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Articles 145051 - 145080 of 302425

Full-Text Articles in Physical Sciences and Mathematics

Hierarchical Analysis Of Genetic Structure In The Habitat-Specialist Eastern Sand Darter (Ammocrypta Pellucida), Robert Ginson, Ryan P. Walter, Nicholas E. Mandrak, Courtney L. Beneteau, Daniel D. Heath Jan 2015

Hierarchical Analysis Of Genetic Structure In The Habitat-Specialist Eastern Sand Darter (Ammocrypta Pellucida), Robert Ginson, Ryan P. Walter, Nicholas E. Mandrak, Courtney L. Beneteau, Daniel D. Heath

Great Lakes Institute for Environmental Research Publications

Quantifying spatial genetic structure can reveal the relative influences of contemporary and historic factors underlying localized and regional patterns of genetic diversity and gene flow - important considerations for the development of effective conservation efforts. Using 10 polymorphic microsatellite loci, we characterize genetic variation among populations across the range of the Eastern Sand Darter (Ammocrypta pellucida), a small riverine percid that is highly dependent on sandy substrate microhabitats. We tested for fine scale, regional, and historic patterns of genetic structure. As expected, significant differentiation was detected among rivers within drainages and among drainages. At finer scales, an unexpected lack of …


Benefits Of Turbid River Plume Habitat For Lake Erie Yellow Perch (Perca Flavescens) Recruitment Determined By Juvenile To Larval Genotype Assignment, Lucia B. Carreon-Martinez, Ryan P. Walter, Timothy B. Johnson, Stuart A. Ludsin, Daniel D. Heath Jan 2015

Benefits Of Turbid River Plume Habitat For Lake Erie Yellow Perch (Perca Flavescens) Recruitment Determined By Juvenile To Larval Genotype Assignment, Lucia B. Carreon-Martinez, Ryan P. Walter, Timothy B. Johnson, Stuart A. Ludsin, Daniel D. Heath

Great Lakes Institute for Environmental Research Publications

Nutrient-rich, turbid river plumes that are common to large lakes and coastal marine ecosystems have been hypothesized to benefit survival of fish during early life stages by increasing food availability and (or) reducing vulnerability to visual predators. However, evidence that river plumes truly benefit the recruitment process remains meager for both freshwater and marine fishes. Here, we use genotype assignment between juvenile and larval yellow perch (Perca flavescens) from western Lake Erie to estimate and compare recruitment to the age-0 juvenile stage for larvae residing inside the highly turbid, south-shore Maumee River plume versus those occupying the less turbid, more …


Particle Backtracking Improves Breeding Subpopulation Discrimination And Natal-Source Identification In Mixed Populations, Michael E. Fraker, Eric J. Anderson, Reed M. Brodnik, Lucia Carreon-Martinez, Kristen M. Devanna, Brian J. Fryer, Daniel D. Heath, Julie M. Reichert, Stuart A. Ludsin Jan 2015

Particle Backtracking Improves Breeding Subpopulation Discrimination And Natal-Source Identification In Mixed Populations, Michael E. Fraker, Eric J. Anderson, Reed M. Brodnik, Lucia Carreon-Martinez, Kristen M. Devanna, Brian J. Fryer, Daniel D. Heath, Julie M. Reichert, Stuart A. Ludsin

Great Lakes Institute for Environmental Research Publications

We provide a novel method to improve the use of natural tagging approaches for subpopulation discrimination and source-origin identification in aquatic and terrestrial animals with a passive dispersive phase. Our method integrates observed site-referenced biological information on individuals in mixed populations with a particle-tracking model to retrace likely dispersal histories prior to capture (i.e., particle backtracking). To illustrate and test our approach, we focus on western Lake Erie's yellow perch (Perca flavescens) population during 2006-2007, using microsatellite DNA and otolith microchemistry from larvae and juveniles as natural tags. Particle backtracking showed that not all larvae collected near a presumed hatching …


Effect Of Cod: So42- Ratio, Hrt And Linoleic Acid Concentration On Mesophilic Sulfate Reduction: Reactor Performance And Microbial Population Dynamics, Chungman Moon, Rajesh Singh, Sathyanarayan S. Veeravalli, Saravanan R. Shanmugam, Subba Rao Chaganti, Jerald A. Lalman, Daniel D. Heath Jan 2015

