SEARCH · Search NASA

Results for “morphometric analysis”

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.

SourceResearch connectionFrom yearThrough year

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

At least 73 records · Page 4

All sources NASA NTRS DOE OSTI

NASA NTRS1991

Compressive strain in Lunae Planum-shortening across wrinkle ridges

Wrinkle ridges have long been considered to be structural or structurally controlled features. Most, but not all, recent studies have converged on a model in which wrinkle ridges are structural features formed under compressive stress; the deformation being accommodated by faulting and folding. Given that wrinkle ridges are compressive tectonic features, an analysis of the associated shortening and strain provides important quantitative information about local and regional deformation. Lunae Planum is dominated by north-south trending ridges extending from Kasei Valles in the north to Valles Marineris in the south. To quantify the morphometric character, a photoclinometric study was undertaken for ridges on Lunae Planum using the Davis and Soderblom. More than 25 ridges were examined between long. 57 and 80 deg, lat. 5 to 25 deg N. For each ridge, several profiles were obtained along its length. Ridge width, total relief, and elevation offset were measured for each ridge. Analyses are given.

Plescia, J. B.↗

NASA NTRS1981

Morphometric consistency with the Hausdorff-Besicovich dimension

Studies using different measurement resolutions on a single morphologic feature may yield vastly different measured values for the perimeter. Apparent internal inconsistencies such as these have greatly impeded the numerical taxonomy, description, and modeling of landforms. Fortunately, the underlying internal consistency of measurements can often be reestablished by introducing the Hausdorff-Besicovich dimension into the analysis. This is demonstrated here by the example of perimeter-area ratio measurements made on some of the complicated ejecta deposits that surround many Martian meteorite-impact craters.

Woronow, A.↗

NASA NTRS1977

Crater morphometry from bistatic radar

In the present paper, bistatic radar techniques are discussed which can be used to identify and measure the dimensions of anomalously scattering regions on planetary surfaces. The morphometric potential of the bistatic radar is demonstrated by an example in which spectral features in Apollo 14 echoes are correlated with parts of the lunar crater Lansberg. Crater dimensions, including width of interior walls and extent of the ejecta blanket, are determined from a quantitative analysis. It is shown that the technique can be generalized for scattering areas at arbitrary positions with respect to the ground track, and could easily be inverted for characterization of a 'blind' target, such as Venus.

Simpson, R. A.↗

DOE OSTI2020

Validation and Sensitivity Analysis of a 1-D Lake Model Across Global Lakes

Lakes have important influence on weather and climate from local to global scales. However, their prediction using numerical models is notoriously difficult because lakes are highly heterogeneous across the globe, but observations are sparse. In this study, we assessed the performance of a 1-D lake model in simulating the thermal structures of 58 lakes with diverse morphometric and geographic characteristics by following the phase 2a local lake protocol of the Inter-sectoral Impact Model Intercomparison Project (ISIMIP2a). After calibration, the root-mean-square errors (RMSE) were below 2 °C for 70% and 75% of the lakes for epilimnion and full-profile temperature simulations, with an average of 1.71 °C and 1.43 °C, respectively. The model performance mainly depended on lake shape rather than location, supporting the possibility of grouping model parameters by lake shape for global applications. Furthermore, through machine-learning based parameter sensitivity tests, we identified turbulent heat fluxes, wind-driven mixing and water transparency as the major processes controlling lake thermal and mixing regimes. Snow density was also important for modeling the ice phenology of high-latitude lakes. The relative influence of the key processes and the corresponding parameters mainly depended on lake latitude and depth. Turbulent heat fluxes showed a decreasing importance in affecting epilimnion temperature with increasing latitude. Wind-driven mixing was less influential to lake stratification for deeper lakes while the impact of light extinction, on the contrary, showed a positive correlation with depth. Our findings may guide improvements in 1-D lake model parameterizations to achieve higher fidelity in simulating global lake thermal dynamics.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2022

From Mouse to Human: Cellular Morphometric Subtype Learned From Mouse Mammary Tumors Provides Prognostic Value in Human Breast Cancer

