalent in astronauts due to the effect of microgravity. However, the impact of the space environment, especially the microgravity environment, on the virulence factors of Streptococcus mutans, a major caries-associated bacterium, is yet to be explored. In the present study, we investigated the impact of simulated microgravity on the physiology and biofilm structure of S. mutans. We also explored the dual-species interaction between S. mutans and Streptococcus sanguinis under a simulated microgravity condition. Results indicated that the simulated microgravity condition can enhance the acid tolerance ability, modify the biofilm architecture and extracellular polysaccharide distribution of S. mutans, and increase the proportion of S. mutans within a dual-species biofilm, probably through the regulation of various gene expressions. We hypothesize that the enhanced competitiveness of S. mutans under simulated microgravity may cause a multispecies micro-ecological imbalance, which would result in the initiation of dental caries. Our current findings are consistent with previous studies, which revealed a higher astronaut-associated incidence of caries. Further research is required to explore the detailed mechanisms. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Terrestrial Microgravity Model and Threshold Gravity Simulation sing Magnetic Levitation

NASA Technical Reports Server (NTRS)

Ramachandran, N.

2005-01-01

What is the threshold gravity (minimum gravity level) required for the nominal functioning of the human system? What dosage is required? Do human cell lines behave differently in microgravity in response to an external stimulus? The critical need for such a gravity simulator is emphasized by recent experiments on human epithelial cells and lymphocytes on the Space Shuttle clearly showing that cell growth and function are markedly different from those observed terrestrially. Those differences are also dramatic between cells grown in space and those in Rotating Wall Vessels (RWV), or NASA bioreactor often used to simulate microgravity, indicating that although morphological growth patterns (three dimensional growth) can be successiblly simulated using RWVs, cell function performance is not reproduced - a critical difference. If cell function is dramatically affected by gravity off-loading, then cell response to stimuli such as radiation, stress, etc. can be very different from terrestrial cell lines. Yet, we have no good gravity simulator for use in study of these phenomena. This represents a profound shortcoming for countermeasures research. We postulate that we can use magnetic levitation of cells and tissue, through the use of strong magnetic fields and field gradients, as a terrestrial microgravity model to study human cells. Specific objectives of the research are: 1. To develop a tried, tested and benchmarked terrestrial microgravity model for cell culture studies; 2. Gravity threshold determination; 3. Dosage (magnitude and duration) of g-level required for nominal functioning of cells; 4. Comparisons of magnetic levitation model to other models such as RWV, hind limb suspension, etc. and 5. Cellular response to reduced gravity levels of Moon and Mars.

Changes in gravity inhibit lymphocyte locomotion through type I collagen

NASA Technical Reports Server (NTRS)

Pellis, N. R.; Goodwin, T. J.; Risin, D.; McIntyre, B. W.; Pizzini, R. P.; Cooper, D.; Baker, T. L.; Spaulding, G. F.

1997-01-01

Immunity relies on the circulation of lymphocytes through many different tissues including blood vessels, lymphatic channels, and lymphoid organs. The ability of lymphocytes to traverse the interstitium in both nonlymphoid and lymphoid tissues can be determined in vitro by assaying their capacity to locomote through Type I collagen. In an attempt to characterize potential causes of microgravity-induced immunosuppression, we investigated the effects of simulated microgravity on human lymphocyte function in vitro using a specialized rotating-wall vessel culture system developed at the Johnson Space Center. This very low shear culture system randomizes gravitational vectors and provides an in vitro approximation of microgravity. In the randomized gravity of the rotating-wall vessel culture system, peripheral blood lymphocytes did not locomote through Type I collagen, whereas static cultures supported normal movement. Although cells remained viable during the entire culture period, peripheral blood lymphocytes transferred to unit gravity (static culture) after 6 h in the rotating-wall vessel culture system were slow to recover and locomote into collagen matrix. After 72 h in the rotating-wall vessel culture system and an additional 72 h in static culture, peripheral blood lymphocytes did not recover their ability to locomote. Loss of locomotory activity in rotating-wall vessel cultures appears to be related to changes in the activation state of the lymphocytes and the expression of adhesion molecules. Culture in the rotating-wall vessel system blunted the ability of peripheral blood lymphocytes to respond to polyclonal activation with phytohemagglutinin. Locomotory response remained intact when peripheral blood lymphocytes were activated by anti-CD3 antibody and interleukin-2 prior to introduction into the rotating-wall vessel culture system. Thus, in addition to the systemic stress factors that may affect immunity, isolated lymphocytes respond to gravitational changes by ceasing locomotion through model interstitium. These in vitro investigations suggest that microgravity induces non-stress-related changes in cell function that may be critical to immunity. Preliminary analysis of locomotion in true microgravity revealed a substantial inhibition of cellular movement in Type I collagen. Thus, the rotating-wall vessel culture system provides a model for analyzing the microgravity-induced inhibition of lymphocyte locomotion and the investigation of the mechanisms related to lymphocyte movement.

Adrenergic Receptor Stimulation Prevents Radiation-Induced DNA Strand Breaks, Apoptosis and Gene Expression in Simulated Microgravity

NASA Technical Reports Server (NTRS)

Moreno-Villanueva, Maria; Krieger, Stephanie; Feiveson, Alan; Kovach, Annie Marie; Buerkle, Alexander; Wu, Honglu

2017-01-01

Under Earth gravity conditions cellular damage can be counteracted by activation of the physiological defense mechanisms or through medical interventions. The mode of action of both, physiological response and medical interventions can be affected by microgravity leading to failure in repairing the damage. There are many studies reporting the effects of microgravity and/or radiation on cellular functions. However, little is known about the synergistic effects on cellular response to radiation when other endogenous cellular stress-response pathways are previously activated. Here, we investigated whether previous stimulation of the adrenergic receptor, which modulates immune response, affects radiation-induced apoptosis in immune cells under simulated microgravity conditions. Peripheral blood mononuclear cells (PBMCs) were stimulated with isoproterenol (a sympathomimetic drug) and exposed to 0.8 or 2Gy gamma-radiation in simulated microgravity versus Earth gravity. Expression of genes involved in adrenergic receptor pathways, DNA repair and apoptosis as well as the number of apoptotic cells and DNA strand breaks were determined. Our results showed that, under simulated microgravity conditions, previous treatment with isoproterenol prevented radiation-induced i) gene down regulation, ii) DNA strand breaks formation and iii) apoptosis induction. Interestedly, we found a radiation-induced increase of adrenergic receptor gene expression, which was also abolished in simulated microgravity. Understanding the mechanisms of isoproterenol-mediated radioprotection in simulated microgravity can help to develop countermeasures for space-associated health risks as well as radio-sensitizers for cancer therapy.

Soot agglomeration in isolated, free droplet combustion

NASA Technical Reports Server (NTRS)

Choi, M. Y.; Dryer, F. L.; Green, G. J.; Sangiovanni, J. J.

1993-01-01

Under the conditions of an isolated, free droplet experiment, hollow, carbonaceous structures, called soot spheres, were observed to form during the atmospheric pressure, low Reynolds number combustion of 1-methylnaphthalene. These structures which are agglomerates composed of smaller spheroidal units result from both thermophoretic effects induced by the envelope flame surrounding each drop and aerodynamic effects caused by changes in the relative gas/drop velocities. A chemically reacting flow model was used to analyze the process of sootshell formation during microgravity droplet combustion. The time-dependent temperature and gas property field surrounding the droplet was determined, and the soot cloud location for microgravity combustion of n-heptane droplets was predicted. Experiments showed that the sooting propensity of n-alkane fuel droplets can be varied through diluent substitution, oxygen-index variations, and ambient pressure reductions.

The Response of wnt/ ß-Catenin Signaling Pathway in Osteocytes Under Simulated Microgravity

NASA Astrophysics Data System (ADS)

Yang, Xiao; Sun, Lian-Wen; Liang, Meng; Wang, Xiao-Nan; Fan, Yu-Bo

2015-11-01

Osteocytes were considered as potential sensors of mechanical loading and orchestrate the bone remodeling adapted to mechanical loading. On the other hand, osteocytes are also considered as the unloading sensors in vivo. Previous studies showed that the mechanosensation and mechanotransduction of osteocytes may play an essential role in mediating bone response to microgravity, and one of the most important molecular signaling pathway involved in the mechanotransduction is the Wnt/ ß-catenin signaling pathway. In order to investigate the effect of simulated microgravity on the Wnt/ ß-catenin signaling pathway in osteocytes, MLO-Y4 cells (an osteocyte-like cell line) were cultured under controlled rotation to simulate microgravity for 5 days. The cytoskeleton and ß-catenin nuclear translocation of MLO-Y4 cells were detected by laser scanning confocal microscope and the fluorescence intensity was quantified; the mRNA expressions of upstream and downstream key components in Wnt canonical signaling were detected with RT-PCR. Two regulators of the Wnt/ ß-catenin pathway, NMP4/CIZ and Smads, were also investigated by RT-PCR; finally the expression of Wnt target genes and Sost protein level were detected with the absence or presence of the Sclerostin antibody (Scl-AbI) under simulated microgravity. The results showed that under simulated microgravity, (1) F-actin filaments were disassembled and some short dendritic processes appeared at the cell periphery; (2) the gene expression of Wnt3a, Wnt5a, DKK1, CyclinD1, LEF-1 and CX43 in the simulated microgravity group were significantly lower whereas Wnt1 and Sost in the simulated microgravity group were significantly higher than the control group; (3) the gene and protein level of ß-catenin were reduced, and no ß-catenin nuclear translocation observed; (4) the gene expression of Smad1, Smad4 and Smad7 were significantly lower whereas NMP4/CIZ and Smad3 in the simulated microgravity were significantly higher than the control group; (5) Scl-AbI partially inhibited the down-regulation of simulated microgravity to Wnt target gene expression and Sclerostin protein expression. The results suggested that firstly the cytoskeleton was disturbed in MLO-Y4 by simulated microgravity; secondly the activity of Wnt/ ß-catenin signaling pathway was depressed, with the nuclear translocation of ß-catenin suppressed by simulated microgravity; thirdly the Wnt/ ß-catenin signaling pathway positive regulators (Smads) were decreased, while the negative regulator (NMP4/CIZ) was increased under simulated microgravity; finally Scl-AbI could partially restore the adverse effect of simulated microgravity to Wnt signaling. This study may help us to understand the mechanotransduction alteration of Wnt/ ß-catenin signaling pathway in osteocytes under simulated microgravity, and further may partly clarify the mechanism of microgravity-induced osteoporosis.

Terrestrial Microgravity Model and Threshold Gravity Simulation using Magnetic Levitation

NASA Technical Reports Server (NTRS)

Ramachandran, N.

2005-01-01

What is the threshold gravity (minimum gravity level) required for the nominal functioning of the human system? What dosage is required? Do human cell lines behave differently in microgravity in response to an external stimulus? The critical need for such a gravity simulator is emphasized by recent experiments on human epithelial cells and lymphocytes on the Space Shuttle clearly showing that cell growth and function are markedly different from those observed terrestrially. Those differences are also dramatic between cells grown in space and those in Rotating Wall Vessels (RWV), or NASA bioreactor often used to simulate microgravity, indicating that although morphological growth patterns (three dimensional growth) can be successfully simulated using RWVs, cell function performance is not reproduced - a critical difference. If cell function is dramatically affected by gravity off-loading, then cell response to stimuli such as radiation, stress, etc. can be very different from terrestrial cell lines. Yet, we have no good gravity simulator for use in study of these phenomena. This represents a profound shortcoming for countermeasures research. We postulate that we can use magnetic levitation of cells and tissue, through the use of strong magnetic fields and field gradients, as a terrestrial microgravity model to study human cells. Specific objectives of the research are: 1. To develop a tried, tested and benchmarked terrestrial microgravity model for cell culture studies; 2. Gravity threshold determination; 3. Dosage (magnitude and duration) of g-level required for nominal functioning of cells; 4. Comparisons of magnetic levitation model to other models such as RWV, hind limb suspension, etc. and 5. Cellular response to reduced gravity levels of Moon and Mars. The paper will discuss experiments md modeling work to date in support of this project.

Animal surgery in microgravity

NASA Technical Reports Server (NTRS)

Campbell, Mark R.; Billica, Roger D.; Johnston, Smith L., III

1993-01-01

Prototype hardware and procedures which could be applied to a surgical support system on SSF are realistically evaluated in microgravity using an animal model. Particular attention is given to the behavior of bleeding in a surgical scenario and techniques for hemostasis and fluid management.

Two-Fluid Models and Interfacial Area Transport in Microgravity Condition

NASA Technical Reports Server (NTRS)

Ishii, Mamoru; Sun, Xiao-Dong; Vasavada, Shilp

2004-01-01

The objective of the present study is to develop a two-fluid model formulation with interfacial area transport equation applicable for microgravity conditions. The new model is expected to make a leapfrog improvement by furnishing the constitutive relations for the interfacial interaction terms with the interfacial area transport equation, which can dynamically model the changes of the interfacial structures. In the first year of this three-year project supported by the U.S. NASA, Office of Biological and Physics Research, the primary focus is to design and construct a ground-based, microgravity two-phase flow simulation facility, in which two immiscible fluids with close density will be used. In predicting the two-phase flow behaviors in any two-phase flow system, the interfacial transfer terms are among the most essential factors in the modeling. These interfacial transfer terms in a two-fluid model specify the rate of phase change, momentum exchange, and energy transfer at the interface between the two phases. For the two-phase flow under the microgravity condition, the stability of the fluid particle interface and the interfacial structures are quite different from those under normal gravity condition. The flow structure may not reach an equilibrium condition and the two fluids may be loosely coupled such that the inertia terms of each fluid should be considered separately by use of the two-fluid model. Previous studies indicated that, unless phase-interaction terms are accurately modeled in the two-fluid model, the complex modeling does not necessarily warrant an accurate solution.

Acute effects of Dry Immersion on kinematic characteristics of postural corrective responses

NASA Astrophysics Data System (ADS)

Sayenko, D. G.; Miller, T. F.; Melnik, K. A.; Netreba, A. I.; Khusnutdinova, D. R.; Kitov, V. V.; Tomilovskaya, E. S.; Reschke, M. F.; Gerasimenko, Y. P.; Kozlovskaya, I. B.

2016-04-01

Impairments in balance control are inevitable following exposure to microgravity. However, the role of particular sensory system in postural disorders at different stages of the exposure to microgravity still remains unknown. We used a method called Dry Immersion (DI), as a ground-based model of microgravity, to elucidate the effects of 6-h of load-related afferent inputs on kinematic characteristics of postural corrective responses evoked by pushes to the chest of different intensities during upright standing. The structure of postural corrective responses was altered following exposure to DI, which was manifested by: (1) an increase of the ankle and knee flexion during perturbations of medium intensity, (2) the lack of the compensatory hip extension, as well as diminished knee and ankle flexion with a further increase of the perturbation intensity to submaximal level. We suggest that the lack of weight-bearing increases the reactivity of the balance control system, whereas the ability to scale the responses proportionally to the perturbation intensity decreases. Disrupted neuromuscular coordination of postural corrective responses following DI can be attributed to adaptive neural modifications on the spinal and cortical levels. The present study provides evidence that even a short-term lack of load-related afferent inputs alters kinematic patterns of postural corrective responses, and can result in decreased balance control. Because vestibular input is not primarily affected during the DI exposure, our results indicate that activity and the state of the load-related afferents play critical roles in balance control following real or simulated microgravity.

Emulation of Condensed Fuel Flames Using a Burning Rate Emulator (BRE) in Microgravity

NASA Technical Reports Server (NTRS)

Markan, A.; Quintiere, J. G.; Sunderland, P. B.; De Ris, J. L.; Stocker, D. P.

2017-01-01

The Burning Rate Emulator (BRE) is a gaseous fuel burner developed to emulate the burning of condensed phase fuels. The current study details several tests at the NASA Glenn 5-s drop facility to test the BRE technique in microgravity conditions. The tests are conducted for two burner diameters, 25 mm and 50 mm respectively, with methane and ethylene as the fuels. The ambient pressure, oxygen content and fuel flow rate are additional parameters. The microgravity results exhibit a nominally hemispherical flame with decelerating growth and quasi-steady heat flux after about 5 seconds. The BRE burner was evaluated with a transient analysis to assess the extent of steady-state achieved. The burning rate and flame height recorded at the end of the drop are correlated using two steady-state purely diffusive models. A higher burning rate for the bigger burner as compared to theory indicates the significance of gas radiation. The effect of the ambient pressure and oxygen concentration on the heat of gasification are also examined.

Simulation of Combustion Systems with Realistic g-Jitter

NASA Technical Reports Server (NTRS)

Mell, W. E.; McGrattan, K. B.; Nakamura, Y.; Baum, H. R.

2001-01-01

A number of facilities are available for microgravity combustion experiments: aircraft, drop towers, sounding rockets, the space shuttle, and, in the future, the International Space Station (ISS). Acceleration disturbances or g-jitter about the background level of reduced gravity exist in all these microgravity facilities. While g-jitter is routinely measured, a quantitative comparison of the quality of g-jitter among the different microgravity facilities, in terms of its affects on combustion experiments, has not been compiled. Low frequency g-jitter (< 1 Hz) has been repeatedly observed to disturb a number of combustion systems. Guidelines regarding tolerable levels of acceleration disturbances for combustion experiments have been developed for use in the design of ISS experiments. The validity of these guidelines, however, remains unknown. In this project a transient, 3-D numerical model is under development to simulate the effects of realistic g-jitter on a number of combustion systems. The measured acceleration vector or some representation of it can be used as input to the simulation.

Effect of microgravity on crystallization of ZBLAN fibers

NASA Technical Reports Server (NTRS)

Tucker, Dennis S.

1994-01-01

ZrF4-BaF2-LaF3-AIF3-NaF (ZBLAN) optical fiber was flown on board the NASA's KC-135 microgravity aircraft to determine the effects of microgravity on crystal growth in this material. Fiber samples were placed in evacuated quartz ampoules and heated to the crystallization temperature in 0g, 1g, and 2g. The 1g and 2g samples were observed to slump and crystallize. The 0g samples showed no evidence of crystallization.

Characterization of Microgravity Environment on Mir

NASA Technical Reports Server (NTRS)

Kim, Hyoung; Kaouk, Mohamed

2000-01-01

This paper presents the microgravity analysis results using dynamic response data collected during the first phase of the Mir Structural Dynamics Experiment (MiSDE). Although MiSDE was designed and performed to verify structural dynamic models, it also provided information for determining microgravity characteristics of the structure. This study analyzed ambient responses acquired during orbital day-to-night and night-to-day transitions, crew treadmill and ergometer exercises, and intentional crew activities. Acceleration levels for one-third octave bands were calculated to characterize the microgravity environment of the station. Spectrograms were also used to analyze the time transient nature of the responses. Detailed theoretical background and analysis results will also be included in the final draft.

Microgravity isolation system design: A modern control synthesis framework

NASA Technical Reports Server (NTRS)

Hampton, R. D.; Knospe, C. R.; Allaire, P. E.; Grodsinsky, C. M.

1994-01-01

Manned orbiters will require active vibration isolation for acceleration-sensitive microgravity science experiments. Since umbilicals are highly desirable or even indispensable for many experiments, and since their presence greatly affects the complexity of the isolation problem, they should be considered in control synthesis. In this paper a general framework is presented for applying extended H2 synthesis methods to the three-dimensional microgravity isolation problem. The methodology integrates control and state frequency weighting and input and output disturbance accommodation techniques into the basic H2 synthesis approach. The various system models needed for design and analysis are also presented. The paper concludes with a discussion of a general design philosophy for the microgravity vibration isolation problem.

Microgravity isolation system design: A modern control synthesis framework

NASA Technical Reports Server (NTRS)

Hampton, R. D.; Knospe, C. R.; Allaire, P. E.; Grodsinsky, C. M.

1994-01-01

Manned orbiters will require active vibration isolation for acceleration-sensitive microgravity science experiments. Since umbilicals are highly desirable or even indispensable for many experiments, and since their presence greatly affects the complexity of the isolation problem, they should be considered in control synthesis. A general framework is presented for applying extended H2 synthesis methods to the three-dimensional microgravity isolation problem. The methodology integrates control and state frequency weighting and input and output disturbance accommodation techniques into the basic H2 synthesis approach. The various system models needed for design and analysis are also presented. The paper concludes with a discussion of a general design philosophy for the microgravity vibration isolation problem.

Effect of Gravity Level on the Particle Shape and Size During Zeolite Crystal Growth

NASA Technical Reports Server (NTRS)

Song, Hong-Wei; Ilebusi, Olusegun J.; Sacco, Albert, Jr.

2003-01-01

A microscopic diffusion model is developed to represent solute transport in the boundary layer of a growing zeolite crystal. This model is used to describe the effect of gravity on particle shape and solute distribution. Particle dynamics and crystal growth kinetics serve as the boundary conditions of flow and convection-diffusion equations. A statistical rate theory is used to obtain the rate of solute transport across the growing interface, which is expressed in terms of concentration and velocity of solute species. Microgravity can significantly decrease the solute velocity across the growing interface compared to its earth-based counterpart. The extent of this reduction highly depends on solute diffusion constant in solution. Under gravity, the flow towards the crystal enhances solute transport rate across the growing interface while the flow away from crystals reduces this rate, suggesting a non-uniform growth rate and thus an elliptic final shape. However, microgravity can significantly reduce the influence of flow and obtain a final product with perfect spherical shape. The model predictions compare favorably with the data of space experiment of zeolites grown in space.

Sounding Rocket Microgravity Experiments Elucidating Diffusive and Radiative Transport Effects on Flame Spread over Thermally-Thick Solids

NASA Technical Reports Server (NTRS)

Olson, Sandra L.; Hegde, U.; Bhattacharjee, S.; Deering, J. L.; Tang, L.; Altenkirch, R. A.

2003-01-01

A series of 6-minute microgravity combustion experiments of opposed flow flame spread over thermally-thick PMMA has been conducted to extend data previously reported at high opposed flows to almost two decades lower in flow. The effect of flow velocity on flame spread shows a square root power law dependence rather than the linear dependence predicted by thermal theory. The experiments demonstrate that opposed flow flame spread is viable to very low velocities and more robust than expected from the numerical model, which predicts that at very low velocities (less than 5 centimeters per second), flame spread rates fall off more rapidly as flow is reduced. It is hypothesized that the enhanced flame spread observed in the experiments may be due to three- dimensional hydrodynamic effects, which are not included in the zero-gravity, two-dimensional hydrodynamic model. The effect of external irradiation was found to be more complex that the model predicted over the 0-2 Watts per square centimeter range. In the experiments, the flame compensated for the increased irradiation by stabilizing farther from the surface. A surface energy balance reveals that the imposed flux was at least partially offset by a reduced conductive flux from the increased standoff distance, so that the effect on flame spread was weaker than anticipated.

Effect Of Low External Flow On Flame Spreading Over ETFE Insulated Wire Under Microgravity

NASA Technical Reports Server (NTRS)

Nishizawa, Katsuhiro; Fujita, Osamu; Ito, Kenichi; Kikuchi, Masao; Olson, Sandra L.; Kashiwagi, Takashi

2003-01-01

Fire safety is one of the most important issues for manned space missions. A likely cause of fires in spacecraft is wire insulation combustion in electrical system. Regarding the wire insulation combustion it important to know the effect of low external flow on the combustion because of the presence of ventilation flow in spacecraft. Although, there are many researches on flame spreading over solid material at low external flows under microgravity, research dealing with wire insulation is very limited. An example of wire insulation combustion in microgravity is the Space Shuttle experiments carried out by Greenberg et al. However, the number of experiments was very limited. Therefore, the effect of low flow velocity is still not clear. The authors have reported results on flame spreading over ETFE (ethylene - tetrafluoroetylene) insulated wire in a quiescent atmosphere in microgravity by 10 seconds drop tower. The authors also performed experiments of polyethylene insulated nichrom wire combustion in low flow velocity under microgravity. The results suggested that flame spread rate had maximum value in low flow velocity condition. Another interesting issue is the effect of dilution gas, especially CO2, which is used for fire extinguisher in ISS. There are some researches working on dilution gas effect on flame spreading over solid material in quiescent atmosphere in microgravity. However the research with low external flow is limited and, of course, the research discussing a relation of the appearance of maximum wire flammability in low flow velocity region with different dilution gas cannot be found yet. The present paper, therefore, investigates the effect of opposed flow with different dilution gas on flame spreading over ETFE insulated wire and change in the presence of the maximum flammability depending on the dilution gas type is discussed within the limit of microgravity time given by ground-based facility.

Material research in microgravity

NASA Technical Reports Server (NTRS)

Langbein, D.

1984-01-01

A popular discussion is given of microgravity effects in engineering and medicine gained from Skylab experience. Areas covered include crystal growing, liquid surface properties, diffusion, ferromagnetism, and emulsions.

The Microgravity Vibration Isolation Mount: A Dynamic Model for Optimal Controller Design

NASA Technical Reports Server (NTRS)

Hampton, R. David; Tryggvason, Bjarni V.; DeCarufel, Jean; Townsend, Miles A.; Wagar, William O.

1997-01-01

Vibration acceleration levels on large space platforms exceed the requirements of many space experiments. The Microgravity Vibration Isolation Mount (MIM) was built by the Canadian Space Agency to attenuate these disturbances to acceptable levels, and has been operational on the Russian Space Station Mir since May 1996. It has demonstrated good isolation performance and has supported several materials science experiments. The MIM uses Lorentz (voice-coil) magnetic actuators to levitate and isolate payloads at the individual experiment/sub-experiment (versus rack) level. Payload acceleration, relative position, and relative orientation (Euler-parameter) measurements are fed to a state-space controller. The controller, in turn, determines the actuator currents needed for effective experiment isolation. This paper presents the development of an algebraic, state-space model of the MIM, in a form suitable for optimal controller design.

Glovebox Integrated Microgravity Isolation Technology (g-LIMIT): A Linearized State-Space Model

NASA Technical Reports Server (NTRS)

Hampton, R. David; Calhoun, Philip C.; Whorton, Mark S.

2001-01-01

Vibration acceleration levels on large space platforms exceed the requirements of many space experiments. The Glovebox Integrated Microgravity Isolation Technology (g-LIMIT) is being built by the NASA Marshall Space Flight Center to attenuate these disturbances to acceptable levels. G-LIMIT uses Lorentz (voice-coil) magnetic actuators to levitate and isolate payloads at the individual experiment/sub-experiment (versus rack) level. Payload acceleration, relative position, and relative orientation measurements are fed to a state-space controller. The controller, in turn, determines the actuator Currents needed for effective experiment isolation. This paper presents the development of an algebraic, state-space model of g-LIMIT, in a form suitable for optimal controller design. The equations are first derived using Newton's Second Law directly, then simplified to a linear form for the purpose of controller design.

