5-Methoxyl Participation in Solvolysis and Secondary Deuterium Isotope Effects

Specifically deuterated 4-methoxy-1-pentyl broij\u27ylates (IP- 1,1-d2, IP-2,2-d2) and 5-methoxy-2-pentyl brosylates (IS-2-d, 1S- -1 ,1,1 - d3, 1S-OCD3) were prepared, their solvolysis rates measured in 950/o ethanol and the corresponding kinetic secondary deuterium isotope effects calculated. It was found that the a-effects are strongly reduced in magnitude, which is in contrast with results obtained with several compounds solvolyzing via n- or CJ-participation. The effect found with IP-l,1-d2 (kHfkD = 0.96) is significantly different from the one measured with IS-2-d (kHfkD = 1.06). This difference in the magnitude of the effects must reflect a relatively small difference in the structures of the two transition states, since both IP and IS solvolyze via the same intermediate 2. It is concluded that the magnitude of the u- effP.ct is a sensitive measure of the amount of bridging only if the new bond is already quite strong in the transition state. B-Deuterated brosylates give small effects which differ in magnitude (kH/kD = 0.96 with IP-2,2-d2 and 1.08 with IS-1,1,1-da) corroborating the conclusion that the new C-0 bond is strong in the transition state of both reactions but stronger with IP than with IS. Results obtained in this work are in accord with the earlier conclusion that reduced B-effects in solvolysis of exo-2-norbornyl, 3-cholesteryl, cyclobutyl and 1-methylcyclobutyl derivatives are due to bridging. The inverse isotope effect obtained with IS-OCD3 (kH/kD=0.95) is »inductive« in origin and indicates that the methoxy oxygen bears a considerable amount of positive charge in the reaction transition state

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

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

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

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

Fertilizer Guidelines for Agronomic Crops in Minnesota

This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

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

Population-Based Prevalence of CDKN2A Mutations in Utah Melanoma Families

Cyclin-dependent kinase inhibitor 2A (CDKN2A or p16) is the major melanoma predisposition gene. In order to evaluate the candidacy for genetic testing of CDKN2A mutations among melanoma prone families, it is important to identify characteristics that predict a high likelihood of carrying a CDKN2A mutation. We primarily used a unique Utah genealogical resource to identify independent melanoma prone families whom we tested for mutations in CDKN2A, cyclin-dependent kinase 4, and alternate reading frame. We sampled 60 families which met the inclusion criteria of two or more affected first-degree relatives. We found four different pathogenic CDKN2A mutations in five families, mutations of uncertain significance in two families, and known polymorphisms in three families. One of the mutations of uncertain significance, 5′ untranslated region −25C>T, has not been previously described. Among our population-based set of Utah families, the prevalence of CDKN2A mutations was 8.2% (4/49); the overall prevalence when physician-referred pedigrees were also considered was between 8.3% (5/60) and 10% (6/60). Having four or more first- or second-degree relatives with melanoma, or a family member with ≥3 primary melanomas, correlated strongly with carrying a CDKN2A mutation. We observed a significantly elevated rate of pancreatic cancer in one of four families with a deleterious CDKN2A mutation