Mouse models of cancer provide a powerful tool for investigating all aspects of cancer biology. In this study, we used our recently developed machine learning approach to identify the cellular morphometric biomarkers (CMB) from digital images of hematoxylin and eosin (H&E) micrographs of orthotopic Trp53-null mammary tumors (n = 154) and to discover the corresponding cellular morphometric subtypes (CMS). Of the two CMS identified, CMS-2 was significantly associated with shorter survival (p = 0.0084). We then evaluated the learned CMB and corresponding CMS model in MMTV-Erbb2 transgenic mouse mammary tumors (n = 53) in which CMS-2 was significantly correlated with the presence of metastasis (p = 0.004). We next evaluated the mouse CMB and CMS model on The Cancer Genome Atlas breast cancer (TCGA-BRCA) cohort (n = 1017). Kaplan–Meier analysis showed significantly shorter overall survival (OS) of CMS-2 patients compared to CMS-1 patients (p = 0.024) and added significant prognostic value in multi-variable analysis of clinical and molecular factors, namely, age, pathological stage, and PAM50 molecular subtype. Thus, application of CMS to digital images of routine workflow H&E preparations can provide unbiased biological stratification to inform patient care.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2021

First report of Seville root-knot nematode, Meloidogyne hispanica (Nematoda: Meloidogynidae) in the USA and North America

A high number of second stage juveniles of the root-knot nematode were recovered from soil samples collected from a corn field, located in Pickens County, South Carolina, USA in 2019. Extracted nematodes were examined morphologically and molecularly for species identification which indicated that the specimens of root knot juveniles were Meloidogyne hispanica. The morphological examination and morphometric details from second-stage juveniles were consistent with the original description and redescriptions of this species. The ITS rRNA, D2-D3 expansion segments of 28S rRNA, intergenic COII-16S region, nad5 and COI gene sequences were obtained from the South Carolina population of M. hispanica. Phylogenetic analysis of the intergenic COII-16S region of mtDNA gene sequence alignment using statistical parsimony showed that the South Carolina population clustered with Meloidogyne hispanica from Portugal and Australia. To our best knowledge, this finding represents the first report of Meloidogyne hispanica in the USA and North America.

59 BASIC BIOLOGICAL SCIENCES↗

NASA NTRS2023

Elucidating the morphology and ecology of Eoandromeda octobrachiata from the Ediacaran of South Australia

Eoandromeda octobrachiata is a poorly understood Ediacaran organism, with spiral octoradial arms, found in South Australia and South China. The informal Nilpena member of the Rawnsley Quartzite, Flinders Ranges in South Australia preserves more than 200 specimens of Eoandromeda. Here we use the novel application of rotational geometric morphometrics together with palaeoenvironmental information to provide a better insight into their palaeobiology and ecology, and to address conflicting hypotheses regarding mode of life and taxonomic affinity. We find that Eoandromeda probably had a radially symmetrical shape in life, was cone shaped and had a high relief off the microbial mat. Analysis of the symmetric and asymmetric shape components showed that they deform strongly in the direction of palaeocurrent, therefore they are thought to be made of a flexible material. Almost all specimens are compressed flat. Specimens that appear to have not fully collapsed support the idea that Eoandromeda was probably cone shaped and suggest that they possibly collapsed spirally. Our shape analysis, along with observed morphological features, support a benthic rather than pelagic mode of life. Morphological and ecological inconsistencies do not fully support the hypothesis of a Ctenophora taxonomic affinity.

Tory L. Botha↗

NASA NTRSDate not supplied

Changes in Plants Developed from Imbibed Seeds Irradiated by Simulated Solar Particle Events

One of the major concerns for long-term exploration missions beyond the Earth’s magnetosphere is radiation risk primarily from solar particle events (SPEs) and galactic cosmic rays (GCRs). With the goal of enabling manned Mars exploration, the production of fresh food during long duration space missions may provide nutritional supplementation and benefit astronauts’ behavioral health. However, the effects of space radiation on plants and plant propagules have not been sufficiently investigated and characterized. In this study, we evaluated the effect of simulated SPEs on imbibed seeds of mizuna mustard, ‘Outredgeous’ red romaine lettuce, and ‘Red Robin’ dwarf tomato. Seeds were exposed to various doses of simulated SPEs (0, 40, 80 cGy, and 200 cGy), either acutely or at a low dose rate (LDR only for 40 and 80 cGy doses), using the NASA Space Radiation Laboratory (NSRL) facility at Brookhaven National Lab (BNL). Simulated SPE exposure was achieved using sequential exposures to protons with a broad energy range at 50-150 MeV/n. Control and irradiated seeds were planted either onto 0.5% MS-based agar plates containing required nutrients for early seedling analysis, or in peat plugs/pots for 28 day (mizuna and lettuce) and 91 day (tomato) grow outs. All plants were maintained under space-vehicle relevant conditions at 3000 ppm CO2, 50% RH, and 23°C, and a 16/8 h photoperiod with 300 μmol·m(exp -2)·s(exp -1) photosynthetically active radiation. Plant/fruit morphometrics and edible fresh mass were measured. Additionally, nutrient analyses were performed on mizuna and tomato fruit. Seedlings from irradiated seeds (both 40 and 80 cGy) showed significant and dose dependent impacts on cotyledon development and root length. Interestingly, small, but significant changes in vitamin content were found in mizuna and tomato fruits grown from 80 cGy (LDR) irradiated seeds. In addition, 80 cGy (LDR) simulated SPEs significantly delayed tomato early seedling development and plant growth, and reduced the quantity of fruits produced from the surviving plants. (This study was supported by NASA Human Research Program.)

