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2015

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Articles 8791 - 8820 of 9578

Full-Text Articles in Physical Sciences and Mathematics

Communication Of Lava Flow Hazards At The San Francisco Volcanic Field, Flagstaff, Arizona, Catherine St. John Carter Jan 2015

Communication Of Lava Flow Hazards At The San Francisco Volcanic Field, Flagstaff, Arizona, Catherine St. John Carter

USF Tampa Graduate Theses and Dissertations

This thesis examines different methods of communicating volcanic hazards to the population of Flagstaff, Arizona using the results of a recent lava flow hazard assessment of the nearby San Francisco Volcanic Field (SFVF). Harburger (2014) determined that given a lava flow originating in the SFVF, there is a statistical probability that it will inundate the city of Flagstaff or even originate from a vent within the city limits. Based on the recurrence rates for the most recent eruptions (3 x 10-4/year), the probability of lava flow inundation in Flagstaff is 1.1 x 10-5 per year.

This study considers the effects …


Effects Of Solids Retention Time And Feeding Frequency On Performance And Pathogen Fate In Semi-Continuous Mesophilic Anaerobic Digesters, Nathan Daniel Manser Jan 2015

Effects Of Solids Retention Time And Feeding Frequency On Performance And Pathogen Fate In Semi-Continuous Mesophilic Anaerobic Digesters, Nathan Daniel Manser

USF Tampa Graduate Theses and Dissertations

Anaerobic digestion is a biochemical process in which organic carbon is biodegraded in an oxygen free environment through a microbial consortium. Engineered biological systems used for resource recovery often utilize anaerobic digestion to treat anthropogenic organic wastes by reclaiming the carbon as energy (methane gas) and a soil amendment (biosolids). Small-scale, or household, semi-continuous anaerobic digesters have been used in developed and developing countries for many decades to produce biogas from human and livestock waste, which is used for heating, lighting, and cooking. This application has been shown to improve the quality of life of the user. Although there is …


Metal Organic Frameworks (Mofs) And Porous Organic Polymers (Pops) For Heterogeneous Asymmetric Catalysis, Youngran Ji Jan 2015

Metal Organic Frameworks (Mofs) And Porous Organic Polymers (Pops) For Heterogeneous Asymmetric Catalysis, Youngran Ji

USF Tampa Graduate Theses and Dissertations

The administration of enantiopure drugs brings advantages such as improved efficacy, more predictable pharmacokinetics and reduced toxicity from the point of view of the pharmaceutical area.[1] For this reason, a tremendous amount of supply and demand for enantiomeric pure compounds has been shown not only in market, but industry and academia.[2-4] According to the industry publication Genetic Engineering and Biotechnology News (GEN) in 2014, 22 billion dollars were accounted for enantiopure form of drugs such as Sovaldi® (Sofosbuvir), Crestor® (Rosuvastatin), and Advair® (fluticasone/salmeterol).

The fact that one enantiomer can be pharmacologically effective whereas the other enantiomer can be …


Development Of Orally Bioavailable 4(1H)-Quinolones And 1,2,3,4-Tetrahydroacridin-9(10H)-Ones With Potent Anti-Malarial Activity, Jordany Richarlson Maignan Jan 2015

Development Of Orally Bioavailable 4(1H)-Quinolones And 1,2,3,4-Tetrahydroacridin-9(10H)-Ones With Potent Anti-Malarial Activity, Jordany Richarlson Maignan

USF Tampa Graduate Theses and Dissertations

Although Malaria rates are on the decline due to the efforts of the World Health Organization and other organizations dedicated to the eradication of this disease, a relaxed attitude towards the development of new antimalarial entities would be flawed. Due to the emergence of resistance in the parasite, the almost 50% world-wide reduction in malarial death rates that have been produced over the past 15 years are threatening to be lost

New drugs are urgently needed and our approach focuses on the re-evaluation and optimization of the historic antimalarial ICI 56,780. Due to its causal prophylactic activity, along with its …


Relational Agency, Networked Technology, And The Social Media Aftermath Of The Boston Marathon Bombing, Megan M. Mcintyre Jan 2015

Relational Agency, Networked Technology, And The Social Media Aftermath Of The Boston Marathon Bombing, Megan M. Mcintyre

