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Articles 31 - 60 of 111

Full-Text Articles in Astrophysics and Astronomy

Methanogens, Plausible Extraterrestrial Life Forms On Mars, And Their Tolerance To Increasing Concentrations Of Illite Clay, Chandler Kern Dec 2018

Methanogens, Plausible Extraterrestrial Life Forms On Mars, And Their Tolerance To Increasing Concentrations Of Illite Clay, Chandler Kern

Biological Sciences Undergraduate Honors Theses

Methanogens, some of Earth’s most primitive prokaryotic organisms, are candidates for possible life forms capable of inhabiting Mars. Specifically, four different species (Methanobacterium formicicum, Methanococcus maripaludis, Methanosarcina barkeri, Methanothermobacter wolfeii) were analyzed for their tolerance to the presence of illite clay. Illite is a crystalline mineral that has been identified from regions of Mars’s surface. Results indicated that all four species grew with some success in the illite at different concentrations. This experimentation with methanogens’ abilities to survive and reproduce in the presence of illite allows for a more accurate understanding of the potential capability of microbial …


Astromimetics: The Dawn Of A New Era For (Bio)Materials Science?, Vuk Uskoković, Victoria M. Wu Aug 2018

Astromimetics: The Dawn Of A New Era For (Bio)Materials Science?, Vuk Uskoković, Victoria M. Wu

Pharmacy Faculty Articles and Research

Composite, multifunctional fine particles are likely to be at the frontier of materials science in the foreseeable future. Here we present a submicron composite particle that mimics the stratified structure of the Earth by having a zero-valent iron core, a silicate/silicide mantle, and a thin carbonaceous crust resembling the biosphere and its biotic deposits. Particles were formulated in a stable colloidal form and made to interact with various types of healthy and cancer cells in vitro. A selective anticancer activity was observed, promising from the point of view of the intended use of the particles for tumor targeting across the …


Cause Of Cambrian Explosion - Terrestrial Or Cosmic?, Edward J. Steele, Shirwan Al-Mufti, Kenneth A. Augustyn, Rohana Chandrajith, John P. Coghlan, S. G. Coulson, Et. Al. Aug 2018

Cause Of Cambrian Explosion - Terrestrial Or Cosmic?, Edward J. Steele, Shirwan Al-Mufti, Kenneth A. Augustyn, Rohana Chandrajith, John P. Coghlan, S. G. Coulson, Et. Al.

Michigan Tech Publications, Part 1

We review the salient evidence consistent with or predicted by the Hoyle-Wickramasinghe (H-W) thesis of Cometary (Cosmic) Biology. Much of this physical and biological evidence is multifactorial. One particular focus are the recent studies which date the emergence of the complex retroviruses of vertebrate lines at or just before the Cambrian Explosion of ∼500 Ma. Such viruses are known to be plausibly associated with major evolutionary genomic processes. We believe this coincidence is not fortuitous but is consistent with a key prediction of H-W theory whereby major extinction-diversification evolutionary boundaries coincide with virus-bearing cometary-bolide bombardment events. A second focus is …


Table Of Contents Jul 2018

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


Effects Of Radiation On Neurite Morphology And Cytoskeleton Structure, Melissa Sassman Apr 2018

Effects Of Radiation On Neurite Morphology And Cytoskeleton Structure, Melissa Sassman

Student Scholarship

Long-term manned space exploration to the moon, Mars, and other areas beyond Earth's protective magnetic field poses possible acute and late central nervous systems (CNS) risks. Of particular concern for astronauts is exposure to high atomic number, high energy particles known as HZE particles, a component of galactic cosmic radiation (GCR). Although NASA has radiation safety requirements, the possible effects of GCR and HZE particles on the central nervous systems of astronauts remains unknown. Understanding the risks and effects of galactic cosmic radiation and HZE particles on the central nervous system will allow for safer space exploration.