Microgravity

NASA Image and Video Library

2001-01-24

Advanced finite element models are used to study three-dimensional, time-dependent flow and segregation in crystal growth systems. In this image of a prototypical model for melt and crystal growth, pathlines at one instant in time are shown for the flow of heated liquid silicon in a cylindrical container. The container is subjected to g-jitter disturbances along the vertical axis. A transverse magnetic field is applied to control them. Such computations are extremely powerful for understanding melt growth in microgravity where g-jitter drives buoyant flows. The simulation is part of the Theoretical Analysis of 3D, Transient Convection and Segregation in Microgravity Bridgman Crystal Growth investigation by Dr. Jeffrey J. Derby of the University of Mirnesota, Minneapolis.

Microgravity crystal growth

NASA Technical Reports Server (NTRS)

2001-01-01

Advanced finite element models are used to study three-dimensional, time-dependent flow and segregation in crystal growth systems. In this image of a prototypical model for melt and crystal growth, pathlines at one instant in time are shown for the flow of heated liquid silicon in a cylindrical container. The container is subjected to g-jitter disturbances along the vertical axis. A transverse magnetic field is applied to control them. Such computations are extremely powerful for understanding melt growth in microgravity where g-jitter drives buoyant flows. The simulation is part of the Theoretical Analysis of 3D, Transient Convection and Segregation in Microgravity Bridgman Crystal Growth investigation by Dr. Jeffrey J. Derby of the University of Mirnesota, Minneapolis.

DARTFire Sees Microgravity Fires in a New Light--Large Data Base of Images Obtained

NASA Technical Reports Server (NTRS)

Olson, Sandra L.; Hegde, Uday; Altenkirch, Robert A.; Bhatacharjee, Subrata

1999-01-01

The recently completed DARTFire sounding rocket microgravity combustion experiment launched a new era in the imaging of flames in microgravity. DARTFire stands for "Diffusive and Radiative Transport in Fires," which perfectly describes the two primary variables--diffusive flow and radiation effects--that were studied in the four launches of this program (June 1996 to September 1997). During each launch, two experiments, which were conducted simultaneously during the 6 min of microgravity, obtained results as the rocket briefly exited the Earth s atmosphere.

Gender differences in organ density in a rat simulated microgravity model

NASA Astrophysics Data System (ADS)

Pettis, Christopher Ryan; Witten, Mark Lee

2004-01-01

Research investigating the physiological effects of microgravity on the human body has demonstrated a shift of body fluids in actual spaceflight and in simulated Earth-based microgravity models in both males and females, possibly causing many deleterious physiological effects. Twenty-five anatomically normal female (NF) and 20 ovariectomized (OE) Fischer 344 rats were randomly selected to be in an experimental ( 1 h of 45° head-down tilt, 45HDT) or control ( 1 h of prone position) group. At the end of the hour experimental period, the density of the brain, lungs, heart, liver, and left and right kidneys were measured using spiral computed tomography (SCT) while the rats remained in their experimental positions. A sub-group of OE rats ( N=6) was administered estrogen replacement therapy on a daily basis ( 5 μg/kg body weight, s.c.) for 4 days and then underwent 1 h of 45HDT and SCT analysis at one day, 2 days, and 5 days to determine if estrogen replacement therapy would alter organ densities. Our data demonstrate that 1 h of 45HDT produced significant increases ( p<0.05) in the organ densities of the brain, liver, left kidney, and lung of the OE female group compared to their prone controls. However, only the brain density was significantly increased in the NF group. Estrogen replacement therapy caused a significant decrease in brain organ density at the 5 day time point compared to the 24 h time point. We conclude that estrogen plays a role in fluid distribution in a rat 45HDT model.

Lung volumes during sustained microgravity on Spacelab SLS-1

NASA Technical Reports Server (NTRS)

Elliott, Ann R.; Prisk, G. Kim; Guy, Harold J. B.; West, John B.

1994-01-01

Gravity is known to influence the mechanical behavior of the lung and chest wall. However, the effect of sustained microgravity (microgravity) on lung volumes has not been reported. Pulmonary function tests were performed by four subjects before, during, and after 9 days of microgravity exposure. Ground measurements were made in standing and supine postures. Tests were performed using a bag-in-box-and-flowmeter system and a respiratory mass spectrometer. Measurements included functional residual capacity (FRC), expiratory reserve volume (ERV), residual volume (RV), inspiratory and expiratory vital capacities (IVC and EVC), and tidal volume (V9sub T)). Total lung capacity (TLC) was derived from the measured EVC and RV values. With preflight standing values as a comparison, FRC was significantly reduced by 15% (approximately 500 ml) in microgravity and 32% in the supine posture. ERV was reduced by 10 - 20% in microgravity and decreased by 64% in the supine posture. RV was significantly reduced by 18% (310 ml) in microgravity but did not significantly change in the supine posture compared with standing. IVC and EVC were slightly reduced during the first 24 h of microgravity but returned to 1-G standing values within 72 h of microgravity exposure. IVC and EVC in the supine posture were significantly reduced by 12% compared with standing. During microgravity, V(sub T) decreased by 15% (approximately 90 ml), but supine V(sub T) was unchanged compared with preflight standing values. TLC decreased by approximately 8% during microgravity and in the supine posture compared with preflight standing. The reductions in FRC, ERV, and RV during microgravity are probably due to the cranial shift of the diaphragm, an increase in intrathoracic blood volume, and more uniform alveolar expansion.

Strategic Research to Enable NASA's Exploration Missions Conference

NASA Technical Reports Server (NTRS)

Nahra, Henry (Compiler)

2004-01-01

Abstracts are presented from a conference sponsored by the NASA Office of Biological and Physical Research and hosted by NASA Glenn Research Center and the National Center for Microgravity Research on Fluids and Combustion, held in Cleveland, Ohio, June 22-23, 2004. Topics pertained to the behavior of processes and materials in microgravity as well as physiological-biological studies and microgravity effects.

Effects of Gravity on Ignition and Combustion Characteristics of Externally Heated Polyethylene Film

NASA Astrophysics Data System (ADS)

Ikeda, Mitsumasa

2018-04-01

The objective of this research is to investigate the effects of gravity on the ignition and the combustion characteristics of the Polyethylene (PE) film by outer heating. Combustion experiments of PE film were carried out in a normal gravity field and the microgravity field. In the microgravity experiments, it was carried out in 50 m-class drop facility. Here it can be realized 10- 4G microgravity field in about 2.5-3.0 second. The PE film is heated by the inserted high-temperature chamber. In the experiments, the PE was used film type. The chamber temperature was fixed at 900 K and 1000 K. In the case of microgravity field, the ignition delay period has become about 50 percent shorter than that in the case of the normal gravitational field. In the normal gravity field, since the PE surface layer is cooled by natural convection, the ignition delay period is considered to be longer than that in the microgravity field. The combustion time in the normal gravity was about 0.8 sec. In the microgravity field, the combustion time was more than 2 sec, and it could not be measured during the free fall period.

Gravitational Role in Liquid Phase Sintering

NASA Technical Reports Server (NTRS)

Upadhyaya, Anish; Iacocca, Ronald G.; German, Randall M.

1998-01-01

To comprehensively understand the gravitational effects on the evolution of both the microstructure and the macrostructure during liquid phase sintering, W-Ni-Fe alloys with W content varying from 35 to 98 wt.% were sintered in microgravity. Compositions that slump during ground-based sintering also distort when sintered under microgravity. In ground-based sintering, low solid content alloys distort with a typical elephant-foot profile, while in microgravity, the compacts tend to spheroidize. This study shows that microstructural segregation occurs in both ground-based as well as microgravity sintering. In ground-based experiments, because of the density difference between the solid and the liquid phase, the solid content increases from top to the bottom of the sample. In microgravity, the solid content increases from periphery to the center of the samples. This study also shows that the pores during microgravity sintering act as a stable phase and attain anomalous shapes.

Bubble dynamics, two-phase flow, and boiling heat transfer in a microgravity environment

NASA Technical Reports Server (NTRS)

Chung, Jacob N.

1994-01-01

The two-phase bubbly flow and boiling heat transfer in microgravity represents a substantial challenge to scientists and engineers and yet there is an urgent need to seek fundamental understanding in this area for future spacecraft design and space missions. At Washington State University, we have successfully designed, built and tested a 2.1 second drop tower with an innovation airbag deceleration system. Microgravity boiling experiments performed in our 0.6 second Drop Tower produced data flow visualizations that agree with published results and also provide some new understanding concerning flow boiling and microgravity bubble behavior. On the analytical and numerical work, the edge effects of finite divergent electrode plates on the forces experienced by bubbles were investigated. Boiling in a concentric cylinder microgravity and an electric field was numerically predicted. We also completed a feasibility study for microgravity boiling in an acoustic field.

Effects of Gravity, Microgravity or Microgravity Simulation on Early Mammalian Development.

PubMed

Ruden, Douglas M; Bolnick, Alan; Awonuga, Awoniyi; Abdulhasan, Mohammed; Perez, Gloria; Puscheck, Elizabeth E; Rappolee, Daniel A

2018-06-11

Plant and animal life forms evolved mechanisms for sensing and responding to gravity on Earth where homeostatic needs require responses. The lack of gravity, such as in the International Space Station (ISS), causes acute, intra-generational changes in the quality of life. These include maintaining calcium levels in bone, maintaining muscle tone, and disturbances in the vestibular apparatus in the ears. These problems decrease work efficiency and quality of life of humans not only during microgravity exposures but also after return to higher gravity on Earth or destinations such as Mars or the Moon. It has been hypothesized that lack of gravity during mammalian development may cause prenatal, postnatal and transgenerational effects that conflict with the environment, especially if the developing organism and its progeny are returned, or introduced de novo, into the varied gravity environments mentioned above. Although chicken and frog pregastrulation development, and plant root development, have profound effects due to orientation of cues by gravity-sensing mechanisms and responses, mammalian development is not typically characterized as gravity-sensing. Although no effects of microgravity simulation (MGS) on mouse fertilization were observed in two reports, negative effects of MGS on early mammalian development after fertilization and before gastrulation are presented in four reports that vary with the modality of MGS. This review will analyze the positive and negative mammalian early developmental outcomes, and enzymatic and epigenetic mechanisms known to mediate developmental responses to simulated microgravity on Earth and microgravity during spaceflight experiments. We will update experimental techniques that have already been developed or need to be developed for zero gravity molecular, cellular, and developmental biology experiments.

Proceedings of the Twentieth International Microgravity Measurements Group Meeting

NASA Technical Reports Server (NTRS)

DeLombard, Richard (Compiler)

2001-01-01

The International Microgravity Measurements Group annual meetings provide a forum for an exchange of information and ideas about various aspects of microgravity acceleration research in international microgravity research programs. These meetings are sponsored by the PI Microgravity Services (PIMS) project at the NASA Glenn Research Center. The twentieth MGMG meeting was held 7-9 August 2001 at the Hilton Garden Inn Hotel in Cleveland, Ohio. The 35 attendees represented NASA, other space agencies, universities, and commercial companies; eight of the attendees were international representatives from Canada, Germany, Italy, Japan, and Russia. Seventeen presentations were made on a variety of microgravity environment topics including the International Space Station (ISS), acceleration measurement and analysis results, science effects from microgravity accelerations, vibration isolation, free flyer satellites, ground testing, and microgravity outreach. Two working sessions were included in which a demonstration of ISS acceleration data processing and analyses were performed with audience participation. Contained within the minutes is the conference agenda which indicates each speaker, the title of their presentation, and the actual time of their presentation. The minutes also include the charts for each presentation which indicate the author's name(s) and affiliation. In some cases, a separate written report was submitted and has been included here.

Antibody binding in altered gravity: implications for immunosorbent assay during space flight

NASA Technical Reports Server (NTRS)

Maule, Jake; Fogel, Marilyn; Steele, Andrew; Wainwright, Norman; Pierson, Duane L.; McKay, David S.

2003-01-01

A single antibody-incubation step of an indirect, enzyme-linked immunosorbent assay (ELISA) was performed during microgravity, Martian gravity (0.38 G) and hypergravity (1.8 G) phases of parabolic flight, onboard the NASA KC-135 aircraft. Antibody-antigen binding occurred within 15 seconds; the level of binding did not differ between microgravity, Martian gravity and 1 G (Earth's gravity) conditions. During hypergravity and 1 G, antibody binding was directly proportional to the fluid volume (per microtiter well) used for incubation; this pattern was not observed during microgravity. These effects in microgravity may be due to "fluid spread" within the chamber (observed during microgravity with digital photography), leading to greater fluid-surface contact and subsequently antibody-antigen contact. In summary, these results demonstrate that: i) ELISA antibody-incubation and washing steps can be successfully performed by human operators during microgravity, Martian gravity and hypergravity; ii) there is no significant difference in antibody binding between microgravity, Martian gravity and 1 G conditions; and iii) a smaller fluid volume/well (and therefore less antibody) was required for a given level of binding during microgravity. These conclusions indicate that reduced gravity would not present a barrier to successful operation of immunosorbent assays during spaceflight.

Numerical Modeling of HgCdTe Solidification: Effects of Phase Diagram, Double-Diffusion Convection and Microgravity Level

NASA Technical Reports Server (NTRS)

Bune, Andris V.; Gillies, Donald C.; Lehoczky, Sandor L.

1997-01-01

Melt convection, along with species diffusion and segregation on the solidification interface are the primary factors responsible for species redistribution during HgCdTe crystal growth from the melt. As no direct information about convection velocity is available, numerical modeling is a logical approach to estimate convection. Furthermore influence of microgravity level, double-diffusion and material properties should be taken into account. In the present study, HgCdTe is considered as a binary alloy with melting temperature available from a phase diagram. The numerical model of convection and solidification of binary alloy is based on the general equations of heat and mass transfer in two-dimensional region. Mathematical modeling of binary alloy solidification is still a challenging numericial problem. A Rigorous mathematical approach to this problem is available only when convection is not considered at all. The proposed numerical model was developed using the finite element code FIDAP. In the present study, the numerical model is used to consider thermal, solutal convection and a double diffusion source of mass transport.

Modeled microgravity-induced protein kinase C isoform expression in human lymphocytes

NASA Technical Reports Server (NTRS)

Sundaresan, A.; Risin, D.; Pellis, N. R.

2004-01-01

In long-term space travel, the crew is exposed to microgravity and radiation that invoke potential hazards to the immune system. T cell activation is a critical step in the immune response. Receptor-mediated signaling is inhibited in both microgravity and modeled microgravity (MMG) as reflected by diminished DNA synthesis in peripheral blood lymphocytes and their locomotion through gelled type I collagen. Direct activation of protein kinase C (PKC) bypassing cell surface events using the phorbol ester PMA rescues MMG-inhibited lymphocyte activation and locomotion, whereas the calcium ionophore ionomycin had no rescue effect. Thus calcium-independent PKC isoforms may be affected in MMG-induced locomotion inhibition and rescue. Both calcium-dependent isoforms and calcium-independent PKC isoforms were investigated to assess their expression in lymphocytes in 1 g and MMG culture. Human lymphocytes were cultured and harvested at 24, 48, 72, and 96 h, and serial samples were assessed for locomotion by using type I collagen and expression of PKC isoforms. Expression of PKC-alpha, -delta, and -epsilon was assessed by RT-PCR, flow cytometry, and immunoblotting. Results indicated that PKC isoforms delta and epsilon were downregulated by >50% at the transcriptional and translational levels in MMG-cultured lymphocytes compared with 1-g controls. Events upstream of PKC, such as phosphorylation of phospholipase Cgamma in MMG, revealed accumulation of inactive enzyme. Depressed calcium-independent PKC isoforms may be a consequence of an upstream lesion in the signal transduction pathway. The differential response among calcium-dependent and calcium-independent isoforms may actually result from MMG intrusion events earlier than PKC, but after ligand-receptor interaction.

Boiling Experiment Facility for Heat Transfer Studies in Microgravity

NASA Technical Reports Server (NTRS)

Delombard, Richard; McQuillen, John; Chao, David

2008-01-01

Pool boiling in microgravity is an area of both scientific and practical interest. By conducting tests in microgravity, it is possible to assess the effect of buoyancy on the overall boiling process and assess the relative magnitude of effects with regards to other "forces" and phenomena such as Marangoni forces, liquid momentum forces, and microlayer evaporation. The Boiling eXperiment Facility is now being built for the Microgravity Science Glovebox that will use normal perfluorohexane as a test fluid to extend the range of test conditions to include longer test durations and less liquid subcooling. Two experiments, the Microheater Array Boiling Experiment and the Nucleate Pool Boiling eXperiment will use the Boiling eXperiment Facility. The objectives of these studies are to determine the differences in local boiling heat transfer mechanisms in microgravity and normal gravity from nucleate boiling, through critical heat flux and into the transition boiling regime and to examine the bubble nucleation, growth, departure and coalescence processes. Custom-designed heaters will be utilized to achieve these objectives.

Smoldering Combustion Experiments in Microgravity

NASA Technical Reports Server (NTRS)

Walther, David C.; Fernandez-Pello, A. Carlos; Urban, David L.

1997-01-01

The Microgravity Smoldering Combustion (MSC) experiment is part of a study of the smolder characteristics of porous combustible materials in a microgravity environment. Smoldering is a non-flaming form of combustion that takes place in the interior of porous materials and takes place in a number of processes ranging from smoldering of porous insulation materials to high temperature synthesis of metals. The objective of the study is to provide a better understanding of the controlling mechanisms of smolder, both in microgravity and normal-gravity. As with many forms of combustion, gravity affects the availability of oxidizer and transport of heat, and therefore the rate of combustion. Microgravity smolder experiments, in both a quiescent oxidizing environment, and in a forced oxidizing flow have been conducted aboard the NASA Space Shuttle (STS-69 and STS-77 missions) to determine the effect of the ambient oxygen concentration and oxidizer forced flow velocity on smolder combustion in microgravity. The experimental apparatus is contained within the NASA Get Away Special Canister (GAS-CAN) Payload. These two sets of experiments investigate the propagation of smolder along the polyurethane foam sample under both diffusion driven and forced flow driven smoldering. The results of the microgravity experiments are compared with identical ones carried out in normal gravity, and are used to verify present theories of smolder combustion. The results of this study will provide new insights into the smoldering combustion process. Thermocouple histories show that the microgravity smolder reaction temperatures (Ts) and propagation velocities (Us) lie between those of identical normal-gravity upward and downward tests. These observations indicate the effect of buoyancy on the transport of oxidizer to the reaction front.

Quantitative Measurement of Oxygen in Microgravity Combustion

NASA Technical Reports Server (NTRS)

Silver, Joel A.

1997-01-01

A low-gravity environment, in space or in ground-based facilities such as drop towers, provides a unique setting for studying combustion mechanisms. Understanding the physical phenomena controlling the ignition and spread of flames in microgravity has importance for space safety as well as for better characterization of dynamical and chemical combustion processes which are normally masked by buoyancy and other gravity-related effects. Due to restrictions associated with performing measurements in reduced gravity, diagnostic methods which have been applied to microgravity combustion studies have generally been limited to capture of flame emissions on film or video, laser Schlieren imaging and (intrusive) temperature measurements using thermocouples. Given the development of detailed theoretical models, more sophisticated diagnostic methods are needed to provide the kind of quantitative data necessary to characterize the properties of microgravity combustion processes as well as provide accurate feedback to improve the predictive capabilities of the models. When the demands of space flight are considered, the need for improved diagnostic systems which are rugged, compact, reliable, and operate at low power becomes apparent. The objective of this research is twofold. First, we want to develop a better understanding of the relative roles of diffusion and reaction of oxygen in microgravity combustion. As the primary oxidizer species, oxygen plays a major role in controlling the observed properties of flames, including flame front speed (in solid or liquid flames), extinguishment characteristics, flame size and flame temperature. The second objective is to develop better diagnostics based on diode laser absorption which can be of real value in both microgravity combustion research and as a sensor on-board Spacelab as either an air quality monitor or as part of a fire detection system. In our prior microgravity work, an eight line-of-sight fiber optic system measured water vapor mole fractions in the NASA Lewis 2.2-sec Drop Tower. In that system, the laser and all electronics resided at the top of the drop tower and was connected via a fiber optic cable to the rig, on which a 'pitch and catch' set of fiber collimating lenses were used to transmit the laser beam across a jet diffusion flame. This system required eight independent detection/demodulation units and had poor spatial resolution. This research builds on this earlier work, resulting in an improved capability for quantitative, nonintrusive measurement of major combustion species. A vertical cavity surface-emitting diode laser (VCSEL) and a continuous spatial scanning method permit the measurement of temporal and spatial profiles of the concentrations and temperatures of molecular oxygen. High detection sensitivity is achieved with wavelength modulation spectroscopy (WMS). One-g experiments are performed using a slot diffusion flame. Microgravity measurements on a solid fuel (cellulose sheet) system are planned for the NASA Lewis 2.2-second Drop Tower Facility.

Locomotion in Lymphocytes is Altered by Differential PKC Isoform Expression

NASA Technical Reports Server (NTRS)

Sundaresan, A.; Risin, D.; Pellis, N. R.

1999-01-01

Lymphocyte locomotion is critical for proper elicitation of the immune response. Locomotion of immune cells via the interstitium is essential for optimal immune function during wound healing, inflammation and infection. There are conditions which alter lymphocyte locomotion and one of them is spaceflight. Lymphocyte locomotion is severely inhibited in true spaceflight (true microgravity) and in rotating wall vessel culture (modeled microgravity). When lymphocytes are activated prior to culture in modeled microgravity, locomotion is not inhibited and the levels are comparable to those of static cultured lymphocytes. When a phorbol ester (PMA) is used in modeled microgravity, lymphocyte locomotion is restored by 87%. This occurs regardless if PMA is added after culture in the rotating wall vessel or during culture. Inhibition of DNA synthesis also does not alter restoration of lymphocyte locomotion by PMA. PMA is a direct activator of (protein kinase C) PKC . When a calcium ionophore, ionomycin is used it does not possess any restorative properties towards locomotion either alone or collectively with PMA. Since PMA brings about restoration without help from calcium ionophores (ionomycin), it is infer-red that calcium independent PKC isoforms are involved. Changes were perceived in the protein levels of PKC 6 where levels of the protein were downregulated at 24,72 and 96 hours in untreated rotated cultures (modeled microgravity) compared to untreated static (1g) cultures. At 48 hours there is an increase in the levels of PKC & in the same experimental set up. Studies on transcriptional and translational patterns of calcium independent isoforms of PKC such as 8 and E are presented in this study.

Physical Vapor Transport of Mercurous Chloride Crystals: Design of a Microgravity Experiment

NASA Technical Reports Server (NTRS)

Duval, W, M. B.; Singh, N. B.; Glicksman, M. E.

1997-01-01

Flow field characteristics predicted from a computational model show that the dynamical state of the flow, for practical crystal growth conditions of mercurous chloride, can range from steady to unsteady. Evidence that the flow field can be strongly dominated by convection for ground-based conditions is provided by the prediction of asymmetric velocity profiles bv the model which show reasonable agreement with laser Doppler velocimetry experiments in both magnitude and planform. Unsteady flow is shown to be correlated with a degradation of crystal quality as quantified by light scattering pattern measurements, A microgravity experiment is designed to show that an experiment performed with parameters which yield an unsteady flow becomes steady (diffusive-advective) in a microgravity environment of 10(exp -3) g(sub 0) as predicted by the model, and hence yields crystals with optimal quality.

Effects of Simulated Microgravity on a Host-Pathogen System

NASA Technical Reports Server (NTRS)

Gilbert, Rachel; Lo, Rachel; Bhattacharya, Sharmila

2017-01-01

While it has been shown that decades of astronauts and cosmonauts can suffer from illnesses both during and after spaceflight, the underlying causes are still poorly understood, due in part to the fact that there are so many variables to consider when investigating the human immune system in a complex environment. Invertebrates have become popular models for studying human disease because they are cheap, highly amenable to experimental manipulation, and have innate immune systems with a high genetic similarity to humans. Fruit flies (Drosophila melanogaster) have been shown to experience a dramatic shift in immune gene expression following spaceflight, but are still able to fight off infections when exposed to bacteria. However, the common bacterial pathogen Serratia marcescens was shown to become more lethal to fruit flies after being cultured in space, suggesting that not only do we need to consider host changes in susceptibility, but also changes in the pathogen itself after spaceflight conditions. Being able to simulate spaceflight conditions in a controlled environment on the ground gives us the ability to not only evaluate the effects of microgravity on the host immune system, but also how the microorganisms that cause immune disorders are being affected by these drastic environmental shifts. In this study, I use a ground-based simulated microgravity environment to examine the genetic changes associated with increased S. marcescens virulence in order to understand how microgravity is affecting this pathogen, as well as how these genetic changes influence and interact with the host immune system. This study will provide us with more directed approaches to studying the effects of spaceflight on human beings, with the ultimate goal of being able to counteract immune dysfunction in future space exploration.

Experiments and Model Development for the Investigation of Sooting and Radiation Effects in Microgravity Droplet Combustion

NASA Technical Reports Server (NTRS)

Choi, Mun Young; Yozgatligil, Ahmet; Dryer, Frederick L.; Kazakov, Andrei; Dobashi, Ritsu

2001-01-01

Today, despite efforts to develop and utilize natural gas and renewable energy sources, nearly 97% of the energy used for transportation is derived from combustion of liquid fuels, principally derived from petroleum. While society continues to rely on liquid petroleum-based fuels as a major energy source in spite of their finite supply, it is of paramount importance to maximize the efficiency and minimize the environmental impact of the devices that burn these fuels. The development of improved energy conversion systems, having higher efficiencies and lower emissions, is central to meeting both local and regional air quality standards. This development requires improvements in computational design tools for applied energy conversion systems, which in turn requires more robust sub-model components for combustion chemistry, transport, energy transport (including radiation), and pollutant emissions (soot formation and burnout). The study of isolated droplet burning as a unidimensional, time dependent model diffusion flame system facilitates extensions of these mechanisms to include fuel molecular sizes and pollutants typical of conventional and alternative liquid fuels used in the transportation sector. Because of the simplified geometry, sub-model components from the most detailed to those reduced to sizes compatible for use in multi-dimensional, time dependent applied models can be developed, compared and validated against experimental diffusion flame processes, and tested against one another. Based on observations in microgravity experiments on droplet combustion, it appears that the formation and lingering presence of soot within the fuel-rich region of isolated droplets can modify the burning rate, flame structure and extinction, soot aerosol properties, and the effective thermophysical properties. These observations led to the belief that perhaps one of the most important outstanding contributions of microgravity droplet combustion is the observation that in the absence of asymmetrical forced and natural convection, a soot shell is formed between the droplet surface and the flame, exerting an influence on the droplet combustion response far greater than previously recognized. The effects of soot on droplet burning parameters, including burning rate, soot shell dynamics, flame structure, and extinction phenomena provide significant testing parameters for studying the structure and coupling of soot models with other sub-model components.

