Enhanced LANDSAT images of Antarctica and planetary exploration

Since early in the LANDSAT program, black-and-white paper prints of band 7 (near infrared) of the LANDSAT multispectral scanner have been used extensively to prepare semicontrolled maps of Antarctica. Image-processing techniques are now employed to enhance fine detail and to make controlled image-mosaic maps in color. LANDSAT multispectral images of Antarctica help to expand our knowledge of extraterrestrial bodies by showing bare-ice areas as bright blue patches; on such patches meteorites tend to be concentrated and are collected. Many subtle flow features in Antarctic ice streams resemble features at the mouths of Martian outflow channels, which suggests that the channels also contained ice. Furthermore, flow lines in Antarctic ice sheets that merge with ice shelves resemble Martian flow features associated with dissected terrain along the Martian northern highland margin, and support the concept that ice was involved in the transport of material from the southern highlands to the northern lowland plains. In Antarctica, as on Mars, the virtual absence of fluvial activity over millions of years has permitted the growth of glacial and eolian features to unusually large sizes

CD-ROM publication of the Mars digital cartographic data base

The recently completed Mars mosaicked digital image model (MDIM) and the soon-to-be-completed Mars digital terrain model (DTM) are being transcribed to optical disks to simplify distribution to planetary investigators. These models, completed in FY 1991, provide a cartographic base to which all existing Mars data can be registered. The digital image map of Mars is a cartographic extension of a set of compact disk read-only memory (CD-ROM) volumes containing individual Viking Orbiter images now being released. The data in these volumes are pristine in the sense that they were processed only to the extent required to view them as images. They contain the artifacts and the radiometric, geometric, and photometric characteristics of the raw data transmitted by the spacecraft. This new set of volumes, on the other hand, contains cartographic compilations made by processing the raw images to reduce radiometric and geometric distortions and to form geodetically controlled MDIM's. It also contains digitized versions of an airbrushed map of Mars as well as a listing of all feature names approved by the International Astronomical Union. In addition, special geodetic and photogrammetric processing has been performed to derive rasters of topographic data, or DTM's. The latter have a format similar to that of MDIM, except that elevation values are used in the array instead of image brightness values. The set consists of seven volumes: (1) Vastitas Borealis Region of Mars; (2) Xanthe Terra of Mars; (3) Amazonis Planitia Region of Mars; (4) Elysium Planitia Region of Mars; (5) Arabia Terra of Mars; (6) Planum Australe Region of Mars; and (7) a digital topographic map of Mars

LANDSAT TM image data quality analysis for energy-related applications

This project represents a no-cost agreement between National Aeronautic Space Administration Goddard Space Flight Center (NASA GSFC) and the Pacific Northwest Laboratory (PNL). PNL is a Department of Energy (DOE) national laboratory operted by Battelle Memorial Institute at its Pacific Northwest Laboratories in Richland, Washington. The objective of this investigation is to evaluate LANDSAT's thematic mapper (TM) data quality and utility characteristics from an energy research and technological perspective. Of main interest is the extent to which repetitive TM data might support DOE efforts relating to siting, developing, and monitoring energy-related facilities, and to basic geoscientific research. The investigation utilizes existing staff and facility capabilities, and ongoing programmatic activities at PNL and other DOE national laboratories to cooperatively assess the potential usefulness of the improved experimental TM data. The investigation involves: (1) both LANDSAT 4 and 5 TM data, (2) qualitative and quantitative use consideration, and 3) NASA P (corrected) and A (uncorrected) CCT analysis for a variety of sites of DOE interest. Initial results were presented at the LANDSAT Investigator's Workshops and at specialized LANDSAT TM sessions at various conferences

Consumption of fruits among students: A case of a public university in Ghana

Despite the enormous health and nutritional benefits that could be derived from the consumption of fruits, studies have shown that most adolescents and adults do not consume fruits as per the recommended daily intake. This study aimed at identifying the factors that hamper the consumption of fruits among university students. Four hundred and fifty-six (n = 456) out of a total population of nine thousand (N = 9000) undergraduate students were considered for the study. A pre-tested structured questionnaire was used to solicit answers to questions on: fruit intake and preferences, perception on fruit consumption, fruit availability, and factors that hamper students’ fruit intake. Descriptive statistical techniques (frequency counts, percentage, mean and standard deviations) as well as inferential tools (one-sample T-test, Pearson product-moment correlation, Chi-square one variable test, and Binomial test) were used in the data analysis, and statistical significance determined at the 5% level (P≤0.05). Major findings from the study were that, students (65%) significantly do not eat the recommended serving of fruits in a day (P<0.05), whereas approximately 6% (P<0.05) do not eat fruits at all, although their perception on the consumption of fruits was good (P<0.05). Out of nine fruit types, that were readily available on the market for the subjects, pear (Pyrus communis) was the most preferred by students (x̄ = 3.37, P<0.05); whereas orange (Citrus sinensis) was the least preferred (x̄ = 2.31, P<0.05). A weak positive correlation, which was statistically significant (r = 0.13, P<0.0005), was observed for students’ fruit and fruit-fibre intake with respect to tangerine (Citrus reticulata). Also, a weak negative relationship, which was statistically significant (r = -0.14, P<0.0005), was observed for the intake of oranges (Citrus sinensis) and its fibrous part. Variables such as taste, time-wasting, religious belief, knowledge, illhealth, and proximity did not significantly (P>0.05) influence the intake of fruits by the respondents (x̄<2.50, P<0.05). Price scores (x̄ = 3.21) as well as satiety scores (x̄ = 3.32) were the significant variables found to hinder students’ fruit intake (P<0.05). Strategies to increase intake of fruits, should give more attention to the price and satiety variables

