Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2017

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 10561 - 10590 of 11102

Full-Text Articles in Physical Sciences and Mathematics

Oasis - Identifying The Core Attributes For Rdbms Alternatives, Benjamin P. Mcpherson Jan 2017

Oasis - Identifying The Core Attributes For Rdbms Alternatives, Benjamin P. Mcpherson

College of Graduate Studies: Theses & Dissertations

Since their introduction in the 1970s, relational database management systems have served as the dominate data storage technology. However, the demands of big data and Web 2.0 necessitated a change in the market, sparking the beginning of the NoSQL movement in the late 2000s. NoSQL databases exchanged the relational model and the guaranteed consistency of ACID transactions for improved performance and massive scalability [1]. While the benefits NoSQL provided proved useful, the lack of sufficient SQL functionality presented a major hurdle for organizations which require it to properly operate. It was clear that new RDBMS solutions which did not compromise …


Audio-Based Productivity Forecasting Of Construction Cyclic Activities, Chris A. Sabillon Jan 2017

Audio-Based Productivity Forecasting Of Construction Cyclic Activities, Chris A. Sabillon

College of Graduate Studies: Theses & Dissertations

Due to its high cost, project managers must be able to monitor the performance of construction heavy equipment promptly. This cannot be achieved through traditional management techniques, which are based on direct observation or on estimations from historical data. Some manufacturers have started to integrate their proprietary technologies, but construction contractors are unlikely to have a fleet of entirely new and single manufacturer equipment for this to represent a solution. Third party automated approaches include the use of active sensors such as accelerometers and gyroscopes, passive technologies such as computer vision and image processing, and audio signal processing. Hitherto, most …


Potential For Scaling Up Climate Smart Agricultural Practices: Examples From Sub-Saharan Africa, Kindie Tesfaye, Menale Kassie, Jill E. Cairns, Misiko Michael, Clare Stirling, Tsedeke Abate, B. M. Prasanna, Mulugetta Mekuria, Habtamu Hailu, Dil Bahadur Rahut, Olaf Erenstein, Bruno Gerard Jan 2017

Potential For Scaling Up Climate Smart Agricultural Practices: Examples From Sub-Saharan Africa, Kindie Tesfaye, Menale Kassie, Jill E. Cairns, Misiko Michael, Clare Stirling, Tsedeke Abate, B. M. Prasanna, Mulugetta Mekuria, Habtamu Hailu, Dil Bahadur Rahut, Olaf Erenstein, Bruno Gerard

All Peer-Reviewed Publications

Agriculture in Sub-Saharan Africa (SSA) is predominantly rain-fed, and erratic weather patterns and extreme weather events, exacerbated by the changing climate, adds to the challenges faced by smallholder farmers in producing enough food to feed the ever growing population of the region. While the farming communities are responding to these challenges, there is an intensive need for scaling-up adoption of appropriate interventions that can help increase crop yields and resilience to climate change. A review and analysis of potential climate-smart agricultural practices (CSAs) in SSA indicate that some CSAs are increasingly adopted by farmers and show potential for scaling up. …


Mursamacin: A Novel Class Of Antibiotics From Soil-Dwelling Roundworms Of Central Kenya That Inhibits Methicillin-Resistant Staphylococcus Aureus, Ryan Musumba Awori, Peter Njenga Ng'ang'a, Lorine Nanjala Nyongesa, Nelson Onzere Amugune, Daniel Masiga Jan 2017

Mursamacin: A Novel Class Of Antibiotics From Soil-Dwelling Roundworms Of Central Kenya That Inhibits Methicillin-Resistant Staphylococcus Aureus, Ryan Musumba Awori, Peter Njenga Ng'ang'a, Lorine Nanjala Nyongesa, Nelson Onzere Amugune, Daniel Masiga

All Peer-Reviewed Publications

Antibiotic-resistant bacteria, also called " superbugs", can at worst retrogress modern medicine to an era where even sore throats resulted in death. A solution is the development of novel types of antibiotics from untapped natural sources. Yet, no new class of antibiotic has been developed in clinical medicine in the last 30 years. Here, bacteria from insect-killing Steinernema roundworms found in the soils of Central Kenya were isolated and subjected to specific molecular identification. These were then assayed for production of antibiotic compounds with potential to treat methicillin-resistant Staphylococcus aureus infections. The bacteria were identified as Xenorhabdus griffiniae and produced …


