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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.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

Using NASA's GeneLab for VESGEN Systems Analysis of Vascular Phenotypes from Stress and Other Signaling Pathways

One fundamental requirement shared by humans with all higher terrestrial life forms, including other vertebrates, insects, and higher land plants, is a complex, fractally branching vascular system. NASA's VESsel GENeration Analysis (VESGEN) software maps and quantifies vascular trees, networks, and tree-network composites according to weighted physiological rules such as vessel connectivity, tapering and bifurcational branching. According to fluid dynamics, successful vascular transport requires a complex distributed system of highly regulated laminar flow. Microvascular branching rules within vertebrates, dicot leaves and the other organisms therefore display many similarities. A unifying perspective is that vascular patterning offers a useful readout of molecular signaling that necessarily integrates these complex pathways. VESGEN has elucidated changes in vascular pattern resulting from inflammatory, developmental and other signaling within numerous tissues and major model organisms studied for Space Biology. For a new VESGEN systems approach, we analyzed differential gene expression in leaves of Arabidopsis thaliana reported by GeneLab (GLDS-7) for spaceflight. Vascularrelated changes in leaf gene expression were identified that can potentially be phenocopied by mutants in ground-based experiments. To link transcriptional, protein and other molecular change with phenotype, alterations in the spatial and dynamic dimensions of vascular patterns for Arabidopsis leaves and other model species are being co-localized with signaling patterns of single molecular expression analyzed as information dimensions. Previously, Drosophila microarray data returned from space suggested significant changes in genes related to wing venation development that include EGF, Notch, Hedghog, Wingless and Dpp signaling. Phenotypes of increasingly abnormal ectopic wing venation in the (non-spaceflight) Drosophila wing generated by overexpression of a Notch antagonist were analyzed by VESGEN. Other VESGEN research applications include the mouse retina, GI and coronary vessels, avian placental analogs and translational studies in the astronaut retina related to health challenges for long-duration missions.

Venation↗
NASA NTRS2018

A Diverse Mammal-Dominated, Footprint Assemblage from Wetland Deposits in the Lower Cretaceous of Maryland

A newly discovered assemblage of predominantly small tracks from the Cretaceous Patuxent Formation at NASA’s Goddard Space Flight Center, Maryland, reveals one of the highest track densities and diversities ever reported (~70 tracks, representing at least eight morphotypes from an area of only ~2 m(exp 2)). The assemblage is dominated by small mammal tracks including the new ichnotxon Sederipes goddardensis, indicating sitting postures. Small crow-sized theropod trackways, the first from this unit, indicate social trackmakers and suggest slow-paced foraging behavior. Tracks of pterosaurs, and other small vertebrates suggest activity on an organic-rich substrate. Large well-preserved sauropod and nodosaurs tracks indicate the presence of large dinosaurs. The Patuxent Formation together with the recently reported Angolan assemblage comprise the world’s two largest Mesozoic mammal footprint assemblages. The high density of footprint registration at the NASA site indicates special preservational and taphonomic conditions. These include early, penecontemporaneous deposition of siderite in organic rich, reducing wetland settings where even the flesh of body fossils can be mummified. Thus, the track-rich ironstone substrates of the Patuxent Formation, appear to preserve a unique vertebrate ichnofacies, with associated, exceptionally-preserved body fossil remains for which there are currently no other similar examples preserved in the fossil record.

Ray Stanford↗
NASA NTRSDate not supplied

Murine Spine Composition and Mechanics are Maintained After 30-Days of Spaceflight

As NASA prepares to send astronauts on deep space missions, understanding the detrimental effects of spaceflight on the body is imperative. Spaceflight is known to negatively affect the spine, with astronauts experiencing systemic bone loss and increased post-flight risk of intervertebral disc herniation. Space investigations with rodent models have characterized some of the effects of spaceflight on the mammalian body, but variable experimental conditions have made it difficult to cohesively interpret results. These conditions include housing, flight duration, and for the spine, anatomical location. Thus, the objective of this study was to comprehensively characterize the effects of spaceflight on the bulk properties of the murine lumbar spine. To do this, we examined the lumbar spine of mice flown on the NASA Rodent Research 10 mission and analyzed disc biochemical content, disc joint material properties, lumbar vertebral body microarchitecture, and proximal tibia microarchitecture. Finally, we qualitatively examined bone growth in the vertebral bodies using confocal microscopy and on-orbit injections of calcein. Contrary to prior results, we found little to no effect of spaceflight on lumbar spine properties. Spaceflight, however, did negatively affect both cortical and trabecular bone properties of the proximal tibia load-bearing site. We hypothesize that this may be due to loading associated with increased physical activity in the second half of the mission, observed on in-flight videos, that reload the lumbar spine as mice utilize quadruped ambulation. This increased activity occurs after an initial period of relative inactivity in microgravity. In support of this hypothesis, we observed new L5 bone formation in the last seven days of spaceflight, suggesting that current 30-day experimental flight conditions may not be as effective at lumbar spine unloading as previous shorter flights.