The Clementine Mission: Initial Results from lunar mapping

Clementine was a mission designed to test the space-worthiness of a variety of advanced sensors for use on military surveillance satellites while, at the same time, gathering useful scientific information on the composition and structure of the Moon and a near-Earth asteroid. Conducted jointly by the Ballistic Missile Defense Organization (BMDO, formerly the Strategic Defense Initiative Organization) of the US Department of Defense and NASA, Clementine was dispatched for an extended stay in the vicinity of Earth's moon on 25 January 1994 and arrived at the Moon on 20 February 1994. The spacecraft started systematic mapping on 26 February, completed mapping on 22 April, and left lunar orbit on 3 May. The entire Clementine project, from conception through end-of-mission, lasted approximately 3 years

A biochemical and ultrastructural evaluation of the type 2 Gaucher mouse

Gaucher mice, created by targeted disruption of the glucocerebrosidase gene, are totally deficient in glucocerebrosidase and have a rapidly deteriorating clinical course analogous to the most severely affected type 2 human patients. An ultrastructural study of tissues from these mice revealed glucocerebroside accumulation in bone marrow, liver, spleen, and brain. This glycolipid had a characteristic elongated tubular structure and was contained in lysosomes, as demonstrated by colocalization with both ingested carbon particles and cathepsin D. In the central nervous system (CNS), glucocerebroside was diffusely stored in microglia cells and in brainstem and spinal cord neurons, but not in neurons of the cerebellum or cerebral cortex. This rostralcaudal pattern of neuronal lipid storage in these Gaucher mice replicates the pattern seen in type 2 human Gaucher patients and clearly demonstrates that glycosphingolipid catabolism and/or accumulation varies within different brain regions. Surprisingly, the cellular pathology of tissue from these Gaucher mice was relatively mild, and suggests that the early and rapid demise of both Gaucher mice and severely affected type 2 human neonates may be the result of both a neurotoxic metabolite, such as glucosylsphingosine, and other factors, such as skin water barrier dysfunction secondary to the absence of glucocerebrosidase activity

Interspecific hybridization explains rapid gorget colour divergence in Heliodoxa hummingbirds (Aves: Trochilidae)

Hybridization is a known source of morphological, functional and communicative signal novelty in many organisms. Although diverse mechanisms of established novel ornamentation have been identified in natural populations, we lack an understanding of hybridization effects across levels of biological scales and upon phylogenies. Hummingbirds display diverse structural colours resulting from coherent light scattering by feather nanostructures. Given the complex relationship between feather nanostructures and the colours they produce, intermediate coloration does not necessarily imply intermediate nanostructures. Here, we characterize nanostructural, ecological and genetic inputs in a distinctive Heliodoxa hummingbird from the foothills of eastern Peru. Genetically, this individual is closely allied with Heliodoxa branickii and Heliodoxa gularis, but it is not identical to either when nuclear data are assessed. Elevated interspecific heterozygosity further suggests it is a hybrid backcross to H. branickii. Electron microscopy and spectrophotometry of this unique individual reveal key nanostructural differences underlying its distinct gorget colour, confirmed by optical modelling. Phylogenetic comparative analysis suggests that the observed gorget coloration divergence from both parentals to this individual would take 6.6–10 My to evolve at the current rate within a single hummingbird lineage. These results emphasize the mosaic nature of hybridization and suggest that hybridization may contribute to the structural colour diversity found across hummingbirds

Consequences of “natural” disasters on aquatic life and habitats

“Natural” disasters (also known as geophysical disasters) involve physical processes that have a direct or indirect impact on humans. These events occur rapidly and may have severe consequences for resident flora and fauna as their habitat undergoes dramatic and sudden change. Although most studies have focused on the impact of natural disasters on humans and terrestrial systems, geophysical disasters can also impact aquatic ecosystems. Here, we provide a synthesis on the effects of the most common and destructive geophysical disasters on aquatic systems (life and habitat). Our approach spanned realms (i.e., freshwater, estuarine, and marine) and taxa (i.e., plants, vertebrates, invertebrates, and microbes) and included floods, droughts, wildfires, hurricanes/cyclones/typhoons, tornadoes, dust storms, ice storms, avalanches (snow), landslides, volcanic eruptions, earthquakes (including limnic eruptions), tsunamis, and cosmic events. Many geophysical disasters have dramatic effects on aquatic systems. The evidence base is somewhat limited for some natural disasters because transient events (e.g., tornadoes and floods) are difficult to study. Most natural disaster studies focus on geology/geomorphology and hazard assessment for humans and infrastructure. However, the destruction of aquatic systems can impact humans indirectly through loss of food security, cultural services, or livelihoods. Many geophysical disasters interact in complex ways (e.g., wildfires often lead to landslides and flooding) and can be magnified or otherwise mediated by human activities. Our synthesis reveals that geophysical events influence aquatic ecosystems, often in negative ways, yet systems can be resilient provided that effects are not compounded by anthropogenic stressors. It is difficult to predict or prevent geophysical disasters but understanding how aquatic ecosystems are influenced by geophysical events is important given the inherent connection between peoples and aquatic ecosystems.acceptedVersio