Increased efficiency of mammalian somatic cell hybrid production under microgravity conditions during ballistic rocket flight

NASA Technical Reports Server (NTRS)

Schnettler, R.; Gessner, P.; Zimmermann, U.; Neil, G. A.; Urnovitz, H. B.

1989-01-01

The electrofusion of hybridoma cell lines under short-duration microgravity during a flight of the TEXUS 18 Black Brand ballistic sounding rocket at Kiruna, Sweden is reported. The fusion partners, growth medium, cell fusion medium, cell fusion, cell viability in the fusion medium, and postfusion cell culture are described, and the rocket, cell fusion chamber, apparatus, and module are examined. The experimental timeline, the effects of fusion medium and incubation time on cell viability and hybrid yields, and the effect of microgravity on hybrid yields are considered.

Health maintenance facility: Dental equipment requirements

NASA Technical Reports Server (NTRS)

Young, John; Gosbee, John; Billica, Roger

1991-01-01

The objectives were to test the effectiveness of the Health Maintenance Facility (HMF) dental suction/particle containment system, which controls fluids and debris generated during simulated dental treatment, in microgravity; to test the effectiveness of fiber optic intraoral lighting systems in microgravity, while simulating dental treatment; and to evaluate the operation and function of off-the-shelf dental handheld instruments, namely a portable dental hand drill and temporary filling material, in microgravity. A description of test procedures, including test set-up, flight equipment, and the data acquisition system, is given.

Motor function in microgravity: movement in weightlessness

NASA Technical Reports Server (NTRS)

Lackner, J. R.; DiZio, P.

1996-01-01

Microgravity provides unique, though experimentally challenging, opportunities to study motor control. A traditional research focus has been the effects of linear acceleration on vestibular responses to angular acceleration. Evidence is accumulating that the high-frequency vestibulo-ocular reflex (VOR) is not affected by transitions from a 1 g linear force field to microgravity (<1 g); however, it appears that the three-dimensional organization of the VOR is dependent on gravitoinertial force levels. Some of the observed effects of microgravity on head and arm movement control appear to depend on the previously undetected inputs of cervical and brachial proprioception, which change almost immediately in response to alterations in background force levels. Recent studies of post-flight disturbances of posture and locomotion are revealing sensorimotor mechanisms that adjust over periods ranging from hours to weeks.

Fluid and electrolyte control in simulated and actual spaceflight

NASA Technical Reports Server (NTRS)

Leach, C. S.; Johnson, P. C., Jr.

1985-01-01

Effects of microgravity on body fluid distribution and electrolyte and hormonal levels of astronauts have been studied since the early manned space missions. Bedrested subjects have been used as controls to separate effects of microgravity from those of hypokinesia. These investigations have led to documentation of the physiological effects of spaceflight and to a unified theory of response to microgravity. During flight, crewmembers have decreased thirst and a net loss of body water, sodium, and potassium. These changes seem to be initiated by passive transfer of extracellular fluid resulting in increased central venous pressure (CVP), to which the homeostatic mechanisms respond. A new equilibrium state is maintained during flight; it does not change in response to negative calcium and nitrogen balances during flight. On reexposure to gravity, profound water and salt retention occurs to replete extracellular fluid. Attempts to avoid cardiac deconditioning by repleting water and salt before leaving microgravity have somewhat ameliorated postural hypotension but have had little effect on CVP, cardiac chamber size or electrolyte dynamics.

Flammability Aspects of a Cotton-Fiberglass Fabric in Opposed and Concurrent Airflow in Microgravity

NASA Technical Reports Server (NTRS)

Ferkul, Paul V.; Olson, Sandra; Johnston, Michael C.; T'ien, James

2012-01-01

Microgravity combustion tests burning fabric samples were performed aboard the International Space Station. The cotton-fiberglass blend samples were mounted inside a small wind tunnel which could impose air flow speeds up to 40 cm/s. The wind tunnel was installed in the Microgravity Science Glovebox which supplied power, imaging, and a level of containment. The effects of air flow speed on flame appearance, flame growth, and spread rates were determined in both the opposed and concurrent flow configuration. For the opposed flow configuration, the flame quickly reached steady spread for each flow speed, and the spread rate was fastest at an intermediate value of flow speed. These tests show the enhanced flammability in microgravity for this geometry, since, in normal gravity air, a flame self-extinguishes in the opposed flow geometry (downward flame spread). In the concurrent flow configuration, flame size grew with time during the tests. A limiting length and steady spread rate were obtained only in low flow speeds ( 10 cm/s) for the short-length samples that fit in the small wind tunnel. For these conditions, flame spread rate increased linearly with increasing flow. This is the first time that detailed transient flame growth data was obtained in purely forced flows in microgravity. In addition, by decreasing flow speed to a very low value (around 1 cm/s), quenching extinction was observed. The valuable results from these long-duration experiments validate a number of theoretical predictions and also provide the data for a transient flame growth model under development.

Laser-Induced Incandescence in Microgravity

NASA Technical Reports Server (NTRS)

VanderWal, Randall L.

1997-01-01

Microgravity offers unique opportunities for studying both soot growth and the effect of soot radiation upon flame structure and spread. LII has been characterized and developed at NASA-Lewis for soot volume fraction determination in a wide range of 1-g combustion applications. Reported here are the first demonstrations of LII performed in a microgravity environment. Examples are shown for laminar and turbulent gas-jet diffusion flames in 0-g.

Lung volumes during sustained microgravity on Spacelab SLS-1

NASA Technical Reports Server (NTRS)

Elliott, Ann R.; Prisk, Gordon Kim; Guy, Harold J. B.; West, John B.

1994-01-01

Gravity is known to influence the topographical gradients of pulmonary ventilation, perfusion, and pleural pressures. The effect of sustained microgravity on lung volumes has not previously been investigated. Pulmonary function tests were performed by four subjects before, during, and after 9 days of microgravity exposure. Ground measurements were made in standing and supine postures. Tests were performed using a bag-in-box and flowmeter system and a respiratory mass spectrometer. Measurements of tidal volume (V(sub T)), expiratory reserve volume (ERV), inspiratory and expiratory vital capacities (IVC, EVC), functional residual capacity (FRC), and residual volume (RV) were made. During microgravity, V(sub T) decreased by 15%. IVC and EVC were slightly reduced during the first 24 hrs of microgravity and returned to 1 g standing values within 72 hrs after the onset of microgravity. FRC was reduced by 15% and ERV decreased by 10-20%. RV was significantly reduced by 18%. The reductions in FRC, ERV, and V(sub T) during microgravity are probably due to the cranial shift of the diaphragm and an increase in intrathoracic blood volume.

Effect of Dietary Countermeasures and Impact of Gravity on Renal Calculi Size Distributions Predicted by PBE-System and PBE-CFD Models

NASA Technical Reports Server (NTRS)

Kassemi, M.; Thompson, D.; Goodenow, D.; Gokoglu, S.; Myers, J.

2016-01-01

Renal stone disease is not only a concern on earth but can conceivably pose a serious risk to the astronauts health and safety in Space. In this work, two different deterministic models based on a Population Balance Equation (PBE) analysis of renal stone formation are developed to assess the risks of critical renal stone incidence for astronauts during space travel. In the first model, the nephron is treated as a continuous mixed suspension mixed product removal crystallizer and the PBE for the nucleating, growing and agglomerating renal calculi is coupled to speciation calculations performed by JESS. Predictions of stone size distributions in the kidney using this model indicate that the astronaut in microgravity is at noticeably greater but still subcritical risk and recommend administration of citrate and augmented hydration as effective means of minimizing and containing this risk. In the second model, the PBE analysis is coupled to a Computational Fluid Dynamics (CFD) model for flow of urine and transport of Calcium and Oxalate in the nephron to predict the impact of gravity on the stone size distributions. Results presented for realistic 3D tubule and collecting duct geometries, clearly indicate that agglomeration is the primary mode of size enhancement in both 1g and microgravity. 3D numerical simulations seem to further indicate that there will be an increased number of smaller stones developed in microgravity that will likely pass through the nephron in the absence of wall adhesion. However, upon reentry to a 1g (Earth) or 38g (Mars) partial gravitational fields, the renal calculi can lag behind the urinary flow in tubules that are adversely oriented with respect to the gravitational field and grow agglomerate to large sizes that are sedimented near the wall with increased propensity for wall adhesion, plaque formation, and risk to the astronauts.

Microgravity-driven remodeling of the proteome reveals insights into molecular mechanisms and signal networks involved in response to the space flight environment.

PubMed

Rea, Giuseppina; Cristofaro, Francesco; Pani, Giuseppe; Pascucci, Barbara; Ghuge, Sandip A; Corsetto, Paola Antonia; Imbriani, Marcello; Visai, Livia; Rizzo, Angela M

2016-03-30

Space is a hostile environment characterized by high vacuum, extreme temperatures, meteoroids, space debris, ionospheric plasma, microgravity and space radiation, which all represent risks for human health. A deep understanding of the biological consequences of exposure to the space environment is required to design efficient countermeasures to minimize their negative impact on human health. Recently, proteomic approaches have received a significant amount of attention in the effort to further study microgravity-induced physiological changes. In this review, we summarize the current knowledge about the effects of microgravity on microorganisms (in particular Cupriavidus metallidurans CH34, Bacillus cereus and Rhodospirillum rubrum S1H), plants (whole plants, organs, and cell cultures), mammalian cells (endothelial cells, bone cells, chondrocytes, muscle cells, thyroid cancer cells, immune system cells) and animals (invertebrates, vertebrates and mammals). Herein, we describe their proteome's response to microgravity, focusing on proteomic discoveries and their future potential applications in space research. Space experiments and operational flight experience have identified detrimental effects on human health and performance because of exposure to weightlessness, even when currently available countermeasures are implemented. Many experimental tools and methods have been developed to study microgravity induced physiological changes. Recently, genomic and proteomic approaches have received a significant amount of attention. This review summarizes the recent research studies of the proteome response to microgravity inmicroorganisms, plants, mammalians cells and animals. Current proteomic tools allow large-scale, high-throughput analyses for the detection, identification, and functional investigation of all proteomes. Understanding gene and/or protein expression is the key to unlocking the mechanisms behind microgravity-induced problems and to finding effective countermeasures to spaceflight-induced alterations but also for the study of diseases on earth. Future perspectives are also highlighted. Copyright © 2015 Elsevier B.V. All rights reserved.

An assessment of the microgravity and acoustic environments in Space Station Freedom using VAPEPS

NASA Technical Reports Server (NTRS)

Bergen, Thomas F.; Scharton, Terry D.; Badilla, Gloria A.

1992-01-01

The Vibroacoustic Payload Environment Prediction System (VAPEPS) was used to predict the stationary on-orbit environments in one of the Space Station Freedom modules. The model of the module included the outer structure, equipment and payload racks, avionics, and cabin air and duct systems. Acoustic and vibratory outputs of various source classes were derived and input to the model. Initial results of analyses, performed in one-third octave frequency bands from 10 to 10,000 Hz, show that both the microgravity and acoustic environments will be exceeded in some one-third octave bands with the current SSF design. Further analyses indicate that interior acoustic level requirements will be exceeded even if the microgravity requirements are met.

Microgravitational effects on chromosome behavior (7-IML-1)

NASA Technical Reports Server (NTRS)

Bruschi, Carlo

1992-01-01

The effects of the two major space-related conditions, microgravity and radiation, on the maintenance and transmission of genetic information have been partially documented in many organisms. Specifically, microgravity acts at the chromosomal level, primarily on the structure and segregation of chromosomes, in producing major abberations such as deletions, breaks, nondisjunction, and chromosome loss, and to a lesser degree, cosmic radiation appears to affect the genic level, producing point mutations and DNA damage. To distinguish between the effects from microgravity and from radiation, it is necessary to monitor both mitotic and meiotic genetic damage in the same organism. The yeast Saccharomyces cerevisiae is used to monitor at high resolution the frequency of chromosome loss, nondisjunction, intergenic recombination, and gene mutation in mitotic and meiotic cells, to a degree impossible in other organisms. Because the yeast chromosomes are small, sensitive measurements can be made that can be extrapolated to higher organisms and man. The objectives of the research are: (1) to quantitate the effects of microgravity and its synergism with cosmic radiation on chromosomal integrity and transmission during mitosis and meiosis; (2) to discriminate between chromosomal processes sensitive to microgravity and/or radiation during mitosis and meiosis; and (3) to relate these findings to anomalous mitotic mating type switching and ascosporogenesis following meiosis.

Intestinal microbiota contributes to colonic epithelial changes in simulated microgravity mouse model.

PubMed

Shi, Junxiu; Wang, Yifan; He, Jian; Li, Pingping; Jin, Rong; Wang, Ke; Xu, Xi; Hao, Jie; Zhang, Yan; Liu, Hongju; Chen, Xiaoping; Wu, Hounan; Ge, Qing

2017-08-01

Exposure to microgravity leads to alterations in multiple systems, but microgravity-related changes in the gastrointestinal tract and its clinical significance have not been well studied. We used the hindlimb unloading (HU) mouse model to simulate a microgravity condition and investigated the changes in intestinal microbiota and colonic epithelial cells. Compared with ground-based controls (Ctrls), HU affected fecal microbiota composition with a profile that was characterized by the expansion of Firmicutes and decrease of Bacteroidetes. The colon epithelium of HU mice showed decreased goblet cell numbers, reduced epithelial cell turnover, and decreased expression of genes that are involved in defense and inflammatory responses. As a result, increased susceptibility to dextran sulfate sodium-induced epithelial injury was observed in HU mice. Cohousing of Ctrl mice with HU mice resulted in HU-like epithelial changes in Ctrl mice. Transplantation of feces from Ctrl to HU mice alleviated these epithelial changes in HU mice. Results indicate that HU changes intestinal microbiota, which leads to altered colonic epithelial cell homeostasis, impaired barrier function, and increased susceptibility to colitis. We further demonstrate that alteration in gastrointestinal motility may contribute to HU-associated dysbiosis. These animal results emphasize the necessity of evaluating astronauts' intestinal homeostasis during distant space travel.-Shi, J., Wang, Y., He, J., Li, P., Jin, R., Wang, K., Xu, X., Hao, J., Zhang, Y., Liu, H., Chen, X., Wu, H., Ge, Q. Intestinal microbiota contributes to colonic epithelial changes in simulated microgravity mouse model. © FASEB.

Investigation of Mechanisms Associated with Nucleate Boiling Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Dhir, Vijay K.

1996-01-01

The focus of the present work is to experimentally study and to analytically/numerically model the mechanisms of growth of bubbles attached to, and sliding along, a heated surface. To control the location of the active cavities, the number, the spacing, and the nucleation superheat, artificial cavities will be formed on silicon wafers. In order to study the effect of magnitude of components of gravitational acceleration acting parallel to, and normal to the surface, experiments will be conducted on surfaces inclined at different angles including a downward facing surface. Information on the temperature field around bubbles, bubble shape and size, and bubble induced liquid velocities will be obtained through the use of holography, video/high speed photography and hydrogen bubble techniques, respectively. Analytical/numerical models will be developed to describe the heat transfer including that through the micro-macro layer underneath and around a bubble. In the micro layer model capillary and disjoining pressures will be included. Evolution of the interface along with induced liquid motion will be modelled. Subsequent to the world at normal gravity, experiments will be conducted in the KC-135 or the Lear jet especially to learn about bubble growth/detachment under low gravity conditions. Finally, an experiment will be defined to be conducted under long duration of microgravity conditions in the space shuttle. The experiment in the space shuttle will provide microgravity data on bubble growth and detachment and will lead to a validation of the nucleate boiling heat transfer model developed from the preceding studies performed at normal and low gravity (KC-135 or Lear jet) conditions.

Use of microgravity bioreactors for development of an in vitro rat salivary gland cell culture model

NASA Technical Reports Server (NTRS)

Lewis, M. L.; Moriarity, D. M.; Campbell, P. S.

1993-01-01

During development, salivary gland (SG) cells both secrete factors which modulate cellular behavior and express specific hormone receptors. Whether SG cell growth is modulated by an autocrine epidermal growth factor (EGF) receptor-mediated signal transduction pathway is not clearly understood. SG tissue is the synthesis site for functionally distinct products including growth factors, digestive enzymes, and homeostasis maintaining factors. Historically, SG cells have proven difficult to grow and may be only maintained as limited three-dimensional ductal-type structures in collagen gels or on reconstituted basement membrane gels. A novel approach to establishing primary rat SG cultures is use of microgravity bioreactors originally designed by NASA as low-shear culture systems for predicting cell growth and differentiation in the microgravity environment of space. These completely fluid-filled bioreactors, which are oriented horizontally and rotate, have proven advantageous for Earth-based culture of three-dimensional cell assemblies, tissue-like aggregates, and glandular structures. Use of microgravity bioreactors for establishing in vitro models to investigate steroid-mediated secretion of EGF by normal SG cells may also prove useful for the investigation of cancer and other salivary gland disorders. These microgravity bioreactors promise challenging opportunities for future applications in basic and applied cell research.

Containerless solidification of BiFeO3 oxide under microgravity

NASA Astrophysics Data System (ADS)

Yu, Jianding; Arai, Yasutomo; Koshikawa, Naokiyo; Ishikawa, Takehito; Yoda, Shinichi

1999-07-01

Containerless solidification of BiFeO3 oxide has been carried out under microgravity with Electrostatic Levitation Furnace (ELF) aboard on the sounding rocket (TR-IA). It is a first containerless experiment using ELF under microgravity for studying the solidification of oxide insulator material. Spherical BiFeO3 sample with diameter of 5mm was heated by two lasers in oxygen and nitrogen mixing atmosphere, and the sample position by electrostatic force under pinpoint model and free drift model. In order to compare the solidification behavior in microgravity with on ground, solidification experiments of BiFeO3 in crucible and drop tube were carried out. In crucible experiment, it was very difficult to get single BiFeO3 phase, because segregation of Fe2O3 occured very fast and easily. In drop tube experiment, fine homogeneous BiFeO3 microstructure was obtained in a droplet about 300 μm. It implies that containerless processing can promote the phase selection in solidification. In microgravity experiment, because the heating temperature was lower than that of estimated, the sample was heated into Fe2O3+liquid phase region. Fe2O3 single crystal grew on the surface of the spherical sample, whose sample was clearly different from that observed in ground experiments.

An update to space biomedical research: tissue engineering in microgravity bioreactors.

PubMed

Barzegari, Abolfazl; Saei, Amir Ata

2012-01-01

The severe need for constructing replacement tissues in organ transplanta-tion has necessitated the development of tissue engineering approaches and bioreactors that can bring these approaches to reality. The inherent limitations of conventional bioreactors in generating realistic tissue constructs led to the devise of the microgravity tissue engineering that uses Rotating Wall Vessel (RWV) bioreactors initially developed by NASA. In this review article, we intend to highlight some major advances and accomplishments in the rapidly-growing field of tissue engineering that could not be achieved without using microgravity. Research is now focused on assembly of 3 dimensional (3D) tissue fragments from various cell types in human body such as chon-drocytes, osteoblasts, embryonic and mesenchymal stem cells, hepatocytes and pancreas islet cells. Hepatocytes cultured under microgravity are now being used in extracorporeal bioartificial liver devices. Tissue constructs can be used not only in organ replacement therapy, but also in pharmaco-toxicology and food safety assessment. 3D models of vari-ous cancers may be used in studying cancer development and biology or in high-throughput screening of anticancer drug candidates. Finally, 3D heterogeneous assemblies from cancer/immune cells provide models for immunotherapy of cancer. Tissue engineering in (simulated) microgravity has been one of the stunning impacts of space research on biomedical sciences and their applications on earth.

Time-dependent Computational Studies of Premixed Flames in Microgravity

NASA Technical Reports Server (NTRS)

Kailasanath, K.; Patnaik, Gopal; Oran, Elaine S.

1993-01-01

This report describes the research performed at the Center for Reactive Flow and Dynamical Systems in the Laboratory for Computational Physics and Fluid Dynamics, at the Naval Research Laboratory, in support of NASA Microgravity Science and Applications Program. The primary focus of this research is on investigating fundamental questions concerning the propagation and extinction of premixed flames in earth gravity and in microgravity environments. Our approach is to use detailed time-dependent, multispecies, numerical models as tools to simulate flames in different gravity environments. The models include a detailed chemical kinetics mechanism consisting of elementary reactions among the eight reactive species involved in hydrogen combustion, coupled to algorithms for convection, thermal conduction, viscosity, molecular and thermal diffusion, and external forces. The external force, gravity, can be put in any direction relative to flame propagation and can have a range of values. Recently more advanced wall boundary conditions such as isothermal and no-slip have been added to the model. This enables the simulation of flames propagating in more practical systems than before. We have used the numerical simulations to investigate the effects of heat losses and buoyancy forces on the structure and stability of flames, to help resolve fundamental questions on the existence of flammability limits when there are no external losses or buoyancy forces in the system, to understand the interaction between the various processes leading to flame instabilities and extinguishment, and to study the dynamics of cell formation and splitting. Our studies have been able to bring out the differences between upward- and downward-propagating flames and predict the zero-gravity behavior of these flames. The simulations have also highlighted the dominant role of wall heat losses in the case of downward-propagating flames. The simulations have been able to qualitatively predict the formation of multiple cells and the cessation of cell-splitting. Our studies have also shown that some flames in a microgravity environment can be extinguished due to a chemical instability and without any external losses. However, further simulations are needed to more completely understand upward-propagating and zero-gravity flames as well as to understand the potential effect of radiative heat losses.

BASS-II Hardware Repair

NASA Image and Video Library

2014-03-27

ISS039-E-005726 (27 March 2014) --- Expedition 39 Flight Engineer Rick Mastracchio performs inflight maintenance on an experiment called Burning and Suppression of Solids (BASS)-II. The investigation examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The BASS-II experiment will guide strategies for materials flammability screening for use in spacecraft as well as provide valuable data on solid fuel burning behavior in microgravity. BASS-II results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

Cassidy conducts BASS Experiment Test Operations

NASA Image and Video Library

2013-04-05

ISS035-E-015081 (5 April 2013) --- Astronaut Chris Cassidy, Expedition 35 flight engineer, conducts a session of the Burning and Suppression of Solids (BASS) experiment onboard the Earth-orbiting International Space Station. Following a series of preparations, Cassidy conducted a run of the experiment, which examined the burning and extinction characteristics of a wide variety of fuel samples in microgravity and will guide strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

BASS-II Experiment

NASA Image and Video Library

2014-08-02

Image taken on card 8 during BASS-II flame test session with reduced O2 partial pressure. Session conducted on GMT 213. The Burning and Suppression of Solids - II (BASS-II) investigation examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The BASS-II experiment will guide strategies for materials flammability screening for use in spacecraft as well as provide valuable data on solid fuel burning behavior in microgravity. BASS-II results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

Acceleration Environment of the International Space Station

NASA Technical Reports Server (NTRS)

McPherson, Kevin; Kelly, Eric; Keller, Jennifer

2009-01-01

Measurement of the microgravity acceleration environment on the International Space Station has been accomplished by two accelerometer systems since 2001. The Microgravity Acceleration Measurement System records the quasi-steady microgravity environment, including the influences of aerodynamic drag, vehicle rotation, and venting effects. Measurement of the vibratory/transient regime, comprised of vehicle, crew, and equipment disturbances, has been accomplished by the Space Acceleration Measurement System-II. Until the arrival of the Columbus Orbital Facility and the Japanese Experiment Module, the location of these sensors, and therefore, the measurement of the microgravity acceleration environment, has been limited to within the United States Laboratory. Japanese Aerospace Exploration Agency has developed a vibratory acceleration measurement system called the Microgravity Measurement Apparatus which will be deployed within the Japanese Experiment Module to make distributed measurements of the Japanese Experiment Module's vibratory acceleration environment. Two Space Acceleration Measurement System sensors from the United States Laboratory will be re-deployed to support vibratory acceleration data measurement within the Columbus Orbital Facility. The additional measurement opportunities resulting from the arrival of these new laboratories allows Principal Investigators with facilities located in these International Space Station research laboratories to obtain microgravity acceleration data in support of their sensitive experiments. The Principal Investigator Microgravity Services project, at NASA Glenn Research Center, in Cleveland, Ohio, has supported acceleration measurement systems and the microgravity scientific community through the processing, characterization, distribution, and archival of the microgravity acceleration data obtained from the International Space Station acceleration measurement systems. This paper summarizes the PIMS capabilities available to the International Space Station scientific community, introduces plans for extending microgravity analysis results to the newly arrived scientific laboratories, and provides summary information for known microgravity environment disturbers.

Clinical Aspects of the Control of Plasma Volume at Microgravity and During Return to One Gravity

NASA Technical Reports Server (NTRS)

Convertino, Victor A.

1995-01-01

Plasma volume is reduced by 10%-20% within 24 to 48 h of exposure to simulated or actual microgravity. The clinical importance of microgravity-induced hypovolemia is manifested by its relationship with orthostatic intolerance and reduced VO2max after return to one gravity (1G). Since there is no evidence to suggest plasma volume reduction during microgravity is associated with thirst or renal dysfunctions, a diuresis induced by an immediate blood volume shift to the central circulation appears responsible for microgravity-induced hypovolemia. Since most astronauts choose to restrict their fluid intake before a space mission, absence of increased urine output during actual spaceflight may be explained by low central venous pressure (CVP) which accompanies dehydration. Compelling evidence suggests that prolonged reduction in CVP during exposure to microgravity reflects a 'resetting' to a lower operating point which acts to limit plasma volume expansion during attempts to increase fluid intake. In groudbase and spaceflight experiments, successful restoration and maintenance of plasma volume prior to returning to an upright posture may depend upon development of treatments that can return CVP to its baseline 10 operating point. Fluid-loading and LBNP have not proved completely effective in restoring plasma volume, suggesting that they may not provide the stimulus to elevate the CVP operating point. On the other, exercise, which can chronically increase CVP, has been effective in expanding plasma volume when combined with adequate dietary intake of fluid and electrolytes. The success of designing experiments to understand the physiological mechanisms of and development of effective countermeasures for the control of plasma volume in microgravity and during return to one gravity will depend upon testing that can be conducted under standardized controlled baseline condi

Lysozyme

NASA Technical Reports Server (NTRS)

2004-01-01

Protein isolated from hen egg-white and functions as a bacteriostatic enzyme by degrading bacterial cell walls. First enzyme ever characterized by protein crystallography. It is used as an excellent model system for better understanding parameters involved in microgravity experiments with data from laboratory experiments to study the equilibrium rate of hanging drop experiments in microgravity.