Additionally, and perhaps …


Symmetry Of Energy Divergence Anomalies Associated With The El Niño-Southern Oscillation, Evan Kutta, Jason A. Hubbart, Timothy P. Eichler, Anthony R. Lupo Jan 2018

Symmetry Of Energy Divergence Anomalies Associated With The El Niño-Southern Oscillation, Evan Kutta, Jason A. Hubbart, Timothy P. Eichler, Anthony R. Lupo

Faculty & Staff Scholarship

The El Niño-Southern Oscillation (ENSO) is a dominant source of global climate variability. The effects of this phenomenon alter the flow of heat from tropical to polar latitudes, resulting in weather and climate anomalies that are difficult to forecast. The current work quantified two components of the vertically integrated equation for the total energy content of an atmospheric column, to show the anomalous horizontal redistribution of surface heat flux anomalies. Symmetric and asymmetric components of the vertically integrated latent and sensible heat flux divergence were quantified using ERA-Interim atmospheric reanalysis output on 30 model layers between 1979 and 2016. Results …


Enhanced Hot Electron Lifetimes In Quantum Wells With Inhibited Phonon Coupling, Hamidreza Esmaielpour, Vincent R. Whiteside, Herath P. Piyathilaka, Sangeetha Vijeyaragunathan, Bin Wang, Echo Adcock-Smith, Kenneth P. Roberts, Tetsuya D. Mishima, Michael B. Santos, Alan D. Bristow, Ian R. Sellers Jan 2018

Enhanced Hot Electron Lifetimes In Quantum Wells With Inhibited Phonon Coupling, Hamidreza Esmaielpour, Vincent R. Whiteside, Herath P. Piyathilaka, Sangeetha Vijeyaragunathan, Bin Wang, Echo Adcock-Smith, Kenneth P. Roberts, Tetsuya D. Mishima, Michael B. Santos, Alan D. Bristow, Ian R. Sellers

Faculty & Staff Scholarship

Hot electrons established by the absorption of high-energy photons typically thermalize on a picosecond time scale in a semiconductor, dissipating energy via various phonon-mediated relaxation pathways. Here it is shown that a strong hot carrier distribution can be produced using a type-II quantum well structure. In such systems it is shown that the dominant hot carrier thermalization process is limited by the radiative recombination lifetime of electrons with reduced wavefunction overlap with holes. It is proposed that the subsequent reabsorption of acoustic and optical phonons is facilitated by a mismatch in phonon dispersions at the InAs-AlAsSb interface and serves to …


Unseen Science: Modern Discoveries Too Far Away Or Tiny For Human Eyes, Lucy Huang Dec 2017

Unseen Science: Modern Discoveries Too Far Away Or Tiny For Human Eyes, Lucy Huang

Capstones

As science has progressed, scientists have realized that evidence goes beyond the realms of physical sight. Whether it is too small or difficult to find, scientists have developed different ways to get around this problem. We see this in cancer genomics and in extrasolar planetary research. Scientists use what they know and what they measure to validate their work.

https://lucy-huang-9tge.squarespace.com/


Detection Of Survival And Proliferation Of Sulfate Reducers Under Simulated Martian Atmospheric And Soil Conditions, Sergio Mosquera Mora Dec 2017

Detection Of Survival And Proliferation Of Sulfate Reducers Under Simulated Martian Atmospheric And Soil Conditions, Sergio Mosquera Mora

Graduate Theses and Dissertations

Numerous studies have tried to determine the survivability and proliferation of microorganisms under simulated Martian conditions. Furthermore, most of them have been focused on the ability of these microbes to cope with high brines’ salt (NaCl) concentrations inherent of the Martian surface. However, there are not studies related to the ability of bacteria to survive on subsurface environments that have increasing concentrations of sulfate compounds. For this research, a group of microorganisms known as sulfate-reducing bacteria or simply sulfate reducers were chosen due to their ability to use sulfate compounds as terminal electron acceptors to produce metabolic energy, their tolerance …


Table Of Contents Nov 2017

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


Growth And Survivability Of Microorganisms At Martian Temperatures And Pressures, Rebecca Lynne Mickol Aug 2017

Growth And Survivability Of Microorganisms At Martian Temperatures And Pressures, Rebecca Lynne Mickol

Graduate Theses and Dissertations

The discovery of methane in the martian atmosphere via numerous ground- and space-based sources has prompted the study of methanogens as models for life on Mars. Methanogens are microorganisms within the domain Archaea, many of which utilize carbon dioxide (CO2) and hydrogen to produce methane. The non-photosynthetic nature of methanogens indicates that they could exist in sub-surface environments, protected from harmful UV and ionizing radiation on the surface of Mars. These organisms also do not require organics, which are sparse on the planet.

