Search NASA⌕ Search

SEARCH · Search NASA

Results for “cultural differences”

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

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

At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1996

Microbial Diffraction Gratings as Optical Detectors for Heavy Metal Pollutants

As a significant industrial pollutant, cadmium is implicated as the cause of itai-itai disease. For biological detection of cadmium toxicity, an assay device has been developed using the motile response of the protozoa species, Tetrahymena pyriformis. This mobile protozoa measures 50 microns in diameter, swims at 10 body lengths per second, and aggregates into macroscopically visible patterns at high organism concentrations. The assay demonstrates a Cd(+2) sensitivity better than 1 micro-M and a toxicity threshold to 5 micro-M, thus encouraging the study of these microbial cultures as viable pollution detectors. Using two-dimensional diffraction patterns within a Tetrahymena culture, the scattered light intensity varies with different organism densities (population counts). The resulting density profile correlates strongly with the toxic effects at very low dosages for cadmium (less than 5 ppm) and then for poison protection directly (with nickel and copper antagonists competing with cadmium absorption). In particular, copper dosages as low as 0.1-0.5 mM Cu have shown protective antagonism against cadmium, have enhanced density variability for cultures containing 1 mM Cd(+2) and therefore have demonstrated the sensitivity of the optical detection system. In this way, such microbial diffraction patterns give a responsive optical measure of biological culture changes and toxicity determination in aqueous samples of heavy metals and industrial pollutants.

Noever, David↗
NASA NTRS1999

Effects of space flight and mixing on bacterial growth in low volume cultures

Previous investigations have shown that liquid suspension bacterial cultures grow to higher cell concentrations in spaceflight than on Earth. None of these studies included ground-control experiments designed to evaluate the fluid effects potentially responsible for the reported increases. Therefore, the emphasis of this research was to both confirm differences in final cell concentration between 1g and microgravity cultures, and to examine the effects of mixing as a partial explanation for this difference. Flight experiments were performed in the Fluid Processing Apparatus (FPA), aboard Space Shuttle Missions STS-63 and STS-69, with simultaneous 1g static and agitated controls. Additional static 1g, agitated, and clino-rotated controls were performed in 9-ml culture tubes. This research revealed that both E. coli and B. subtilis samples cultured in space flight grew to higher final cell densities (120-345% increase) than simultaneous static 1g controls. The final cell concentration of E. coli cells cultured under agitation was 43% higher than in static 1g cultures and was 102% higher with clino-rotation. However, for B. subtilis cultures grown while being agitated on a shaker or clino-rotated, the final cell concentrations were nearly identical to those of the simultaneous static 1g controls. Therefore, these data suggest that the unique fluid quiescence in the microgravity environment (lack of sedimentation, creating unique transfer of nutrients and waste products), was responsible for the enhanced bacterial proliferation reported in this and other studies.

STS-63 Shuttle Project↗
NASA NTRS2002

Fluid flow increases mineralized matrix deposition in 3D perfusion culture of marrow stromal osteoblasts in a dose-dependent manner

Bone is a complex highly structured mechanically active 3D tissue composed of cellular and matrix elements. The true biological environment of a bone cell is thus derived from a dynamic interaction between responsively active cells experiencing mechanical forces and a continuously changing 3D matrix architecture. To investigate this phenomenon in vitro, marrow stromal osteoblasts were cultured on 3D scaffolds under flow perfusion with different rates of flow for an extended period to permit osteoblast differentiation and significant matrix production and mineralization. With all flow conditions, mineralized matrix production was dramatically increased over statically cultured constructs with the total calcium content of the cultured scaffolds increasing with increasing flow rate. Flow perfusion induced de novo tissue modeling with the formation of pore-like structures in the scaffolds and enhanced the distribution of cells and matrix throughout the scaffolds. These results represent reporting of the long-term effects of fluid flow on primary differentiating osteoblasts and indicate that fluid flow has far-reaching effects on osteoblast differentiation and phenotypic expression in vitro. Flow perfusion culture permits the generation and study of a 3D, actively modeled, mineralized matrix and can therefore be a valuable tool for both bone biology and tissue engineering.