Effect Of Cod: So42- Ratio, Hrt And Linoleic Acid Concentration On Mesophilic Sulfate Reduction: Reactor Performance And Microbial Population Dynamics, Chungman Moon, Rajesh Singh, Sathyanarayan S. Veeravalli, Saravanan R. Shanmugam, Subba Rao Chaganti, Jerald A. Lalman, Daniel D. Heath

Great Lakes Institute for Environmental Research Publications

Biological sulfate (SO42-) reduction was examined in anaerobic sequential batch reactors (ASBRs) operated under different hydraulic retention times (HRTs) ranging from 12 to 36 h and COD (Chemical Oxygen Demand)/SO42- ratios of 2.4, 1.6 and 0.8. Competition between SO42- reducing bacteria (SRBs), methane producing archaea (MPAs) and homoacetogens (HACs) was examined in controls and cultures treated with linoleic acid (LA). The ASBR performance was influenced by the COD/SO42- ratio in control cultures with a SO42- reduction of 87% at a COD/SO42- ratio of 0.8. At a 12 h HRT, in both control and LA treated cultures, greater than 75% SO42- …


The Effects Of Inbreeding On Sperm Quality Traits In Captive-Bred Lake Trout, Salvelinus Namaycush (Walbaum, 1972), K. Johnson, Ian A.E. Butts, J. L. Smith, C. C. Wilson, Trevor E. Pitcher Jan 2015

The Effects Of Inbreeding On Sperm Quality Traits In Captive-Bred Lake Trout, Salvelinus Namaycush (Walbaum, 1972), K. Johnson, Ian A.E. Butts, J. L. Smith, C. C. Wilson, Trevor E. Pitcher

Great Lakes Institute for Environmental Research Publications

The effects of inbreeding in both captive and wild-caught species and populations have been reported to affect a wide variety of life history traits. Recently, the effects of inbreeding on reproductive traits such as sperm quality have become a subject of particular interest for conservation biology, evolutionary ecology, and management of captive populations. This study investigated the effects of inbreeding on sperm quality in a captive population of experimentally inbred and outbred lake trout, Salvelinus namaycush. It was found for moderately to highly inbred males (males with half-sib and full-sib parents, respectively), that sperm quality traits (velocity, motility, linearity, longevity, …


The Role Of Icts In Native American Owned Micro-Enterprises-A Framing Analysis, Jie Xiong, Sajda Qureshi, Teresa Trumbly Lamsam Jan 2015

The Role Of Icts In Native American Owned Micro-Enterprises-A Framing Analysis, Jie Xiong, Sajda Qureshi, Teresa Trumbly Lamsam

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

Information and Communication Technologies (ICTs) are seen to be drivers for the development of emerging regions. Many small businesses in the United States, including Native American owned microenterprises, are facing unique challenges in the adoption of ICTs to improve business performance. This research follows an inductive qualitative approach to find out which of the factors could potentially lead to the adoption of technologies by Native American micro-enterprises owners. Based on interviews from four Native American owned micro-enterprises, Characteristics of ICTs, Personal Inequality, and Community Engagement are identified as key factors that lead to the adoption of ICTs. The contribution of …


A Framing Analysis Of African-American And Native-American Owned Micro-Enterprises: How Can Information And Communication Technology Support Their Development?, Jie Xiong, Sajda Qureshi, Teresa A. Lamsam Jan 2015

A Framing Analysis Of African-American And Native-American Owned Micro-Enterprises: How Can Information And Communication Technology Support Their Development?, Jie Xiong, Sajda Qureshi, Teresa A. Lamsam

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

Information and Communication Technologies (ICTs) have been touted as means of increasing economic development by providing improvements in the lives of people where the use of technology leads to better livelihoods. Despite the high access and use of ICTs in the United States, high unemployment and poverty rates among Native Americans and African Americans continues to rise while deepening existing income inequalities. Through a framing analysis of Native American and African American microentrepreneurs, this paper investigates the use of ICTs in six micro-enterprises. Our findings reveal strong community and infrastructure frames in Native American micro-enterprises and their use of Information …


Undergraduate Research Experience Aids Progression, Graduation Rates At Texas Southern University, David Owerbach Jan 2015

Undergraduate Research Experience Aids Progression, Graduation Rates At Texas Southern University, David Owerbach

Office of Research Institutional Research and Scholarship

Undergraduate research experiences have become a widely accepted goal of colleges and universities for enhancing student development and success. Texas Southern University (TSU) is an Historically Black College and University (HBCU) with approximately 6,000 undergraduate students and as with most HBCUs, retention and graduation rates are extremely low. This study addresses the relationship between undergraduate research at TSU and progression, graduation rates and GPA. The experimental population includes 34 students that participated at a 10-week undergraduate research program (URP) during the summers of 2012 or 2013. The control group was selected from the 2006 freshmen class (n=268) admitted to the …


Research Week 2015, Linda Gardiner, David Owerbach Jan 2015

Research Week 2015, Linda Gardiner, David Owerbach

Office of Research Institutional Research and Scholarship

No abstract provided.