French research program on the physiological problems caused by weightlessness. Use of the primate model

NASA Astrophysics Data System (ADS)

Pesquies, P. C.; Milhaud, C.; Nogues, C.; Klein, M.; Cailler, B.; Bost, R.

The need to acquire a better knowledge of the main biological problems induced by microgravity implies—in addition to human experimentation—the use of animal models, and primates seem to be particularly well adapted to this type of research. The major areas of investigation to be considered are the phospho-calcium metabolism and the metabolism of supporting tissues, the hydroelectrolytic metabolism, the cardiovascular function, awakeness, sleep-awakeness cycles, the physiology of equilibrium and the pathophysiology of space sickness. Considering this program, the Centre d'Etudes et de Recherches de Medecine Aerospatiale, under the sponsorship of the Centre National d'Etudes Spatiales, developed both a program of research on restrained primates for the French-U.S. space cooperation (Spacelab program) and for the French-Soviet space cooperation (Bio-cosmos program), and simulation of the effects of microgravity by head-down bedrest. Its major characteristics are discussed in the study.

Powder agglomeration in a microgravity environment

NASA Technical Reports Server (NTRS)

Cawley, James D.

1994-01-01

This is the final report for NASA Grant NAG3-755 entitled 'Powder Agglomeration in a Microgravity Environment.' The research program included both two types of numerical models and two types of experiments. The numerical modeling included the use of Monte Carlo type simulations of agglomerate growth including hydrodynamic screening and molecular dynamics type simulations of the rearrangement of particles within an agglomerate under a gravitational field. Experiments included direct observation of the agglomeration of submicron alumina and indirect observation, using small angle light scattering, of the agglomeration of colloidal silica and aluminum monohydroxide. In the former class of experiments, the powders were constrained to move on a two-dimensional surface oriented to minimize the effect of gravity. In the latter, some experiments involved mixture of suspensions containing particles of opposite charge which resulted in agglomeration on a very short time scale relative to settling under gravity.

In Vivo Physiological Experiments in the Random Positioning Macine: A Study on the Rat Intestinal Transit

NASA Astrophysics Data System (ADS)

Peana, A. T.; Marzocco, S.; Bianco, G.; Autore, G.; Pinto, A.; Pippia, P.

2008-06-01

The aim of this work is to evaluate the rat intestinal transit as well as the expression of enzymes involved in this process and in gastrointestinal homeostasis as ciclooxygenase (COX-1 and COX-2), the inducibile isoform of nitric oxide synthase (iNOS), ICAM-1 and heat shock proteins HSP70 and HSP90. The modeled microgravity conditions were performed utilizing a three-dimensional clinostat, the Random Positioning Machine (RPM). Our results indicate that modeled microgravity significantly reduce rat intestinal transit. Western blot analysis on small intestine tissues of RPM rats reveals a significant increase in iNOS expression, a significant reduction in COX-2 levels, while COX-1 expression remains unaltered, and a significant increase in ICAM-1 and HSP 70 expression. Also a significant increase in HSP 90 stomach expression indicates a strong effect of simulated low g on gastrointestinal homeostasis.

Animal models and their importance to human physiological responses in microgravity

NASA Technical Reports Server (NTRS)

Tipton, C. M.

1996-01-01

Two prominent theories to explain the physiological effects of microgravity relate to the cascade of changes associated with the cephalic shifts of fluids and the absence of tissue deformation forces. One-g experiments for humans used bed rest and the head-down tilt (HDT) method, while animal experiments have been conducted using the tail-suspended, head-down, and hindlimbs non-weightbearing model. Because of the success of the HDT approach with rats to simulate the gravitational effects on the musculoskeletal system exhibited by humans, the same model has been used to study the effects of gravity on the cardiopulmonary systems of humans and other vertebrates. Results to date indicate the model is effective in producing comparable changes associated with blood volume, erythropoiesis, cardiac mass, baroreceptor responsiveness, carbohydrate metabolism, post-flight VO2max, and post-flight cardiac output during exercise. Inherent with these results is the potential of the model to be useful in investigating responsible mechanisms. The suspension model has promise in understanding the capillary blood PO2 changes in space as well as the arterial PO2 changes in subjects participating in a HDT experiment. However, whether the model can provide insights on the up-or-down regulation of adrenoreceptors remains to be determined, and many investigators believe the HDT approach should not be followed to study gravitational influences on pulmonary function in either humans or animals. It was concluded that the tail-suspended animal model had sufficient merit to study in-flight and post-flight human physiological responses and mechanisms.

Regulation of ICAM-1 in cells of the monocyte/macrophage system in microgravity.

PubMed

Paulsen, Katrin; Tauber, Svantje; Dumrese, Claudia; Bradacs, Gesine; Simmet, Dana M; Gölz, Nadine; Hauschild, Swantje; Raig, Christiane; Engeli, Stephanie; Gutewort, Annett; Hürlimann, Eva; Biskup, Josefine; Unverdorben, Felix; Rieder, Gabriela; Hofmänner, Daniel; Mutschler, Lisa; Krammer, Sonja; Buttron, Isabell; Philpot, Claudia; Huge, Andreas; Lier, Hartwin; Barz, Ines; Engelmann, Frank; Layer, Liliana E; Thiel, Cora S; Ullrich, Oliver

2015-01-01

Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells.

Regulation of ICAM-1 in Cells of the Monocyte/Macrophage System in Microgravity

PubMed Central

Paulsen, Katrin; Tauber, Svantje; Dumrese, Claudia; Bradacs, Gesine; Simmet, Dana M.; Gölz, Nadine; Hauschild, Swantje; Raig, Christiane; Engeli, Stephanie; Gutewort, Annett; Hürlimann, Eva; Biskup, Josefine; Rieder, Gabriela; Hofmänner, Daniel; Mutschler, Lisa; Krammer, Sonja; Philpot, Claudia; Huge, Andreas; Lier, Hartwin; Barz, Ines; Engelmann, Frank; Layer, Liliana E.; Thiel, Cora S.

2015-01-01

Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells. PMID:25654110

Combustion Of Interacting Droplet Arrays In Microgravity

NASA Technical Reports Server (NTRS)

Dietrich, D. L.; Struk, P. M.; Ikegami, M.; Xu, G.

2003-01-01

Theory and experiments involving single droplet combustion date back to 1953, with the first microgravity work appearing in 1956. The problem of a spherical droplet burning in an infinite, quiescent microgravity environment is a classical problem in combustion research with the classical solution appearing in nearly every textbook on combustion. The microgravity environment offered by ground-based facilities such as drop towers and space-based facilities is ideal for studying the problem experimentally. A recent review by Choi and Dryer shows significant advances in droplet combustion have been made by studying the problem experimentally in microgravity and comparing the results to one dimensional theoretical and numerical treatments of the problem. Studying small numbers of interacting droplets in a well-controlled geometry represents a logical step in extending single droplet investigations to more practical spray configurations. Studies of droplet interactions date back to Rex and co-workers, and were recently summarized by Annamalai and Ryan. All previous studies determined the change in the burning rate constant, k, or the flame characteristics as a result of interactions. There exists almost no information on how droplet interactions a effect extinction limits, and if the extinction limits change if the array is in the diffusive or the radiative extinction regime. Thus, this study examined experimentally the effect that droplet interactions have on the extinction process by investigating the simplest array configuration, a binary droplet array. The studies were both in normal gravity, reduced pressure ambients and microgravity facilities. The microgravity facilities were the 2.2 and 5.2 second drop towers at the NASA Glenn Research Center and the 10 second drop tower at the Japan Microgravity Center. The experimental apparatus and the data analysis techniques are discussed in detail elsewhere.

Plasticity of mesenchymal stem cells under microgravity: from cytoskeletal reorganization to commitment shift

NASA Astrophysics Data System (ADS)

Buravkova, Ludmila

Mesenchymal stem cells (MSCs) can be used to examine osteogenesis of uncommitted cells maintaining the bone differentiation potential such as osteogenic gene expression, osteogenic markers, matrix maturation and mineralization. MSCs are therefore a good model for studying osteogenesis in the space environment. Recent investigations have demonstrated that MSCs change in response to microgravity and, consequently, can be involved in the development of osteopenia detected in space travelers. This is a factor that can limit human space missions due to potential risks of osteoporosis and its aftereffects during and after flight. Simulated microgravity inhibited MSC differentiation towards osteoblasts and accelerated adipocyte development due to cytoskeleton modifications, including its structure and regulation associated with signal transduction cascades. We identified transient changes in the actin cytoskeleton of non-committed human bone marrow MSCs in short-term RPM experiments. In addition, we detected transient changes in the expression of genes encoding actin cytoskeleton proteins and associated elements (ACTA1, ACTG, RHOA, CFL1, VCL). When discussing the microgravity effects on MSC osteogenic differentiation, it should be mentioned the inhibition of Runx2 and ALPL and stimulation of PPARg2 in the MSCs induced for osteogenesis. It is probable that the reciprocal regulation of the two transcription factors is a molecular mechanism underlying progenitor cell response to microgravity. It is very likely that these genes are involved in the universal circuits within which mechanical (or gravity ) signals are sensed by MSCs. Recently, the list of osteogenic markers was extended to include several new proteins as microgravity targets (proteoglycans, osteomodulin, osteoglycin). It can be believed that exposure to microgravity produces similar effects on mature bone cells (osteoblasts) and non-committed osteogenic cells (MSCs). This finds a support in the fact that terminal differentiation stages, i.e., bone matrix mineralization, are inhibited to the same extent in both osteoblasts and MSCs. When examining gravity-dependent molecular processes responsible for susceptibility and/or adaptation of progenitor cells to microgravity, it is important to concentrate not only on recognized pathways of signal transduction, such as MAPK-kinase and cytoskeleton kinase, but also on the expression pattern of genes, which are allegedly not directly involved in the MSC differentiation. Progenitor cells change their transcriptomic profile in the course of their growth, differentiation and maturation It is important to take into account the fact that MSCs can display their differentiation potential as a result of up- or down-regulation of associated or independent genes or their groups. Any interference in this process may cause significant changes in MSC metabolism and commitment. Although the number of relevant studies is much smaller than that of investigations into the typical markers of MSC differentiation in microgravity, there are publications suggesting that the pattern of MSC gene expression undergoes changes when exposed to microgravity. Our RPM experiments with human MSCs revealed significant changes in the so-called stem cell markers: up-regulation of genes associated with cell proliferation, adhesion and intracellular signaling and down-regulation of genes, most of which are involved in cell differentiation. In spite of significant progress achieved in our understanding of the cell gravitational biology, we, however, need to gain better insight into the specific molecular mechanisms underlying the susceptibility of MSCs and more committed osteogenic precursor cells to microgravity effects in vivo and in vitro. A comprehensive study of the biology of these cells is of particular importance in view of the fact that at present age- and drug-related osteoporosis has transformed into a major medical and social problem. This work was supported by grant NSc #371.2014.4

Scaling analysis of gas-liquid two-phase flow pattern in microgravity

NASA Technical Reports Server (NTRS)

Lee, Jinho

1993-01-01

A scaling analysis of gas-liquid two-phase flow pattern in microgravity, based on the dominant physical mechanism, was carried out with the goal of predicting the gas-liquid two-phase flow regime in a pipe under conditions of microgravity. The results demonstrated the effect of inlet geometry on the flow regime transition. A comparison of the predictions with existing experimental data showed good agreement.

Pros and Cons of Using Water Immersion to Simulate Physiological Responses to Microgravity

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Tomko, David L. (Technical Monitor)

1995-01-01

Head-out water immersion (HOI) has been employed as a remedial treatment for various ills and ailments for many millennia, and total body immersion even longer as protective encapsulation for the mammalian fetus. Two discrete differences between stimuli induced by true microgravity (10(exp -4) g) and HOI are readily apparent. External water pressure on the skin and accompanying negative pressure breathing cause blood to shift headward. Secondly, the gravitational force is ever present during immersion and microgravity, but its effect is essentially neutralized during Earth orbital flight. Thus, the physiological responses to immersion should not be expected to match those during microgravity. Immersion has been used mainly to study and understand kidney function and associated cardiovascular responses for control of body fluid volume and osmotic content, with some application to and simulation of microgravity responses. There is a plethora of data from human HOI studies, but relatively few controlled data from microgravity studies. In general, it appears that physiological responses occur more quickly with water immersion than in microgravity, but this may be due to less rigorous control (voluntary and involuntary) of the preflight state of crew members. The central venous pressure-vasopressin (Gauer-Henry) reflex control for fluid balance may not be of prime importance in microgravity. Gross functions such as reduced body weight and water, level of hypovolemia, decreased isokinetic strength, and lower nitrogen balance found during immersion are qualitatively similar in microgravity, but the mechanisms controlling these and other functions are, for the most part, unclear. Only acquisition of data from well-controlled microgravity experiments will resolve this discrepancy.

The Pleurodele, an animal model for space biology studies

NASA Astrophysics Data System (ADS)

Gualandris, L.; Grinfeld, S.; Foulquier, F.; Kan, P.; Duprat, A. M.

Pleurodeles waltl, an Urodele amphibian is proposed as a model for space biology studies. Our laboratory is developing three types of experiments in space using this animal: 1) in vivo fertilization and development (``FERTILE'' project); 2) influence of microgravity and space radiation on the organization and preservation of spacialized structures in the neurons and muscle cells (in vitro; ``CELIMENE'' PROJECT); 3) influence of microgravity on tissue regeneration (muscle, bone, epidermis and spinal cord).

Acoustic Excitation of Liquid Fuel Droplets and Coaxial Jets

DTIC Science & Technology

2009-01-01

would also like to acknowledge the support of the NASA Microgravity Combustion program which made possible the completion of this research and Maj...fuels exposed to different acoustic excitation conditions in a laboratory environment and during free-fall (microgravity) conditions in a NASA drop tower...then sent to two amplifiers, one for each piezo-siren. The amplifiers were a Krohn-Hite (model 7500) and a Trek (model PZD2000A), which amplified the

Development of a computational model for astronaut reorientation.

PubMed

Stirling, Leia; Willcox, Karen; Newman, Dava

2010-08-26

The ability to model astronaut reorientations computationally provides a simple way to develop and study human motion control strategies. Since the cost of experimenting in microgravity is high, and underwater training can lead to motions inappropriate for microgravity, these techniques allow for motions to be developed and well-understood prior to any microgravity exposure. By including a model of the current space suit, we have the ability to study both intravehicular and extravehicular activities. We present several techniques for rotating about the axes of the body and show that motions performed by the legs create a greater net rotation than those performed by the arms. Adding a space suit to the motions was seen to increase the resistance torque and limit the available range of motion. While rotations about the body axes can be performed in the current space suit, the resulting motions generated a reduced rotation when compared to the unsuited configuration. 2010 Elsevier Ltd. All rights reserved.

Effect of gravity on the caloric stimulation of the inner ear

NASA Technical Reports Server (NTRS)

Kassemi, Mohammad; Deserranno, Dimitri; Oas, John G.

2004-01-01

Robert Barany won the 1914 Nobel Prize in medicine for his convection hypothesis for caloric stimulation. Microgravity caloric tests aboard the 1983 SpaceLab 1 mission produced nystagmus results that contradicted the basic premise of Barany's convection theory. In this paper, we present a fluid structural analysis of the caloric stimulation of the lateral semicircular canal. Direct numerical simulations indicate that on earth, natural convection is the dominant mechanism for endolymphatic flow. However, in the microgravity environment of orbiting spacecraft, where buoyancy effects are mitigated, an expansive convection becomes the sole mechanism for producing endolymph motion and cupular displacement. Transient 1 g and microgravity case studies are presented to delineate the different dynamic behaviors of the 1 g and microgravity endolymphatic flows. The associated fluid-structural interactions are also analyzed based on the time evolution of cupular displacements.

Microgravity effects on water flow and distribution in unsaturated porous media: Analyses of flight experiments

NASA Astrophysics Data System (ADS)

Jones, Scott B.; Or, Dani

1999-04-01

Plants grown in porous media are part of a bioregenerative life support system designed for long-duration space missions. Reduced gravity conditions of orbiting spacecraft (microgravity) alter several aspects of liquid flow and distribution within partially saturated porous media. The objectives of this study were to evaluate the suitability of conventional capillary flow theory in simulating water distribution in porous media measured in a microgravity environment. Data from experiments aboard the Russian space station Mir and a U.S. space shuttle were simulated by elimination of the gravitational term from the Richards equation. Qualitative comparisons with media hydraulic parameters measured on Earth suggest narrower pore size distributions and inactive or nonparticipating large pores in microgravity. Evidence of accentuated hysteresis, altered soil-water characteristic, and reduced unsaturated hydraulic conductivity from microgravity simulations may be attributable to a number of proposed secondary mechanisms. These are likely spawned by enhanced and modified paths of interfacial flows and an altered force ratio of capillary to body forces in microgravity.

Effects of simulated microgravity on gene expression and biological phenotypes of a single generation Caenorhabditis elegans cultured on 2 different media

NASA Astrophysics Data System (ADS)

Tee, Ling Fei; Neoh, Hui-min; Then, Sue Mian; Murad, Nor Azian; Asillam, Mohd Fairos; Hashim, Mohd Helmy; Nathan, Sheila; Jamal, Rahman

2017-11-01

Studies of multigenerational Caenorhabditis elegans exposed to long-term spaceflight have revealed expression changes of genes involved in longevity, DNA repair, and locomotion. However, results from spaceflight experiments are difficult to reproduce as space missions are costly and opportunities are rather limited for researchers. In addition, multigenerational cultures of C. elegans used in previous studies contribute to mixture of gene expression profiles from both larvae and adult worms, which were recently reported to be different. Usage of different culture media during microgravity simulation experiments might also give rise to differences in the gene expression and biological phenotypes of the worms. In this study, we investigated the effects of simulated microgravity on the gene expression and biological phenotype profiles of a single generation of C. elegans worms cultured on 2 different culture media. A desktop Random Positioning Machine (RPM) was used to simulate microgravity on the worms for approximately 52 to 54 h. Gene expression profile was analysed using the Affymetrix GeneChip® C. elegans 1.0 ST Array. Only one gene (R01H2.2) was found to be downregulated in nematode growth medium (NGM)-cultured worms exposed to simulated microgravity. On the other hand, eight genes were differentially expressed for C. elegans Maintenance Medium (CeMM)-cultured worms in microgravity; six were upregulated, while two were downregulated. Five of the upregulated genes (C07E3.15, C34H3.21, C32D5.16, F35H8.9 and C34F11.17) encode non-coding RNAs. In terms of biological phenotype, we observed that microgravity-simulated worms experienced minimal changes in terms of lifespan, locomotion and reproductive capabilities in comparison with the ground controls. Taking it all together, simulated microgravity on a single generation of C. elegans did not confer major changes to their gene expression and biological phenotype. Nevertheless, exposure of the worms to microgravity lead to higher expression of non-coding RNA genes, which may play an epigenetic role in the worms during longer terms of microgravity exposure.

The combined effects of real or simulated microgravity and red-light photoactivation on plant root meristematic cells.

PubMed

Valbuena, Miguel A; Manzano, Aránzazu; Vandenbrink, Joshua P; Pereda-Loth, Veronica; Carnero-Diaz, Eugénie; Edelmann, Richard E; Kiss, John Z; Herranz, Raúl; Medina, F Javier

2018-06-08

Red light is able to compensate for deleterious effects of microgravity on root cell growth and proliferation. Partial gravity combined with red light produces differential signals during the early plant development. Light and gravity are environmental cues used by plants throughout evolution to guide their development. We have investigated the cross-talk between phototropism and gravitropism under altered gravity in space. The focus was on the effects on the meristematic balance between cell growth and proliferation, which is disrupted under microgravity in the dark. In our spaceflight experiments, seedlings of three Arabidopsis thaliana genotypes, namely the wild type and mutants of phytochrome A and B, were grown for 6 days, including red-light photoactivation for the last 2 days. Apart from the microgravity and the 1g on-board control conditions, fractional gravity (nominally 0.1g, 0.3g, and 0.5g) was created with on-board centrifuges. In addition, a simulated microgravity (random positioning machine, RPM) experiment was performed on ground, including both dark-grown and photostimulated samples. Photoactivated samples in spaceflight and RPM experiments showed an increase in the root length consistent with phototropic response to red light, but, as gravity increased, a gradual decrease in this response was observed. Uncoupling of cell growth and proliferation was detected under microgravity in darkness by transcriptomic and microscopic methods, but red-light photoactivation produced a significant reversion. In contrast, the combination of red light and partial gravity produced small but consistent variations in the molecular markers of cell growth and proliferation, suggesting an antagonistic effect between light and gravity signals at the early plant development. Understanding these parameters of plant growth and development in microgravity will be important as bioregenerative life support systems for the colonization of the Moon and Mars.

Is skeletal muscle ready for long-term spaceflight and return to gravity?

NASA Technical Reports Server (NTRS)

Riley, D. A.

1999-01-01

It is now clear that prevention of muscle debilitation during spaceflight will require a broader approach than simple exercise aimed at strengthening of the muscle fibers. The levels of several hormones and receptors are altered by unloading and must be returned to homeostasis. Pharmacotherapy and gene transfer strategies to raise the relative level of structural proteins may minimize the problems faced by astronauts in readapting to Earth-gravity. Up to now, we have only minimally exploited microgravity for advancing our understanding of muscle biology. A research laboratory in the space station with a centrifuge facility (gravity control) is essential for conducting basic research in this field. Microgravity has proven an excellent tool for noninvasively perturbing the synthesis of muscle proteins in the search for molecular signals and gene regulatory factors influencing differentiation, growth, maintenance and atrophy of muscle. Understanding the relation between blood flow and interstitial edema and between workload and subsequent structural failure are but two important problems that require serious attention. The roles of hormones and growth factors in regulating gene expression and their microgravity-induced altered production are other urgent issues to pursue. These types of studies will yield information that advances basic knowledge of muscle biology and offers insights into countermeasure design. This knowledge is likely to assist rehabilitation of diseased or injured muscles in humans on Earth, especially individuals in the more vulnerable aging population and persons participating in strenuous sports. Will the skeletal muscle system be prepared for the increased exposure to microgravity and the return to gravity loading without injury when space station is operational? The answer depends in large part on continued access to space and funding of ground-based models and flight experiments. The previous two decades of spaceflight research have described the effects of microgravity on multiple systems. The next generation of experiments promises to be even more exciting as we are challenged to define the cellular and molecular mechanisms of microgravity-induced changes.

Cytoskeleton disorder and cell cycle arrest may be associated with the alteration of protein CEP135 by microgravity

NASA Astrophysics Data System (ADS)

Hang, Xiaoming; Sun, Yeqing; Wu, Di; Li, Yixiao; Liu, Zhiyuan

In the past decades, alterations in the morphology, cytoskeleton and cell cycle have been observed in cells in vitro under microgravity conditions. But the underlying mechanisms are not absolutely identified yet. Our previous study on proteomic and microRNA expression profiles of zebrafish embryos exposed to simulated-microgravity has demonstrated a serial of microgravity-sensitive molecules. Centrosomal protein of 135 kDa (CEP135) was found down-regulated, but the mRNA expression level of it was up-regulated in zebrafish embryos after simulated-microgravity. However, the functional study on CEP135 is very limited and it has not been cloned in zebrafish till now. In this study, we try to determine whether the cytoskeleton disorder and cell cycle arrest is associated with the alteration of CEP135 by microgravity. Full-length cDNA of cep135 gene was firstly cloned from mitosis phase of ZF4. The sequence was analyzed and the phylogenetic tree was constructed based on the similarity to other species. Zebrafish embryonic cell line ZF4 were exposed to simulated microgravity for 24 and 48 hours, using a rotary cell culture system (RCCS) designed by NASA. Quantitative analysis by western blot showed that CEP135 expression level was significantly decreased two times after 24 hour simulated microgravity. Cell cycle detection by flow cytometer indicated ZF4 cells were blocked in G1 phase after 24 and 48 hour simulated microgravity. Moreover, double immunostained ZF4 cells with anti-tubulin and anti-CEP135antibodies demonstrated simulated microgravity could lead to cytoskeleton disorder and CEP135 abnormality. Further investigations are currently being carried out to determine whether knockdown and over-expression of CEP135 will modulate cytoskeleton and cell cycle. In vitro data in combination within vivo results might, at least in part, explain the dramatic effects of microgravity. Key Words: microgravity; CEP135; Cytoskeleton disorder; G1 arrest; ZF4 cell line

Geophysical fingerprints of shallow cultural structures from microgravity and GPR measurements in the Church of St. George, Svätý Jur, Slovakia

NASA Astrophysics Data System (ADS)

Panisova, Jaroslava; Murín, Igor; Pašteka, Roman; Haličková, Jana; Brunčák, Peter; Pohánka, Vladimír; Papčo, Juraj; Milo, Peter

2016-04-01

Recording of the historic edifice using the state-of-the-art geodetic and geophysical techniques brings easier visualisation in form of a three-dimensional (3D) model, thus allowing better understanding of its historical construction by the public and non-experts. We have applied this approach at the Church of St. George, one of the most significant religious buildings in south-western Slovakia, which dominates a silhouette of the town Svätý Jur. The geodetic survey allowed to record the actual state of the church. The church exterior was surveyed using a total station. Due to the intricate shape of the interior components of the church, it was decided to use a terrestrial laser scanner to generate the point cloud data, which were processed into floor plan, elevations, sectional 2D drawings and 3D model. The geophysical survey was carried out in the interior of the church in order to identify potential subsurface anthropogenic structures. Microgravity and ground penetrating radar (GPR) methods were selected as the most effective geophysical tools for such task. In microgravity data processing we focused on the calculation and removal of the gravitational effects of the building masses. The main negative gravity anomalies of interest in the nave, which also have been confirmed by GPR measurements, are interpreted as medieval crypts. Another very important outcome of the geophysical survey is the discovery of the west wall foundations of the oldest Romanesque construction. From each geophysical data acquired we derived 3D polygonal models, which are compared to achieve more realistic picture of the subsurface structures. Verification of these structures by means of archaeological excavation has not been carried out yet.