mouse↗
NASA NTRS1971

Reference earth orbital research and applications investigations (blue book). Volume 8: Life sciences

The functional program element for the life sciences facilities to operate aboard manned space stations is presented. The life sciences investigations will consist of the following subjects: (1) medical research, (2) vertebrate research, (3) plant research, (4) cells and tissue research, (5) invertebrate research, (6) life support and protection, and (7) man-system integration. The equipment required to provide the desired functional capability for the research facilities is defined. The goals and objectives of each research facility are described.

Source record↗
NASA NTRS1971

Comparisons of the polypeptide chains of globins.

Discussion of the amino acid differences and minimum base differences per codon due to mutations which took place during divergent evolution of vertebrates from a common ancestral gene. The ?random mutation model' of evolution is examined by comparing a carp alpha Hb chain and six mammalian alpha Hb chains in terms of the genetic code. The occurrence of recognizable three-base changes is analyzed and a summary of the distribution of changes in the hemoglobin and myoglobin chains is given for 148 sites.

Jukes, T. H.↗
NASA NTRS1974

Comments on papers by Reichert and Wong

Papers of Reichert and Wong (1971) and Reichert (1972) are referred to as erroneous in stating that in their work with cytochrome c sequences they demonstrated that vertebrates have achieved a higher organized genetic message with a higher fidelity in the DNA-to-protein information processing channel. Arguments are given to contest that statement.

Gatlin, L. L.↗
NASA NTRS1972

Applications of the direct photon absorption technique for measuring bone mineral content in vivo. Determination of body composition in vivo

The bone mineral content, BMC, determined by monoenergetic photon absorption technique, of 29 different locations on the long bones and vertebral columns of 24 skeletons was measured. Compressive tests were made on bone from these locations in which the maximum load and maximum stress were measured. Also the ultimate strain, modulus of elasticity and energy absorbed to failure were determined for compact bone from the femoral diaphysis and cancellous bone from the eighth through eleventh thoracic vertebrae. Correlations and predictive relationships between these parameters were examined to investigate the applicability of using the BMC at sites normally measured in vivo, i.e. radius and ulna in estimating the BMC and/or strength of the spine or femoral neck. It was found that the BMC at sites on the same bone were highly correlated r = 0.95 or better; the BMC at sites on different bones were also highly interrelated, r = 0.85. The BMC at various sites on the long bones could be estimated to between 10 and 15 per cent from the BMC of sites on the radius or ulna.

Cameron, J. R.↗
NASA NTRS1975

Principles of Gravitational Biology

Physical principles of gravitation are enumerated, including gravitational and inertial forces, weight and mass, weightlessness, size and scale effects, scale limits of gravitational effects, and gravity as biogenic factor. Statocysts, otolithic organs of vertebrates, gravity reception in plants, and clinostat studies for gravitation orientation are reviewed. Chronic acceleration is also studied, as well as physiology of hyper and hypodynamic fields. Responses of animals to a decreased acceleration field are examined, considering postural changes, work capacity, growth, and physiologic deadaptation.

Arthur H Smith↗
NASA NTRS1976

Organism support for life sciences spacelab experiments

This paper presents an overview of the U.S. life sciences laboratory concepts envisioned for the Shuttle/Spacelab era. The basic development approach is to provide a general laboratory facility supplemented by specific experiment hardware as required. The laboratory concepts range from small carry-on laboratories to fully dedicated laboratories in the Spacelab pressurized module. The laboratories will encompass a broad spectrum of research in biology and biomedicine requiring a variety of research organisms. The environmental control and life support of these organisms is a very important aspect of the success of the space research missions. Engineering prototype organism habitats have been designed and fabricated to be compatible with the Spacelab environment and the experiment requirements. These first-generation habitat designs and their subsystems have supported plants, cells/tissues, invertebrates, and small vertebrates in limited evaluation tests. Special handling and transport equipment required for the ground movement of the experiment organisms at the launch/landing site have been built and tested using these initial habitat prototypes.

Drake, G. L.↗