Non-NASA Center↗
NASA NTRS2003

Multilineage differentiation of rhesus monkey embryonic stem cells in three-dimensional culture systems

In the course of normal embryogenesis, embryonic stem (ES) cells differentiate along different lineages in the context of complex three-dimensional (3D) tissue structures. In order to study this phenomenon in vitro under controlled conditions, 3D culture systems are necessary. Here, we studied in vitro differentiation of rhesus monkey ES cells in 3D collagen matrixes (collagen gels and porous collagen sponges). Differentiation of ES cells in these 3D systems was different from that in monolayers. ES cells differentiated in collagen matrixes into neural, epithelial, and endothelial lineages. The abilities of ES cells to form various structures in two chemically similar but topologically different matrixes were different. In particular, in collagen gels ES cells formed gland-like circular structures, whereas in collagen sponges ES cells were scattered through the matrix or formed aggregates. Soluble factors produced by feeder cells or added to the culture medium facilitated ES cell differentiation into particular lineages. Coculture with fibroblasts in collagen gel facilitated ES cell differentiation into cells of a neural lineage expressing nestin, neural cell adhesion molecule, and class III beta-tubulin. In collagen sponges, keratinocytes facilitated ES cell differentiation into cells of an endothelial lineage expressing factor VIII. Exogenous granulocyte-macrophage colony-stimulating factor further enhanced endothelial differentiation. Thus, both soluble factors and the type of extracellular matrix seem to be critical in directing differentiation of ES cells and the formation of tissue-like structures. Three-dimensional culture systems are a valuable tool for studying the mechanisms of these phenomena.

Pluripotent Stem Cells/cytology/physiology↗
NASA NTRS1977

Application of wheat yield model to United States and India

The author has identified the following significant results. The wheat yield model was applied to the major wheat-growing areas of the US and India. In the US Great Plains, estimates from the winter and spring wheat models agreed closely with USDA-SRS values in years with the lowest yields, but underestimated in years with the highest yields. Application to the Eastern Plains and Northwest indicated the importance of cultural factors, as well as meteorological ones in the model. It also demonstrated that the model could be used, in conjunction with USDA-SRRS estimates, to estimate yield losses due to factors not included in the model, particularly diseases and freezes. A fixed crop calendar for India was built from a limited amount of available plot data from that country. Application of the yield model gave measurable evidence that yield variation from state to state was due to different mixes of levels of meteorological and cultural factors.

Feyerherm, A. M.↗
NASA NTRS1996

Microgravity Effects on Transendothelial Transport

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.

Tarbell, John M.↗
DOE OSTI2021

Cometabolic Vinyl Chloride Degradation at Acidic pH Catalyzed by Acidophilic Methanotrophs Isolated from Alpine Peat Bogs

Remediation of toxic chlorinated ethenes via microbial reductive dechlorination can lead to ethene formation; however, the process stalls in acidic groundwater, leading to the accumulation of carcinogenic vinyl chloride (VC). This study explored the feasibility of cometabolic VC degradation by moderately acidophilic methanotrophs. Furthermore, two novel isolates, Methylomonas sp. strain JS1 and Methylocystis sp. strain MJC1, were obtained from distinct alpine peat bogs located in South Korea. Both isolates cometabolized VC with CH 4 as the primary substrate under oxic conditions at pH at or below 5.5. VC cometabolism in axenic cultures occurred in the presence (10 μM) or absence (<0.01 μM) of copper, suggesting that VC removal had little dependence on copper availability, which regulates expression and activity of soluble and particulate methane monooxygenases in methanotrophs. The model neutrophilic methanotroph Methylosinus trichosporium strain OB3b also grew and cometabolized VC at pH 5.0 regardless of copper availability. Bioaugmentation of acidic peat soil slurries with methanotroph isolates demonstrated enhanced VC degradation and VC consumption below the maximum concentration level of 2 μg L –1 . Community profiling of the microcosms suggested species-specific differences, indicating that robust bioaugmentation with methanotroph cultures requires further research.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2001

Whole Blood Activation Results in Enhanced Detection of T Cell and Monocyte Cytokine Production by Flow Cytometry