Focal Gray Matter Plasticity as a Function of Long Duration Head-down Tilt Bed Rest

NASA Technical Reports Server (NTRS)

Koppelmans, Vincent; Erdeniz, Burak; DeDios, Yiri; Wood, Scott; Reuter-Lorenz, Patricia; Kofman, Igor; Bloomberg, Jacob; Mulavara, Ajitkumar; Seidler, Rachael

2014-01-01

Long duration spaceflight (i.e., 22 days or longer) has been associated with changes in sensorimotor systems, resulting in difficulties that astronauts experience with posture control, locomotion, and manual control. The microgravity environment is an important causal factor for spaceflight induced sensorimotor changes. Whether these sensorimotor changes may be related to structural and functional brain changes is yet unknown. However, increased intracranial pressure that by itself has been related to microgravity-induced bodily fluid shifts: [1] has been associated with white matter microstructural damage, [2] Thus, it is possible that spaceflight may affect brain structure and thereby cognitive functioning. Long duration head-down tilt bed rest has been suggested as an exclusionary analog to study microgravity effects on the sensorimotor system, [3] Bed rest mimics microgravity in body unloading and bodily fluid shifts. In consideration of the health and performance of crewmembers both in- and post-flight, we are conducting a prospective longitudinal 70-day bed rest study as an analog to investigate the effects of microgravity on brain structure, and [4] Here we present results of the first eight subjects.

Colorimetric-Solid Phase Extraction Technology for Water Quality Monitoring: Evaluation of C-SPE and Debubbling Methods in Microgravity

NASA Technical Reports Server (NTRS)

Hazen-Bosveld, April; Lipert, Robert J.; Nordling, John; Shih, Chien-Ju; Siperko, Lorraine; Porter, Marc D.; Gazda, Daniel B.; Rutz, Jeff A.; Straub, John E.; Schultz, John R.;

Does vector-free gravity simulate microgravity? Functional and morphologic attributes of clinorotated nerve and muscle grown in cell culture

NASA Technical Reports Server (NTRS)

Gruener, R.; Hoeger, G.

1988-01-01

Cocultured Xenopus neurons and myocytes were subjected to non-vectorial gravity by clinostat rotation to determine if microgravity, during space flights, may affect cell development and communications. Clinorotated cells showed changes consistent with the hypothesis that cell differentiation, in microgravity, is altered by interference with cytoskeleton-related mechanisms. We found: increases in the myocyte and its nuclear area, "fragmentation" of nucleoli, appearance of neuritic "aneurysms", decreased growth in the presence of "trophic" factors, and decreased yolk utilization. The effects were most notable at 1-10 rpm and depended on the onset and duration of rotation. Some parameters returned to near control values within 48 hrs after cessation of rotation. Cells from cultures rotated at higher speeds (>50 rpm) appeared comparable to controls. Compensation by centrifugal forces may account for this finding. Our data are consistent, in principle, with effects on other, flighted cells and suggest that "vector-free" gravity may simulate certain aspects of microgravity. The distribution of acetylcholine receptor aggregates, on myocytes, was also altered. This indicates that brain development, in microgravity, may also be affected.

Response of SAOS-2 cells to simulated microgravity and effect of biocompatible sol-gel hybrid coatings

NASA Astrophysics Data System (ADS)

Catauro, M.; Bollino, F.; Papale, F.

2016-05-01

The health of astronauts, during space flight, is threatened by bone loss induced by microgravity, mainly attributed to an imbalance in the bone remodeling process. In the present work, the response to the microgravity of bone cells has been studied using the SAOS-2 cell line grown under the condition of weightlessness, simulated by means of a Random Positioning Machine (RPM). Cell viability after 72 h of rotation has been evaluated by means of WST-8 assay and compared to that of control cells. Although no significant difference between the two cell groups has been observed in terms of viability, F-actin staining showed that microgravity environment induces cell apoptosis and altered F-actin organization. To investigate the possibility of hindering the trend of the cells towards the death, after 72 h of rotation the cells have been seeded onto biocompatible ZrO2/PCL hybrid coatings, previously obtained using a sol-gel dip coating procedure. WST-8 assay, carried out after 24 h, showed that the materials are able to inhibit the pro-apoptotic effect of microgravity on cells.

STS-41 crewmembers conduct DSO 0472 Intraocular Pressure on OV-103's middeck

NASA Image and Video Library

1990-10-10

STS-41 crewmembers conduct Detailed Supplementary Objective (DSO) 0472 Intraocular Pressure on the middeck of Discovery, Orbiter Vehicle (OV) 103. Mission Specialist (MS) William M. Shepherd rests his head on the stowed treadmill while Pilot Robert D. Cabana, holding Shepherd's eye open, prepares to measure Shepherd's intraocular pressure using a tono pen (in his right hand). Objectives include: establishing a database of changes in intraocular pressures that can be used to evaluate crew health; validating ten degree head down bedrest as a model for cephalad fluid shifts in microgravity; facilitating the interpretation of data by providing a quantative measure of microgravity induced cephalad fluid shifts; and validating the tono pen as an effective tool for diagnostic and scientific data collection.

Methods for the culture of C. elegans and S. cerevisiae in microgravity

NASA Technical Reports Server (NTRS)

Fahlen, Thomas; Sunga, June; Rask, Jon; Herrera, Anna; Lam, Kitty; Sing, Luke; Sato, Kevin; Ramos, Ross A.; Kirven-Brooks, Melissa; Reiss-Bubenheim, Debra

2005-01-01

To support the study of the effects of microgravity on biological systems, our group is developing and testing methods that allow the cultivation of C. elegans and S. cerevisiae in microgravity. Our aim is to develop the experimental means by which investigators may conduct peer reviewed biological experiments with C. elegans or S. cerevisiae in microgravity. Our protocols are aimed at enabling investigators to grow these organisms for extended periods during which samples may be sub-cultured, collected, preserved, frozen, and/or returned to earth for analysis. Data presented include characterization of the growth phenotype of these organisms in liquid medium in OptiCells(TM) (Biocrystal, LTD).

Characterization of annular two-phase gas-liquid flows in microgravity

NASA Technical Reports Server (NTRS)

Bousman, W. Scott; Mcquillen, John B.

1994-01-01

A series of two-phase gas-liquid flow experiments were developed to study annular flows in microgravity using the NASA Lewis Learjet. A test section was built to measure the liquid film thickness around the perimeter of the tube permitting the three dimensional nature of the gas-liquid interface to be observed. A second test section was used to measure the film thickness, pressure drop and wall shear stress in annular microgravity two-phase flows. Three liquids were studied to determine the effects of liquid viscosity and surface tension. The result of this study provide insight into the wave characteristics, pressure drop and droplet entrainment in microgravity annular flows.

The Effect of Microgravity on Flame Spread over a Thin Fuel

NASA Technical Reports Server (NTRS)

Olson, Sandra L.

1987-01-01

A flame spreading over a thermally thin cellulose fuel was studied in a quiescent microgravity environment. Flame spread over two different fuel thicknesses was studied in ambient oxygen-nitrogen environments from the limiting oxygen concentration to 100 percent oxygen at 1 atm pressure. Comparative normal-gravity tests were also conducted. Gravity was found to play an important role in the mechanism of flame spread. In lower oxygen environments, the buoyant flow induced in normal gravity was found to accelerate the flame spread rate as compared to the microgravity flame spread rates. It was also found to stabilize the flame in oxidizer environments, where microgravity flames in a quiescent environment extinguish. In oxygen-rich environments, however, it was determined that gravity does not play an important role in the flame spread mechanism. Fuel thickness influences the flame spread rate in both normal gravity and microgravity. The flame spread rate varies inversely with fuel thickness in both normal gravity and in an oxygen-rich microgravity environment. In lower oxygen microgravity environments, however, the inverse relationship breaks down because finite-rate kinetics and heat losses become important. Two different extinction limits were found in microgravity for the two thicknesses of fuel. This is in contrast to the normal-gravity extinction limit, which was found to be independent of fuel thickness. In microgravity the flame is quenched because of excessive thermal losses, whereas in normal gravity the flame is extinguished by blowoff.

Protection against neurodegenerative disease on Earth and in space.

PubMed

Takamatsu, Yoshiki; Koike, Wakako; Takenouchi, Takato; Sugama, Shuei; Wei, Jianshe; Waragai, Masaaki; Sekiyama, Kazunari; Hashimoto, Makoto

2016-01-01

All living organisms have evolutionarily adapted themselves to the Earth's gravity, and failure to adapt to gravity changes may lead to pathological conditions. This perspective may also apply to abnormal aging observed in bedridden elderly patients with aging-associated diseases such as osteoporosis and sarcopenia. Given that bedridden elderly patients are partially analogous to astronauts in that both cannot experience the beneficial effects of gravity on the skeletal system and may suffer from bone loss and muscle weakness, one may wonder whether there are gravity-related mechanisms underlying diseases among the elderly. In contrast to numerous studies of the relevance of microgravity in skeletal disorders, little attention has been paid to neurodegenerative diseases. Therefore, the objective of this paper is to discuss the possible relevance of microgravity in these diseases. We particularly noted a proteomics paper showing that levels of hippocampal proteins, including β-synuclein and carboxyl-terminal ubiquitin hydrolase L1, which have been linked to familial neurodegenerative diseases, were significantly decreased in the hippocampus of mice subjected to hindlimb suspension, a model of microgravity. We suggest that microgravity-induced neurodegeneration may be further exacerbated by diabetes and other factors. On the basis of this view, prevention of neurodegenerative diseases through 'anti-diabetes' and 'hypergravity' approaches may be important as a common therapeutic approach on Earth and in space. Collectively, neurodegenerative diseases and space medicine may be linked to each other more strongly than previously thought.

Microgravity-Induced Physiological Fluid Redistribution: Computational Analysis to Assess Influence of Physiological Parameters

NASA Technical Reports Server (NTRS)

Myers, J. G.; Eke, Chika; Werner, C.; Nelson, E. S.; Mulugeta, L.; Feola, A.; Raykin, J.; Samuels, B.; Ethier, C. R.

2016-01-01

Space flight impacts human physiology in many ways, the most immediate being the marked cephalad (headward) shift of fluid upon introduction into the microgravity environment. This physiological response to microgravity points to the redistribution of blood and interstitial fluid as a major factor in the loss of venous tone and reduction in heart muscle efficiency which impact astronaut performance. In addition, researchers have hypothesized that a reduction in astronaut visual acuity, part of the Visual Impairment and Intracranial Pressure (VIIP) syndrome, is associated with this redistribution of fluid. VIIP arises within several months of beginning space flight and includes a variety of ophthalmic changes including posterior globe flattening, distension of the optic nerve sheath, and kinking of the optic nerve. We utilize a suite of lumped parameter models to simulate microgravity-induced fluid redistribution in the cardiovascular, central nervous and ocular systems to provide initial and boundary data to a 3D finite element simulation of ocular biomechanics in VIIP. Specifically, the lumped parameter cardiovascular model acts as the primary means of establishing how microgravity, and the associated lack of hydrostatic gradient, impacts fluid redistribution. The cardiovascular model consists of 16 compartments, including three cerebrospinal fluid (CSF) compartments, three cranial blood compartments, and 10 thoracic and lower limb blood compartments. To assess the models capability to address variations in physiological parameters, we completed a formal uncertainty and sensitivity analysis that evaluated the relative importance of 42 input parameters required in the model on relative compartment flows and compartment pressures. Utilizing the model in a pulsatile flow configuration, the sensitivity analysis identified the ten parameters that most influenced each compartment pressure. Generally, each compartment responded appropriately to parameter variations associated with itself and adjacent compartments. However, several unexpected interactions between components, such as between the choroid plexus and the lower capillaries, were found, and are due to simplifications in the formulation of the model. The analysis illustrates that highly influential parameters and those that have unique influences within the model formulation must be tightly controlled for successful model application.

Modeled Microgravity-Induced Protein Kinase C Isoform Expression in Human Lymphocytes

NASA Technical Reports Server (NTRS)

Sundaresan, A.; Risin, D.; Pellis, N. R.

2003-01-01

In long-term space travel, the crew is exposed to microgravity and radiation that invoke potential hazards to the immune system. T cell activation is a critical step in the immune response. Receptor-mediated signaling is inhibited both in microgravity and modeled microgravity (MMG) as reflected in diminished DNA synthess in peripheral blood lymphocytes and their locomotion through gelled type 1 collagen. Direct activation of Protein Kinase C (PKC) bypassing cell surface events using the phorbol ester PMA rescues MMG-inhibited lymphocyte activation and locomotion, whereas calcium ionophore ionomycin had no rescue effect. Thus calcium-independent PKC isoforms may be affected in MMG-induced locomotion inhibition and rescue. Both calcium-dependent isoforms and calcium-independent PKC isoforms were investigated to assess their expression in lymphocytes in 19 and MMG-culture. Human lymphocytes were cultured and harvested at 24, 48, 72 and 96 hours and serial samples assessed for locomotion using type I collagen and expression of PKC isoforms. Expression of PKC-alpha, -delta and -epsilon was assessed by RT-PCR, flow cytometry and immunoblotting. Results indicated that PKC isoforms delta and epsilon were down-regulated by more than 50% at the transcriptional and translational levels in MMG-cultured lymphocytes compared with 19 controls. Events upstream of PKC such as phosphorylation of Phospholipase C(gamma) (PLC-gamma) in MMG, revealed accumulation of inactive enzyme. Depressed Ca++ -independent PKC isoforms may be a consequence of an upstream lesion in the signal transduction pathway. The differential response among calcium-dependent and calcium-independent isoforms may actually result from MMG intrusion events earlier than, but after ligand-receptor interaction. Keywords: Signal transduction, locomotion, immunity

Measurement of hydraulic characteristics of porous media used to grow plants in microgravity

NASA Technical Reports Server (NTRS)

Steinberg, Susan L.; Poritz, Darwin

2005-01-01

Understanding the effect of gravity on hydraulic properties of plant growth medium is essential for growing plants in space. The suitability of existing models to simulate hydraulic properties of porous medium is uncertain due to limited understanding of fundamental mechanisms controlling water and air transport in microgravity. The objective of this research was to characterize saturated and unsaturated hydraulic conductivity (K) of two particle-size distributions of baked ceramic aggregate using direct measurement techniques compatible with microgravity. Steady state (Method A) and instantaneous profile measurement (Method B) methods for K were used in a single experimental unit with horizontal flow through thin sections of porous medium providing an earth-based analog to microgravity. Comparison between methods was conducted using a crossover experimental design compatible with limited resources of space flight. Satiated (natural saturation) K ranged from 0.09 to 0.12 cm s-1 and 0.5 to >1 cm s-1 for 0.25- to 1- and 1- to 2-mm media, respectively. The K at the interaggregate/intraaggregate transition was approximately 10(-4) cm s-1 for both particle-size distributions. Significant differences in log(10)K due to method and porous medium were less than one order of magnitude and were attributed to variability in air entrapment. The van Genuchten/Mualem parametric models provided an adequate prediction of K of the interaggregate pore space, using residual water content for that pore space. The instantaneous profile method covers the range of water contents relevant to plant growth using fewer resources than Method A, all advantages for space flight where mass, volume, and astronaut time are limited.

Gravitational Effects on Flow Instability and Transition in Low Density Jets

NASA Technical Reports Server (NTRS)

Agrawal, Ajay K.; Parthasarathy, Ramkumar

2004-01-01

Experiments were conducted in Earth gravity and microgravity to acquire quantitative data on near field flow structure of helium jets injected into air. Microgravity conditions were simulated in the 2.2-second drop tower at NASA Glenn Research Center. The jet flow was observed by quantitative rainbow schlieren deflectometry, a non-intrusive line of sight measurement technique suited for the microgravity environment. The flow structure was characterized by distributions of helium mole fraction obtained from color schlieren images taken at 60 Hz. Results show that the jet in microgravity was up to 70 percent wider than that in Earth gravity. Experiments reveal that the global flow oscillations observed in Earth gravity are absent in microgravity. The report provides quantitative details of flow evolution as the experiment undergoes change in gravity in the drop tower.

Microgravity Effects on Plant Growth and Lignification

NASA Astrophysics Data System (ADS)

Cowles, Joe R.; Lemay, Richard; Jahns, Gary

1988-12-01

Lignin is a major cellular component of higher plants. One function of lignin is to support vertical plant growth in a gravity environment. Various investigators working in the 1 g environment have concluded that lignification is influenced by gravity. An experiment was designed for flight on Spacelab II to determine the effect of microgravity on lignification in young plant seedlings. A secondary objective of the experiment was to examine the effect of microgravity on overall seedling growth. Mung bean and oat seeds germinated and the seedlings grew during the Spacelab II mission. Growth of flight mung bean and oat seedlings, however, was slower, and the seedlings exhibited stem and root orientation difficulties. Flight pine seedlings were similar in appearance and growth to 1 g controls. The rate of lignin formation in seedlings grown in space was significantly less in all three species in comparison to 1 g controls. The experiment provided direct evidence that lignification is slowed in a microgravity environment.

NASA's Microgravity Science Research Program

NASA Technical Reports Server (NTRS)

1996-01-01

The ongoing challenge faced by NASA's Microgravity Science Research Program is to work with the scientific and engineering communities to secure the maximum return from our Nation's investments by: assuring that the best possible science emerges from the science community for microgravity investigations; ensuring the maximum scientific return from each investigation in the most timely and cost-effective manner; and enhancing the distribution of data and applications of results acquired through completed investigations to maximize their benefits.

Use of Microgravity to Control the Microstructure of Eutectics

NASA Technical Reports Server (NTRS)

Wilcox. William R.; Regel, Liya L.

1999-01-01

This grant began in June of 1996. Its long term goal is to be able to control the microstructure of directionally solidified eutectic alloys, through an improved understanding of the influence of convection. The primary objective of the projects in the present grant is to test hypotheses for the reported influence of microgravity on the microstructure of eutectics. The prior experimental results on the influence of microgravity on the microstructure of eutectics have been contradictory. With lamellar eutectics, microgravity had a negligible effect on the microstructure. Microgravity experiments with fibrous eutectics sometimes showed a finer microstructure and sometimes a coarser microstructure. Most research has been done on the MnBi/Bi rod-like eutectic. Larson and Pirich obtained a two-fold finer microstructure both from microgravity and by use of a magnetic field to quench buoyancy-driven convection. Smith, on the other hand, observed no change in microgravity. Prior theoretical work at Clarkson University showed that buoyancy-driven convection in the vertical Bridgman configuration is not vigorous enough to alter the concentration field in front of a growing eutectic sufficiently to cause a measurable change in microstructure. We assumed that the bulk melt was at the eutectic composition and that freezing occurred at the extremum, i.e. with minimum total undercooling at the freezing interface. There have been four hypotheses attempting to explain the observed changes in microstructure of fibrous eutectics caused by convection: I .A fluctuating freezing rate, combined with unequal kinetics for fiber termination and branching. 2. Off-eutectic composition, either in the bulk melt due to an off-eutectic feed or at the freezing interface because of departure from the extremum condition. 3. Presence of a strong habit modifying impurity whose concentration at the freezing interface would be altered by convection. At the beginning of the present grant, we favored the first of these hypotheses and set out to test it both experimentally and theoretically. We planned the following approaches: I .Pass electric current pulses through the MnBi/Bi eutectic during directional solidification in order to produce an oscillatory freezing rate. 2. Directionally solidify the MnBi/Bi eutectic on Mir using the QUELD II gradient freeze furnace developed by Professor Smith at Queen's University. 3. Select another fibrous eutectic system for investigation using the Accelerated Crucible Rotation Technique to introduce convection. 4. Develop theoretical models for eutectic solidification with an oscillatory freezing rate. Because of the problems with Mir, we substituted ground-based experiments at Queen's University with QUELD II vertical and horizontal, with and without vibration of the furnace. The Al-Si system was chosen for the ACRT experiments. Three related approaches were used to model eutectic solidification with an oscillatory freezing rate. A sharp interface model was used to calculate composition oscillations at the freezing interface in response to imposed freezing rate oscillations.

The effect of pseudo-microgravity on the symbiosis of plants and microorganisms

NASA Astrophysics Data System (ADS)

Tomita-Yokotani, Kaori; Maki, Asano; Aoki, Toshio; Tamura, Kenji; Wada, Hidenori; Hashimoto, Hirofumi; Yamashita, Masamichi

The symbiosis of plants and microorganisms is important to conduct agriculture under space environment. However, we have less knowledge on whether this kind of symbiosis can be established under space condition. We examined the functional compounds responsible to symbiosis between rhizobiaum and Lotus japonicus as a model of symbiotic combination. The existence of the substances for their symbiosis, some flavonoids, have already been known from the study of gene expression, but the detail structures have not yet been elucidated. Pseudomicrogravity was generated by the 3D-clinorotation. Twenty flavonoids were found in the extracts of 16 days plants of Lotus japonicus grown under the normal gravity by HPLC. Content of two flavonoids among them was affected by the infection of Mesorhizobium loti to them. It has a possibility that the two flavonoids were key substances for their combination process. The productions of those flavonoids were confirmed also under the pseudo-microgravity. The amount of one flavonoid was increased by both infection of rhizobium and exposure to the normal and pseudo-micro gravity. Chemical species of these flavonoids were identified by LC- ESI/MS and spectroscopic analysis. To show the effects of pseudo-microgravity on the gene expression, enzymic activities related to the functional compounds are evaluated after the rhizobial infection.

Simplified numerical approach for estimation of effective segregation coefficient at the melt/crystal interface

NASA Astrophysics Data System (ADS)

Prostomolotov, A. I.; Verezub, N. A.; Voloshin, A. E.

2014-09-01

A thermo-gravitational convection and impurity transfer in the melt were investigated using a simplified numerical model for Bridgman GaSb(Te) crystal growth in microgravity conditions. Simplifications were as follows: flat melt/crystal interface, fixed melt sizes and only lateral ampoule heating. Calculations were carried out by Ansys®Fluent® code employing a two-dimensional Navier-Stokes-Boussinesq and heat and mass transfer equations in a coordinate system moving with the melt/crystal interface. The parametric dependence of the effective segregation coefficient Keff at the melt/crystal interface was studied for various ampoule sizes and for microgravity conditions. For the uprising one-vortex flow, the resulting dependences were presented as Keff vs. Vmax-the maximum velocity value. These dependences were compared with the formulas by Burton-Prim-Slichter's, Ostrogorsky-Muller's, as well as with the semi-analytical solutions.

Gravity affects the closure of the traps in Dionaea muscipula.

PubMed

Pandolfi, Camilla; Masi, Elisa; Voigt, Boris; Mugnai, Sergio; Volkmann, Dieter; Mancuso, Stefano

2014-01-01

Venus flytrap (Dionaea muscipula Ellis) is a carnivorous plant known for its ability to capture insects thanks to the fast snapping of its traps. This fast movement has been long studied and it is triggered by the mechanical stimulation of hairs, located in the middle of the leaves. Here we present detailed experiments on the effect of microgravity on trap closure recorded for the first time during a parabolic flight campaign. Our results suggest that gravity has an impact on trap responsiveness and on the kinetics of trap closure. The possible role of the alterations of membrane permeability induced by microgravity on trap movement is discussed. Finally we show how the Venus flytrap could be an easy and effective model plant to perform studies on ion channels and aquaporin activities, as well as on electrical activity in vivo on board of parabolic flights and large diameter centrifuges.

Crystal growth from the vapor phase experiment MA-085

NASA Technical Reports Server (NTRS)

Wiedemeir, H.; Sadeek, H.; Klaessig, F. C.; Norek, M.

1976-01-01

Three vapor transport experiments on multicomponent systems were performed during the Apollo Soyuz mission to determine the effects of microgravity forces on crystal morphology and mass transport rates. The mixed systems used germanium selenide, tellurium, germanium tetraiodide (transport agent), germanium monosulfide, germanium tetrachloride (transport agent), and argon (inert atmosphere). The materials were enclosed in evacuated sealed ampoules of fused silica and were transported in a temperature gradient of the multipurpose electric furnace onboard the Apollo Soyuz spacecraft. Preliminary evaluation of 2 systems shows improved quality of space grown crystals in terms of growth morphology and bulk perfection. This conclusion is based on a direct comparison of space grown and ground based crystals by means of X-ray diffraction, microscopic, and chemical etching techniques. The observation of greater mass transport rates than predicted for a microgravity environment by existing vapor transport models indicates the existence of nongravity caused transport effects in a reactive solid/gas phase system.

STS-31 preflight press conference with SSIP participant Gregory S. Peterson

NASA Technical Reports Server (NTRS)

1990-01-01

During STS-31 thirty days before launch (T-30) press conference, Shuttle Student Involvement Project (SSIP) participant Gregory S. Peter (right), a senior at Utah State University in Logan, fields questions about his student experiment (SE) to be flown on STS-31. Others pictured are Ed Mason (left) of Morton-Thiokol and Jeff Blakely of Utah State Space Dynamics Laboratory. A model of the experiment titled 'Ion Arc Behavior in Microgravity' SE 82-16 was used during the briefing (pictured). SE 82-16 will be located on Discovery, Orbiter Vehicle (OV) 103, middeck to observe the effects of microgravity on an electric arc. The absence of convection currents in a weightless environment will keep the arc from rising. SE 82-16 will also study the effect of a magnetic field on an arc without correction. An Arriflex 16mm camera will be used to photograph the experiment.

Responses, applications, and analysis of microgravity effects on bacteria

NASA Astrophysics Data System (ADS)

Benoit, Michael Robert

Spaceflight causes many changes to the growth and behavior of bacteria, most likely because of microgravity. However, we do not fully understand the gravity-dependent mechanisms that alter bacterial cell physiology. Furthermore, the literature consists of many contradictory results, creating controversy over the mechanisms by which spaceflight affects bacterial cultures. The research described in this dissertation combines empirical, analytical, and numerical modeling techniques aimed at characterizing the various gravity-dependent phenomena that act on bacteria. While reviewing the literature, I identified an interesting trend in prior experimental results regarding bacterial motility. With this information, we can begin to explain some of the seemingly contradictory findings. This discovery should help to resolve several controversial theories in the field of space microbiology. Chapter 3 describes a microbial antibiotic production experiment conducted onboard the International Space Station. The results corroborated earlier findings of increased antibiotic production for samples taken during the first two weeks of spaceflight. For later samples, however, a reversal occurred, showing decreased production in the spaceflight samples. This insight highlights the benefit of conducting long duration experiments in space to fully evaluate biological responses. Chapter 4 describes a novel technique for preventing bacterial cell sedimentation to partially simulate microgravity in ground-based experiments. The results of this study showed a correlation between cell sedimentation and bacterial growth. As documented in Chapter 5, I investigated the use of digital holographic interferometry to measure extracellular fluid density changes caused by bacterial metabolism. The results showed that fluid density changes surrounding individual bacteria were too small to measure directly. Therefore, I used mathematical analyses and numerical model simulations (described in Chapter 6) to evaluate changes in extracellular fluid density on convective mass transport. From the theoretical analysis results, I predicted convective and diffusive transport regimes for bacteria grown under microgravity, 1 g, and hyper-gravity conditions. Finally, using a numerical model, I successfully simulated an experimentally observed phenomenon of buoyancy-driven convection created by cellular metabolism.