Additionally, the wide variety of environments we find life in on Earth, as well as evidence for …


Mechanosensing Of Shear By Pseudomonas Aeruginosa Leads To Increased Levels Of The Cyclic-Di-Gmp Signal Initiating Biofilm Development, Christopher A. Rodesney, Brian Roman, Numa Dhamani, Benjamin J. Cooley, Ahmed Touhami, Vernita D. Gordon Jun 2017

Mechanosensing Of Shear By Pseudomonas Aeruginosa Leads To Increased Levels Of The Cyclic-Di-Gmp Signal Initiating Biofilm Development, Christopher A. Rodesney, Brian Roman, Numa Dhamani, Benjamin J. Cooley, Ahmed Touhami, Vernita D. Gordon

Physics & Astronomy Faculty Publications

Biofilms are communities of sessile microbes that are phenotypically distinct from their genetically identical, free-swimming counterparts. Biofilms initiate when bacteria attach to a solid surface. Attachment triggers intracellular signaling to change gene expression from the planktonic to the biofilm phenotype. For Pseudomonas aeruginosa, it has long been known that intracellular levels of the signal cyclic-di-GMP increase upon surface adhesion and that this is required to begin biofilm development. However, what cue is sensed to notify bacteria that they are attached to the surface has not been known. Here, we show that mechanical shear acts as a cue for surface adhesion …


Beyond 3 Au From The Sun: The Hypervolatiles Ch4, C2h6, And Co In The Distant Comet C/2006 W3 (Christensen), Boncho Bonev, Geronimo Villanueva, Michael Disanti, Hermann Boehnhardt, Manuela Lippi, Erika Gibb, Lucas Paganini, Michael Mumma May 2017

Beyond 3 Au From The Sun: The Hypervolatiles Ch4, C2h6, And Co In The Distant Comet C/2006 W3 (Christensen), Boncho Bonev, Geronimo Villanueva, Michael Disanti, Hermann Boehnhardt, Manuela Lippi, Erika Gibb, Lucas Paganini, Michael Mumma

Physics Faculty Works

Comet C/2006 W3 (Christensen) remained outside a heliocentric distance (R h) of 3.1 au throughout its apparition, but it presented an exceptional opportunity to directly sense a suite of molecules released from its nucleus. The Cryogenic Infrared Echelle Spectrograph at ESO-VLT detected infrared emissions from the three "hypervolatiles" (CO, CH4, and C2H6) that have the lowest sublimation temperatures among species that are commonly studied in comets by remote sensing. Even at R h = 3.25 au, the production rate of each molecule exceeded those measured for the same species in a number of other comets, although these comets were observed …


Table Of Contents Apr 2017

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


The Composition Of Comet C/2012 K1 (Panstarrs) And The Distribution Of Primary Volatile Abundances Among Comets, Nathan Roth, Erika Gibb, Boncho Bonev, Michael Disanti, Michael Mumma, Geronimo Villanueva, Lucas Paganini Mar 2017

The Composition Of Comet C/2012 K1 (Panstarrs) And The Distribution Of Primary Volatile Abundances Among Comets, Nathan Roth, Erika Gibb, Boncho Bonev, Michael Disanti, Michael Mumma, Geronimo Villanueva, Lucas Paganini

Physics Faculty Works

On 2014 May 22 and 24 we characterized the volatile composition of the dynamically new Oort cloud comet C/2012 K1 (PanSTARRS) using the long-slit, high resolution (λ/Δλ ≈ 25,000) near-infrared echelle spectrograph (NIRSPEC) at the 10 m Keck II telescope on Maunakea, Hawaii. We detected fluorescent emission from six primary volatiles (H2O, HCN, CH4, C2H6, CH3OH, and CO). Upper limits were derived for C2H2, NH3, and H2CO. We report rotational temperatures, production rates, and mixing ratios (relative to water). Compared with median abundance ratios for primary volatiles in other sampled Oort cloud comets, trace gas abundance ratios in C/2012 K1 …


Repository Review: Nasa Pubspace, Laura Pope Robbins Mar 2017

Repository Review: Nasa Pubspace, Laura Pope Robbins

Publications

Laura Pope Robbins is an advisor for The Charleston Advisor, and the review below is included in Scholarly Commons with the permission of the publisher.

PubSpace is a repository of full-text peer-reviewed articles resulting from NASA-funded research going back to 1961. The National Center for Biotechnology Information has integrated PubSpace into PubMed Central, a freely available repository of medical research. Using an established, stable, government-hosted platform for PubSpace seems to make sense. However, the lack of clear branding, an uneven application of phrase searching, and a missing thesaurus of NASA terminology highlights that this integration may not be the best.