An excellent monitor of the immune balance of peripheral circulating cells is to determine their cytokine production patterns in response to stimuli. Using flow cytometry a positive identification of cytokine producing cells in a mixed culture may be achieved. Recently, the ability to assess cytokine production following a wholeblood activation culture has been described. We compared whole blood culture to standard PBMC culture and determined the individual cytokine secretion patterns for both T cells and monocytes via flow cytometry. For T cells cytokine assessment following PMA +ionomycin activation: (1) a significantly greater percentages of T cells producing IFNgamma and IL-2 were observed following whole-blood culture; (2) altered T cell cytokine production kinetics were observed by varying whole blood culture times. In addition, a four-color cytometric analysis was used to allow accurate phenotyping and quantitation of cytokine producing lymphocyte populations. Using this technique we found IFNgamma production to be significantly elevated in the CD3+/CD8+ T cell population as compared to the CD3+/CD8- population following five hours of whole blood activation. Conversely, IL-2 and IL-10 production were significantly elevated in the CD3+/CD8- T cell population as compared to the CD3+/CD8+ population. Monocyte cytokine production was assessed in both culture systems following LPS activation for 24 hours. A three-color flow cytometric was used to assess two cytokines in conjunction with CD 14. The cytokine pairs used for analysis were IL-1a/IL-12, and IL-10ITNFa. Nearly all monocytes were stimulated to produce IL-1a, IL-12 and TNFalpha equally well in both culture systems. Monocyte production of IL-10 was significantly elevated following whole blood culture as compared to PBMC culture. IL-12 producing monocytes appeared to be a distinct subpopulation of the IL-1a producing set, whereas IL-10 and TNFa producing monocytes were largely mutually exclusive. IL-10 and TNFa producing monocytes may represent functionally different monocyte subsets with distinct functions. Whole blood culture eliminates the need to purify cell populations prior to culture and may have significant utility for the routine monitoring of the cytokine balances of the peripheral blood T cell and monocyte populations. In addition, there are distinct advantages to performing whole-blood (WB) activation as compared to PBMC activation. These advantages would include retaining all various cell-cell interactions as well as any soluble factors present in serum that influence cell activation. It is likely that the altered cytokine production observed following whole blood culture more accurately represents the in-vivo immune balance.

Sams, Clarence F.↗
NASA NTRS1998

Variability in Beta-Adrenergic Receptor Population in Cultured Chicken Muscle Cells

Investigations into expression of the beta-adrenergic receptor (bAR) in chicken skeletal muscle cells in culture were initiated because several beta-adrenergic receptor agonists are known to increase skeletal muscle protein deposition in avian and mammalian species. During initial attempts to study the bAR population on the surface of chicken skeletal muscle cells, we observed a high degree of variability that was later found to be the result of using different batches of horse serum in the cell culture media. The separation between total binding and nonspecific binding in cells grown in two serum samples was approximately two-fold The number of nuclei within multinucleated myotubes was not significantly different in cells grown in the two serum samples. To investigate whether these two sera had an effect on coupling efficiency between bAR population and cAMP production, the ability of these cells to synthesize cAMP was also assessed. Despite the two-fold difference in receptor population, the ability of these cells to synthesize cAMP was not significantly different. Because of the possible link between bAR population and muscle protein, we also determined if the quantity of the major skeletal muscle protein, myosin, was affected by conditions that so drastically affected the bAR population. The quantity of myosin heavy chain was not significantly different.

Young, Ronald B↗
NASA NTRS2011

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

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.

Zhang, Ye↗
DOE OSTI2023

Butyric Acid Production from Delignified Corn Stover Using Thermophilic Bacterial Co-Cultures

