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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of insect behavior 2 (1989), S. 523-543 
    ISSN: 1572-8889
    Keywords: chemotaxonomy ; aggression ; kin recognition ; kin discrimination ; Zootermopsis ; Isoptera ; species interactions ; cuticular hydrocarbons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The dampwood termite genus ZootermopsisEmerson contains three recognized species with four distinct and consistent hydrocarbon phenotypes. Agonistic behaviors among nonreproductive insects from colonies of the same and different hydrocarbon phenotypes were observed in the laboratory. Various combinations of soldier versus nymphs, pseudergate versus pseudergate, and soldier versus soldier encounters were used in experimental trials. Soldiers or pseudergates seldom attack individuals of the same hydrocarbon phenotype. Z. angusticollis(Hagen) (phenotype II) is typically aggressive toward phenotype III of Z. nevadensis(Hagen) but not always aggressive against phenotype I of Z. nevadensis.The variation in response is dependent on which castes are placed in the bioassay arena: soldier versus soldier bouts result in consistent aggression, while pseudergate versus pseudergate or soldier versus nymphs contacts do not. Both pseudergates and soldiers of Z. laticeps(Banks) (phenotype IV) respond agonistically toward the other three phenotypes: Z. angusticollis (II) and Z. nevadensis(I and III). Although hydrocarbon phenotypes I and III, both Z. nevadensis,are morphologically indistinguishable, agonistic behavioral responses between phenotype I and phenotype III are not equivalent to I versus I or III versus III behavioral responses. The I versus III engagements, regardless of the castes involved, display a greater proportion of avoidance and aggressive responses than I or III intraphenotype encounters. We interpret the lack of avoidance or aggressive behavior within each of the two phenotypes of Z. nevadensisand the significant avoidance and aggressive behavior between phenotypes as definite evidence of discrimination between disparate hydrocarbon phenotypes. These agonistic bioassays along with data on distinct hydrocarbon patterns and geographic distributions serve as the basis for creating two subspecies of Z. nevadensis: Z. n. nevadensis(Hagen) and Z. n. nuttingiHaverty and Thorne, ssp. nov.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 23 (1997), S. 927-964 
    ISSN: 1573-1561
    Keywords: Cuticular hydrocarbons ; chemotaxonomy ; Isoptera ; tropical termites ; gas chromatography ; mass spectrometry ; Virgin Islands ; Caribbean termites ; olefins ; methylalkanes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A survey of the termites (Isoptera) of 17 islands of the British Virgin Island (BVI) complex yielded eight taxa belonging to three families. The Kalotermitidae include Neotermes mona (Banks), Cryptotermes brevis (Walker), Procryptotermes corniceps (Snyder), and an undetermined species of Incisitermes, likely Incisitermes nr snyderi (Light) or I. incisus (Silvestri). The only rhinotermitid collected is an undetermined species of Heterotermes (Froggatt). Parvitermes wolcotti (Snyder), Nasutitermes costalis (Holmgren), and N. acajutlae (Holmgren) comprise the Termitidae. Cuticular hydrocarbon mixtures were characterized for each of the taxa. Blends of abundant hydrocarbons are species-specific and can be used to identify a given taxon without the diagnostic castes, soldiers, or imagoes, although the species of Incisitermes were not separable on the basis of cuticular hydrocarbons.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1573-1561
    Keywords: Nasutitermes acajutlae ; chemotaxonomy ; Isoptera ; Termitidae ; tropical termites ; gas chromatography ; cuticular hydrocarbons ; olefins ; mass spectrometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Using data from the arboreal nestingNasutitermes acajutlae (Holmgren), we propose standard collection and extraction methodology for characterization of cuticular hydrocarbons of termites under field conditions in the tropics. Specifically, we evaluated: (1) the effect of the duration and the number of extractions; (2) the effect of drying termites before extraction; (3) the effect of sample size; (4) the effect of solvents (ethanol versus hexane) on cuticular hydrocarbon profiles. Olefins comprise ca. 70% of the cuticular hydrocarbons ofN. acajutlae. Hydrocarbons consist of two distinct groups: early-eluting components, primarilyn-alkanes and methyl-branched alkanes, and late-eluting compounds, which consist almost exclusively of unsaturated components with one to six double bonds. Soldiers have more early-eluting compounds than workers or alates. Nests from the same island had qualitatively similar, but quantitatively dissimilar hydrocarbon mixtures. Brief extractions of 300 live workers in 10 ml of hexane for only 20 sec produced a hydrocarbon mixture equivalent to a 10-min extraction. Long-term extraction of 300 workers in hexane for two years resulted in different mixtures of hydrocarbons. Drying workers tended to enhance extraction of the less abundant unsaturated compounds such as C41.4 and C41.5. A single extraction of a minimum of 100 workers (live or dried), with hexane for 20 sec to 10 min is best; these extraction regimes resulted in mixtures of hydrocarbons that are quantitatively very similar. For quantitative comparisons, extracts from dried samples should not be compared to those from live samples. Storage in ethanol caused numerous unidentified, nonhydrocarbon compounds to be extracted either from the cuticle or from internal tissues.