USF Tampa Graduate Theses and Dissertations

Agency is a foundational and ongoing concern for the field of Rhetoric and Composition. Long thought to be a product and possession of human action, rhetorical agency represents the most obvious connection between the educational and theoretical work of the field and the civic project of liberal arts and humanities education. Existing theories of anthropocentric rhetorical agency are insufficient, however, to account for the complex technological work of digitally enmeshed networks of humans and nonhumans. To better account for these complex networks, this project argues for the introduction of new materialist theories of distributed agency into conversations about agency within …


Theoretical Investigations Of Gas Sorption And Separation In Metal-Organic Materials, Tony Pham Jan 2015

Theoretical Investigations Of Gas Sorption And Separation In Metal-Organic Materials, Tony Pham

USF Tampa Graduate Theses and Dissertations

Metal--organic frameworks (MOFs) are porous crystalline materials that are synthesized from rigid organic ligands and metal-containing clusters. They are highly tunable as a number of different structures can be made by simply changing the organic ligand and/or metal ion. MOFs are a promising class of materials for many energy-related applications, including H2 storage and CO2 capture and sequestration. Computational studies can provide insights into MOFs and the mechanism of gas sorption and separation. Theoretical studies on existing MOFs are performed to determine what structural characteristics leads to favorable gas sorption mechanisms. The results from these studies can provide …


Statistical Modeling Of Microrna Expression With Human Cancers, Ke-Sheng Wang, Yue Pan, Chun Xu Jan 2015

Statistical Modeling Of Microrna Expression With Human Cancers, Ke-Sheng Wang, Yue Pan, Chun Xu

Health & Biomedical Sciences Faculty Publications

MicroRNAs (miRNAs) are small non-coding RNAs (containing about 22 nucleotides) that regulate gene expression. MiRNAs are involved in many different biological processes such as cell proliferation, differentiation, apoptosis, fat metabolism, and human cancer genes; while miRNAs may function as candidates for diagnostic and prognostic biomarkers and predictors of drug response. This paper emphasizes the statistical methods in the analysis of the associations of miRNA gene expression with human cancers and related clinical phenotypes: 1) simple statistical methods include chi-square test, correlation analysis, t-test and one-way ANOVA; 2) regression models include linear and logistic regression; 3) survival analysis approaches such as …


Surface Science Studies Of Graphene Interfaces, Arjun Dahal Jan 2015

Surface Science Studies Of Graphene Interfaces, Arjun Dahal

USF Tampa Graduate Theses and Dissertations

Interfaces between graphene and dissimilar materials are needed for making devices, but those interfaces also modify the graphene properties due to charge transfer and/or symmetry breaking. In this dissertation we investigate the technology of preparing graphene on different substrates and how the substrate influences the electronic properties of graphene.

Synthesizing large area graphene on late transition metals by chemical vapor deposition is a promising approach for many applications of graphene. Among the transition metals, nickel has advantages because the good lattice match and strong interaction between graphene/Ni(111) enables the synthesis of a single domain of graphene on Ni(111). However, the …


Context-Based Access For Infrequent Requests In Tanzania's Health Care System, Zanifa Omary Jan 2015

Context-Based Access For Infrequent Requests In Tanzania's Health Care System, Zanifa Omary

Doctoral

Access control is an important aspect of any information system. It is a way of ensuring that users can only access what they are authorised to and no more. This can be achieved by granting users access to resources based on pre-defined organisational and legislative rules. Although access control has been extensively studied, and as a result, a wide range of access control models, mechanisms and systems have been proposed, specific access control requirements for healthcare systems that needs to support the continuity of care in an accountable manner have not been addressed. This results in a gap between what …


Ecosystem-Based Management And Refining Governance Of Wind Energy In The Massachusetts Coastal Zone: A Case Study Approach, Enid C. Kumin Jan 2015

Ecosystem-Based Management And Refining Governance Of Wind Energy In The Massachusetts Coastal Zone: A Case Study Approach, Enid C. Kumin

Antioch University Dissertations & Theses

While there are as yet no wind energy facilities in New England coastal waters, a number of wind turbine projects are now operating on land adjacent to the coast. In the Gulf of Maine region (from Maine to Massachusetts), at least two such projects, one in Falmouth, Massachusetts, and another on the island of Vinalhaven, Maine, began operation with public backing only to face subsequent opposition from some who were initially project supporters. I investigate the reasons for this dynamic using content analysis of documents related to wind energy facility development in three case study communities. For comparison and contrast …