J. T. Richards↗

NASA NTRSDate not supplied

Changes in Plants Developed from Imbibed Seeds Irradiated by Simulated Solar Particle Events

One of the major concerns for long-term exploration missions beyond the Earth’s magnetosphere is radiation risk primarily from solar particle events (SPEs) and galactic cosmic rays (GCRs). With the goal of manned Mars exploration, the production of fresh food during long duration space missions may provide nutritional supplementation and benefit astronauts’ behavioral health. However, the effects of space radiation on plants and plant propagules have not been sufficiently investigated and characterized. In this study, we evaluated the effect of simulated SPEs on imbibed seeds of mizuna mustard, ‘Outredgeous’ red romaine lettuce, and ‘Red Robin’ dwarf tomato. Seeds were exposed to various doses of simulated SPEs (0, 40, 80 cGy, and 200 cGy), either acutely or at a low dose rate (LDR only for 40 and 80 cGy doses), using the NASA Space Radiation Laboratory (NSRL) facility at Brookhaven National Lab (BNL). Simulated SPE exposure was achieved using sequential exposures to protons with a broad energy range at 50-150 MeV/n. Control and irradiated seeds were planted either onto 0.5% MS-based agar plates containing required nutrients for early seedling analysis, or in peat plugs/pots for 28 day (mizuna and lettuce) and 91 day (tomato) grow outs. All plants were maintained under space-vehicle relevant controlled environment conditions at 3000 ppm CO2, 50% RH, and 23°C, and a 16/8 h photoperiod with 300 μmol·m-2·s-1 photosynthetically active radiation. Plant/fruit morphometrics and edible fresh mass were measured. In addition, nutrient analyses were performed for both mizuna and ripe tomatoe fruit. Seedlings from irradiated seeds (both 40 cGy and 80 cGy) showed significant changes in cotyledon development, as well as root length. Interestingly, small, but significant changes in vitamin content were found in mizuna and tomato fruits grown from 80 cGy (LDR) irradiated seeds. In addition, 80 cGy (LDR) simulated SPEs significantly affected tomato early seedling development, plant growth, and the quantity of fruits produced from the surviving plants. Generally, compared to 80 cGy, 40 cGy (LDR) of simulated SPEs displayed some impacts to the seeds and seedlings, but to a much lesser degree. (This study was supported by NASA Human Research Program.)

J.T. Richards↗

DOE OSTI2024

First Report and Molecular Variability of Belonolaimus longicaudatus Associated with Turfgrass in Maryland

Abstract Turfgrass is a crop used extensively in athletic fields and golf courses in Maryland. A soil sample collected in July 2023 from an athletic field in Baltimore County, Maryland, part of a turfgrass nematode survey, containedBelonolaimus longicaudatus. In the southeastern United States,B. longicaudatusis an economically important pathogen of warm season turfgrass. The density was four individuals/100 cm 3 of soil, and no visual symptoms were observed in the bermudagrass field. Morphological features and morphometrics of males and females were consistent withB. longicaudatusand placed the Maryland population in a subclade that was geographically represented by populations from north and west Florida, Texas, and South Carolina. Sequencing of the internal transcribed spacer region ITS1 and ITS2 and 28S large ribosomal subunit D2-23 expansion region confirmed the species' identity. Phylogenetic trees and parsimony network analysis placed the Maryland isolate in a large grouping ofB. longicaudatuspopulations including those from Alabama, Delaware, Florida, Indiana, Mississippi, South Carolina, and Texas. To our knowledge, this is the first report ofB. longicaudatusin Maryland.

Zoology↗

NASA NTRS1982

Tharsis volcanoes - Separation distances, relative ages, sizes, morphologies, and depths of burial

Network analysis indicates the separation distances of the Tharsis volcanoes to be 700 to 900 km; this is considered to be the thickness of the Tharsis thermal lithosphere or 'tectosphere' which has thickened with time. Although as a whole the Tharsis volcanoes exhibit a random distribution, preferential alignments emerge when the history of the region is divided into separate periods. The preferential alignments mimic those of fractures in the surrounding terrain. Photogeologic and morphometric data indicate that the volcanoes fall into four distinct classes: montes, tholi, paterae, and a class whose sole representative is Alba Patera. The volcanoes have been buried by lava up to about 4 km in thickness. The sizes of the volcanoes directly correlate with their separation distances from their nearest neighbors. It is concluded that the greater the lithosphere thickness, the larger will be the volcano and the greater its separation distance from its nearest neighbor.