Butyric acid (BA) is a valuable platform chemical in the food and pharmaceutical industries, and it is also a potential precursor for the production of biobutanol and sustainable aviation fuels (SAFs). BA is mainly synthesized from petroleum; thus, cost-effective, and sustainable alternatives for its production are attracting the interest of several sectors. The present work proposes a solids-to-acids bioprocess to produce BA from corn stover utilizing a co-culture that consists of two thermophilic bacteria, Clostridium thermocellum, a well-known efficient degrader of insoluble and oligomeric cellulosic substrates, and Clostridium thermobutyricum, a highly efficient BA producer from monomeric sugars. After initial proof of concept experiments, a series of optimization studies were carried out to evaluate the process limits of this co-culture. First, the co-cultivation of both microorganisms at different inoculum sizes in deacetylated and mechanically refined corn stover (DMR) was evaluated. No significant differences were found on the solids deconstruction and carbohydrates utilization among all the treatments. In addition, BA production was similar under all conditions, ranging between 2.1 and 2.4 g/L. Next, the deconstruction, and BA production capabilities of the co-culture at increased DMR solids contents (3, 4.5, and 6% (w/v)) were tested. Although no difference was observed in the solids deconstruction and carbohydrates utilization among treatments, BA production increased concomitantly to solids loading; the maximum values observed were 2.8, 3.6, and 6.2 g/L in the 3, 4.5, and 6% treatments, respectively. In fact, BA production did not reach its absolute maximum in the 6% treatment after 160 h of fermentation. Lastly, a fed-batch experiment was performed to investigate the co-culture capabilities and possible system constraints to achieve higher BA titers. Data on substrate modifications and product formation as well as on the growth of each microorganism will be shown. Results from this work demonstrate a promising bioprocess approach for the production of BA from lignocellulosic biomass using a thermophilic bacterial co-culture.

bacteria↗
NASA NTRS2019

Predicting Cancer Risk from Ionizing Radiation

The ability to predict cancer risk associated with exposure to low doses of high-LET ionizing radiation (IR) remains a challenge. Epidemiological methods lack the sensitivity and power to provide detailed risk estimates for cancer and ignore individual variance in IR sensitivity. We have hypothesized that DNA repair capacity can be used as a marker to evaluate and differentiate individual radiation sensitivity. More specifically, this work is based on the concept that the combined time-dose dependence of radiation-induced foci (RIF) of p53-binding protein 1 (53BP1) following low-LET exposure contains sufficient information to infer sensitivity to any other LET. Our hypothesis was tested in 15 different mouse strains as well as in primary human immune cells. We first approached individual ionizing radiation sensitivity in a mouse model by culturing primary skin fibroblasts extracted from 76 mice of 15 different genetic backgrounds and exposing them to HZE particles and X-rays. This work is one of the most extensive studies on the kinetics and possible genetic underpinnings of radiation-induced DNA damage and repair. Our results is in agreement with a DNA repair model we previously postulated, where nearby DNA double strand breaks (DSB) in the nucleus are brought together for more efficient repair, leading to RIF clustering. Such mechanism was evidenced by a specific dose and LET dependence of RIF numbers. Briefly, RIF quantification after low-LET X-ray exposure showed an asymptotic saturation for doses between 1 Gy and 4 Gy 4 hours post-irradiation across all 15 strains. The clustering of DSB across all strains also led to more RIF/Gy for lower LET (X-ray and 350 MeV/n Ar) than for higher LET (600 MeV/n Fe) 4 hours post-exposure. Considering the fact that the number of DSB/Gy should be independent of LET, our data suggest there are more DSB in individual RIF as the LET increases. RIF numbers for 24 and 48 hours post-exposure led to the inverse trend, with more remaining RIF/Gy for higher LET (by 600 MeV/n Fe). This result suggests cells have more difficulty resolving RIF from higher LET as they the number DSB/RIF increases. Note that for most conditions, the variance of RIF/Gy was small within individual animals of the same strain and large between strains, suggesting a strong genetics component. Furthermore, we present our preliminary data from an ongoing study on human genetic associations with IR sensitivity. To address the human variability in responses to HZE particle irradiation in a maximally comprehensive manner, we are in the process of collecting and isolating primary blood mononuclear cells from 768 healthy subjects of European descent, 18-75 years of age, 50/50 male/female distribution. We have analyzed 53BP1+ RIF formation as well as oxidative stress and cell death in primary cells from 192 subjects in response to the same HZE particles as used in mice: 600 MeV/n Fe, 350 MeV/n Ar and 350 MeV/n Si, 1.1 and 3 particles/100m2, 4 and 24 hours after irradiation. We will next complete the quantification of HZE particle-induced DNA and cellular damage in the remaining subjects and compare it to their responses to low-LET irradiation. Finally, we will perform GWAS analysis to identify human genomic associations with IR sensitivity and potential targets for biomarker development.