Introducing Machine Learning Via Baseball's Hall Of Fame, David Hansen Jan 2015

Introducing Machine Learning Via Baseball's Hall Of Fame, David Hansen

Faculty Publications - Department of Electrical Engineering and Computer Science

Machine Learning via Artificial Neural Networks (ANNs) is often introduced in a one-semester course on Artificial Intelligence. Baseball’s annual Hall of Fame election provides a simple, tractable, data-rich domain for learning how to use ANNs for predictive analytics. We describe how we use the Fast Artificial Neural Network (FANN) toolkit for a course assignment that predicts which players are likely to be elected to Baseball’s Hall of Fame.


Algae Population Self-Replenishment, R. Corban Harwood Jan 2015

Algae Population Self-Replenishment, R. Corban Harwood

Faculty Publications - Department of Mathematics

This modeling scenario investigates the massive algal blooms that struck Lake Chapala, Mexico, in 1994. After reading a summary of news articles on the incident, students create an ODE system model from a verbal description of the factors, visualize this system using an executable Java applet (PPLANE) to predict overall behavior, and then analyze the nonlinear system using the Jacobian matrix, eigenvalues, phase plane, and feasibility conditions on parameters to fully describe the system behavior. Students are expected to be familiar with systems of differential equations, equilibria, jacobian matrices, and eigenvalues. Students will learn modeling from qualitative descriptions, nondimensionalization, applying …


Interpreting Ulysses Data Using Inverse Scattering Theory: Oblique Alfven Waves, Harry R. Wheeler, M A. Reynolds, Robert L. Hamilton Jan 2015

Interpreting Ulysses Data Using Inverse Scattering Theory: Oblique Alfven Waves, Harry R. Wheeler, M A. Reynolds, Robert L. Hamilton

Faculty Publications - Department of Mathematics

Solitary wave structures observed by the Ulysses spacecraft in the solar wind were analyzed using both inverse scattering theory as well as direct numerical integration of the derivative nonlinear Schrodinger (DNLS) equation. Several of these structures were found to be consistent with soliton solutions of the DNLS equation. Such solitary structures have been commonly observed in the space plasma environment and may, in fact, be longlived solitons. While the generation of these solitons may be due to an instability mechanism, e.g., the mirror instability, they may be observable far from the source region due to their coherent nature.


Get Two For One—The Same Strategies Help You Go Green And Improve Wellness, Jean S. Waters Jan 2015

Get Two For One—The Same Strategies Help You Go Green And Improve Wellness, Jean S. Waters

White Papers

Going green and losing weight may very well be two of the biggest ever lifestyle buzzwords. Both require conscious effort, planning and systematic changes and both yield beneficial results. Drawing comparisons between green and wellness campaigns, Jean Waters, environmental engineer, discusses costs, benefits and strategies of pursuing sustainability.


Imber- Research For Marine Sustainability: Synthesis And The Way Forward, Eileen Hofmann, Alida Bundy, Ken Drinkwater, Alberto R. Piola, Bernard Avril, Carol Robinson Jan 2015

Imber- Research For Marine Sustainability: Synthesis And The Way Forward, Eileen Hofmann, Alida Bundy, Ken Drinkwater, Alberto R. Piola, Bernard Avril, Carol Robinson

CCPO Publications

The Integrated Marine Biogeochemistry and Ecosystem Research (IMBER) project aims at developing a comprehensive understanding of and accurate predictive capacity of ocean responses to accelerating global change and the consequent effects on the Earth system and human society. Understanding the changing ecology and biogeochemistry of marine ecosystems and their sensitivity and resilience to multiple drivers, pressures and stressors is critical to developing responses that will help reduce the vulnerability of marine-dependent human communities. This overview of the IMBER project provides a synthesis of project achievements and highlights the value of collaborative, interdisciplinary, integrated research approaches as developed and implemented through …