Identification And Quantification Of Diffuse Fresh Submarine Groundwater Discharge Via Airborne Thermal Infrared Remote Sensing, Joseph T. Tamborski, A Deanne Rogers, Henry J. Bokuniewicz, J Kirk Cochran, Caitlin R. Young Jan 2015

Identification And Quantification Of Diffuse Fresh Submarine Groundwater Discharge Via Airborne Thermal Infrared Remote Sensing, Joseph T. Tamborski, A Deanne Rogers, Henry J. Bokuniewicz, J Kirk Cochran, Caitlin R. Young

Department of Geosciences Faculty Publications

Airborne thermal infrared (TIR) overflights were combined with shoreline radionuclide surveys to investigate submarine groundwater discharge (SGD) along the north shore of Long Island, NY between June 2013 and September 2014. Regression equations developed for three distinct geomorphological environments suggest a positive linear relationship between the rate of diffuse SGD and the spatial extent of the observed coastal TIR anomalies; such a relationship provides quantitative evidence of the ability to use TIR remote sensing as a tool to remotely identify and measure SGD. Landsat TIR scenes were unable to resolve any of the 18 TIR anomalies identified during the various …


Morphological, Structural, And Spectral Characteristics Of Amorphous Iron Sulfates, Elizabeth Sklute, Heidi Jensen, Deanne Rogers, Richard Reeder Jan 2015

Morphological, Structural, And Spectral Characteristics Of Amorphous Iron Sulfates, Elizabeth Sklute, Heidi Jensen, Deanne Rogers, Richard Reeder

Department of Geosciences Faculty Publications

Current or past brine hydrologic activity on Mars may provide suitable conditions for the formation of amorphous ferric sulfates. Once formed, these phases would likely be stable under current Martian conditions, particularly at low- to mid-latitudes. Therefore, we consider amorphous iron sulfates (AIS) as possible components of Martian surface materials. Laboratory AIS were created through multiple synthesis routes and characterized with total X-ray scattering, thermogravimetric analysis, scanning electron microscopy, visible/near-infrared (VNIR), thermal infrared (TIR), and Mössbauer techniques. We synthesized amorphous ferric sulfates (Fe(III)2(SO4)3 · ~ 6–8H2O) from sulfate-saturated fluids via vacuum dehydration or exposure to low relative humidity (


Feldspathic Rocks On Mars: Compositional Constraints From Infrared Spectroscopy And Possible Formation Mechanisms, Deanne Rogers, Hanna Nekvasil Jan 2015

Feldspathic Rocks On Mars: Compositional Constraints From Infrared Spectroscopy And Possible Formation Mechanisms, Deanne Rogers, Hanna Nekvasil

Department of Geosciences Faculty Publications

Rare feldspar-dominated surfaces on Mars were previously reported based on near-infrared (NIR) spectral data and were interpreted to consist of anorthosite or felsic rocks. Using thermal infrared (TIR) data over the feldspar detections with the largest areal extent in Nili Patera and Noachis Terra, we rule out felsic interpretations. Basaltic or anorthositic compositions are consistent with TIR measurements, but the geologic contexts for these regions do not support a plutonic origin. Laboratory NIR spectral measurements demonstrate that large plagioclase crystals (>~840 μm) can be detected in mixtures with as much as 50 vol % mafics, which is higher than …


Haverstraw Bay Benthic Mapping Project Gis Data, Robert M. Cerrato Jan 2015

Haverstraw Bay Benthic Mapping Project Gis Data, Robert M. Cerrato

SoMAS Research Data

High-resolution backscatter and bathymetric maps created by multibeam and sidescan sonar surveys were used to identify five different seafloor bottom types within Haverstraw Bay. Grab samples were collected within these areas to characterize sediment properties and macrofauna. Selected sampling locations were revisited and seafloor images were obtained with an HD underwater camera. Multivariate analysis was used to identify the most important factors explaining variations in community structure. Results indicated that categorical variables defining bottom types, grain size, and water depth can explain about 42% of community structure variation. In addition, shell length data collected for Rangia cuneata, an introduced species, …