High-LET radiation↗
DOE OSTI2022

Movement with meaning: integrating information into meta-ecology

Fluxes of matter, energy and information over space and time contribute to ecosystems' functioning and stability. The meta-ecosystem framework addresses the dynamics of ecosystems linked by these fluxes but, to date, has focused solely on energy and matter. Here, we synthesize existing knowledge of information's effects on local and connected ecosystems and demonstrate how new hypotheses emerge from the integration of ecological information into meta-ecosystem theory. First, we begin by defining information and reviewing how it flows among ecosystems to affect connectivity, local ecosystem function and meta-ecosystem dynamics. We focus on the role of semiotic information: that which can reduce an individual's – or a group's – uncertainty about the state of the world. Semiotic information elicits behavioral, developmental and life history responses from organisms, potentially leading to fitness consequences. Organisms' responses to information can ripple through trophic interactions to influence ecosystem processes, their local and regional dynamics, and the spatiotemporal flows of energy and matter, therefore information should affect meta-ecosystem dynamics such as stability and productivity. While specific subdisciplines of ecology currently consider different types of information (e.g. social and cultural information, natural and artificial light or sound, body condition, genotype and phenotype), many ecological models currently account for neither the spatio–temporal distribution of information nor its perception by organisms. We identify the empirical, theoretical and philosophical challenges in developing a robust information meta-ecology and offer ways to overcome them. Finally, we present new hypotheses for how accounting for realistic information perception and responses by organisms could impact processes such as home range formation and spatial insurance, and thus our understanding of ecological dynamics across spatial and temporal scales. Accounting for information will be essential to understanding how dynamics such as fitness, organismal movement and trophic interactions influence meta-ecosystem functioning, and predicting how ecosystem processes are affected by anthropogenic pressures.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

S. elongatus PCC 7942 Carbon Metabolism Proteomics (MC-DP2)

The purpose of this experiment was to examine the redox proteome of S. elongatus PCC 7942 CscB/SPS under different light conditions (light and dark) and culture conditions (dense and dilute optical density). Samples were processed using a resin-assisted capture (RAC) workflow with TMT labeling to enrich and quantify protein cysteines which were differentially oxidized under four conditions. The datasets were generated by a Q Exactive Plus Orbitrap Mass Spectrometer coupled with a Waters nanoAcquity UPLC, then searched by MSGF+ for downstream redox PTM analysis.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1990

Growing And Assembling Cells Into Tissues

Laboratory process for growth and assembly of mammalian cells into tissue-like masses demonstrated with hamster and rat cells. New process better able to provide culture environment with reduced fluid shear stress, freedom for three-dimensional spatial orientation of particles suspended in culture medium, and localization of particles of different or similar sedimentation properties in similar spatial region.

Wolf, David A.↗
NASA NTRS1989

In vitro regeneration of Basella alba L

Basella alba L. is a tropical vine used as a vegetable in some Asian and African countries. It has potential as a nontraditional crop for small family farms. A short day plant, it blooms during the fall, provided the temperatures are mild. In the southeastern U.S., the short days of fall are associated with subfreezing temperatures, and plants are killed before blooming. Attempts were made to regenerate the plant using tissue culture techniques. Several trials were conducted with different media, hormones, and explants. It was found that nodal segments on Gamborg medium regenerated shoots. Interaction studies of auxins and cytokinins indicated that its endogeneous auxin content might be high because callus proliferated in almost all treatments and roots initiated even when the medium was not supplemented with an auxin.

Edney, Norris Allen↗
NASA NTRS1998

Rapid System to Quantitatively Characterize the Airborne Microbial Community

Bioaerosols have been linked to a wide range of different allergies and respiratory illnesses. Currently, microorganism culture is the most commonly used method for exposure assessment. Such culture techniques, however, generally fail to detect between 90-99% of the actual viable biomass. Consequently, an unbiased technique for detecting airborne microorganisms is essential. In this Phase II proposal, a portable air sampling device his been developed for the collection of airborne microbial biomass from indoor (and outdoor) environments. Methods were evaluated for extracting and identifying lipids that provide information on indoor air microbial biomass, and automation of these procedures was investigated. Also, techniques to automate the extraction of DNA were explored.

Macnaughton, Sarah J.↗