Dissolved Oxygen Dynamics During A Phytoplankton Bloom In The Ross Sea Polyna, Bastien Y. Queste, Karen J. Heywood, Walker O. Smith Jr., Daniel E. Kaufman, Timothy D. Jickells, Michael S. Dinniman Jan 2015

Dissolved Oxygen Dynamics During A Phytoplankton Bloom In The Ross Sea Polyna, Bastien Y. Queste, Karen J. Heywood, Walker O. Smith Jr., Daniel E. Kaufman, Timothy D. Jickells, Michael S. Dinniman

CCPO Publications

The Ross Sea polynya is one of the most productive regions in the Southern Ocean. However, limited access and high spatio-temporal variability of physical and biological processes limit the use of conventional oceanographic methods to measure early season primary productivity. High-resolution observations from two Seagliders provide insights into the timing of a bloom in the southern Ross Sea polynya in December 2010. Changes in chlorophyll and oxygen concentrations are used to assess bloom dynamics. Using a ratio of dissolved oxygen to carbon, net primary production is estimated over the duration of the bloom showing a sensitive balance between net autotrophy …


Acclimation, Adaptation, Traits And Trade-Offs In Plankton Functional Type Models: Reconciling Terminology For Biology And Modelling, Kevin J. Flynn, Michael St. John, John A. Raven, David O. F. Skibinski, J. Icarus Allen, Aditee Mitra, Eileen E. Hofmann Jan 2015

Acclimation, Adaptation, Traits And Trade-Offs In Plankton Functional Type Models: Reconciling Terminology For Biology And Modelling, Kevin J. Flynn, Michael St. John, John A. Raven, David O. F. Skibinski, J. Icarus Allen, Aditee Mitra, Eileen E. Hofmann

CCPO Publications

We propose definitions in terminology to enhance ongoing collaborations between biologists and modellers on plankton ecology. Organism "functional type" should refer to commonality in ecology not biogeochemistry; the latter is largely an emergent property of the former, while alignment with ecology is also consistent with usage in terrestrial science. Adaptation should be confined, as in genetics, to consideration of species inter-generational change; most so-called "adaptive" plankton models are thus acclimative, modifying vital rates in response to stimuli. Trait trade-off approaches should ideally only be considered for describing intra-generational interactions; in applications between generations, and certainly between unrelated species, such concepts …


Outcomes Of Asymmetric Selection Pressure And Larval Dispersal On Evolution Of Disease Resistance: A Metapopulation Modeling Study With Oysters, Daphne M. Munroe, Eric N. Powell, Susan E. Ford, Eileen E. Hofmann, John M. Klinck Jan 2015

Outcomes Of Asymmetric Selection Pressure And Larval Dispersal On Evolution Of Disease Resistance: A Metapopulation Modeling Study With Oysters, Daphne M. Munroe, Eric N. Powell, Susan E. Ford, Eileen E. Hofmann, John M. Klinck

CCPO Publications

Marine diseases are a strong selective force that can have important economic and ecological consequences. Larval dispersal patterns, selective mortality and individual growth rates can modulate metapopulation responses to disease pressure. Here, we use a modeling framework that includes distinct populations, connected via larval transport, with varying disease selection pressure and connectivity to examine how these dynamics enhance or inhibit the evolution of disease resistance in metapopulations. Our system, oysters and MSX disease, is one in which disease resistance is highly and demonstrably heritable. Simulations show that under conditions of population isolation (i.e. local retention of larvae) and strong disease …


Tropical Linear Algebra: Notions Of Rank Over The Tropical Semiring, William D. Wise Jan 2015

Tropical Linear Algebra: Notions Of Rank Over The Tropical Semiring, William D. Wise

Honors Papers

Three formulations of the rank of a matrix that are equivalent in classical linear algebra give rise to distinct notions of rank over the tropical semiring. This paper explores these three concepts of tropical rank and their relationships with one another, working up to a proof of the inequality that relates the three.