The Module Isomorphism Problem Reconsidered, Peter A. Brooksbank Jan 2015

The Module Isomorphism Problem Reconsidered, Peter A. Brooksbank

Faculty Journal Articles

Algorithms to decide isomorphism of modules have been honed continually over the last 30 years, and their range of applicability has been extended to include modules over a wide range of rings. Highly efficient computer implementations of these algorithms form the bedrock of systems such as GAP and MAGMA, at least in regard to computations with groups and algebras. By contrast, the fundamental problem of testing for isomorphism between other types of algebraic structures -- such as groups, and almost any type of algebra -- seems today as intractable as ever. What explains the vastly different complexity status of the …


Lithostratigraphic Investigation And Components Of A Complete Petroleum System Within An Upper Devonian Carbonate-Evaporite Sequence : The Birdbear Formation, Williston Basin, North Dakota, Benjamin L. Engleman Jan 2015

Lithostratigraphic Investigation And Components Of A Complete Petroleum System Within An Upper Devonian Carbonate-Evaporite Sequence : The Birdbear Formation, Williston Basin, North Dakota, Benjamin L. Engleman

Theses and Dissertations

The Birdbear Formation of the Williston Basin of southwestern North Dakota represents one carbonate-evaporite sequence of the Late Devonian. The formation was deposited during regression on a broad, shallow epeiric shelf and is composed principally of dolomite, limestone and anhydrite. The Birdbear Formation is conformable with the Duperow Formation below and the Three Forks Formation above. The designations of 17 lithofacies form the context for describing hydrocarbon generation, migration and accumulation. Rock-Eval 6 and total organic carbon of 42 samples were used to identify the quality of source rocks present in the formation. Good and excellent source rocks were identified …


Divergent Responses Of Atlantic Coastal And Oceanic Synechococcus To Iron Limitation, Katherine R. M. Mackey, Anton F. Post, Matthew R. Mcilvin, Gregory A. Cutter, Seth G. John, Mak A. Saito Jan 2015

Divergent Responses Of Atlantic Coastal And Oceanic Synechococcus To Iron Limitation, Katherine R. M. Mackey, Anton F. Post, Matthew R. Mcilvin, Gregory A. Cutter, Seth G. John, Mak A. Saito

OES Faculty Publications

Marine Synechococcus are some of the most diverse and ubiquitous phytoplankton, and iron (Fe) is an essential micronutrient that limits productivity in many parts of the ocean. To investigate how coastal and oceanic Atlantic Synechococcus strains acclimate to Fe availability, we compared the growth, photophysiology, and quantitative proteomics of two Synechococcus strains from different Fe regimes. Synechococcus strain WH8102, from a region in the southern Sargasso Sea that receives substantial dust deposition, showed impaired growth and photophysiology as Fe declined, yet used few acclimation responses. Coastal WH8020, from the dynamic, seasonally variable New England shelf, displayed a multitiered, hierarchical cascade …


The Relative Importance Of Methanogenesis In The Decomposition Of Organic Matter In Northern Peatlands, J. Elizabeth Corbett, Malak M. Tfaily, David J. Burdige, Paul H. Glaser, Jeffrey P. Chanton Jan 2015

The Relative Importance Of Methanogenesis In The Decomposition Of Organic Matter In Northern Peatlands, J. Elizabeth Corbett, Malak M. Tfaily, David J. Burdige, Paul H. Glaser, Jeffrey P. Chanton

OES Faculty Publications

Using an isotope-mass balance approach and assuming the equimolar production of CO2 and CH4 from methanogenesis (e.g., anaerobic decomposition of cellulose), we calculate that the proportion of total CO2 production from methanogenesis varies from 37 to 83% across a variety of northern peatlands. In a relative sense, methanogenesis was a more important pathway for decomposition in bogs (80 ± 13% of CO2 production) than in fens (64 ± 5.7% of CO2 production), but because fens contain more labile substrates they may support higher CH4 production overall. The concentration of CO2 produced from methanogenesis (CO …


Predicting Effects Of Ocean Warming, Acidification, And Water Quality On Chesapeake Region Eelgrass, Richard C. Zimmerman, Victoria J. Hill, Charles L. Gallegos Jan 2015

Predicting Effects Of Ocean Warming, Acidification, And Water Quality On Chesapeake Region Eelgrass, Richard C. Zimmerman, Victoria J. Hill, Charles L. Gallegos