Hpcnmf: A High-Performance Toolbox For Non-Negative Matrix Factorization, Karthik Devarajan, Guoli Wang Feb 2016

Hpcnmf: A High-Performance Toolbox For Non-Negative Matrix Factorization, Karthik Devarajan, Guoli Wang

COBRA Preprint Series

Non-negative matrix factorization (NMF) is a widely used machine learning algorithm for dimension reduction of large-scale data. It has found successful applications in a variety of fields such as computational biology, neuroscience, natural language processing, information retrieval, image processing and speech recognition. In bioinformatics, for example, it has been used to extract patterns and profiles from genomic and text-mining data as well as in protein sequence and structure analysis. While the scientific performance of NMF is very promising in dealing with high dimensional data sets and complex data structures, its computational cost is high and sometimes could be critical for …


Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt Jan 2015

Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt

Physics & Astronomy Faculty Publications

Supervised image classifications developed from 23 x 23 cm aerial color-infrared aerial photographs (1:5,000 scale) were used to evaluate temporal changes in vegetative cover occurring within three 150 x 300-m research sites on South Padre Island, Texas. Use of high-resolution digitized imagery (ground pixel resolution of ca. 0.1 m) and survey-grade GPS for positional measurements of ground control points (20-25 1.0m2 targets within each research site) resulted in consistently high levels of geometric accuracy, with root mean square errors (RMSEs) ranging between 0.397 – 2.867. Similarly, use of relatively simple information categories (dry and wet sand, live and dead vegetative …


2014 Scas Annual Meeting Program Sep 2014

2014 Scas Annual Meeting Program

Journal of the South Carolina Academy of Science

No abstract provided.


Scas Officers And Council Members 2014-2015 Sep 2014

Scas Officers And Council Members 2014-2015

Journal of the South Carolina Academy of Science

No abstract provided.


Table Of Contents Sep 2014

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


Phylogenetic Diversity Of Microbial Isolates From The Mars Pathfinder, Kyla Bradylong, Adriana Blachowicz, Parag Vaishampayan, James N. Benardini, Wayne Schubert Aug 2014

Phylogenetic Diversity Of Microbial Isolates From The Mars Pathfinder, Kyla Bradylong, Adriana Blachowicz, Parag Vaishampayan, James N. Benardini, Wayne Schubert

STAR Program Research Presentations

As spacecraft are sent to different planets, they take with them microscopic pieces of life from Earth. It is the task of the Biotechnology and Planetary Protection Group to keep as much of this life off other planets as possible as well as document any life that may have been sent. During the construction of the Mars Pathfinder, samples were collected from various locations on the spacecraft to test for contamination. These samples were then isolated, grown, documented, preserved and their 16S rRNA genes were sequenced for identification. The 16S rRNA gene sequence is utilized because it is a highly …


Light Pollution Research Through Citizen Science, John Kanemoto Aug 2014

Light Pollution Research Through Citizen Science, John Kanemoto

STAR Program Research Presentations

Light pollution (LP) can disrupt and/or degrade the health of all living things, as well as, their environments. The goal of my research at the NOAO was to check the accuracy of the citizen science LP reporting systems entitled: Globe at Night (GaN), Dark Sky Meter (DSM), and Loss of the Night (LoN). On the GaN webpage, the darkness of the night sky (DotNS) is reported by selecting a magnitude chart. Each magnitude chart has a different density/number of stars around a specific constellation. The greater number of stars implies a darker night sky. Within the DSM iPhone application, a …


Ice Caves On Extraterrestrial Bodies: What Are The Prospects For Speleogenesis And Detection?, Penelope J. Boston Aug 2014

Ice Caves On Extraterrestrial Bodies: What Are The Prospects For Speleogenesis And Detection?, Penelope J. Boston

The International Workshop on Ice Caves

Potential mechanisms for creating cavities in icy extraterrestrial bodies have been tentatively explored by several authors. On one hand we have examples of mechanisms that create caves in water ice here on Earth. In addition, there may be unique mechanisms on other Solar System objects that do not occur on Earth but might produce cavities, e.g. sublimation of comets upon perihelion passage. The methods of detecting such cavities depend upon the nature of the icy body in question, the potential for orbital or landed missions to visit those bodies in the future, and remote or landed methods for detecting the …


Mars-Relevant Phosphate Minerals And Implications For Martian Habitability, Christopher Adcock Aug 2014

Mars-Relevant Phosphate Minerals And Implications For Martian Habitability, Christopher Adcock

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation is comprised of three studies focused on martian phosphate availability, with an introductory chapter introducing and linking the three studies. Chapter two is on the subject of merrillite synthesis. Merrillite is an extraterrestrial Ca-phosphate mineral similar to the mineral whitlockite and is found as a dominant primary phosphate mineral in martian meteorites. The chapter includes methods of whitlockite and merrillite synthesis as well as a detailed characterization of the produced minerals and a mechanism by which charge balance can be maintained when merrillite is synthesized through dehydrogenation of whitlockite.