And Or Not – The System, The Body And Time, Brian Fay Jan 2015

And Or Not – The System, The Body And Time, Brian Fay

Articles

This catalogue text discusses artists and artworks featured in the exhibition BOOLEAN EXPRESSIONS: Contemporary Art and Mathematical Data, presented at The Lewis Glucksman Gallery, University College Cork, Ireland, 23 July – 8 November 2015. For an overview of the exhibition see the link https://vimeo.com/137620854


Preparation Of Scanning Tunneling Microscopy Tips Using Pulsed Alternating Current Etching, Victor A. Valencia, Avesh A. Thaker, Johnathan Derouin, Damian N. Valencia, Rachael G. Farber, Dana A. Gebel, Daniel Killelea Jan 2015

Preparation Of Scanning Tunneling Microscopy Tips Using Pulsed Alternating Current Etching, Victor A. Valencia, Avesh A. Thaker, Johnathan Derouin, Damian N. Valencia, Rachael G. Farber, Dana A. Gebel, Daniel Killelea

Chemistry: Faculty Publications and Other Works

An electrochemical method using pulsed alternating current etching (PACE) to produce atomically sharp scanning tunneling microscopy (STM) tips is presented. An Arduino Uno microcontroller was used to control the number and duration of the alternating current (AC) pulses, allowing for ready optimization of the procedures for both Pt:lr and W tips using a single apparatus. W tips prepared using constant and pulsed AC power were compared. Tips fashioned using PACE were sharper than those etched with continuous AC power alone. Pt:lr tips were prepared with an initial coarse etching stage using continuous AC power followed by fine etching using PACE. …


Hash-Map-Eradicator: Filtering Non-Target Sequences From Next Generation Sequencing Reads, Jonathon Brenner, Catherine Putonti Jan 2015

Hash-Map-Eradicator: Filtering Non-Target Sequences From Next Generation Sequencing Reads, Jonathon Brenner, Catherine Putonti

Bioinformatics Faculty Publications

Contemporary DNA sequencing technologies are continuously increasing throughput at ever decreasing costs. Moreover, due to recent advances in sequencing technology new platforms are emerging. As such computational challenges persist. The average read length possible has taken a giant leap forward with the PacBio and Nanopore solutions. Regardless of the platform used, impurities within the DNA preparation of the sample - be it from unintentional contaminants or pervasive symbiots - remains an issue. We have developed a new tool, HAsh-MaP-ERadicator (HAMPER), for the detection and removal of non-target, contaminating DNA sequences. Integrating hash-based and mapping-based strategies, HAMPER is both memory and …


Young Tableaux, Multisegments, And Pbw Bases, John Claxton, Peter Tingley Jan 2015

Young Tableaux, Multisegments, And Pbw Bases, John Claxton, Peter Tingley

Mathematics and Statistics: Faculty Publications and Other Works

The crystals for finite dimensional representations of sln+1 can be realized using Young tableaux. The infinity crystal on the other hand is naturally realized using multisegments, and there is a simple description of each embedding B(λ) ,→ B(∞) in terms of these realizations. The infinity crystal is also parameterized by Lusztig’s PBW basis with respect to any reduced expression for w0. We give an explicit description of the unique crystal isomorphism from PBW bases to multisegments in the case where w0 = s1s2s3 · · · sns1 · · · s1s2s1, thus obtaining simple formulas for the actions of all …


The Characteristic Polynomial Of The Adams Operators On Graded Connected Hopf Algebras, Marcelo Aguiar, Aaron Lauve Jan 2015

The Characteristic Polynomial Of The Adams Operators On Graded Connected Hopf Algebras, Marcelo Aguiar, Aaron Lauve

Mathematics and Statistics: Faculty Publications and Other Works

The Adams operators ‰n on a Hopf algebra H are the convolution powers of the identity of H. They are also called Hopf powers or Sweedler powers. We study the Adams operators when H is graded connected. The main result is a complete description of the characteristic polynomial — both eigenvalues and their multiplicities — for the action of the operator ‰n on each homogeneous component of H. The eigenvalues are powers of n. The multiplicities are independent of n, and in fact only depend on the dimension sequence of H. These results apply in particular to the antipode of …


Design, Synthesis, And Biological Evaluation Of Folate Targeted Photosensitizers For Photodynamic Therapy, Laura Jean Donahue Jan 2015

Design, Synthesis, And Biological Evaluation Of Folate Targeted Photosensitizers For Photodynamic Therapy, Laura Jean Donahue

Dissertations

Photodynamic therapy (PDT) is used to treat cancer, and involves a highly conjugated molecule, called a photosensitizer (PS), which is excited by wavelengths of light from visible to infrared. Photosensitizers that are highly conjugated will absorb longer wavelengths (600 – 900 nm), and have the potential to destroy cells of deeper tissue cancers. In PDT, a PS is administered to the patient, and after an appropriate time delay, the tissue is then exposed to light of a specific wavelength necessary for excitation of the PS. A transfer of energy can take place between the excited PS and oxygen that is …