Fiber-Supported Droplet Combustion Experiment-2

NASA Technical Reports Server (NTRS)

Colantonio, Renato O.

1998-01-01

A major portion of the energy produced in the world today comes from the burning of liquid hydrocarbon fuels in the form of droplets. Understanding the fundamental physical processes involved in droplet combustion is not only important in energy production but also in propulsion, in the mitigation of combustion-generated pollution, and in the control of the fire hazards associated with handling liquid combustibles. Microgravity makes spherically symmetric combustion possible, allowing investigators to easily validate their droplet models without the complicating effects of gravity. The Fiber-Supported Droplet Combustion (FSDC-2) investigation was conducted in the Microgravity Glovebox facility of the shuttles' Spacelab during the reflight of the Microgravity Science Laboratory (MSL- 1R) on STS-94 in July 1997. FSDC-2 studied fundamental phenomena related to liquid fuel droplet combustion in air. Pure fuels and mixtures of fuels were burned as isolated single and duo droplets with and without forced air convection. FSDC-2 is sponsored by the NASA Lewis Research Center, whose researchers are working in cooperation with several investigators from industry and academia. The rate at which a droplet burns is important in many commercial applications. The classical theory of droplet burning assumes that, for an isolated, spherically symmetric, single-fuel droplet, the gas-phase combustion processes are much faster than the droplet surface regression rate and that the liquid phase is at a uniform temperature equal to the boiling point. Recent, more advanced models predict that both the liquid and gas phases are unsteady during a substantial portion of the droplet's burning history, thus affecting the instantaneous and average burning rates, and that flame radiation is a dominant mechanism that can extinguish flames in a microgravity environment. FSDC-2 has provided well-defined, symmetric droplet burning data including radiative emissions to validate these theoretical models for heptane, decane, ethanol, and methanol fuels. Since most commercial combustion systems burn droplets in a convective environment, data were obtained without and with convective flow over the burning droplet (see the following photos).

Combination of geophysical prospecting techniques into areas of high protection value: Identification of shallow volcanic structures

NASA Astrophysics Data System (ADS)

Gómez-Ortiz, David; Montesinos, Fuensanta G.; Martín-Crespo, Tomás; Solla, Mercedes; Arnoso, José; Vélez, Emilio

2014-10-01

Timanfaya National Park is a volcanic area located in the southwest of Lanzarote Island (Canary Islands, Spain). Several lava tubes have been found in the lava flows but many others remain unknown. Its location and identification are important to mitigate collapse hazards in this touristic area. We present a new study about the location of recent lava tubes by the analysis and joint interpretation of ground penetrating radar (GPR), microgravity and electromagnetic induction (EMI) data along the same profile over an area not previously surveyed. GPR data display a complex pattern of reflections up to ~ 10 m depth. The strongest hyperbolic reflections can be grouped in four different areas. Visual inspections carried out in the field allow confirming the occurrence of lava tubes at two of them. These reflections have been interpreted as the effect of the roof and bottom interfaces of several lava tubes. The microgravity survey defines a wide gravity low with several over-imposed minor highs and lows. Using the GPR data, a 2.5D gravity model has been obtained revealing four lava tubes. EMI data have been used to obtain an inverted resistivity model that displays four high resistivity areas that closely match the locations of the lava tubes derived from the previous methods. This resistivity model exhibits the lower resolution although reaches a deeper investigation depth (~ 20 m). The comparison of the results has revealed that joint interpretation of GPR, microgravity and EMI methods provides reliable models useful for the detection of unknown shallow lava tubes.

Deep Space Gateway as a Platform to Study Synergistic Radiation and Microgravity-Induced Tissue Degeneration Using the Bioculture System Single Cassette Hardware Design

NASA Astrophysics Data System (ADS)

Almeida, E. A. C.

2018-02-01

A major unknown for human exploration of deep space is the question of how the degenerative effects of microgravity unloading of cells and tissues may synergize with radiation. Here we describe cell culture hardware to study those combined effects.

The Effect of Microgravity on the Growth of Silica Nanostructures

NASA Technical Reports Server (NTRS)

Smith, D. D.; Sibille, L.; Cronise, R.; Oldenburg, S. J.; Wolfe, D.; Halas, N. J.

2001-01-01

The process of the formation of structures from coagulating ensembles is fundamentally important since the collective behavior of the constituents often results in dramatically improved or unusual mechanical, thermal, chemical, and optical properties. In this study we examine the effect of microgravity on the formation of silica structures, specifically particles and gels.

Effects of microgravity on circadian rhythms in insects

NASA Technical Reports Server (NTRS)

Alpatov, A. M.; Hoban-Higgins, T. M.; Fuller, C. A.; Lazarev, A. O.; Rietveld, W. J.; Tschernyshev, V. B.; Tumurova, E. G.; Wassmer, G.; Zotov, V. A.

1998-01-01

The desert beetle Trigonoscelis gigas Reitt. was used as a biological model in studies that examined the effects of space flight on the circadian timing system. Results from studies aboard the Bion-10, Bion-11, and Photon-11 missions are reported. The control study is an ongoing Mir experiment. The studies indicate that the free-running period in beetles may be longer during space flight.

Efficacy of Cardiopulmonary Resuscitation in the Microgravity Environment

NASA Technical Reports Server (NTRS)

Johnston, Smith L.; Campbell, Mark R.; Billica, Roger D.; Gilmore, Stevan M.

2001-01-01

End tidal carbon dioxide (EtCO 2) has been previously shown to be an effective non-invasive tool for estimating cardiac output during cardiopulmonary resuscitation (CPR). Animal models have shown that this diagnostic adjunct can be used as a predictor of survival when EtCO 2 values are maintained above 25% of prearrest values.

Stereo Imaging Velocimetry of Mixing Driven by Buoyancy Induced Flow Fields

NASA Technical Reports Server (NTRS)

Duval, W. M. B.; Jacqmin, D.; Bomani, B. M.; Alexander, I. J.; Kassemi, M.; Batur, C.; Tryggvason, B. V.; Lyubimov, D. V.; Lyubimova, T. P.

2000-01-01

Mixing of two fluids generated by steady and particularly g-jitter acceleration is fundamental towards the understanding of transport phenomena in a microgravity environment. We propose to carry out flight and ground-based experiments to quantify flow fields due to g-jitter type of accelerations using Stereo Imaging Velocimetry (SIV), and measure the concentration field using laser fluorescence. The understanding of the effects of g-jitter on transport phenomena is of great practical interest to the microgravity community and impacts the design of experiments for the Space Shuttle as well as the International Space Station. The aim of our proposed research is to provide quantitative data to the community on the effects of g-jitter on flow fields due to mixing induced by buoyancy forces. The fundamental phenomenon of mixing occurs in a broad range of materials processing encompassing the growth of opto-electronic materials and semiconductors, (by directional freezing and physical vapor transport), to solution and protein crystal growth. In materials processing of these systems, crystal homogeneity, which is affected by the solutal field distribution, is one of the major issues. The understanding of fluid mixing driven by buoyancy forces, besides its importance as a topic in fundamental science, can contribute towards the understanding of how solutal fields behave under various body forces. The body forces of interest are steady acceleration and g-jitter acceleration as in a Space Shuttle environment or the International Space Station. Since control of the body force is important, the flight experiment will be carried out on a tunable microgravity vibration isolation mount, which will permit us to precisely input the desired forcing function to simulate a range of body forces. To that end, we propose to design a flight experiment that can only be carried out under microgravity conditions to fully exploit the effects of various body forces on fluid mixing. Recent flight experiments, by the P.I. through collaboration with the Canadian Space Agency (STS-85, August 1997), aimed at determining the stability of the interface between two miscible liquids inside an enclosure show that a long liquid column (5 cm) under microgravity isolation conditions can be stable, i.e. the interface remains sharp and vertical over a short time scale; thus transport occurs by molecular mass diffusion. On the other hand, when the two liquids were excited from a controlled vibration source (Microgravity Vibration Isolation Mount) two to four mode large amplitude quasi-stationary waves were observed. The data was limited to CCD recording of the dynamics of the interface between the two fluids. We propose to carry out flight experiments to quantify the dynamics of the flow field using Stereo Imaging Velocimetry and measure the concentration field using laser fluorescence. The results will serve as a basis to understand effects of g-jitter on transport phenomena, in this case mass diffusion. As the measurement of the kinematics of the flow field will shed light on the instability mechanism. The research will allow measurement of the flow field in microgravity environment to prove two hypotheses: (1) Maxwell's hypothesis: finite convection always exists in diffusing systems, and (2) Quasi-stationary waves inside a bounded enclosure in a microgravity environment is generated by Kelvin-Helmholtz instability; resonance of the interface which produces incipient mixing is due to Rayleigh-Taylor instability. The first hypothesis can be used as a benchmark experiment to illustrate diffusive mixing. The second hypothesis will lead to the understanding of g-jitter effects on buoyancy driven flow fields which occur in many situations involving materials processing, and other basic fluid physics phenomena. In addition, the second hypothesis will also provide insight in how Rayleigh-Taylor and Kelvin-Helmholtz instabilities propagate concentration fronts during mixing. Measurement of the flow field using SIV is important because it is the flow field which causes instability at the interface between the two fluids. Mixing driven by buoyancy induced flow fields will be addressed both experimentally and computationally. The experimental effort will address the kinematics of mixing: stretching, transport and chaos. Quantification of the mechanisms of mixing will consists of measuring the flow field using the SIV system at Glenn and capturing the dynamics of the interface, to measure mass transport, using a CCD camera. These experiments will be carried out within the framework of Earth's gravity and g-jitter microgravity acceleration as in a Space Shuttle environment or the International Space Station. The g-jitter will be induced and controlled using a tunable vibration isolation platform to isolate against vibration as well as input periodic and random vibration to the system. The parametric range of the microgravity experiment will be extended from the experiments on STS-85 to investigate higher mode quasi-stationary waves (8 to 12), as well as resonance regions which leads to chaos and turbulence. Ground-based experiments will focus on effects of vibration on stably stratified fluid layers in order to scale for possible scenarios in a microgravity environment. These vibrations will be subjected perpendicular to the concentration field on the ground since the parallel case can only be carried out in a microgravity environment. The concept of dynamical similarity will be applied to tune the experiments as closely as possible to a Space Shuttle environment or the International Space Station. The computational effort will take advantage of the Computational Laboratory at Glenn to corroborate the experimental findings with predictions of the dynamics of the flow field using the codes FLUENT (finite difference based) and FIDAP (finite element based). We will investigate two important cases, single-fluid model to address dilute systems with negligible jump in viscosity and the more general two-fluid model which accounts for finite jump in viscosity. Apart from its microgravity relevance, this experiment is well suited to study dynamics in nonlinear systems.

A review of the liquid metal diffusion data obtained from the space shuttle endeavour mission STS-47 and the space shuttle columbia mission STS-52

NASA Astrophysics Data System (ADS)

Shirkhanzadeh, Morteza

Accurate data of liquid-phase solute diffusion coefficients are required to validate the condensed -matter physics theories. However, the required data accuracy to discriminate between com-peting theoretical models is 1 to 2 percent(1). Smith and Scott (2) have recently used the measured values of diffusion coefficients for Pb-Au in microgravity to validate the theoretical values of the diffusion coefficients derived from molecular dynamics simulations and several Enskog hard sphere models. The microgravity data used was obtained from the liquid diffusion experiments conducted on board the Space Shuttle Endeavour (mission STS-47) and the Space Shuttle Columbia (mission STS-52). Based on the analysis of the results, it was claimed that the measured values of diffusion coefficients were consistent with the theoretical results and that the data fit a linear relationship with a slope slightly greater than predicted by the molecular dynamics simulations. These conclusions, however, contradict the claims made in previous publications (3-5) where it was reported that the microgravity data obtained from the shuttle experiments fit the fluctuation theory (D proportional to T2). A thorough analysis of data will be presented to demonstrate that the widely-reported micro-gravity results obtained from shuttle experiments are not reliable and sufficiantly accurate to discriminate between competing theoretical models. References: 1. J.P. Garandet, G. Mathiak, V. Botton, P. Lehmann and A. Griesche, Int. J. Thermophysics, 25, 249 (2004). 2.P.J. Scott and R.W. Smith, J. Appl. Physics 104, 043706 (2008). 3. R.W. Smith, Microgravity Sci. Technol. XI (2) 78-84 (1998). 4.Smith et al, Ann. N.Y. Acad. Sci. 974:56-67 (2002) (retracted). 5.R.A. Herring et al, J. Jpn. Soc. Microgravity Appl., Vol.16, 234-244 (1999).

Fluid Physics in a Fluctuating Acceleration Environment

NASA Technical Reports Server (NTRS)

Thomson, J. Ross; Drolet, Francois; Vinals, Jorge

1996-01-01

We summarize several aspects of an ongoing investigation of the effects that stochastic residual accelerations (g-jitter) onboard spacecraft can have on experiments conducted in a microgravity environment. The residual acceleration field is modeled as a narrow band noise, characterized by three independent parameters: intensity (g(exp 2)), dominant angular frequency Omega, and characteristic correlation time tau. Realistic values for these parameters are obtained from an analysis of acceleration data corresponding to the SL-J mission, as recorded by the SAMS instruments. We then use the model to address the random motion of a solid particle suspended in an incompressible fluid subjected to such random accelerations. As an extension, the effect of jitter on coarsening of a solid-liquid mixture is briefly discussed, and corrections to diffusion controlled coarsening evaluated. We conclude that jitter will not be significant in the experiment 'Coarsening of solid-liquid mixtures' to be conducted in microgravity. Finally, modifications to the location of onset of instability in systems driven by a random force are discussed by extending the standard reduction to the center manifold to the stochastic case. Results pertaining to time-modulated oscillatory convection are briefly discussed.

BASS Experiment Imagery

NASA Image and Video Library

2013-04-05

ISS035-E-014971 (6 April 2013) --- This is a close-up image photographed during a run of the Burning and Suppression of Solids (BASS) experiment onboard the Earth-orbiting International Space Station. Following a series of preparations, NASA astronaut Chris Cassidy (out of frame) conducted runs of the experiment, which examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The experiment is planned for guiding strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

Cassidy conducts BASS Flame Test

NASA Image and Video Library

2013-04-09

ISS035-E-16429 (9 April 2013) --- Astronaut Chris Cassidy, Expedition 35 flight engineer, conducts a session of the Burning and Suppression of Solids (BASS) experiment located in the U.S. lab Destiny onboard the Earth-orbiting International Space Station. Cassidy over a period of several days, has conducted several "runs" of the experiment, which examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity and will guide strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

BASS Experiment Imagery

NASA Image and Video Library

2013-04-09

ISS035-E-015900 (10 April 2013) --- This is one of a series of close-up images photographed during a run of the Burning and Suppression of Solids (BASS) experiment onboard the Earth-orbiting International Space Station. Following a series of preparations, NASA astronaut Chris Cassidy (out of frame) conducted several runs of the experiment, which examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The experiment is planned for guiding strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

BASS Experiment Imagery

NASA Image and Video Library

2013-04-09

ISS035-E-015679 (10 April 2013) --- This is one of a series of close-up images photographed during a run of the Burning and Suppression of Solids (BASS) experiment onboard the Earth-orbiting International Space Station. Following a series of preparations, NASA astronaut Chris Cassidy (out of frame) conducted a series of runs of the experiment, which examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The experiment is planned for guiding strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

BASS-II Experiment

NASA Image and Video Library

2014-07-23

ISS040-E-073120 (23 July 2014) --- This is a close-up image photographed during a run of the Burning and Suppression of Solids (BASS) experiment onboard the Earth-orbiting International Space Station. Following a series of preparations, NASA astronaut Reid Wiseman (out of frame), Expedition 40 flight engineer, conducted runs of the experiment, which examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The experiment is planned for guiding strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

BASS Experiment Imagery

NASA Image and Video Library

2013-04-05

ISS035-E-014987 (6 April 2013) --- This is a close-up image photographed during a run of the Burning and Suppression of Solids (BASS) experiment onboard the Earth-orbiting International Space Station. Following a series of preparations, NASA astronaut Chris Cassidy (out of frame) conducted runs of the experiment, which examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The experiment is planned for guiding strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

BASS Experiment Imagery

NASA Image and Video Library

2013-04-09

ISS035-E-015827 (10 April 2013) --- This is one of a series of close-up images photographed during a run of the Burning and Suppression of Solids (BASS) experiment onboard the Earth-orbiting International Space Station. Following a series of preparations, NASA astronaut Chris Cassidy (out of frame) conducted a series of runs of the experiment, which examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The experiment is planned for guiding strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

BASS Experiment Imagery

NASA Image and Video Library

2013-04-09

ISS035-E-015930 (10 April 2013) --- This is one of a series of close-up images photographed during a run of the Burning and Suppression of Solids (BASS) experiment onboard the Earth-orbiting International Space Station. Following a series of preparations, NASA astronaut Chris Cassidy (out of frame) conducted several runs of the experiment, which examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The experiment is planned for guiding strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

BASS-II Experiment

NASA Image and Video Library

2014-06-27

ISS040-E-023287 (27 June 2014) --- This is a close-up image photographed during a run of the Burning and Suppression of Solids (BASS) experiment onboard the Earth-orbiting International Space Station. Following a series of preparations, NASA astronaut Reid Wiseman (out of frame), Expedition 40 flight engineer, conducted runs of the experiment, which examines the burning and extinction characteristics of a wide variety of fuel samples in microgravity. The experiment is planned for guiding strategies for extinguishing fires in microgravity. BASS results contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

CAFE simulation of columnar-to-equiaxed transition in Al-7wt%Si alloys directionally solidified under microgravity

NASA Astrophysics Data System (ADS)

Liu, D. R.; Mangelinck-Noël, N.; Gandin, Ch-A.; Zimmermann, G.; Sturz, L.; Nguyen Thi, H.; Billia, B.

2016-03-01

A two-dimensional multi-scale cellular automaton - finite element (CAFE) model is used to simulate grain structure evolution and microsegregation formation during solidification of refined Al-7wt%Si alloys under microgravity. The CAFE simulations are first qualitatively compared with the benchmark experimental data under microgravity. Qualitative agreement is obtained for the position of columnar to equiaxed transition (CET) and the CET transition mode (sharp or progressive). Further comparisons of the distributions of grain elongation factor and equivalent diameter are conducted and reveal a fair quantitative agreement.

Microgravity-associated Changes in Cellular Signal Processing

NASA Astrophysics Data System (ADS)

Mednieks, M. I.; Hand, Arthur

It has been an ongoing interest in the NASA Life Sciences Division to determine the physiologic effects of space travel and to devise countermeasures to those effects that can be detrimental to humans. In addition to study of animals flown on the US STS-131, 133 and 135 shuttle missions, participating in the Russian COSMOS and BION-M1 missions has provided important opportunities to study the effects of microgravity on hormonal regulation of cell and tissue responses and on a defined molecular basis. A mouse model was employed to study the effects of space flight on regulation of protein secretion in oral fluid. Using morphologic, and molecular methods it was determined that the expression of a number of proteins is altered after space flight when compared to that of controls. Shown by microarray analyses, some salivary gland genes are down regulated, others up-regulated, while the majority are unaffected. Electron microscopic examination of salivary glands showed no overall tissue damage, but specific morphologic effects were seen that are consistent with an increase in apoptosis and altered duct cell function. Immuno-cytochemical and biochemical methods were used to identify the specific proteins. Initial studies indicate that some of the effects appear transient and could be an adjustment or homeostatic response to microgravity conditions. Further studies will determine if a pharmacologic means can serve as a countermeasure to physiologic changes in humans in catecholamine hormone regulated responses due to travel in space. Support: CT Space Grant College Consortium, School of Dental Medicine Alumni Research Fellowship and the NASA Award Number, NNX09AP13G,

Microgravity induced changes in the control of motor units

NASA Astrophysics Data System (ADS)

de Luca, C.; Roy, S.

The goal of this project is to understand the effects of microgravity on the control of muscles. It is motivated by the notion that in order to adequately address microgravity-induced deterioration in the force generating capacity of muscles, one needs to understand the changes in the control aspects in addition to histochemical and morphological changes. The investigations into muscle control need to include the regulation of the firing activity of motor units that make up a muscle and the coordination of different muscles responsible for the control of a joint. In order to understand the effects of microgravity on these two aspects of muscle control, we will test astronauts before and after spaceflight. The investigations of the control of motor units will involve intramuscular EMG techniques developed in our laboratory. We will use a quadrifilar electrode to detect simultaneously three differential channels of EMG activity. These data will be decomposed accurately using a sophisticated set of algorithms constructed with artificial intelligence knowledge- based techniques. Particular attention will be paid to the firing rate and recruitment behavior of motor units and we will study the degree of cross-correlation of the firing rates. This approach will enable us to study the firing behavior of several (approx. 10) concurrently active motor units. This analysis will enable us to detect modifications in the control of motor units. We will perform these investigations in a hand muscle, which continues being used in prehensile tasks in space, and a leg muscle whose antigravity role is not needed in space. The comparison of the effects of weightlessness on these muscles will determine if continued use of muscles in space deters the possible deleterious effects of microgravity on the control of motor units, in addition to slowing down atrophy. We are particularly interested in comparing the results of this study to similar data already obtained from elderly subjects, because the deleterious effects of migrogravity on muscles is in many ways similar to that of aging. Additionally, we will employ surface EMG techniques to evaluate the effects of microgravity on the coordination of muscles controlling a joint. We will study if the relative contributions from the muscles around the knee joint are redistributed after exposure to microgravity. The insight to be gained from this study will be important in developing countermeasures for maintaining the force generating capacity of muscles in microgravity and rehabilitation programs for aiding in recovery upon return to earth.

COSMOS 2044. Experiment K-7-19. Pineal physiology in microgravity: Relation to rat gonadal function

NASA Technical Reports Server (NTRS)

Holley, D.; Soliman, M. R. I.; Krasnov, I.; Asadi, H.

1989-01-01

It is now known that the pineal organ can interact with many endocrine and nonendocrine tissues in a regulatory fashion. Given its key role in the regulation of melatonin synthesis, its high concentration, and that its levels may persist longer than the more rapidly changing melatonin, it was felt that serotonin might give a more accurate assessment of the effects of microgravity on pineal function following recovery of animals from flight. Five-hydroxyindole acetic acid (5-HIAA), a major metabolite of serotonin metabolism, was also measured. One of the most interesting concomitants to spaceflight and exposure to microgravity has been the disturbing alteration in calcium metabolism and resulting skeletal effects. Given the link between exposure to microgravity and perturbation of calcium metabolism and the fact that the pineal is apparently one of the only soft tissues to calcify, pineal calcium content was examined following spaceflight.

Effects of Microgravity and Hypergravity on Invertebrate Development

NASA Technical Reports Server (NTRS)

Miquel, J.

1985-01-01

Data suggest that abnormal gravity loads do not increase the rate of mutations in lower animals. Insects such as Drosophila melanogaster and Tribolium confusum have been able to reproduce aboard unmanned and manned space satellites, though no precise quantitative data have been obtained on mating competence and various aspects of development. Research with Drosophila flown on Cosmos spacecraft suggests that flight behavior is seriously disturbed in insects exposed to microgravity, which is reflected in increased oxygen utilization and concomitant life shortening. The decrease in longevity was less striking when the flies were enclosed in space, which suggests that they could adapt to the altered gravitational environment when maturation of flight behavior took place in microgravity. The reviewed data suggest that further research on the development of invertebrates in space is in order for clarification of the metabolic and behavioral effects of microgravity and of the development and function of the orientation and gravity sensing mechanisms of lower animals.

Modeling of microgravity combustion experiments

NASA Technical Reports Server (NTRS)

Buckmaster, John

1995-01-01

This program started in February 1991, and is designed to improve our understanding of basic combustion phenomena by the modeling of various configurations undergoing experimental study by others. Results through 1992 were reported in the second workshop. Work since that time has examined the following topics: Flame-balls; Intrinsic and acoustic instabilities in multiphase mixtures; Radiation effects in premixed combustion; Smouldering, both forward and reverse, as well as two dimensional smoulder.

Gravity Vector Changes Induce Alterations in Nervous and Testicular Cells in Cultures and in Testis Slices

NASA Astrophysics Data System (ADS)

Uva, B.; Strollo, F.; Ricci, F.; Masini, M. A.

Cultured astrocytes, neurons and testicular cells (myoid, germ, Sertoli, Leydig cells) as well as rat testes and testes'slices, were subjected to modeled microgravity using a three dimensional Random Positioning Machine (10-6G) for 5min, 30min, 1h, 24h and 32h. Parallel cell cultures and tissues were submitted to hypergravity using an hyperfuge (2.5G) for the same period of time. At the end of the rotations the cultures and tissues were fixed, the tissue was sectioned (5 micron). All the specimens were processed for immunohistochemical identification of microtubules, mitochondria, 3 hydroxysteroid dehydrogenase, 17 hydroxysteroid dehydrogenase, caspase 7, heat shock proteins and identification of DNA fragmentation. At 5min at modeled microgravity and hypergravity, the histology of the cells in culture and the tissues was altered, microtubules and mitochondria were disorganized. Numerous cells underwent apoptosis. Immunostaining for enzymes involved in ion transmembrane transport, as Na+/K+ATPase and cotransporter proteins, and in steroidogenesis diminished or was abolished. At 1h in modeled microgravity or hypergravity, HSPs were expressed and ion transport enzymes as well as steroidogenic enzymes were again immunostainable. These data show that microgravity and hypergravity cause only transient alterations, and tissues and cells in cultures are able to adapt to different gravity conditions.

Effect of Marangoni Convection Generated by Voids on Segregation During Low-G and 1-G Solidification

NASA Technical Reports Server (NTRS)

Kassemi, M.; Fripp, A.; Rashidnia, N.; deGroh, H.