OES Faculty Publications

Although environmental requirements of seagrasses have been studied for years, reliable metrics for predicting their response to current or future conditions remain elusive. Eelgrass (Zostera marina L.) populations of the Chesapeake region lie near the southern limit of their range in the Western North Atlantic, exposing them to increasing thermal stress as the climate warms. However, CO2 stimulated photosynthesis may offset some of the negative effects of temperature stress. The combined effects of temperature, CO2, and light availability controlled by water quality and epiphytes were explored using GrassLight, a bio-optical model that provided a predictive …


Tropical North Atlantic Subsurface Warming Events As A Fingerprint For Amoc Variability During Marine Isotope Stage 3, Andrew O. Parker, Matthew W. Schmidt, Ping Chang Jan 2015

Tropical North Atlantic Subsurface Warming Events As A Fingerprint For Amoc Variability During Marine Isotope Stage 3, Andrew O. Parker, Matthew W. Schmidt, Ping Chang

OES Faculty Publications

The role of Atlantic Meridional Overturning Circulation (AMOC) as the driver of Dansgaard-Oeschger (DO) variability that characterized Marine Isotope Stage 3 (MIS 3) has long been hypothesized. Although there is ample proxy evidence suggesting that DO events were robust features of glacial climate, there is little data supporting a link with AMOC. Recently, modeling studies and subsurface temperature reconstructions have suggested that subsurface warming across the tropical North Atlantic can be used to fingerprint a weakened AMOC during the deglacial because a reduction in the strength of the western boundary current allows warm salinity maximum water of the subtropical gyre …


The Influence Of Sea Ice And Snow Cover And Nutrient Availability On The Formation Of Massive Under-Ice Phytoplankton Blooms In The Chukchi Sea, Jinlun Zhang, Carin Ashjian, Robert Campbell, Yvette H. Spitz, Michael Steele, Victoria Hill Jan 2015

The Influence Of Sea Ice And Snow Cover And Nutrient Availability On The Formation Of Massive Under-Ice Phytoplankton Blooms In The Chukchi Sea, Jinlun Zhang, Carin Ashjian, Robert Campbell, Yvette H. Spitz, Michael Steele, Victoria Hill

OES Faculty Publications

A coupled biophysical model is used to examine the impact of changes in sea ice and snow cover and nutrient availability on the formation of massive under-ice phytoplankton blooms (MUPBs) in the Chukchi Sea of the Arctic Ocean over the period 1988–2013. The model is able to reproduce the basic features of the ICESCAPE (Impacts of Climate on EcoSystems and Chemistry of the Arctic Pacific Environment) observed MUPB during July 2011. The simulated MUPBs occur every year during 1988–2013, mainly in between mid-June and mid-July. While the simulated under-ice blooms of moderate magnitude are widespread in the Chukchi Sea, MUPBs …


Interpretation Of Complexometric Titration Data: An Intercomparison Of Methods For Estimating Models Of Trace Metal Complexation By Natural Organic Ligands, I. Pižeta, S. G. Sander, R. J. M. Hudson, D. Omanović, O. Baars, K. A. Barbeau, K. N. Buck, R. M. Bundy, G. Carrasco, P. L. Croot Jan 2015

Interpretation Of Complexometric Titration Data: An Intercomparison Of Methods For Estimating Models Of Trace Metal Complexation By Natural Organic Ligands, I. Pižeta, S. G. Sander, R. J. M. Hudson, D. Omanović, O. Baars, K. A. Barbeau, K. N. Buck, R. M. Bundy, G. Carrasco, P. L. Croot

OES Faculty Publications

With the common goal of more accurately and consistently quantifying ambient concentrations of free metal ions and natural organic ligands in aquatic ecosystems, researchers from 15 laboratories that routinely analyze trace metal speciation participated in an intercomparison of statistical methods used to model their most common type of experimental dataset, the complexometric titration. All were asked to apply statistical techniques that they were familiar with to model synthetic titration data that are typical of those obtained by applying state-of-the-art electrochemical methods – anodic stripping voltammetry (ASV) and competitive ligand equilibration-adsorptive cathodic stripping voltammetry (CLE-ACSV) – to the analysis of natural …