Chapter three presents the results of kinetic and thermodynamic …


Report On The Workshop For Life Detection In Samples From Mars, Gerhard Kminek, Catherine Conley, Carlton C. Allen, Douglas H. Bartlett, David W. Beaty, Liane G. Benning, Rohit Bhatia, Penelope J. Boston, Caroline Duchaine, Jack D. Farmer, George J. Flynn, Daniel P. Glavin, Yuri Gorby, John E. Hallsworth, Rakesh Mogul, Duane Moser, P. Buford Price, Ruediger Pukall, David Fernandez-Remolar, Caroline L. Smith, Kenneth M. Stedman, Andrew Steele, Ramunas Stepanauskas, Henry Sun, Jorge L. Vago, Mary A. Voytek, Paul S. Weiss, Frances Westfall Jul 2014

Report On The Workshop For Life Detection In Samples From Mars, Gerhard Kminek, Catherine Conley, Carlton C. Allen, Douglas H. Bartlett, David W. Beaty, Liane G. Benning, Rohit Bhatia, Penelope J. Boston, Caroline Duchaine, Jack D. Farmer, George J. Flynn, Daniel P. Glavin, Yuri Gorby, John E. Hallsworth, Rakesh Mogul, Duane Moser, P. Buford Price, Ruediger Pukall, David Fernandez-Remolar, Caroline L. Smith, Kenneth M. Stedman, Andrew Steele, Ramunas Stepanauskas, Henry Sun, Jorge L. Vago, Mary A. Voytek, Paul S. Weiss, Frances Westfall

Biology Faculty Publications and Presentations

The question of whether there is or was life on Mars has been one of the most pivotal since Schiaparellis’ telescopic observations of the red planet. With the advent of the space age, this question can be addressed directly by exploring the surface of Mars and by bringing samples to Earth for analysis. The latter, however, is not free of problems. Life can be found virtually everywhere on Earth. Hence the potential for contaminating the Mars samples and compromising their scientific integrity is not negligible. Conversely, if life is present in samples from Mars, this may represent a potential source …


Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean Mar 2014

Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean

Ogden College of Science & Engineering Publications

No abstract provided.


Table Of Contents, Michele Harmon Dec 2013

Table Of Contents, Michele Harmon

Journal of the South Carolina Academy of Science

No abstract provided.


Dose Dependent Effects Of Caffeine On Cognitive Performance And Neuronal Activation, Stephan Albrecht, Helen Morris, Michelle Vieyra Dec 2013

Dose Dependent Effects Of Caffeine On Cognitive Performance And Neuronal Activation, Stephan Albrecht, Helen Morris, Michelle Vieyra

Journal of the South Carolina Academy of Science

Many students assume that the more caffeine you drink, the better your cognitive performance. Over-consumption of caffeine has many negative effects, so if there are no dose related cognitive benefits to large amounts of caffeine, then college students should limit their intake. This study looked at whether ingesting a medium dose (200 mg) versus a lower dose (100 mg) of caffeine improved short term memory as measured by Flanker and n-back tests, compared to a control group. In addition, we looked at whether larger doses of caffeine produced a difference in neuronal activation during these tests as measured by functional …


Fourier Analysis Of Phase Resetting Curves Of Neural Oscillators, Robert A. Raidt, Sorinel A. Oprisan Dec 2013

Fourier Analysis Of Phase Resetting Curves Of Neural Oscillators, Robert A. Raidt, Sorinel A. Oprisan

Journal of the South Carolina Academy of Science

We investigated the impact of changes in biologically relevant control parameters, such as the shape of an external perturbation or the conductance values of an individual model neuron, on the shape of the phase resetting curve (PRC) of that neuron. For that purpose, PRCs were generated for groups of Morris-Lecar (ML) model neurons with different conductance values but similar firing periods (within 0.005ms) using external rectangular, triangular, or trapezoidal perturbations of varying areas. These PRCs were numerically described and analyzed as a series of coefficient values using a Fourier Discrete Sine Transform (DST). We found that changes in the shape …