Entomopathogens Routinely Used In Pest Control Strategies: Orchards In Tropical Climate, N. K. Maniania, S. Ekesi, C. Dolinski Jan 2017

Entomopathogens Routinely Used In Pest Control Strategies: Orchards In Tropical Climate, N. K. Maniania, S. Ekesi, C. Dolinski

All Peer-Reviewed Publications

Fruit and nut trees such as mango, pineapples, papaya, banana, guava, cashew, passion fruit, and avocado are important components of tropical ecosystems. They are sources of vitamins, minerals and carbohydrates and have great economic importance as sources of both household incomes and national revenues. Fruit and nut trees provide important adaptive values and tend to be more resilient to climate change due to their perennial nature, and they have the property of sequestering carbon. World production and trade of fresh tropical fruit are expected to expand over decades, with developing countries accounting for about 98% of total production, while developed …


Angiostoma Norvegicum N. Sp. (Nematoda: Angiostomatidae) A Parasite Of Arionid Slugs In Norway, Jenna L. Ross, Solveig Haukeland, Bjørn A. Hatteland, Elena S. Ivanova Jan 2017

Angiostoma Norvegicum N. Sp. (Nematoda: Angiostomatidae) A Parasite Of Arionid Slugs In Norway, Jenna L. Ross, Solveig Haukeland, Bjørn A. Hatteland, Elena S. Ivanova

All Peer-Reviewed Publications

Angiostoma norvegicum n. sp. (Angiostomatidae) is described from the oesophagus, crop and the buccal mass of five species of slugs of the family Arionidae, Arion vulgaris (Moquin-Tandon), Arion ater (L.), Arion fasciatus (Nilsson), Arion fuscus (Müller) and Arion rufus/Arion ater hybrid), collected throughout Norway. Angiostoma norvegicum n. sp. was found parasitising arionids at seven of the 30 sample sites examined (23.3%), and 9.9% of all Arion spp. were infected with this nematode. The new species is characterised by its large size (4.0–8.6 mm long) and in having: lateral alae; 6 + 6 papillae at the cephalic end; a large circular …


The Plant As A Habitat For Entomophagous Insects, L. Kaiser, P. Ode, S. Van Nouhuys, P. A. Calatayud, S. Colazza, A. M. Cortesero, A. Thiel, J. Van Baaren Jan 2017

The Plant As A Habitat For Entomophagous Insects, L. Kaiser, P. Ode, S. Van Nouhuys, P. A. Calatayud, S. Colazza, A. M. Cortesero, A. Thiel, J. Van Baaren

All Peer-Reviewed Publications

Populations of herbivorous insects are naturally consumed by other predacious or predatory insect species. These entomophagous insects are thus plant-dwelling organisms that use the plant for several vital functions and are affected by plant traits at the evolutionary, organism and population levels. Many entomophagous species are used for the biological control of insect pests worldwide. The aim of this chapter is to provide an exhaustive review of mechanisms underlying the interactions between plants and entomophagous insects, including those governing life history traits at the individual level, as well as those acting on population and community structure and dynamics. We detail …


Estimating Swiss Chard Foliar Macro- And Micronutrient Concentrations Under Different Irrigation Water Sources Using Ground-Based Hyperspectral Data And Four Partial Least Squares (Pls)-Based (Pls1, Pls2, Spls1 And Spls2) Regression Algorithms, Elfatih M. Abdel-Rahman, Onisimo Mutanga, John Odindi, Elhadi Adam, Alfred Odindo, Riyad Ismail Jan 2017

Estimating Swiss Chard Foliar Macro- And Micronutrient Concentrations Under Different Irrigation Water Sources Using Ground-Based Hyperspectral Data And Four Partial Least Squares (Pls)-Based (Pls1, Pls2, Spls1 And Spls2) Regression Algorithms, Elfatih M. Abdel-Rahman, Onisimo Mutanga, John Odindi, Elhadi Adam, Alfred Odindo, Riyad Ismail

All Peer-Reviewed Publications

Timely information on crop foliar nutrient content provides a measure of crop nutritional and vitality status. Growers and farm managers use such information for precision crop management such as an appropriate fertilizer application to correct for any crop nutrient deficiencies at identified hotspots. Foliar heavy nutrient content could also be a direct indicator of crops having been polluted from the surroundings, which may be a result of heavy metals absorbed from, among others, contaminated soils and waste water. In the present study, we explored the potential use of four partial least squares (PLS)-based regression algorithms for estimating foliar Swiss chard …