    Type of Medium: Electronic Resource
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  • 4
    Publication Date: 2019-07-12
    Description: The NASA Glenn Research Center General Multi-Block Navier-Stokes Convective Heat Transfer Code, Glenn-HT, has been used extensively to predict heat transfer and fluid flow for a variety of steady gas turbine engine problems. Recently, the Glenn-HT code has been completely rewritten in Fortran 90/95, a more object-oriented language that allows programmers to create code that is more modular and makes more efficient use of data structures. The new implementation takes full advantage of the capabilities of the Fortran 90/95 programming language. As a result, the Glenn-HT code now provides dynamic memory allocation, modular design, and unsteady flow capability. This allows for the heat-transfer analysis of a full turbine stage. The code has been demonstrated for an unsteady inflow condition, and gridding efforts have been initiated for a full turbine stage unsteady calculation. This analysis will be the first to simultaneously include the effects of rotation, blade interaction, film cooling, and tip clearance with recessed tip on turbine heat transfer and cooling performance. Future plans call for the application of the new Glenn-HT code to a range of gas turbine engine problems of current interest to the heat-transfer community. The new unsteady flow capability will allow researchers to predict the effect of unsteady flow phenomena upon the convective heat transfer of turbine blades and vanes. Work will also continue on the development of conjugate heat-transfer capability in the code, where simultaneous solution of convective and conductive heat-transfer domains is accomplished. Finally, advanced turbulence and fluid flow models and automatic gridding techniques are being developed that will be applied to the Glenn-HT code and solution process.
    Keywords: Man/System Technology and Life Support
    Type: LEW-17914-1 , NASA Tech Briefs, September 2006; 31-32
    Format: application/pdf
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  • 5
    Publication Date: 2019-07-12
    Description: Nutrition has played a critical role throughout the history of exploration, and space exploration is no exception. While a one- to two-week flight aboard the Space Shuttle might be analogous to a camping trip, adequate nutrition is absolutely critical while spending several months on the International Space Station (Figure 1) or several years on a mission to another planet. To ensure adequate nutrition, space nutrition specialists must know how much of the individual nutrients astronauts need, and these nutrients must be available in the spaceflight food system. To complicate matters, these spaceflight nutritional requirements are influenced by many of the physiological changes that occur during spaceflight. In this chapter, we describe some of these changes, their impact on crew health, and ways NASA is investigating how to minimize these changes. We also review the space food systems, issues involved in setting up a cafeteria in a weightless environment, and information about dietary intake of nutrients during space missions
    Keywords: Man/System Technology and Life Support
    Type: JSC-CN-7319
    Format: application/pdf
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  • 6
    Publication Date: 2019-07-17
    Description: Studies of fluid and electrolyte homeostasis have been completed since the early human space flight programs, with comprehensive research completed on the Spacelab Life Sciences missions SLS-1 and SLS-2 flights, and more recently on the Mir 18 mission. This work documented the known shifts in fluids, the decrease in total blood volume, and indications of reduced thirst. Data from these flights was used to evaluate the nutritional needs for water, sodium, and potassium. Interpretations of the data are confounded by the inadequate energy intakes routinely observed during space flight. This in turn results in reduced fluid intake, as food provides approximately 70% water intake. Subsequently, body weight, lean body mass, total body water, and total body potassium may decrease. Given these issues, there is evidence to support a minimum required water intake of 2 L per day. Data from previous Shuttle flights indicated that water intake is 2285 +/- 715 ml/day (mean +/- SD, n=26). There are no indications that sodium intake or homeostasis is compromised during space flight. The normal or low aldosterone and urinary sodium levels suggest adequate sodium intake (4047 +/- 902 mg/day, n=26). Because excessive sodium intake is associated with hypercalciuria, the recommended maximum amount of sodium intake during flight is 3500 mg/day (i.e., similar to the Recommended Dietary Allowance, RDA). Potassium metabolism appears to be more complex. Data indicate loss of body potassium related to muscle atrophy and low dietary intake (2407 +/- 548 mg/day, n=26). Although possibly related to measurement error, the elevations in blood potassium suggest alterations in potassium homeostasis. The space RDA for minimum potassium intake is 3500 mg/day. With the documented inadequate intakes, efforts are being made to increase dietary consumption of potassium.
    Keywords: Man/System Technology and Life Support
    Type: Proceedings of the First Biennial Space Biomedical Investigators' Workshop; 461
    Format: text
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  • 7
    Publication Date: 2019-07-19
    Description: Background: Maintaining adequate nutrient intake in microgravity is important not only to meet health maintenance needs of astronauts but also to help counteract the negative effects of space flight. Beyond this, food provides psychosocial benefits throughout a mission. Objective: The purpose of this presentation is to discuss dietary intake data from multiple space programs, including Space Shuttle and the International Space Station. Description: These data arise from medical monitoring of both dietary intake and crew health, as well as research protocols designed to assess the role of diet in counteracting bone loss and other health concerns. Ground-based studies are conducted to better understand some of the negative issues related to space flight. Examples of these analog studies are extended bed rest studies, vitamin D supplementation studies in Antarctica, and saturation diving missions on the floor of the ocean. Methods and findings will be presented describing the use of weighed records, diet diaries, and food frequency questionnaires in these various environments. Provision of food and nutrients in spaceflight is important for many body systems including cardiovascular, musculoskeletal, endocrine, immune, and others. Some key areas of concern are loss of body mass, bone and muscle loss, radiation exposure, nutrient intakes during spacewalks, depletion of nutrient stores, and inadequate dietary intake. Initial experimental research studies using food and nutrition as a countermeasure to aid in mitigating these concerns are underway. Conclusion: Beyond their importance for the few individuals leaving the planet, these studies have significant implications for those remaining on Earth.
    Keywords: Man/System Technology and Life Support
    Type: JSC-CN-24988 , 36th National Nutrient Databank Conference; Mar 25, 2012 - Mar 28, 2012; Houston, TX; United States
    Format: application/pdf
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