Synthesis And Testing Of Photosensitizer-Folate Conjugates And Potential Photosensitizers For Photodynamic Therapy, Jeffrey A. Trautmann Jan 2015

Synthesis And Testing Of Photosensitizer-Folate Conjugates And Potential Photosensitizers For Photodynamic Therapy, Jeffrey A. Trautmann

Dissertations

Dissertation Proposal for Jeffrey Trautmann

Photodynamic Therapy (PDT) is a technique that destroys oncogenic (cancerous) cells. It has been used in several countries since the 1980’s. Molecules that contain chromophores can function as photosensitizers, and will absorb light at various wavelengths (that being dependent upon the extent of their conjugation). Certain functional groups, upon absorption of light, can be used to convert O2 to singlet oxygens which are destructive to the cellular environment. Once an in-vitro cell contains a high enough concentration of photosensitizer material and light is able to reach the photosensitizer material, PDT can be used effectively to …


The Influence Of Eastern Oyster (Crassostrea Virginica) Reef Restoration On Nitrogen Cycling In A Eutrophic Estuary., Michael Hassett Jan 2015

The Influence Of Eastern Oyster (Crassostrea Virginica) Reef Restoration On Nitrogen Cycling In A Eutrophic Estuary., Michael Hassett

Master's Theses

Oysters (Crassostrea virginica) are functionally extinct in the urbanized Hudson-Raritan estuary (HRE) in New York City, however, oyster restoration is promoted to mitigate nitrogen (N) pollution via oysters' filtration and excretion. Seasonally, I took 12 sediment cores (45 cm2) adjacent to and 10 m away from a recently constructed reef in the HRE. Cores were incubated in flow-through chambers with site water containing (1) no amendments, (2) 15N-ammonium, or (3) 15N-nitrate, from which I calculated coupled nitrification-denitrification and direct denitrification as isotope-enriched N2. Coupled denitrification was minimal at all sites while direct denitrification was elevated near the reef, suggesting organic …


Spatial Distribution Of Lead In Sacramento, California, Usa, Michael J. Solt, Daniel M. Deocampo, Michelle Norris Jan 2015

Spatial Distribution Of Lead In Sacramento, California, Usa, Michael J. Solt, Daniel M. Deocampo, Michelle Norris

Geosciences Faculty Publications

Chronic exposure to lead remains a health concern in many urban areas; Sacramento, California is one example, with state surveillance data showing nearly 3% of screened children reported with blood lead levels over 4.5 μg/dL in 2009. To investigate the environmental exposure, 91 soil samples were collected and analyzed by ICP-AES and ICP-MS for 14 elements. An additional 28 samples were collected from areas of focus and analyzed by hand-held X-ray fluorescence spectrometry for Pb and Zn. Analysis of the metals data revealed non-normal distributions and positive skewness, consistent with anthropogenic input. In addition, high correlation coefficients (≥0.75) of metal …


Water Current, Volume 47, No. 1, Winter 2015 Jan 2015

Water Current, Volume 47, No. 1, Winter 2015

Water Current Newsletter

March Water Symposium and Water Law Conference at NU Law College

June Water Tour To Republican River Basin


Is The Gefion Dynamical Asteroid Family The Source Of The L-Chondrites?, R. V. Roberts, Michael J. Gaffey, Sherry Fieber-Beyer Jan 2015

Is The Gefion Dynamical Asteroid Family The Source Of The L-Chondrites?, R. V. Roberts, Michael J. Gaffey, Sherry Fieber-Beyer

Space Studies Faculty Publications

No abstract provided.


Chloroamino Acids As A Chemical Explanation For Viking Labeled Release Soil Activity On Mars, John C. Hironimus Jan 2015

Chloroamino Acids As A Chemical Explanation For Viking Labeled Release Soil Activity On Mars, John C. Hironimus

STAR Program Research Presentations

The Viking missions to Mars, which took place in the 1970’s, performed several experiments on martian soil in an attempt to discern if there was microbial life present. In one set of experiments, a nutrient solution containing amino acids and organic substrates tagged with carbon-14 was injected into sample cells containing martian soil, and the evolution of labeled CO2 was monitored. The evolution of labeled CO2 indicated that there was a process occurring that broke down the nutrients in solution and released CO2 as a byproduct. Cellular metabolism releases CO2, so this result supported the idea of microbial life on …