2001-01-01

Solidification experiments, especially microgravity solidification experiments, are often compromised by the evolution of unwanted voids or bubbles in the melt. Although these voids and/or bubbles are highly undesirable, there is currently no effective means of preventing their formation or of eliminating their adverse effects, particularly during microgravity experiments. Marangoni convection caused by these voids can drastically change the transport processes in the melt. Recent microgravity experiments by Matthiesen (1) Andrews (2) and Fripp (3) are perfect examples of how voids and bubbles can affect the outcome of costly space experiments and significantly increase the level of difficulty in interpreting their results. Formation of bubbles have caused problems in microgravity experiments for a long time. Even in the early Skylab mission an unexpectedly large number of bubbles were detected in the four materials processing experiments reported by Papazian and Wilcox (4). They demonstrated that while during ground-based tests bubbles were seen to detach from the interface easily and float to the top of the melt, in low-gravity tests no detachment from the interface occurred and large voids were grown in the crystal. More recently, the lead-tin-telluride crystal growth experiment of Fripp et al.(3) flown aboard the USMP-3 mission has provided very interesting results. The purpose of the study was to investigate the effect of natural convection on the solidification process by growing the samples at different orientations with respect to the gravitational field. Large pores and voids were found in the three solid crystal samples processed in space. Post-growth characterization of the compositional profiles of the cells indicated considerable levels of mixing even in the sample grown in the hot-on-top stable configuration. The mixing was attributed to thermocapillary convection caused by the voids and bubbles which evolved during growth. Since the thermocapillary convection is orientation-independent, diffusion-controlled growth was not possible in any of the samples, even the top-heated one. These results are consistent with recent studies of thermocapillary convection generated by a bubble on a heated surface undertaken by Kassemi and Rashidnia (5-7) where it is numerically and experimentally shown that the thermocapillary flow generated by a bubble in a model fluid (silicone oil) can drastically modify the temperature field through vigorous mixing of the fluid around it, especially under microgravity conditions.

Spinal Stiffness in Prone and Upright Postures During 0-1.8 g Induced by Parabolic Flight.

PubMed

Swanenburg, Jaap; Meier, Michael L; Langenfeld, Anke; Schweinhardt, Petra; Humphreys, B Kim

2018-06-01

The purpose of this study was to analyze posterior-to-anterior spinal stiffness in Earth, hyper-, and microgravity conditions during both prone and upright postures. During parabolic flight, the spinal stiffness of the L3 vertebra of a healthy 37-yr-old man was measured in normal Earth gravity (1.0 g), hypergravity (1.8 g), and microgravity (0.0 g) conditions induced in the prone and upright positions. Differences in spinal stiffness were significant across all three gravity conditions in the prone and upright positions. Most effect sizes were large; however, in the upright posture, the effect size between Earth gravity and microgravity was medium. Significant differences in spinal stiffness between the prone and upright positions were found during Earth gravity and hypergravity conditions. No difference was found between the two postures during microgravity conditions. Based on repeated measurements of a single individual, our results showed detectable changes in posterior-to-anterior spinal stiffness. Spinal stiffness increased during microgravity and decreased during hypergravity conditions. In microgravity conditions, posture did not impact spinal stiffness. More data on spinal stiffness in variable gravitational conditions is needed to confirm these results.Swanenburg J, Meier ML, Langenfeld A, Schweinhardt P, Humphreys BK. Spinal stiffness in prone and upright postures during 0-1.8 g induced by parabolic flight. Aerosp Med Hum Perform. 2018; 89(6):563-567.

Motion of Air Bubbles in Water Subjected to Microgravity Accelerations

NASA Technical Reports Server (NTRS)

DeLombard, Richard; Kelly, Eric M.; Hrovat, Kenneth; Nelson, Emily S.; Pettit, Donald R.

2006-01-01

The International Space Station (ISS) serves as a platform for microgravity research for the foreseeable future. A microgravity environment is one in which the effects of gravity are drastically reduced which then allows physical experiments to be conducted without the over powering effects of gravity. During his 6-month stay on the ISS, astronaut Donald R. Pettit performed many informal/impromptu science experiments with available equipment. One such experiment focused on the motion of air bubbles in a rectangular container nearly filled with de-ionized water. Bubbles were introduced by shaking and then the container was secured in place for several hours while motion of the bubbles was recorded using time-lapse photography. This paper shows correlation between bubble motion and quasi-steady acceleration levels during one such experiment operation. The quasi-steady acceleration vectors were measured by the Microgravity Acceleration Measurement System (MAMS). Essentially linear motion was observed in the condition considered here. Dr. Pettit also created other conditions which produced linear and circulating motion, which are the subjects of further study. Initial observations of this bubble motion agree with calculations from many microgravity physical science experiments conducted on shuttle microgravity science missions. Many crystal-growth furnaces involve heavy metals and high temperatures in which undesired acceleration-driven convection during solidification can adversely affect the crystal. Presented in this paper will be results showing correlation between bubble motion and the quasi-steady acceleration vector.

Investigation of Nucleate Boiling Mechanisms Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Dhir, V. K.; Qiu, D. M.; Ramanujapu, N.; Hasan, M. M.

1999-01-01

The present work is aimed at the experimental studies and numerical modeling of the bubble growth mechanisms of a single bubble attached to a heating surface and of a bubble sliding along an inclined heated plate. Single artificial cavity of 10 microns in diameter was made on the polished Silicon wafer which was electrically heated at the back side in order to control the surface nucleation superheat. Experiments with a sliding bubble were conducted at different inclination angles of the downward facing heated surface for the purpose of studying the effect of magnitude of components of gravity acting parallel to and normal to the heat transfer surface. Information on the bubble shape and size, the bubble induced liquid velocities as well as the surface temperature were obtained using the high speed imaging and hydrogen bubble techniques. Analytical/numerical models were developed to describe the heat transfer through the micro-macro layer underneath and around a bubble formed at a nucleation site. In the micro layer model the capillary and disjoining pressures were included. Evolution of the bubble-liquid interface along with induced liquid motion was modeled. As a follow-up to the studies at normal gravity, experiments are being conducted in the KC-135 aircraft to understand the bubble growth/detachment under low gravity conditions. Experiments have been defined to be performed under long duration of microgravity conditions in the space shuttle. The experiment in the space shuttle will provide bubble growth and detachment data at microgravity and will lead to validation of the nucleate boiling heat transfer model developed from the preceding studies conducted at normal and low gravity (KC-135) conditions.

Influence of cosmic radiation and/or microgravity on development of Carausius morosus.

PubMed

Reitz, G; Bucker, H; Facius, R; Horneck, G; Graul, E H; Berger, H; Ruther, W; Heinrich, W; Beaujean, R; Enge, W; Alpatov, A M; Ushakov, I A; Zachvatkin YuA; Mesland, D A

1989-01-01

Eggs of Carausius morosus were exposed to spaceflight conditions in two spaceflight missions, the German 7 day Spacelab Mission D1 and the Soviet 12.56 day Biosatellite Mission "COSMOS 1887". During spaceflight the eggs continued their development. Eggs of five different ages representing different sensitivity to radiation and different capacity to regeneration were used to investigate the influence of cosmic radiation and/or microgravity on insect development. Using the Biostack concept--eggs in monolayers sandwiched between nuclear track detectors--and the 1 g reference centrifuge of BIORACK in D1 we were able to separate effects of heavy ions of the cosmic radiation from microgravity effects and also from combined effects of these two factors in space. After retrieval, hatching rates, embryonic and larval growth kinetics and anomaly frequencies were determined. Microgravity leads to a reduced hatching rate of eggs exposed in the early stages of development. Hatching was normal in eggs which were exposed on the 1 g reference centrifuge. Hits by heavy ions caused body anomalies. The combined action of heavy ions and microgravity resulted in an unexpectedly high frequency of anomalies. These results obtained from the Spacelab Mission D1, were confirmed in an experiment onboard of COSMOS 1887. In addition to the previous analysis, embryonic development before hatching was followed which showed no major difference between flight and the ground control specimens. Since a reconfirmation of reduced hatching rates was observed in COSMOS 1887, too, the above results suggest some microgravity induced functional impairment of the hatching activity, rather than blockage in embryonic development.

Fish Inner Ear Otolith Growth Under Real Microgravity (Spaceflight) and Clinorotation

NASA Astrophysics Data System (ADS)

Anken, Ralf; Brungs, Sonja; Grimm, Dennis; Knie, Miriam; Hilbig, Reinhard

2016-06-01

Using late larval stages of cichlid fish ( Oreochromis mossambicus) we have shown earlier that the biomineralization of otoliths is adjusted towards gravity by means of a neurally guided feedback loop. Centrifuge experiments, e.g., revealed that increased gravity slows down otolith growth. Microgravity thus should yield an opposite effect, i.e., larger than normal otoliths. Consequently, late larval cichlids (stage 14, vestibular system operational) were subjected to real microgravity during the 12 days FOTON-M3 spaceflight mission (OMEGAHAB-hardware). Controls were kept at 1 g on ground within an identical hardware. Animals of another batch were subsequently clinorotated within a submersed fast-rotating clinostat with one axis of rotation (2d-clinostat), a device regarded to simulate microgravity. Temperature and light conditions were provided in analogy to the spaceflight experiment. Controls were maintained at 1 g within the same aquarium. After all experiments, animals had reached late stage 21 (fish can swim freely). Maintenance under real microgravity during spaceflight resulted in significantly larger than normal otoliths (both lapilli and sagittae, involved in sensing gravity and the hearing process, respectively). This result is fully in line with an earlier spaceflight study in the course of which otoliths from late-staged swordtails Xiphophorus helleri were analyzed. Clinorotation resulted in larger than 1 g sagittae. However, no effect on lapilli was obtained. Possibly, an effect was present but too light to be measurable. Overall, spaceflight obviously induces an adaptation of otolith growth, whereas clinorotation does not fully mimic conditions of microgravity regarding late larval cichlids.

Effects of simulated weightlessness on meiosis. Fertilization, and early development in mice

NASA Technical Reports Server (NTRS)

Wolgemuth, D. J.

1986-01-01

The initial goal was to construct a clinostat which could support mammalian cell culture. The clinostat was selected as a means by which to simulate microgravity conditions within the laboratory, by constant re-orientation of cells with respect to the gravity vector. The effects of this simulated microgravity on in-vitro meiotic maturation of oocytes, using mouse as the model system, was investigated. The effects of clinostat rotation on fertilization in-vitro was then examined. Specific endpoints included examining the timely appearance of male and female pronuclei (indicating fertilization) and the efficiency of extrusion of the second polar body. Particular attention was paid to detecting anomalies of fertilization, including parthenogenetic activation and multiple pronuclei. Finally, for the preliminary studies on mouse embryogenesis, a key feature of the clinostat was modified, that of the position of the cells during rotation. A means was found to immobilize the cells during the clinostat reotation, permitting the cells to remain at the axis of rotation yet not interfering with cellular development.

The simulation of microgravity conditions on the ground.

PubMed

Albrecht-Buehler, G

1992-10-01

This chapter defines weightlessness as the condition where the acceleration of an object is independent of its mass. Applying this definition to the clinostat, it argues that the clinostat is very limited as a simulator of microgravity because it (a) generates centrifugal forces, (b) generates particle oscillations with mass-dependent amplitudes of speed and phase shifts relative to the clinorotation, (c) is unable to remove globally the scalar effects of gravity such as hydrostatic pressure, which are independent of the direction of gravity in the first place, and, (d) generates more convective mixing of the gaseous or liquid environment of the test object, rather than eliminating it, as would true weightlessness. It is proposed that attempts to simulate microgravity must accept the simulation of one aspect of microgravity at a time, and urges that the suppression of convective currents be a major feature of experimental methods that simulate microgravity.

Utilizing Advanced Vibration Isolation Technology to Enable Microgravity Science Operations

NASA Technical Reports Server (NTRS)

Alhorn, Dean Carl

1999-01-01

Microgravity scientific research is performed in space to determine the effects of gravity upon experiments. Until recently, experiments had to accept the environment aboard various carriers: reduced-gravity aircraft, sub-orbital payloads, Space Shuttle, and Mir. If the environment is unacceptable, then most scientists would rather not expend the resources without the assurance of true microgravity conditions. This is currently the case on the International Space Station, because the ambient acceleration environment will exceed desirable levels. For this reason, the g-LIMIT (Glovebox Integrated Microgravity Isolation Technology) system is currently being developed to provide a quiescent acceleration environment for scientific operations. This sub-rack isolation system will provide a generic interface for a variety of experiments for the Microgravity Science Glovebox. This paper describes the motivation for developing of the g-LIMIT system, presents the design concept and details some of the advanced technologies utilized in the g-LIMIT flight design.

Structural Biology of Proteins of the Multi-enzyme Assembly Human Pyruvate Dehydrogenase Complex

NASA Technical Reports Server (NTRS)

2003-01-01

Objectives and research challenges of this effort include: 1. Need to establish Human Pyruvate Dehydrogenase Complex protein crystals; 2. Need to test value of microgravity for improving crystal quality of Human Pyruvate Dehydrogenase Complex protein crystals; 3. Need to improve flight hardware in order to control and understand the effects of microgravity on crystallization of Human Pyruvate Dehydrogenase Complex proteins; 4. Need to integrate sets of national collaborations with the restricted and specific requirements of flight experiments; 5. Need to establish a highly controlled experiment in microgravity with a rigor not yet obtained; 6. Need to communicate both the rigor of microgravity experiments and the scientific value of results obtained from microgravity experiments to the national community; and 7. Need to advance the understanding of Human Pyruvate Dehydrogenase Complex structures so that scientific and commercial advance is identified for these proteins.

Neurology of microgravity and space travel

NASA Technical Reports Server (NTRS)

Fujii, M. D.; Patten, B. M.

1992-01-01

Exposure to microgravity and space travel produce several neurologic changes, including SAS, ataxia, postural disturbances, perceptual illusions, neuromuscular weakness, and fatigue. Inflight SAS, perceptual illusions, and ocular changes are of more importance. After landing, however, ataxia, perceptual illusions, neuromuscular weakness, and fatigue play greater roles in astronaut health and readaptation to a terrestrial environment. Cardiovascular adjustments to microgravity, bone demineralization, and possible decompression sickness and excessive radiation exposure contribute further to medical problems of astronauts in space. A better understanding of the mechanisms by which microgravity adversely affects the nervous system and more effective treatments will provide healthier, happier, and longer stays in space on the space station Freedom and during the mission to Mars.

von Neumann's Law: Theoretical and Microgravity Experimental Comparison for Coarsening Diffusion in Bubble Lattices

NASA Technical Reports Server (NTRS)

Noever, David A.

2000-01-01

The effects of gravity in influencing the theoretical limit for bubble lattice coarsening and aging behavior, otherwise called von Neumann's law, is examined theoretically and experimentally. Preliminary microgravity results will be discussed.

Microgravity and the lung

NASA Technical Reports Server (NTRS)

West, John B.

1991-01-01

Results are presented from studies of the effect of microgravity on the lungs of rats flown on the Cosmos 2044 mission, and from relevant laboratory experiments. The effects of microgravity fall into five categories: topographical structure and function, the lung volumes and mechanics, the intrathoracic blood pressures and volumes, the pulmonary deposition of aerosol, and denitrogenaton during EVA. The ultrastructure of the left lungs of rats flown for 14 days on the Cosmos 2044 spacecraft and that of some tail-suspended rats disclosed presence of red blood cells in the alveolar spaces, indicating that pulmonary hemorrhage and pulmonary edema occurred in these rats. Possible causes for this phenomenon are discussed.

Microgravity Storage Vessels and Conveying-Line Feeders for Cohesive Regolith

NASA Technical Reports Server (NTRS)

Walton, Otis R.; Vollmer, Hubert J.

2013-01-01

Under microgravity, the usual methods of placing granular solids into, or extracting them from, containers or storage vessels will not function. Alternative methods are required to provide a motive force to move the material. New configurations for microgravity regolith storage vessels that do not resemble terrestrial silos, hoppers, or tanks are proposed. The microgravity-compatible bulk-material storage vessels and exit feed configurations are designed to reliably empty and feed cohesive material to transfer vessels or conveying ducts or lines without gravity. A controllable motive force drives the cohesive material to the exit opening(s), and provides a reliable means to empty storage vessels and/or to feed microgravity conveying lines. The proposed designs will function equally well in vacuum, or inside of pressurized enclosures. Typical terrestrial granular solids handling and storage equipment will not function under microgravity, since almost all such equipment relies on gravity to at least move material to an exit location or to place it in the bottom of a container. Under microgravity, there effectively are no directions of up or down, and in order to effect movement of material, some other motive force must be applied to the material. The proposed storage vessels utilize dynamic centrifugal force to effect movement of regolith whenever material needs to be removed from the storage vessel. During simple storage, no dynamic motion or forces are required. The rotation rate during emptying can be controlled to ensure that material will move to the desired exit opening, even if the material is highly cohesive, or has acquired an electrostatic charge. The general concept of this Swirl Action Utilized for Centrifugal Ejection of Regolith (SAUCER) microgravity storage unit/dynamic feeder is to have an effective slot-hopper (based on the converging angles of the top and bottom conical section of the vessel) with an exit slot around the entire periphery of the SAUCER. The basic shape of such a unit is like two Chinese straw hats (douli) - one upside down, on the bottom, and another on top; or two wokpans, one upright on the bottom and another inverted on top, with a small gap between the upright and inverted pans or hats (around the periphery). A stationary outer ring, much like an unmounted bicycle tire, surrounds the gap between the two coaxial, nearly conical pieces, forming the top and bottom of the unit.

Proper selection of 1 g controls in simulated microgravity research as illustrated with clinorotated plant cell suspension cultures

NASA Astrophysics Data System (ADS)

Kamal, Khaled Y.; Hemmersbach, Ruth; Medina, F. Javier; Herranz, Raúl

2015-04-01

Understanding the physical and biological effects of the absence of gravity is necessary to conduct operations on space environments. It has been previously shown that the microgravity environment induces the dissociation of cell proliferation from cell growth in young seedling root meristems, but this source material is limited to few cells in each row of meristematic layers. Plant cell cultures, composed by a large and homogeneous population of proliferating cells, are an ideal model to study the effects of altered gravity on cellular mechanisms regulating cell proliferation and associated cell growth. Cell suspension cultures of Arabidopsis thaliana cell line (MM2d) were exposed to 2D-clinorotation in a pipette clinostat for 3.5 or 14 h, respectively, and were then processed either by quick freezing, to be used in flow cytometry, or by chemical fixation, for microscopy techniques. After long-term clinorotation, the proportion of cells in G1 phase was increased and the nucleolus area, as revealed by immunofluorescence staining with anti-nucleolin, was decreased. Despite the compatibility of these results with those obtained in real microgravity on seedling meristems, we provide a technical discussion in the context of clinorotation and proper 1 g controls with respect to suspension cultures. Standard 1 g procedure of sustaining the cell suspension is achieved by continuously shaking. Thus, we compare the mechanical forces acting on cells in clinorotated samples, in a control static sample and in the standard 1 g conditions of suspension cultures in order to define the conditions of a complete and reliable experiment in simulated microgravity with corresponding 1 g controls.

Inverse dynamic investigation of voluntary leg lateral movements in weightlessness: a new microgravity-specific strategy.

PubMed

Pedrocchi, Alessandra; Baroni, Guido; Pedotti, Antonio; Massion, Jean; Ferrigno, Giancarlo

2005-04-01

This study deals with the quantitative assessment of exchanged forces and torques at the restraint point during whole body posture perturbation movements in long-term microgravity. The work was based on the results of a previous study focused on trunk bending protocol, which suggested that the minimization of the torques exchanged at the restraint point could be a strategy for movement planning in microgravity (J. Biomech. 36(11) (2003) 1691). Torques minimization would lead to the optimization of muscles activity, to the minimization of energy expenditure and, ultimately, to higher movement control capabilities. Here, we focus on leg lateral abduction from anchored stance. The analysis was based on inverse dynamic modelling, leading to the estimation of the total angular momentum at the supporting ankle joint. Results agree with those obtained for trunk bending movements and point out a consistent minimization of the torques exchanged at the restraint point in weightlessness. Given the kinematic features of the examined motor task, this strategy was interpreted as a way to master the rotational dynamic effects on the frontal plane produced by leg lateral abduction. This postural stabilizing effects was the result of a multi-segmental compensation strategy, consisting of the counter rotation of the supporting limb and trunk accompanying the leg raising. The observed consistency of movement-posture co-ordination patterns among lateral leg raising and trunk bending is put forward as a novel interpretative issue of the adaptation mechanisms of the motor system to sustained microgravity, especially if one considers the completely different kinematics of the centre of mass, which was observed in weightlessness for these two motor tasks.

[Cordyceps sinensis enhances lymphocyte proliferation and CD markers expression in simulated microgravity environment].

PubMed

Hao, Tong; Li, Jun-Jie; Du, Zhi-Yan; Duan, Cui-Mi; Wang, Yan-Meng; Wang, Chang-Yong; Song, Jing-Ping; Wang, Lin-Jie; Li, Ying-Hui; Wang, Yan

2012-10-01

This study was aimed to explore the effect of cordyceps sinensis enhancing lymphocyte proliferation and surface CD marker expression in simulated microgravity environment. The splenic lymphocytes were separated from mice and cultured in the rotary cell culture system simulated microgravity environment. The cells were treated with different concentration of cordyceps sinensis solution (0, 6.25, 12.5, 25 and 50 µg/ml) for 24, 48 and 72 h respectively, then the cells were harvested, and analyzed for cell proliferation and the expression of cell surface markers (CD4 and CD8). The results showed that under simulated microgravity environment, the lymphocyte proliferation was inhibited. When the concentration of cordyceps sinensis was 25 or 50 µg/ml, the lymphocyte proliferation, CD4 and CD8 expressions all increased, but 50 µg/ml cordyceps sinensis could inhibit the proliferation ability with the time prolonging. It is concluded that the suitable concentration of cordyceps sinensis displayed the ability to enhance the lymphocyte proliferation and CD marker expression in simulated microgravity environment. These results may be valuable for screening drugs which can be potentially against immunosuppression under simulated microgravity.

Effect of science laboratory centrifuge of space station environment

NASA Technical Reports Server (NTRS)

Searby, Nancy

1990-01-01

It is argued that it is essential to have a centrifuge operating during manned space station operations. Background information and a rationale for the research centrifuge are given. It is argued that we must provide a controlled acceleration environment for comparison with microgravity studies. The lack of control groups in previous studies throws into question whether the obseved effects were the result of microgravity or not. The centrifuge could be used to provide a 1-g environment to supply specimens free of launch effects for long-term studies. With the centrifuge, the specimens could be immediately transferred to microgravity without undergoing gradual acclimation. Also, the effects of artificial gravity on humans could be investigated. It is also argued that the presence of the centrifuge on the space station will not cause undo vibrations or other disturbing effects.

Project JOVE. [microgravity experiments and applications

NASA Technical Reports Server (NTRS)

Lyell, M. J.

1994-01-01

The goal of this project is to investigate new areas of research pertaining to free surface-interface fluids mechanics and/or microgravity which have potential commercial applications. This paper presents an introduction to ferrohydrodynamics (FHD), and discusses some applications. Also, computational methods for solving free surface flow problems are presented in detail. Both have diverse applications in industry and in microgravity fluids applications. Three different modeling schemes for FHD flows are addressed and the governing equations, including Maxwell's equations, are introduced. In the area of computational modeling of free surface flows, both Eulerian and Lagrangian schemes are discussed. The state of the art in computational methods applied to free surface flows is elucidated. In particular, adaptive grids and re-zoning methods are discussed. Additional research results are addressed and copies of the publications produced under the JOVE Project are included.

PIV Measurements in Weakly Buoyant Gas Jet Flames

NASA Technical Reports Server (NTRS)

Sunderland, Peter B.; Greenbberg, Paul S.; Urban, David L.; Wernet, Mark P.; Yanis, William

2001-01-01

Despite numerous experimental investigations, the characterization of microgravity laminar jet diffusion flames remains incomplete. Measurements to date have included shapes, temperatures, soot properties, radiative emissions and compositions, but full-field quantitative measurements of velocity are lacking. Since the differences between normal-gravity and microgravity diffusion flames are fundamentally influenced by changes in velocities, it is imperative that the associated velocity fields be measured in microgravity flames. Velocity measurements in nonbuoyant flames will be helpful both in validating numerical models and in interpreting past microgravity combustion experiments. Pointwise velocity techniques are inadequate for full-field velocity measurements in microgravity facilities. In contrast, Particle Image Velocimetry (PIV) can capture the entire flow field in less than 1% of the time required with Laser Doppler Velocimetry (LDV). Although PIV is a mature diagnostic for normal-gravity flames , restrictions on size, power and data storage complicate these measurements in microgravity. Results from the application of PIV to gas jet flames in normal gravity are presented here. Ethane flames burning at 13, 25 and 50 kPa are considered. These results are presented in more detail in Wernet et al. (2000). The PIV system developed for these measurements recently has been adapted for on-rig use in the NASA Glenn 2.2-second drop tower.

Clinical aspects of the control of plasma volume at microgravity and during return to one gravity

NASA Technical Reports Server (NTRS)

Convertino, V. A.

1996-01-01

Plasma volume is reduced by 10-20% within 24-48 h of exposure to simulated or actual microgravity. The clinical importance of microgravity induced hypovolemia is manifested by its relationship with orthostatic intolerance and reduced maximal oxygen uptake (VO2max) after return to one gravity (1G). Since there is no evidence to suggest that plasma volume reduction during microgravity is associated with thirst or renal dysfunctions, a diuresis induced by an immediate blood volume shift to the central circulation appears responsible for microgravity-induced hypovolemia. Since most astronauts choose to restrict their fluid intake before a space mission, absence of increased urine output during actual space flight may be explained by low central venous pressure (CVP) which accompanies dehydration. Compelling evidence suggests that prolonged reduction in CVP during exposure to microgravity reflects a "resetting" to a lower operating point, which acts to limit plasma volume expansion during attempts to increase fluid intake. In ground based and space flight experiments, successful restoration and maintenance of plasma volume prior to returning to an upright posture may depend upon development of treatments that can return CVP to its baseline IG operating point. Fluid-loading and lower body negative pressure (LBNP) have not proved completely effective in restoring plasma volume, suggesting that they may not provide the stimulus to elevate the CVP operating point. On the other hand, exercise, which can chronically increase CVP, has been effective in expanding plasma volume when combined with adequate dietary intake of fluid and electrolytes. The success of designing experiments to understand the physiological mechanisms of and development of effective counter measures for the control of plasma volume in microgravity and during return to IG will depend upon testing that can be conducted under standardized controlled baseline conditions during both ground-based and space flight investigations.