Visualizing Morphogenesis With The Processing Programming Language, Avik Patel, Amar Bains, Richard Millet, Tamira Elul Jan 2017

Visualizing Morphogenesis With The Processing Programming Language, Avik Patel, Amar Bains, Richard Millet, Tamira Elul

Faculty Publications & Research of the TUC College of Osteopathic Medicine

We used Processing, a visual artists’ programming language developed at MIT Media Lab, to simulate cellular mechanisms of morphogenesis – the generation of form and shape in embryonic tissues. Based on observations of in vivo time-lapse image sequences, we created animations of neural cell motility responsible for elongating the spinal cord, and of optic axon branching dynamics that establish primary visual connectivity. These visual models underscore the significance of the computational decomposition of cellular dynamics underlying morphogenesis.


Response And Recovery Of A Mixed Tropical Seagrass Assemblage To Variation In The Frequency And Magnitude Of Light Deprivation. Report Of Theme 5 - Project 5.5.3 Prepared For The Dredging Science Node, John Statton, Kathryn Mcmahon, Rosin Mccallum, Gary Kendrick, Paul Lavery Jan 2017

Response And Recovery Of A Mixed Tropical Seagrass Assemblage To Variation In The Frequency And Magnitude Of Light Deprivation. Report Of Theme 5 - Project 5.5.3 Prepared For The Dredging Science Node, John Statton, Kathryn Mcmahon, Rosin Mccallum, Gary Kendrick, Paul Lavery

Research outputs 2014 to 2021

The capacity of seagrasses to cope with episodes of light deprivation from overlying turbid waters may not only depend on the absolute quantity of light they receive during that episode, but also on how the light deprivation varies through time. For example, turbidity and therefore light reduction may be relatively constant over the episode or it may fluctuate depending on the frequency of pulsed turbidity events.

This report presents findings from a controlled mesocosm experiment that aimed to determine the responses of seagrasses to, and recovery from, differences in the pattern of the delivery of light. The study focussed on …


Effects Of Dredging-Related Pressures On Critical Ecological Processes For Organisms Other Than Fish Or Coral. Report Of Theme 9 - Project 9.1 Prepared For The Dredging Science Node, Jessie Short, Matthew Fraser, Dianne Mclean, Gary Kendrick, Maria Byrne, Julian Caley, Doug Clarke, Andy Davis, Paul Ertemeijer, Stuart Field, Sam Gustin-Craig, John Huisman, John Keesing, Mick Keough, Paul Lavery, Ray Mansini, Kathryn Mcmahon, Kerrie Mergersen, Michael Rasheed, John Statton, Jim Stoddart, Paul Wu Jan 2017

Effects Of Dredging-Related Pressures On Critical Ecological Processes For Organisms Other Than Fish Or Coral. Report Of Theme 9 - Project 9.1 Prepared For The Dredging Science Node, Jessie Short, Matthew Fraser, Dianne Mclean, Gary Kendrick, Maria Byrne, Julian Caley, Doug Clarke, Andy Davis, Paul Ertemeijer, Stuart Field, Sam Gustin-Craig, John Huisman, John Keesing, Mick Keough, Paul Lavery, Ray Mansini, Kathryn Mcmahon, Kerrie Mergersen, Michael Rasheed, John Statton, Jim Stoddart, Paul Wu

Research outputs 2014 to 2021

This study reviewed environmental windows for organisms other than corals and fish such as sessile invertebrates, macroalgae and seagrasses. Environmental windows are periods of critical importance to the life history of a marine species, like reproduction and recruitment.

Aims

  • To review the scientific literature on the timing and spatial extent of critical ecological processes relevant to tropical WA for marine primary producers and invertebrates (i.e. organisms other than coral and finfish) and the state of knowledge regarding potential effects of dredging on these key ecological processes. The review also had a particular focus on ecological processes in marine primary producers …


Fukushima Daiichi-Derived Radionuclides In The Ocean: Transport, Fate, And Impacts, Ken O. Buesseler, Minhan Dai, Michio Aoyama, Claudia R. Benítez-Nelson,, Sabine S. Charmasson, Kathryn A. Higley, Vladimir S. Maderich, Pere Masqué, Paul J. Morris, Deborah H. Oughton, John N. Smith Jan 2017