Whitford-Stark, J. L.↗

NASA NTRS1987

Pseudocraters as indicators of ground ice on Mars

Positive identification of Martian pseudocraters would be a strong indication of past occurrence of ice at or near the surface of Mars. The basis for suggesting that small cones on Mars are pseudocraters includes: (1) small size, (2) abundant but patchy distribution on what appear to be volcanic plains, (3) presence of other features suggestive of surface or subsurface ice, (4) morphological similarities to Icelandic pseudocraters, and (5) the similarity in distribution of crater/cone diameter ratios to Icelandic pseudocraters. This last morphometric parameter may be the most important, since other possible small terrestrial volcanic analogs have very different crater/cone diameter ratio distributions. In a survey of the available high resolution Viking Orbiter imagery, abundant fields of possible pseudocraters were found. However, only a small fraction of the plains forming units imaged at high resolution were found to contain the small cones. This low discovery rate, combined with the limited high resolution imagery, restrict Martian pseudocraters as global indicators of surface or subsurface ice. The meanings of this terrain analysis are discussed.

Frey, Herbert↗

NASA NTRS2002

Fiber diameter distributions in the chinchilla's ampullary nerves

A morphometric study of the chinchilla's ampullary nerves was conducted to produce an unbiased accounting of the diameter distribution of their constituent fibers. Diameter analyses were determined from 1 microm plastic-embedded nerve sections taken at a plane immediately proximal to the sensory epithelium. We found these nerves to be composed of 2094+/-573 fibers, having diameters that ranged from 0.5 to 8 microm. The distributions of diameters were positively skewed, where approximately 75% of the fibers were found to have diameters less than 3.5 microm. An analysis of the spatial distribution of diameters within the nerve section revealed that the lateralmost areas of the nerve contained larger fractions of fibers within the smallest diameter quintiles, and the central area harbored greater proportions of the larger diameter quintiles. However, significant fractions of all quintiles were found in all areas. These data were integrated with available data of Fernandez et al. (1998) to produce diameter estimates of calyx, dimorphic, and bouton morphology subpopulations. In view of a general relationship between diameter, innervation locus, and an afferent's physiologic characteristics, these data provide the basis for developing a perspective for the in situ distribution of afferent response dynamics.

Non-NASA Center↗

NASA NTRS1982

Verification of LANDSAT imagery for morphametric and topological studies of drainage basins in a section of the western plateau of Sao Paulo State: Tiete-Aguapei watershed

The potential of using LANDSAT MSS imagery for morphometric and topological studies of drainage basins was verified. Using Tiete and Aguapei watershed (Western Plateau) as the test site because of its homogeneous landscape. Morphometric variables collected for ten drainage basins include: circularity index; river density; drainage density; topographic texture; areal and index length; basin parameter; and main river length 1st order and 2nd order channel length. The topographical variables determined were: order; magnitude; bifuraction ratio; weighted bifuraction ratio; number of segments; number of linking; trajectory length; and topological diameter. Data were collected on topographical maps at the scale of 1:250,000 and 1:59,000 and on LANDSAT imagery at the scale of 1:250,000. The results which were summarized on tables for further analysis, show that LANDSAT imagery can supply the lack of topographic charts for drainage studies.

Parada, N. D. J.↗

NASA NTRS1974

Craters on Earth, Moon, and Mars - Multivariate classification and mode of origin

Testing extraterrestrial craters and candidate terrestrial analogs for morphologic similitude is treated as a problem in numerical taxonomy. According to a principal-components solution and a cluster analysis, 402 representative craters on the Earth, the Moon, and Mars divide into two major classes of contrasting shapes and modes of origin. Craters of net accumulation of material (cratered lunar domes, Martian calderas, and all terrestrial volcanoes except maars and tuff rings) group apart from craters of excavation (terrestrial meteorite impact and experimental explosion craters, typical Martian craters, and all other lunar craters). Maars and tuff rings belong to neither group but are transitional. The classification criteria are four independent attributes of topographic geometry derived from seven descriptive variables by the principal-components transformation. Morphometric differences between crater bowl and raised rim constitute the strongest of the four components.

