The search for an identification of amino acids, nucleobases and nucleosides in samples returned from Mars

The Mars Sample Return mission will provide us with a unique source of material from our solar system; material which could advance our knowledge of the processes of chemical evolution. As has been pointed out, Mars geological investigations based on the Viking datasets have shown that primordial Mars was in many biologically important ways similar to the primordial Earth; the presence of surface liquid water, moderate surface temperatures, and atmosphere of carbon dioxide and nitrogen, and high geothermal heat flow. Indeed, it would seem that conditions on Earth and Mars were fundamentally similar during the first one billion years or so. As has been pointed out, Mars may well contain the best preserved record of the events that transpired on the early planets. Examination of that early record will involve searching for many things, from microfossils to isotopic abundance data. We propose an investigation of the returned Mars samples for biologically important organic compounds, with emphases on amino acids, the purine and pyrimidine bases, and nucleosides

The search for and identification of amino acids, nucleobases and nucleosides in samples returned from Mars

An investigation of the returned Mars samples for biologically important organic compounds, with emphasis on amino acid, the puring and pyrimidine bases, and nucleosides is proposed. These studies would be conducted on subsurface samples obtained by drilling past the surface oxidizing layer with emphasis on samples containing the larges quantities of organic carbon as determined by the rover gas chromatographic mass spectrometer (GCMS). Extraction of these molecules from the returned samples will be performed using the hydrothermal extraction technique described by Cheng and Ponnamperuma. More rigorous extraction methods will be developed and evaluated. For analysis of the extract for free amino acids or amino acids present in a bound or peptidic form, aliquots will be analyzed by capillary GCMS both before and after hydrolysis with 6N hydrochloric acid. Establishment of the presence of amino acids would then lead to the next logical step which would be the use of chiral stationary gas chromatography phases to determine the enatiomeic composition of the amino acids present, and thus potentially establish their biotic or abiotic origin. Confirmational analyses for amino acids would include ion-exchange and reversed-phase liquid chromatographic analysis. For analyses of the returned Mars samples for nucleobases and nucleosides, affinity and reversed-phase liquid chromatography would be utilized. This technology coupled with scanning UV detection for identification, presents a powerful tool for nucleobase and nucleoside analysis. Mass spectrometric analysis of these compounds would confirm their presence in samples returned form Mars

Land Use Mix and Pedestrian Travel Behavior: Advancements in Conceptualization and Measurement

Smart growth policies have often emphasized the importance of land use mix as an intervention beholding of lasting urban planning and public health benefits. Past transportation-land use research has identified potential efficiency gains achieved by mixed-use neighborhoods and the subsequent shortening of trip lengths; whereas, public health research has accredited increased land use mixing as an effective policy for facilitating greater physical activity. However, despite the celebrated transportation, land use, and health benefits of improved land use mixing and the extent of topical attention, no consensus has been reached regarding the conceptualization and measurement of this key smart growth principle or the magnitude of its link to walking. This dissertation, comprised of three empirical studies, explores this topic in detail. In the first study, activity-based transportation and landscape ecology theory contributed to the introduction of a multifaceted land use mix construct reflected by a set of composition and configuration indicators. This activity-related land use mix construct, and not the commonly used entropy index, was a significant built environmental determinant of walk mode choice and home-based walk trip frequency. In the second study, structural equation modeling was used to establish a connection between residing in a smart growth neighborhood and home-based pedestrian travel. This study discovered a multidimensional depiction of the traveler\u27s residential environment that was reflective of local land use mix, employment concentration, and pedestrian-oriented design. The second-order factor, which described a smart growth neighborhood, had a strong and positive effect on the household-level decision to walk for transportation-related and discretionary travel when assessed in a multidirectional conceptual framework. In the final study, the influence of geographic scale selection on the connection between the built environment and active and auto-related travel was explored. Informed by this sensitivity analysis, which underlined the existence of scaling and zoning effects, mode choice for both work and nonwork travel as a function of individual, household, transportation, and built environment features at the home location and destination was modeled. These discrete choice analysis results found that measures of land use mix and density at each trip end had the strongest effect on the decision to walk rather drive or ride in a vehicle for nonwork trips. In all, the findings from this dissertation provide policymakers and practitioners greater specificity in the measurement of land use mix and its connection to pedestrian travel behavior

A manned exobiology laboratory based on the Moon

Establishment of an exobiology laboratory on the Moon would provide a unique opportunity for exploration of extraterrestrial materials on a long-term, ongoing basis, for elucidation of exobiological processes and chemical evolution. A major function of the lunar exobiology laboratory would be to examine samples collected from other planets (e.g., Mars) for the presence of extant or extinct life. By establishing a laboratory on the Moon, preliminary analyses could be conducted away from Earth, thus establishing that extraterrestrial materials are benign before their return to Earth for more extensive investigations. The Moon-based exobiology laboratory would have three major components for study of samples returned from other planets: (1) the search for extant life - this component would focus on the detection and identification of life forms using biological, physical, and chemical methods; (2) the search for extinct life - this component would concentrate on identification of extinct life using micropaleontological physical and chemical means; and (3) the search and evidence of chemical evolution - this component would be devoted to the detection and identification of molecules revealing prebiotic chemical evolution

Vulnérabilité des ressources halieutiques et aquacoles du Pacifique tropical face au changement climatique : résumé à l'intention des Etats et Territoires insulaires océaniens

En complément de l'ouvrage intitulé "Vulnerability of tropical Pacific fisheries and aquaculture to climate change", qui analyse de manière exhaustive les effets possibles du changement climatique sur les plans visant à maximiser les avantages économiques et sociaux tirés de la pêche et de l'aquaculture en Océanie, le présent document fait la synthèse des conclusions de cette évaluation de la vulnérabilité climatique régionale en ce qui concerne les Territoires français du Pacifique. Les mesures d'adaptation, les politiques et les investissements préconisés devraient permettre à chaque Territoire de réduire les menaces que fait peser le changement climatique sur la pêche et l'aquaculture, tout en tirant le meilleur parti des débouchés qui en découlent. Les recommandations formulées répondent directement aux préoccupations de toutes les parties prenantes et de leurs partenaires dans le développement. (Résumé d'auteur

Vulnerability of tropical Pacific fisheries and aquaculture to climate change : summary for Pacific island countries and territories

The purpose of this summary is to present the main results from the regional vulnerability assessment as they apply to each country and territory, making the information easily to use. The practical adaptations, policies and investments described here are needed to maintain the economic and social benefits of fisheries and aquaculture in the face of climate change. They are essential planning tools

Interval type–2 fuzzy decision making

This paper concerns itself with decision making under uncertainty and theconsideration of risk. Type-1 fuzzy logic by its (essentially) crisp nature is limited in modelling decision making as there is no uncertainty in the membership function. We are interested in the role that interval type–2 fuzzy sets might play in enhancing decision making. Previous work by Bellman and Zadeh considered decision making to be based on goals and constraint. They deployed type–1 fuzzy sets. This paper extends this notion to interval type–2 fuzzy sets and presents a new approach to using interval type-2 fuzzy sets in a decision making situation taking into account the risk associated with the decision making. The explicit consideration of risk levels increases the solution space of the decision process and thus enables better decisions. We explain the new approach and provide two examples to show how this new approach works