Fukushima Daiichi-Derived Radionuclides In The Ocean: Transport, Fate, And Impacts, Ken O. Buesseler, Minhan Dai, Michio Aoyama, Claudia R. Benítez-Nelson,, Sabine S. Charmasson, Kathryn A. Higley, Vladimir S. Maderich, Pere Masqué, Paul J. Morris, Deborah H. Oughton, John N. Smith

Research outputs 2014 to 2021

The events that followed the Tohoku earthquake and tsunami on March 11, 2011, included the loss of power and overheating at the Fukushima Daiichi nuclear power plants, which led to extensive releases of radioactive gases, volatiles, and liquids, particularly to the coastal ocean. The fate of these radionuclides depends in large part on their oceanic geochemistry, physical processes, and biological uptake. Whereas radioactivity on land can be resampled and its distribution mapped, releases to the marine environment are harder to characterize owing to variability in ocean currents and the general challenges of sampling at sea. Five years later, it is …


Investigating Stress Response Across Integrated Biological Systems, Alice A. Han Jan 2017

Investigating Stress Response Across Integrated Biological Systems, Alice A. Han

Graduate Theses, Dissertations, and Problem Reports (ETD)

The impact that a stressor has on a living system, whether it is on a cellular, organ, or even a whole organism level, can affect the overall health of the system. Monitoring the biochemical response resulting from a stressful experience offers insight into the numerous potential outcomes ranging on the spectrum of survival and death. Accessing this information not only provides a heightened understanding of the biochemical adaptions that occur, but also allows for the development of prediction models (to assess prospective influences of the stressor) or potential therapeutic treatments (to alleviate adverse effects) using measurable, quantifiable, and comparable metrics. …


Online Health Recommendation System: A Social Support Perspective, Tareq Nasralah, Cherie Noteboom, Abdullah Wahbeh, Mohammad Aref Al-Ramahi Jan 2017

Online Health Recommendation System: A Social Support Perspective, Tareq Nasralah, Cherie Noteboom, Abdullah Wahbeh, Mohammad Aref Al-Ramahi

Research & Publications

Online Health Communities (OHC) aim to support patients through offer them the opportunities to exchange support with others. However, patients have difficulties and problems locating expertise within the online health communities. In this regard, this study aims to create a patient recommender system to help users locate those with relevant experience and similar health status. Specifically, we aim to leverage the type of online social support users seek to determine the patient health status to build a patient status prediction model. Building the model will help create a peer recommendation system for online support group members to easily locate peers …


Evaluating Network Test Scenarios For Network Simulators Systems, A. Zarrad, Izzat M. Alsmadi Jan 2017

Evaluating Network Test Scenarios For Network Simulators Systems, A. Zarrad, Izzat M. Alsmadi

Computer Science Faculty Publications (Archived)

Networks continue to grow as industries use both wired and wireless networks. Creating experiments to test those networks can be very expensive if conducted on production networks; therefore, the evaluation of networks and their performance is usually conducted using emulation. This growing reliance on simulation raises the risk of correctness and validation. Today, many network simulators have widely varying focuses and are employed in different fields of research. The trustworthiness of results produced from simulation models must be investigated. The goal of this work is first to compare and assess the performance of three prominent network simulators—NS-2, NS-3, and OMNet++—by …


Existence Of Mild Solutions For Fractional Nonlocal Evolution Equations With Delay In Partially Ordered Banach Spaces, Y. Liang, H. Yang, Kun Gou Jan 2017

Existence Of Mild Solutions For Fractional Nonlocal Evolution Equations With Delay In Partially Ordered Banach Spaces, Y. Liang, H. Yang, Kun Gou

Mathematics Faculty Publications (Archived)

This paper deals with the existence of mild solutions for the abstract fractional nonlocal evolution equations with noncompact semigroup in partially ordered Banach spaces. Under some mixed conditions, a group of sufficient conditions for the existence of abstract fractional nonlocal evolution equations are obtained by using a Krasnoselskii type fixed point theorem. The results we obtained are a generalization and continuation of the recent results on this issue. At the end, an example is given to illustrate the applicability of abstract result.


Report On The 2016 Texas Water Roadmap Forum, Rudolph A. Rosen Jan 2017

Report On The 2016 Texas Water Roadmap Forum, Rudolph A. Rosen

Water Resources Science and Technology Conference Papers and Abstracts (Archived)

No abstract provided.