Living On The Margin In The Anthropocene: Engagement Arenas For Sustainability Research And Action At The Ocean-Land Interface, B. C. Glavovic, K. Limburg, K-K. Liu, K-C. Emeis, H. Thomas, H. Kremer, B. Avril, J. Zhang, M. R. Mulholland, M. Glaser, D. P. Swaney Jan 2015

Living On The Margin In The Anthropocene: Engagement Arenas For Sustainability Research And Action At The Ocean-Land Interface, B. C. Glavovic, K. Limburg, K-K. Liu, K-C. Emeis, H. Thomas, H. Kremer, B. Avril, J. Zhang, M. R. Mulholland, M. Glaser, D. P. Swaney

OES Faculty Publications

The advent of the Anthropocene underscores the need to develop and implement transformative governance strategies that safeguard the Earth's life-support systems, most critically at the ocean-land interface - the Margin. The seaward realm of the Margin is the new frontier for resource exploitation and colonization to meet the needs of coastal nations and humanity overall. Here, we spotlight the pivotal role of the Margin for planetary resilience and sustainability, highlight priority issues, and outline a research strategy which aims to: (a) better understand Margin social-ecological systems; (b) guide sustainable development of Margin resources; (c) design governance regimes to reverse unsustainable …


The Geotraces Intermediate Data Product 2014, Edward Mawji, Reiner Schlitzer, Elena M. Dodas, Cyril Abadie, Wafa Abouchami, Robert F. Anderson, Gregory A. Cutter Jan 2015

The Geotraces Intermediate Data Product 2014, Edward Mawji, Reiner Schlitzer, Elena M. Dodas, Cyril Abadie, Wafa Abouchami, Robert F. Anderson, Gregory A. Cutter

OES Faculty Publications

The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEls) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in …


Genetic Indicators Of Iron Limitation In Wild Populations Of Thalassiosira Oceanica From The Northeast Pacific Ocean, P. Dreux Chappell, Leann P. Whitney, Joselynn R. Wallace, Adam I. Darer, Samua Jean-Charles, Bethany D. Jenkins Jan 2015

Genetic Indicators Of Iron Limitation In Wild Populations Of Thalassiosira Oceanica From The Northeast Pacific Ocean, P. Dreux Chappell, Leann P. Whitney, Joselynn R. Wallace, Adam I. Darer, Samua Jean-Charles, Bethany D. Jenkins

OES Faculty Publications

Assessing the iron (Fe) nutritional status of natural diatom populations has proven challenging as physiological and molecular responses can differ in diatoms of the same genus. We evaluated expression of genes encoding flavodoxin (FLDA1) and an Fe-starvation induced protein (ISIP3) as indicators of Fe limitation in the marine diatom Thalassiosira oceanica. The specificity of the response to Fe limitation was tested in cultures grown under Fe-and macronutrient-deficient conditions, as well as throughout the diurnal light cycle. Both genes showed a robust and specific response to Fe limitation in laboratory cultures and were detected in small volume samples collected from …


Iron Deficiency Increases Growth And Nitrogen-Fixation Rates Of Phosphorus-Deficient Marine Cyanobacteria, Nathan S. Garcia, Feixue Fu, Peter N. Sedwick, David A. Hutchins Jan 2015

Iron Deficiency Increases Growth And Nitrogen-Fixation Rates Of Phosphorus-Deficient Marine Cyanobacteria, Nathan S. Garcia, Feixue Fu, Peter N. Sedwick, David A. Hutchins

OES Faculty Publications

Marine dinitrogen (N2)-fixing cyanobacteria have large impacts on global biogeochemistry as they fix carbon dioxide (CO2) and fertilize oligotrophic ocean waters with new nitrogen. Iron (Fe) and phosphorus (P) are the two most important limiting nutrients for marine biological N2 fixation, and their availabilities vary between major ocean basins and regions. A long-standing question concerns the ability of two globally dominant N2-fixing cyanobacteria, unicellular Crocosphaera and filamentous Trichodesmium, to maintain relatively high N2-fixation rates in these regimes where both Fe and P are typically scarce. We show that under P-deficient …


Evaluation Of The Effects Of A Plasma Activated Medium On Cancer Cells, S. Mohades, M. Laroussi, J. Sears, N. Barekzi, H. Razavi Jan 2015