A systems biology pipeline identifies new immune and disease related molecular signatures and networks in human cells during microgravity exposure

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Sayak; Saha, Rohini; Palanisamy, Anbarasi; Ghosh, Madhurima; Biswas, Anupriya; Roy, Saheli; Pal, Arijit; Sarkar, Kathakali; Bagh, Sangram

2016-05-01

Microgravity is a prominent health hazard for astronauts, yet we understand little about its effect at the molecular systems level. In this study, we have integrated a set of systems-biology tools and databases and have analysed more than 8000 molecular pathways on published global gene expression datasets of human cells in microgravity. Hundreds of new pathways have been identified with statistical confidence for each dataset and despite the difference in cell types and experiments, around 100 of the new pathways are appeared common across the datasets. They are related to reduced inflammation, autoimmunity, diabetes and asthma. We have identified downregulation of NfκB pathway via Notch1 signalling as new pathway for reduced immunity in microgravity. Induction of few cancer types including liver cancer and leukaemia and increased drug response to cancer in microgravity are also found. Increase in olfactory signal transduction is also identified. Genes, based on their expression pattern, are clustered and mathematically stable clusters are identified. The network mapping of genes within a cluster indicates the plausible functional connections in microgravity. This pipeline gives a new systems level picture of human cells under microgravity, generates testable hypothesis and may help estimating risk and developing medicine for space missions.

Discontinuous pore fluid distribution under microgravity--KC-135 flight investigations

NASA Technical Reports Server (NTRS)

Reddi, Lakshmi N.; Xiao, Ming; Steinberg, Susan L.

2005-01-01

Designing a reliable plant growth system for crop production in space requires the understanding of pore fluid distribution in porous media under microgravity. The objective of this experimental investigation, which was conducted aboard NASA KC-135 reduced gravity flight, is to study possible particle separation and the distribution of discontinuous wetting fluid in porous media under microgravity. KC-135 aircraft provided gravity conditions of 1, 1.8, and 10(-2) g. Glass beads of a known size distribution were used as porous media; and Hexadecane, a petroleum compound immiscible with and lighter than water, was used as wetting fluid at residual saturation. Nitrogen freezer was used to solidify the discontinuous Hexadecane ganglia in glass beads to preserve the ganglia size changes during different gravity conditions, so that the blob-size distributions (BSDs) could be measured after flight. It was concluded from this study that microgravity has little effect on the size distribution of pore fluid blobs corresponding to residual saturation of wetting fluids in porous media. The blobs showed no noticeable breakup or coalescence during microgravity. However, based on the increase in bulk volume of samples due to particle separation under microgravity, groups of particles, within which pore fluid blobs were encapsulated, appeared to have rearranged themselves under microgravity.

Enhancement of Pool Boiling Heat Transfer and Control of Bubble Motion in Microgravity Using Electric Fields - BCOEL

NASA Technical Reports Server (NTRS)

Herman, Cila; Iacona, Estelle; Acquaviva, Tom; Coho, Bill; Grant, Nechelle; Nahra, Henry; Sankaran, Subramanian; Taylor, Al; Julian, Ed; Robinson, Dale;

A systems biology pipeline identifies new immune and disease related molecular signatures and networks in human cells during microgravity exposure.

PubMed

Mukhopadhyay, Sayak; Saha, Rohini; Palanisamy, Anbarasi; Ghosh, Madhurima; Biswas, Anupriya; Roy, Saheli; Pal, Arijit; Sarkar, Kathakali; Bagh, Sangram

2016-05-17

Microgravity is a prominent health hazard for astronauts, yet we understand little about its effect at the molecular systems level. In this study, we have integrated a set of systems-biology tools and databases and have analysed more than 8000 molecular pathways on published global gene expression datasets of human cells in microgravity. Hundreds of new pathways have been identified with statistical confidence for each dataset and despite the difference in cell types and experiments, around 100 of the new pathways are appeared common across the datasets. They are related to reduced inflammation, autoimmunity, diabetes and asthma. We have identified downregulation of NfκB pathway via Notch1 signalling as new pathway for reduced immunity in microgravity. Induction of few cancer types including liver cancer and leukaemia and increased drug response to cancer in microgravity are also found. Increase in olfactory signal transduction is also identified. Genes, based on their expression pattern, are clustered and mathematically stable clusters are identified. The network mapping of genes within a cluster indicates the plausible functional connections in microgravity. This pipeline gives a new systems level picture of human cells under microgravity, generates testable hypothesis and may help estimating risk and developing medicine for space missions.

Enhancement of Pool Boiling Heat Transfer and Control of Bubble Motion in Microgravity Using Electric Fields (BCOEL)

NASA Technical Reports Server (NTRS)

Herman, Cila; Iacona, Estelle; Acquaviva, Tom; Coho, Bill; Grant, Nechelle; Nahra, Henry; Taylor, Al; Julian, Ed; Robinson, Dale; VanZandt, Dave

2001-01-01

The BCOEL project focuses on improving pool boiling heat transfer and bubble control in microgravity by exposing the fluid to electric fields. The electric fields induce a body force that can replace gravity in the low gravity environment, and enhance bubble removal from the heated surface. A better understanding of microgravity effects on boiling with and without electric fields is critical to the proper design of the phase-change-heat-removal equipment for use in spacebased applications. The microgravity experiments will focus on the visualization of bubble formation and shape during boiling. Heat fluxes on the boiling surface will be measured, and, together with the measured driving temperature differences, used to plot boiling curves for different electric field magnitudes. Bubble formation and boiling processes were found to be extremely sensitive to g-jitter. The duration of the experimental run is critical in order to achieve steady state in microgravity experiments. The International Space Station provides conditions suitable for such experiments. The experimental apparatus to be used in the study is described in the paper. The apparatus will be tested in the KC-135 first, and microgravity experiments will be conducted on board of the International Space Station using the Microgravity Science Glovebox as the experimental platform.

Operational factors affecting microgravity levels in orbit

NASA Technical Reports Server (NTRS)

Olsen, R. E.; Mockovciak, J., Jr.

1980-01-01

Microgravity levels desired for proposed materials processing payloads are fundamental considerations in the design of future space platforms. Disturbance sources, such as aerodynamic drag, attitude control torques, crew motion and orbital dynamics, influence the microgravity levels attainable in orbit. The nature of these effects are assessed relative to platform design parameters such as orbital altitude and configuration geometry, and examples are presented for a representative spacecraft configuration. The possible applications of control techniques to provide extremely low acceleration levels are also discussed.

Desert Rats 2011 Mission Simulation: Effects of Microgravity Operational Modes on Fields Geology Capabilities

NASA Technical Reports Server (NTRS)

Bleacher, Jacob E.; Hurtado, J. M., Jr.; Meyer, J. A.

2012-01-01

Desert Research and Technology Studies (DRATS) is a multi-year series of NASA tests that deploy planetary surface hardware and exercise mission and science operations in difficult conditions to advance human and robotic exploration capabilities. DRATS 2011 (Aug. 30-Sept. 9, 2011) tested strategies for human exploration of microgravity targets such as near-Earth asteroids (NEAs). Here we report the crew perspective on the impact of simulated microgravity operations on our capability to conduct field geology.

Microgravity

NASA Image and Video Library

2004-04-15

Fluid Physics is study of the motion of fluids and the effects of such motion. When a liquid is heated from the bottom to the boiling point in Earth's microgravity, small bubbles of heated gas form near the bottom of the container and are carried to the top of the liquid by gravity-driven convective flows. In the same setup in microgravity, the lack of convection and buoyancy allows the heated gas bubbles to grow larger and remain attached to the container's bottom for a significantly longer period.

Microgravity Investigation of Cement Solidification

NASA Technical Reports Server (NTRS)

Neves, Juliana; Radlinska, Aleksandra; Scheetz, Barry

2017-01-01

Concrete is the most widely used man-made material in the world, second only to water. The large-scale production of cements contributes to approximately 5% anthropogenic CO2 emission. Microgravity research can lead to more durable and hence more cost-effective material.

Analysis of Statoliths Displacement in Chara Rhizoids for Validating the Microgravity-Simulation Quality of Clinorotation Modes

NASA Astrophysics Data System (ADS)

Krause, Lars; Braun, Markus; Hauslage, Jens; Hemmersbach, Ruth

2018-05-01

In single-celled rhizoids of the green algae Chara, positively gravitropic growth is governed by statoliths kept in a dynamically stable position 10-25 μ m above the cell tip by a complex interaction of gravity and actomyosin forces. Any deviation of the tube-like cells from the tip-downward orientation causes statoliths to sediment onto the gravisensitive subapical cell flank which initiates a gravitropic curvature response. Microgravity experiments have shown that abolishing the net tip-directed gravity force results in an actomyosin-mediated axial displacement of statoliths away from the cell tip. The present study was performed to critically assess the quality of microgravity simulation provided by different operational modes of a Random Positioning Machine (RPM) running with one axis (2D mode) or two axes (3D mode) and different rotational speeds (2D), speed ranges and directions (3D). The effects of 2D and 3D rotation were compared with data from experiments in real microgravity conditions (MAXUS sounding rocket missions). Rotational speeds in the range of 60-85 rpm in 2D and 3D modes resulted in a similar kinetics of statolith displacement as compared to real microgravity data, while slower clinorotation (2-11 rpm) caused a reduced axial displacement and a more dispersed arrangement of statoliths closer to the cell tip. Increasing the complexity of rotation by adding a second rotation axis in case of 3D clinorotation did not increase the quality of microgravity simulation, however, increased side effects such as the level of vibrations resulting in a more dispersed arrangement of statoliths. In conclusion, fast 2D clinorotation provides the most appropriate microgravity simulation for investigating the graviperception mechanism in Chara rhizoids, whereas slower clinorotation speeds and rotating samples around two axes do not improve the quality of microgravity simulation.

Effect of Actual and Simulated Microgravity on Cardiac Mass and Function in the Rat

NASA Technical Reports Server (NTRS)

Ray, Chester H.; Vasques, Marilyn; Miller, Todd H.; Wilkerson, M. Keith; Delp, Michael D.; Dalton, Bonnie (Technical Monitor)

2001-01-01

The purpose of this study was to test the hypothesis that exposure to actual or simulated microgravity induces cardiac atrophy in male Sprague-Dawley rats. For the microgravity study, rats were subdivided into four groups: Preflight (PF, n = 12); Flight (FL, n = 7); Flight Cage Simulation (SIM, n = 6), and Vivarium Control (VIV, n = 7). Animals in the FL group were exposed to 7 days of microgravity during the Spacelab 3 mission. Animals in the simulated microgravity study were subdivided into three groups: Control (CON, n = 20); 7 day hindlimb unloaded (7HU, n = 10); and 28 day unloaded (28HU, n = 19). In a subset of CON (n = 7) and 28HU (n = 6) rats, a catheter was advanced into the left ventricle to measure the rate of rise in ventricular pressure (+dP/dt) during standing as an estimate of cardiac contractility. After completion of their respective treatments, hearts were removed and weighed. Animals in the PF group were sacrificed 24 hr prior to launch while the FL group was sacrificed 11- 17 hr after landing. The SM and VIV groups were sacrificed 48 and 96 hr after the FL group, respectively. Heart mass was unchanged in adult animals exposed to 7 days of actual microgravity (PF 1.33 +/- .03 g; FL 1.32 +/- 0.02 g; SIM 1.28 +/- 0.04 g; VIV 1.35 +/- 0.04 g). Similarly, heart mass was unaltered with hinlimb unloading (CON 1.40 +/- 0.04 g; 7HU 1.35 +/- 0.06 g; 28HU 1.42 +/- 0.03 g). Hindlimb unloading also had no effect on myocardial contractility (CON 8055 +/- 385 mmHg/sec; 28HU 8545 +/- 755 mmHg/sec). These data suggest that cardiac atrophy does not occur following short-term exposure to microgravity, and that neither short- nor long-term simulated microgravity alter cardiac mass or function.

Analysis of Statoliths Displacement in Chara Rhizoids for Validating the Microgravity-Simulation Quality of Clinorotation Modes

NASA Astrophysics Data System (ADS)

Krause, Lars; Braun, Markus; Hauslage, Jens; Hemmersbach, Ruth

2018-01-01

In single-celled rhizoids of the green algae Chara, positively gravitropic growth is governed by statoliths kept in a dynamically stable position 10-25 μ m above the cell tip by a complex interaction of gravity and actomyosin forces. Any deviation of the tube-like cells from the tip-downward orientation causes statoliths to sediment onto the gravisensitive subapical cell flank which initiates a gravitropic curvature response. Microgravity experiments have shown that abolishing the net tip-directed gravity force results in an actomyosin-mediated axial displacement of statoliths away from the cell tip. The present study was performed to critically assess the quality of microgravity simulation provided by different operational modes of a Random Positioning Machine (RPM) running with one axis (2D mode) or two axes (3D mode) and different rotational speeds (2D), speed ranges and directions (3D). The effects of 2D and 3D rotation were compared with data from experiments in real microgravity conditions (MAXUS sounding rocket missions). Rotational speeds in the range of 60-85 rpm in 2D and 3D modes resulted in a similar kinetics of statolith displacement as compared to real microgravity data, while slower clinorotation (2-11 rpm) caused a reduced axial displacement and a more dispersed arrangement of statoliths closer to the cell tip. Increasing the complexity of rotation by adding a second rotation axis in case of 3D clinorotation did not increase the quality of microgravity simulation, however, increased side effects such as the level of vibrations resulting in a more dispersed arrangement of statoliths. In conclusion, fast 2D clinorotation provides the most appropriate microgravity simulation for investigating the graviperception mechanism in Chara rhizoids, whereas slower clinorotation speeds and rotating samples around two axes do not improve the quality of microgravity simulation.

Proposal of experimental setup on boiling two-phase flow on-orbit experiments onboard Japanese experiment module "KIBO"

NASA Astrophysics Data System (ADS)

Baba, S.; Sakai, T.; Sawada, K.; Kubota, C.; Wada, Y.; Shinmoto, Y.; Ohta, H.; Asano, H.; Kawanami, O.; Suzuki, K.; Imai, R.; Kawasaki, H.; Fujii, K.; Takayanagi, M.; Yoda, S.

2011-12-01

Boiling is one of the efficient modes of heat transfer due to phase change, and is regarded as promising means to be applied for the thermal management systems handling a large amount of waste heat under high heat flux. However, gravity effects on the two-phase flow phenomena and corresponding heat transfer characteristics have not been clarified in detail. The experiments onboard Japanese Experiment Module "KIBO" in International Space Station on boiling two-phase flow under microgravity conditions are proposed to clarify both of heat transfer and flow characteristics under microgravity conditions. To verify the feasibility of ISS experiments on boiling two-phase flow, the Bread Board Model is assembled and its performance and the function of components installed in a test loop are examined.

Microgravity nucleation and particle coagulation experiments support

NASA Technical Reports Server (NTRS)

Lilleleht, L. U.; Ferguson, F. T.

1987-01-01

A preliminary model for diffusion between concentric hemispheres was adapted to the cylindrical geometry of a microgravity nucleation apparatus, and extended to include the effects of radiation and conduction through the containment walls. Computer programs were developed to calculate first the temperature distribution and then the evolving concentration field using a finite difference formulation of the transient diffusion and radiation processes. The following estimations are made: (1) it takes approximately 35 minutes to establish a steady temperature field; (2) magnesium vapors released into the argon environment at the steady temperature distribution will reach a maximum supersaturation ratio of approximately 10,000 in the 20-second period at a distance of 15 cm from the source of vapors; and (3) approximately 750W electrical power will be required to maintain steady operating temperatures within the chamber.

Flame spread across liquids

NASA Technical Reports Server (NTRS)

Ross, Howard D.; Miller, Fletcher; Schiller, David; Sirignano, William

1995-01-01

Recent reviews of our understanding of flame spread across liquids show that there are many unresolved issues regarding the phenomenology and causal mechanisms affecting ignition susceptibility, flame spread characteristics, and flame spread rates. One area of discrepancy is the effect of buoyancy in both the uniform and pulsating spread regimes. The approach we have taken to resolving the importance of buoyancy for these flames is: (1) normal gravity (1g) and microgravity (micro g) experiments; and (2) numerical modeling at different gravitational levels. Of special interest to this work, as discussed at the previous workshop, is the determination of whether, and under what conditions, pulsating spread occurs in micro g. Microgravity offers a unique ability to modify and control the gas-phase flow pattern by utilizing a forced air flow over the pool surface.

Numerical and Experimental Investigation of the Effects of Acceleration Disturbances on Microgravity Experiments

NASA Technical Reports Server (NTRS)

Ramachandran, Narayanan

2000-01-01

Normal vibrational modes on large spacecraft are excited by crew activity, operating machinery, and other mechanical disturbances. Periodic engine burns for maintaining vehicle attitude and random impulse type disturbances also contribute to the acceleration environment of a Spacecraft. Accelerations from these vibrations (often referred to as g-jitter) are several orders of magnitude larger than the residual accelerations from atmospheric drag and gravity gradient effects. Naturally, the effects of such accelerations have been a concern to prospective experimenters wishing to take advantage of the microgravity environment offered by spacecraft operating in low Earth orbit and the topic has been studied extensively, both numerically and analytically. However, these studies have not produced a general theory that predicts the effects of multi-spectral periodic accelerations on a general class of experiments nor have they produced scaling laws that a prospective experimenter could use to assess how his/her experiment might be affected by this acceleration environment. Furthermore, there are no actual flight experimental data that correlates heat or mass transport with measurements of the periodic acceleration environment. The present investigation approaches this problem with carefully conducted terrestrial experiments and rigorous numerical modeling thereby providing comparative theoretical and experimental data. The modeling, it is hoped will provide a predictive tool that can be used for assessing experiment response to Spacecraft vibrations.

Effects of microgravity modeled by large gradient high magnetic field on the osteogenic initiation of human mesenchymal stem cells.

PubMed

Shi, Dongyan; Meng, Rui; Deng, Wanglong; Ding, Wenchao; Zheng, Qiang; Yuan, Wenji; Liu, Liyue; Zong, Chen; Shang, Peng; Wang, Jinfu

2010-12-01

Microgravity (MG) leads to a decrease in osteogenic potential of human bone marrow-derived mesenchymal stem cells (hMSCs). In the present study, we used large gradient high magnetic field (LGHMF) produced by a superconducting magnet to model MG (LGHMF-MG) and analyzed the effects of LGHMF-MG on survival, cytoskeleton and osteogenic potential of hMSCs. Results showed that the LGHMF-MG treatment for 6 h disrupted the cytoskeleton of hMSCs, and the LGHMF-MG treatment for 24 h led to cell death. LGHMF-MG treatments for 6 h in early stages of osteogenic induction (the pre-treatment before osteogenic induction, the beginning-treatment in the beginning-stage of osteogenic induction and the middle-treatment in the middle-stage of osteogenic induction) resulted in suppression on osteogenesis of hMSCs. The suppression intensity was reduced gradually as the treatment stage of LGHMF-MG was postponed. The LGHMF-MG treatment for 6 h in the ending-stage of osteogenic induction (the ending-treatment) had no obvious effect on osteogenesis of hMSCs. These results indicated that LGHMF-MG should affect the initiation of osteogenesis. Finally, the possible mechanism for the inhibition effect of LGHMF-MG on osteogenesis of hMSCs is discussed.

Vertebrate development in the environment of space: models, mechanisms, and use of the medaka

NASA Technical Reports Server (NTRS)

Wolgemuth, D. J.; Herrada, G.; Kiss, S.; Cannon, T.; Forsstrom, C.; Pranger, L. A.; Weismann, W. P.; Pearce, L.; Whalon, B.; Phillips, C. R.

1997-01-01

With the advent of space travel, it is of immediate interest and importance to study the effects of exposure to various aspects of the altered environment of space, including microgravity, on Earth-based life forms. Initial studies of space travel have focused primarily on the short-term effects of radiation and microgravity on adult organisms. However, with the potential for increased lengths of time in space, it is critical to now address the effects of space on all phases of an organism's life cycle, from embryogenesis to post-natal development to reproduction. It is already possible for certain species to undergo multiple generations within the confines of the Mir Space Station. The possibility now exists for scientists to consider the consequences of even potentially subtle defects in development through multiple phases of an organism's life cycle, or even through multiple generations. In this discussion, we highlight a few of the salient observations on the effects of the space environment on vertebrate development and reproductive function. We discuss some of the many unanswered questions, in particular, in the context of the choice of appropriate models in which to address these questions, as well as an assessment of the availability of hardware already existing or under development which would be useful in addressing these questions.

Effects of Traveling Magnetic Field on Dynamics of Solidification

NASA Technical Reports Server (NTRS)

Mazuruk, Konstantin; Grugel, Richard; Motakef, Shariar

2001-01-01

TMF is based on imposing a controlled phase-shift in a train of electromagnets, forming a stack. Thus, the induced magnetic field can be considered to be travelling along the axis of the stack. The coupling of this traveling wave with an electrically conducting fluid results in a basic flow in a form of a single axisymmetric roll. The magnitude and direction of this flow can be remotely controlled. Furthermore, it is possible to localize the effect of this force field though activating only a number of the magnets. This force field generated in the fluid can, in principle, be used to control and modify convection in the molten material. For example, it can be used to enhance convective mixing in the melt, and thereby modify the interface shape, and macrosegregation. Alternatively, it can be used to counteract thermal and/or solutal buoyancy forces. High frequency TMF can be used in containerless processing techniques, such as float zoning, to affect the very edge of the fluid so that Marangoni flow can be counter balanced. The proposed program consists of basic fundamentals and applications. Our goal in conducting the following experiments and analyses is to establish the validity of TMF as a new tool for solidification processes. Due to its low power consumption and simplicity of design, this tool may find wide spread use in a variety of space experiments. The proposed ground based experiments are intended to establish the advantages and limitations of employing this technique. In the fundamentals component of the proposed program, we will use theoretical tools and experiments with mercury to establish the fundamental aspects of TMF-induced convection through a detailed comparison of theoretical predictions and experimental measurements of flow field. In this work, we will conduct a detailed parametric study involving the effects of magnetic field strength, frequency, wave vector, and the fluid geometry. The applications component of this work will be focused on investigating the effect of TMF on the following solidification and pre-directional solidification processes: (1) Bridgman growth of Ga:Ge with the goal of counteracting the buoyancy-driven convection; (2) Mixing of Pb-Ga and Pb-Sn alloys with the aim of initiating and maintaining a uniform melt prior to solidification processing; and (3) Float Zone growth with the aim of identifying, through simulations and model experiments, conditions needed to counteract Marangoni flow in a microgravity environment. The proposed research has strong relevance to microgravity research and the objectives of the NRA. TMF can provide a unique and accurate mechanism for generation and control of desirable flow patterns for microgravity research. These attributes have significant relevance to 1) Alloy mixing prior to solidification in a microgravity environment. TMF can provide this mixing with a low level of power consumption; (2) TMF can offset the deleterious effects of Marangoni convection in microgravity containerless processing. Thus, TMF can be instrumental in further understanding this phenomena; (3) Generation of controlled flows will allow the investigation of the effect of these flows on growth morphology and growth kinetics; and (4) On Earth, TMF has the potential to significantly counter-balance thermosolutal convection, thereby creating conditions similar to those obtained in microgravity. Once demonstrated, this new tool for use in solidification has the strong potential to find applications in a host of microgravity material research projects.

Effects of spaceflight on the muscles of the murine shoulder.

PubMed

Shen, Hua; Lim, Chanteak; Schwartz, Andrea G; Andreev-Andrievskiy, Alexander; Deymier, Alix C; Thomopoulos, Stavros

2017-12-01

Mechanical loading is necessary for the development and maintenance of the musculoskeletal system. Removal of loading via microgravity, paralysis, or bed rest leads to rapid loss of muscle mass and function; however, the molecular mechanisms that lead to these changes are largely unknown, particularly for the spaceflight (SF) microgravity environment. Furthermore, few studies have explored these effects on the shoulder, a dynamically stabilized joint with a large range of motion; therefore, we examined the effects of microgravity on mouse shoulder muscles for the 15-d Space Transportation System (STS)-131, 13-d STS-135, and 30-d Bion-M1 missions. Mice from STS missions were euthanized within 4 h after landing, whereas mice from the Bion-M1 mission were euthanized within 14 h after landing. The motion-generating deltoid muscle was more sensitive to microgravity than the joint-stabilizing rotator cuff muscles. Mice from the STS-131 mission exhibited reduced myogenic ( Myf5 and -6 ) and adipogenic ( Pparg , Cebpa , and Lep ) gene expression, whereas either no change or an increased expression of these genes was observed in mice from the Bion-M1 mission. In summary, muscle responses to microgravity were muscle-type specific, short-duration SF caused dramatic molecular changes to shoulder muscles and responses to reloading upon landing were rapid.-Shen, H., Lim, C., Schwartz, A. G., Andreev-Andrievskiy, A., Deymier, A. C., Thomopoulos, S. Effects of spaceflight on the muscles of the murine shoulder. © FASEB.

Summary Report of Mission Acceleration Measurements for STS-78. Launched June 20, 1996

NASA Technical Reports Server (NTRS)

Hakimzadeh, Roshanak; Hrovat, Kenneth; McPherson, Kevin M.; Moskowitz, Milton E.; Rogers, Melissa J. B.

1997-01-01

The microgravity environment of the Space Shuttle Columbia was measured during the STS-78 mission using accelerometers from three different instruments: the Orbital Acceleration Research Experiment, the Space Acceleration Measurement System and the Microgravity Measurement Assembly. The quasi-steady environment was also calculated in near real-time during the mission by the Microgravity Analysis Workstation. The Orbital Acceleration Research Experiment provided investigators with real-time quasi-steady acceleration measurements. The Space Acceleration Measurement System recorded higher frequency data on-board for post-mission analysis. The Microgravity Measurement Assembly provided investigators with real-time quasi-steady and higher frequency acceleration measurements. The Microgravity Analysis Workstation provided calculation of the quasi-steady environment. This calculation was presented to the science teams in real-time during the mission. The microgravity environment related to several different Orbiter, crew and experiment operations is presented and interpreted in this report. A radiator deploy, the Flight Control System checkout, and a vernier reaction control system reboost demonstration had minimal effects on the acceleration environment, with excitation of frequencies in the 0.01 to 10 Hz range. Flash Evaporator System venting had no noticeable effect on the environment while supply and waste water dumps caused excursions of 2 x lO(exp -6) to 4 x 10(exp -6) g in the Y(sub b) and Z(sub b) directions. Crew sleep and ergometer exercise periods can be clearly seen in the acceleration data, as expected. Accelerations related to the two Life Science Laboratory Equipment Refrigerator/Freezers were apparent in the data as are accelerations caused by the Johnson Space Center Projects Centrifuge. As on previous microgravity missions, several signals are present in the acceleration data for which a source has not been identified. The causes of these accelerations are under investigation.