The Route To Water Security For Texas: The 2015-2016 Texas Water Roadmap Forums, Rudolph A. Rosen Jan 2017

The Route To Water Security For Texas: The 2015-2016 Texas Water Roadmap Forums, Rudolph A. Rosen

Water Resources Science and Technology Conference Papers and Abstracts (Archived)

No abstract provided.


Future Water Stewardship And Fact-Based Water Policy: An Aquatic Science Education Pathway Model, Rudolph A. Rosen, Erin Scanlon, Johnnie Smith Jan 2017

Future Water Stewardship And Fact-Based Water Policy: An Aquatic Science Education Pathway Model, Rudolph A. Rosen, Erin Scanlon, Johnnie Smith

Water Resources Science and Technology Faculty Publications (Archived)

Texas Aquatic Science originated from a project seeking better ways to educate students about water because of concern that current education was failing to promote good decisions about water by adult citizens and political leaders. A comprehensive water education curriculum was developed to engage learners from middle school through university using an education pathway to create water-savvy citizens of tomorrow who will take personal action to ensure effective stewardship of water and support evidence-based water policies. This paper will describe the pathway and present results of research on the pathway’s effectiveness with middle and high school students and teachers.


Stem Pathway For Aquatic Science: Experiential Learning In And Out Of Classrooms, Rudolph A. Rosen, Johnnie Smith Jan 2017

Stem Pathway For Aquatic Science: Experiential Learning In And Out Of Classrooms, Rudolph A. Rosen, Johnnie Smith

Water Resources Science and Technology Conference Papers and Abstracts (Archived)

No abstract provided.


Online Integrity And Authentication Checking For Quran Electronic Versions, Izzat M. Alsmadi, M. Zarour Jan 2017

Online Integrity And Authentication Checking For Quran Electronic Versions, Izzat M. Alsmadi, M. Zarour

Computer Science Faculty Publications (Archived)

The ability to control data and information through the Internet can be challenging. Preliminary analysis showed that some tampering and forgery may occur to some words of the Quran in the electronic versions that span the Internet. Such small modifications may not be noticed by public audience. The holy book of Quran includes a unique feature in that its worldwide copies are all identical. The 114 chapters (Suras) and all their verses and words are preserved in the exact form. As such, we designed and evaluated a model and a tool to evaluate the integrity of the wording in the …


Hard Apple Cider In The New York Hudson Valley Region: A Tourism Study, Meghann Smith, Pankaj Lal Jan 2017

Hard Apple Cider In The New York Hudson Valley Region: A Tourism Study, Meghann Smith, Pankaj Lal

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Hard apple cider production is an emerging industry in apple-growing regions of the United States due to the growing popularity of local craft products in the alcoholic beverage industry. This study strives to understand how hard cideries may affect local product promotion, rural tourism, and agriculture’s economic viability in the Hudson Valley region of New York. Tourism is evolving towards travelling for experiential value; the hard cider industry can offer an authentic environmentally and historically significant experience. By identifying the consumers and their expectations, the possibilities for building tourism specifically surrounding products with regional significance expand significantly. In this study, …


Sugar Versus Lipid For Sustainable Biofuels, Yaşar Demirel Jan 2017

Sugar Versus Lipid For Sustainable Biofuels, Yaşar Demirel

Yaşar Demirel Publications

Introduction

First‐generation biofuels, namely, ethanol and biodiesel, have led to far reaching impact on the peoples’ life world‐wide.[1] However, they inter-fere with the food supply chain and may not be sustainable although some of the biomass are converted to biofuels after those biomasses have met the human needs. Still, the first‐generation–based biofuels have proved that sugar and lipid platforms can be an answer to energy security and global warming concerns without the need for new infrastructure for feedstock delivery as well as for biomass‐to‐biofuel conversion tech-nologies. At the same time, we are discovering and assessing the long‐term environmental im-plications on …


Amino Acid Catabolism In Staphylococcus Aureus And The Function Of Carbon Catabolite Repression, Cortney R. Halsey, Shulei Lei, Jacqueline K. Wax, Mckenzie K. Lehman, Austin S. Nuxoll, Laurey Steinke, Marat Sadykov, Robert Powers, Paul D. Fey Jan 2017