Evaluation Of The Effects Of A Plasma Activated Medium On Cancer Cells, S. Mohades, M. Laroussi, J. Sears, N. Barekzi, H. Razavi

Electrical & Computer Engineering Faculty Publications

The interaction of low temperature plasma with liquids is a relevant topic of study to the field of plasma medicine. This is because cells and tissues are normally surrounded or covered by biological fluids. Therefore, the chemistry induced by the plasma in the aqueous state becomes crucial and usually dictates the biological outcomes. This process became even more important after the discovery that plasma activated media can be useful in killing various cancer cell lines. Here, we report on the measurements of concentrations of hydrogen peroxide, a species known to have strong biological effects, produced by application of plasma to …


Killing Adherent And Nonadherent Cancer Cells With The Plasma Pencil, Mounir Laroussi, Soheila Mohades, Nazir Barekzi Jan 2015

Killing Adherent And Nonadherent Cancer Cells With The Plasma Pencil, Mounir Laroussi, Soheila Mohades, Nazir Barekzi

Electrical & Computer Engineering Faculty Publications

The application of low temperature plasmas in biology and medicine may lead to a paradigm shift in the way various diseases can be treated without serious side effects. Low temperature plasmas generated in gas mixtures that contain oxygen or air produce several chemically reactive species that have important biological implications when they interact with eukaryotic or prokaryotic cells. Here, a review of the effects of low temperature plasma generated by the plasma pencil on different cancerous cells is presented. Results indicate that plasma consistently shows a delayed killing effect that is dose dependent. In addition, there is some evidence that …


Identification Of Magnetite In Lunar Regolith Breccia 60016: Evidence For Oxidized Conditions At The Lunar Surface, Katherine H. Joy, Channon Visscher, Michael E. Zolensky, Takashi Mikouchi, Kenji Hagiya, Kazumasa Ohsumi, David A. Kring Jan 2015

Identification Of Magnetite In Lunar Regolith Breccia 60016: Evidence For Oxidized Conditions At The Lunar Surface, Katherine H. Joy, Channon Visscher, Michael E. Zolensky, Takashi Mikouchi, Kenji Hagiya, Kazumasa Ohsumi, David A. Kring

Faculty Work Comprehensive List

Lunar regolith breccias are temporal archives of magmatic and impact bombardment processes on the Moon. Apollo 16 sample 60016 is an ‘ancient’ feldspathic regolith breccia that was converted from a soil to a rock at ~3.8 Ga. The breccia contains a small (70 × 50 μm) rock fragment composed dominantly of an Fe-oxide phase with disseminated domains of troilite. Fragments of plagioclase (An95-97), pyroxene (En74-75, Fs21-22,Wo3-4) and olivine (Fo66-67) are distributed in and adjacent to the Fe-oxide. The silicate minerals have lunar compositions that are similar to anorthosites. Mineral chemistry, synchrotron X-ray Absorption Near Edge Spectroscopy (XANES) and X-ray Diffraction …


Iron Supply And Demand In Antarctic Shelf Ecosystem, D. J. Mcgillicuddy Jr., Peter N. Sedwick, Michael S. Dinniman, K. R. Arrigo, T. S. Bibby, B. J. W. Greenan, Eileen E. Hofmann, John M. Klinck, W. O. Smith Jr., S. L. Mack, C. M. Marsay, B. M. Sohst, G. L. Van Dijken Jan 2015

Iron Supply And Demand In Antarctic Shelf Ecosystem, D. J. Mcgillicuddy Jr., Peter N. Sedwick, Michael S. Dinniman, K. R. Arrigo, T. S. Bibby, B. J. W. Greenan, Eileen E. Hofmann, John M. Klinck, W. O. Smith Jr., S. L. Mack, C. M. Marsay, B. M. Sohst, G. L. Van Dijken

OES Faculty Publications

The Ross Sea sustains a rich ecosystem and is the most productive sector of the Southern Ocean. Most of this production occurs within a polynya during the November-February period, when the availability of dissolved iron (dFe) is thought to exert the major control on phytoplankton growth. Here we combine new data on the distribution of dFe, high-resolution model simulations of ice melt and regional circulation, and satellite-based estimates of primary production to quantify iron supply and demand over the Ross Sea continental shelf. Our analysis suggests that the largest sources of dFe to the euphotic zone are wintertime mixing and …