Pike, R. J.↗

DOE OSTI2021

Morphological and molecular characterization of Paratylenchus beltsvillensis n. sp. (Tylenchida: Paratylenchidae) from the rhizosphere of pine tree ( Pinus virginiana Mill) in Maryland, USA

The pin nematode, Paratylechus beltsvillensis sp. collected from rhizosphere soil of a Virginia pine tree (Pinus virginiana Mill) growing in Little Paint Branch Park, Beltsville, Prince George’s County, Maryland, USA, is described and illustrated along with light and scanning electron photomicrographs. Females, males, and juveniles of this new species were recovered from soil samples using the sugar centrifugal flotation and Baermann funnel extraction methods. Morphologically, females are short, body length ranging from 245 to 267 μm, stylet from 70 to 75 μm long with anchor shaped knobs, vulva located at 70–73% and small vulval flap, spermatheca large, and ovoid filled with sperms. Lateral field with three incisures, of which the outer two are prominent. Tail slender, having a rounded tail terminus. Males without stylet and have a degenerated pharynx, spicules = 17–20 µm and gubernaculum = 5.0–5.5 µm. Both morphological observations and molecular analysis of ITS and partial 28S ribosomal RNA gene sequences indicated that the specimens collected from the soil at Beltsville Park from rhizosphere soil samples from Virginia pine represents a new pin nematode species.

59 BASIC BIOLOGICAL SCIENCES↗

NASA NTRS2024

Analysis of faults and pit chains in Noctis Labyrinthus: Implications for early extension and possible magmatic plumbing

Noctis Labyrinthus has been a region of disputed origin due to its complexity and poor understanding of how various processes and mechanisms may have combined to form it. The surface is an integrated record of intensive tectonic activity expressed by a multiple extended sets of dip-slip faults oriented in different directions, and thought to have acted on this region over its history. These faults are always coalescent to pits and pit chains displaying a complicated geological history in the region. To understand this geological history, we mapped the surface features in Noctis Labyrinthus using the High-Resolution Stereo Camera (HRSC) onboard Mars Express ND2 nadir channel basemaps, and we adapted the Digital Terrain Map (DTM) from the Mission Experiment Gridded Data Record (MEGDR) of Mars Orbiter Laser Altimeter (MOLA) onboard Mars Global Surveyor (MGS) for the topography. We have investigated the spatial distribution and trend of fault systems, the pit chains' morphology, and the correlation between these two types of features. Our results show three fault systems: i) NS and NNE-SSW, ii) EW and ENE-WSW, and iii) NNW-SSE and NW. The analysis of the faults trending, cross-cutting correlation and the superimposition led to identify multiple intersections between these faults that have been alongside with the reactivations of some inherited faults. We interpreted the first system of fault to be related to coeval lateral extension, generated by regional stress tensor, which is probably related to the slight bending of Valles Marineris within two phases of bidirectional extension. The second system of faults has been generated by the radial oblate stress tensor related to the formation of the small shield volcanoes in Syria Planum. However, the third system is likely related to the external driving process, probably in the Tharsis province. We classified pits in four evolutionary stages based on their morphometric attributes. We believe that the formation of the pit chains in Noctis Labyrinthus is related to a surface collapse after a pressure drop related to the magma chamber deflation associated with Syria Planum volcanic province. We propose a deformational model based on early extension and magmatic plumbing as driving processes for the formation of Noctis Labyrinthus.

Mayssa El Yazidi↗

DOE OSTI2023

A novel statistical methodology for quantifying the spatial arrangements of axons in peripheral nerves

A thorough understanding of the neuroanatomy of peripheral nerves is required for a better insight into their function and the development of neuromodulation tools and strategies. In biophysical modeling, it is commonly assumed that the complex spatial arrangement of myelinated and unmyelinated axons in peripheral nerves is random, however, in reality the axonal organization is inhomogeneous and anisotropic. Present quantitative neuroanatomy methods analyze peripheral nerves in terms of the number of axons and the morphometric characteristics of the axons, such as area and diameter. In this study, we employed spatial statistics and point process models to describe the spatial arrangement of axons and Sinkhorn distances to compute the similarities between these arrangements (in terms of first- and second-order statistics) in various vagus and pelvic nerve cross-sections. We utilized high-resolution transmission electron microscopy (TEM) images that have been segmented using a custom-built high-throughput deep learning system based on a highly modified U-Net architecture. Our findings show a novel and innovative approach to quantifying similarities between spatial point patterns using metrics derived from the solution to the optimal transport problem. We also present a generalizable pipeline for quantitative analysis of peripheral nerve architecture. Our data demonstrate differences between male- and female-originating samples and similarities between the pelvic and abdominal vagus nerves.

59 BASIC BIOLOGICAL SCIENCES↗