Amino Acid Catabolism In Staphylococcus Aureus And The Function Of Carbon Catabolite Repression, Cortney R. Halsey, Shulei Lei, Jacqueline K. Wax, Mckenzie K. Lehman, Austin S. Nuxoll, Laurey Steinke, Marat Sadykov, Robert Powers, Paul D. Fey

Department of Chemistry: Faculty Publications

Staphylococcus aureus must rapidly adapt to a variety of carbon and nitrogen sources during invasion of a host. Within a staphylococcal abscess, preferred carbon sources such as glucose are limiting, suggesting that S. aureus survives through the catabolism of secondary carbon sources. S. aureus encodes pathways to catabolize multiple amino acids, including those that generate pyruvate, 2-oxoglutarate, and oxaloacetate. To assess amino acid catabolism, S. aureus JE2 and mutants were grown in complete defined medium containing 18 amino acids but lacking glucose (CDM). A mutation in the gudB gene, coding for glutamate dehydrogenase, which generates 2-oxoglutarate from glutamate, significantly reduced …


Laterally Extended Atomically Precise Graphene Nanoribbons With Improved Electrical Conductivity For Efficient Gas Sensing, Mohammad Mehdi Pour, Andrey Lashkov, Adrian Radocea, Ximeng Liu, Tao Sun, Alexey Lipatov, Rafal A. Korlacki, Mikhail Shekhirev, Narayana R. Aluru, Joseph W. Lyding, Victor Sysoev, Alexander Sinitskii Jan 2017

Laterally Extended Atomically Precise Graphene Nanoribbons With Improved Electrical Conductivity For Efficient Gas Sensing, Mohammad Mehdi Pour, Andrey Lashkov, Adrian Radocea, Ximeng Liu, Tao Sun, Alexey Lipatov, Rafal A. Korlacki, Mikhail Shekhirev, Narayana R. Aluru, Joseph W. Lyding, Victor Sysoev, Alexander Sinitskii

Department of Chemistry: Faculty Publications

Narrow atomically precise graphene nanoribbons hold great promise for electronic and optoelectronic applications, but the previously demonstrated nanoribbon-based devices typically suffer from low currents and mobilities. In this study, we explored the idea of lateral extension of graphene nanoribbons for improving their electrical conductivity. We started with a conventional chevron graphene nanoribbon, and designed its laterally extended variant. We synthesized these new graphene nanoribbons in solution and found that the lateral extension results in decrease of their electronic bandgap and improvement in the electrical conductivity of nanoribbon-based thin films. These films were employed in gas sensors and an electronic nose …


Nanomaterials As Stationary Phases And Supports In Liquid Chromatography: A Review, Sandya Beeram, Elliott Rodriguez, Suresh Doddavenkatanna, Zhao Li, Allegra Pekarek, Darin Peev, Kathryn Goerl, Gianfranco Trovato, Tino Hofmann, David S. Hage Jan 2017

Nanomaterials As Stationary Phases And Supports In Liquid Chromatography: A Review, Sandya Beeram, Elliott Rodriguez, Suresh Doddavenkatanna, Zhao Li, Allegra Pekarek, Darin Peev, Kathryn Goerl, Gianfranco Trovato, Tino Hofmann, David S. Hage

Department of Chemistry: Faculty Publications

The development of various nanomaterials over the last few decades has led to many applications for these materials in liquid chromatography (LC). This review will look at the types of nanomaterials that have been incorporated into LC systems and the applications that have been explored for such systems. A number of carbon-based nanomaterials and inorganic nanomaterials have been considered for use in LC, ranging from carbon nanotubes, fullerenes and nanodiamonds to metal nanoparticles and nanostructures based on silica, alumina, zirconia and titanium dioxide. Many ways have been described for incorporating these nanomaterials into LC systems. These methods have included covalent …


A Surface-Stabilized Ozonide Triggers Bromide Oxidation At The Aqueous Solution-Vapour Interface, Luca Artiglia, Jacinta Edebeli, Fabrizio Orlando, Shuzhen Chen, Ming-Tao Lee, Pablo Corral Arroyo, Anina Gilgen, Thorsten Bartels-Rausch, Armin Kleibert, Mario Vazdar, Marcelo Andrea Carignano, Joseph S. Francisco, Paul B. Shepson, Ivan Gladich, Markus Ammann Jan 2017

A Surface-Stabilized Ozonide Triggers Bromide Oxidation At The Aqueous Solution-Vapour Interface, Luca Artiglia, Jacinta Edebeli, Fabrizio Orlando, Shuzhen Chen, Ming-Tao Lee, Pablo Corral Arroyo, Anina Gilgen, Thorsten Bartels-Rausch, Armin Kleibert, Mario Vazdar, Marcelo Andrea Carignano, Joseph S. Francisco, Paul B. Shepson, Ivan Gladich, Markus Ammann

Department of Chemistry: Faculty Publications

Oxidation of bromide in aqueous environments initiates the formation of molecular halogen compounds, which is important for the global tropospheric ozone budget. In the aqueous bulk, oxidation of bromide by ozone involves a [Br•OOO−] complex as intermediate. Here we report liquid jet X-ray photoelectron spectroscopy measurements that provide direct experimental evidence for the ozonide and establish its propensity for the solution-vapor interface. Theoretical calculations support these findings, showing that water stabilizes the ozonide and lowers the energy of the transition state at neutral pH. Kinetic experiments confirm the dominance of the heterogeneous oxidation route established by this precursor …


Cytotoxic Polyketides With An Oxygen-Bridged Cyclooctadiene Core Skeleton From The Mangrove Endophytic Fungus Phomosis Sp. A818, Wei Zhang, Baobing Zhao, Liangcheng Du, Yuemao Shen Jan 2017

Cytotoxic Polyketides With An Oxygen-Bridged Cyclooctadiene Core Skeleton From The Mangrove Endophytic Fungus Phomosis Sp. A818, Wei Zhang, Baobing Zhao, Liangcheng Du, Yuemao Shen

Department of Chemistry: Faculty Publications

Plant endophytic microorganisms represent a largely untapped resource for new bioactive natural products. Eight polyketide natural products were isolated from a mangrove endophytic fungus Phomosis sp. A818. The structural elucidation of these compounds revealed that they share a distinct feature in their chemical structures, an oxygen-bridged cyclooctadiene core skeleton. The study on their structure–activity relationship showed that the α,β-unsaturated δ-lactone moiety, as exemplified in compounds 1 and 2, was critical to the cytotoxic activity of these compounds. In addition, compound 4 might be a potential agonist of AMPK (5'-adenosine monophosphate-activated protein kinase).


Chemoselective Alteration Of Fluorophore Scaffolds As A Strategy For The Development Of Ratiometric Chemodosimeters, Xinqi Zhou, Lauren Lesiak, Rui Lai, Jon R. Beck, Jia Zhao, Christian Elowsky, Hui Li, Cliff I. Stains Jan 2017

Chemoselective Alteration Of Fluorophore Scaffolds As A Strategy For The Development Of Ratiometric Chemodosimeters, Xinqi Zhou, Lauren Lesiak, Rui Lai, Jon R. Beck, Jia Zhao, Christian Elowsky, Hui Li, Cliff I. Stains

Department of Chemistry: Faculty Publications

Ratiometric sensors generally couple binding events or chemical reactions at a distal site to changes in the fluorescence of a core fluorophore scaffold. However, such approaches are often hindered by spectral overlap of the product and reactant species. We provide a strategy to design ratiometric sensors that display dramatic spectral shifts by leveraging the chemoselective reactivity of novel functional groups inserted within fluorophore scaffolds. As a proof-of-principle, fluorophores containing a borinate (RF620) or silanediol (SiOH2R) functionality at the bridging position of the xanthene ring system are developed as endogenous H2O2 sensors. Both …


The Future Of Nmr-Based Metabolomics, John L. Markley, Rafael Bruschweiler, Arthur S. Edison, Hamid R. Eghbalnia, Robert Powers, Daniel Raftery, David S. Wishart Jan 2017

The Future Of Nmr-Based Metabolomics, John L. Markley, Rafael Bruschweiler, Arthur S. Edison, Hamid R. Eghbalnia, Robert Powers, Daniel Raftery, David S. Wishart

Department of Chemistry: Faculty Publications

The two leading analytical approaches to metabolomics are mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Although currently overshadowed by MS in terms of numbers of compounds resolved, NMR spectroscopy offers advantages both on its own and coupled with MS. NMR data are highly reproducible and quantitative over a wide dynamic range and are unmatched for determining structures of unknowns. NMR is adept at tracing metabolic pathways and fluxes using isotope labels. Moreover, NMR is non-destructive and can be utilized in vivo. NMR results have a proven track record of translating in vitro findings to in vivo clinical …