Antifragility Analysis And Measurement Framework For Systems Of Systems,
2013
Old Dominion University
Antifragility Analysis And Measurement Framework For Systems Of Systems, John Johnson, Adrian V. Gheorghe
Engineering Management & Systems Engineering Faculty Publications
The twenty-first century is defined by the social and technical hazards we face. A hazardous situation is a condition, or event, that threatens the well-being of people, organizations, societies, environments, and property. The most extreme of the hazards are considered X-Events and are an exogenous source of extreme stress to a system. X-Events can also be the unintended outputs of a system with both positive (serendipitous) and negative (catastrophic) consequences. Systems can vary in their ability to withstand these stress events. This ability exists on a continuum of fragility that ranges from fragile (degrading with stress), to robust (unchanged by …
Arsenic And Phosphorus Biogeochemistry In The Ocean: Arsenic Species As Proxies For P-Limitation,
2013
Old Dominion University
Arsenic And Phosphorus Biogeochemistry In The Ocean: Arsenic Species As Proxies For P-Limitation, Oliver Wurl, Louise Zimmer, Gregory A. Cutter
OES Faculty Publications
Arsenic and phosphorus are biochemically very similar, and hence arsenate (As5+) is toxic by interfering with the energy metabolism, in particular during P limitation. However, many phytoplankton detoxify As by reducing arsenate to arsenite (As3+), and/or methylating it to mono and dimethyl As. Such As detoxification becomes operative in oligotrophic waters when phosphate concentrations are below those for As; therefore, we evaluated the potential use of these detoxification products as indicators of P-limitation by measuring As speciation during the US GEOTRACES North Atlantic transect. The distribution of As3+ concentrations in surface waters is similar to …
Intercalibraton In Chemical Oceanography-- Getting The Right Number,
2013
Old Dominion University
Intercalibraton In Chemical Oceanography-- Getting The Right Number, Gregory A. Cutter
OES Faculty Publications
Intercalibration has a strict metrological definition, but in brief, it's an open sharing of methods and results between laboratories to achieve the most accurate data with the fewest random and systematic errors. In the field of chemical oceanography where concentrations of many constituents can be in the nano- to picomolar range, the salt water matrix can be difficult to analyze, and knowing the exact concentrations, or even chemical forms, of biologically required elements is essential, intercalibration is a very relevant and needed tool. Implementing it is not simple because errors can occur at any step in the process of taking …
Using Ammonium Pore Water Profiles To Assess Stoichiometry Of Deep Remineralization Processes In Methanogenic Continental Margin Sediments,
2013
Old Dominion University
Using Ammonium Pore Water Profiles To Assess Stoichiometry Of Deep Remineralization Processes In Methanogenic Continental Margin Sediments, David J. Burdige, Tomoko Komada
OES Faculty Publications
In many continental margin Sediments, a deep reaction zone exists which is separated from remineralization processes near the sediment surface. Here, methane diffuses upward to a depth where it is oxidized by downwardly diffusing sulfate. However, the methane sources that drive this anaerobic oxidation of methane (AOM) in the sulfate-methane transition zone (SMT) may vary among sites. In particular, these sources can be thought of as either (i) "internal" sources from in situ methanogenesis (regardless of where it occurs in the sediment column) that are ultimately coupled to organic matter deposition and burial, or (ii) "external" sources such as hydrocarbon …
Surface Production Fuels Deep Heterotrophic Respiration In Northern Peatlands,
2013
Old Dominion University
Surface Production Fuels Deep Heterotrophic Respiration In Northern Peatlands, J. Elizabeth Corbett, David J. Burdige, Malak M. Tfaily, Angela R. Dial, William T. Cooper, Paul H. Glaser, Jeffrey P. Chanton
OES Faculty Publications
Multiple analyses of dissolved organic carbon (DOC) from pore waters were conducted to define the processes that govern carbon balance in peatlands: (1) source, reactivity, and transport of DOC with respect to vegetation, peat, and age of carbon substrate, (2) reactivity of DOC with respect to molecular size, and (3) lability to photoxidation of surficial DOC. We found that surface organic production fuels heterotrophic respiration at depth in advection-dominated peatlands, especially in fens. Fen DOC was Δ14Cenriched relative to the surrounding fen peat, and fen respiration products were similar to this enriched DOC indicating that DOC was the …
Diatom Proteomics Reveals Unique Acclimation Strategies To Mitigate Fe Limitation,
2013
Old Dominion University
Diatom Proteomics Reveals Unique Acclimation Strategies To Mitigate Fe Limitation, Brook L. Nunn, Jessica F. Faux, Anna A. Hippman, Maria T. Maldonado, H. Rodger Harvey, David R. Goodlett, Philip W. Boyd, Robert F. Strzepek
OES Faculty Publications
Phytoplankton growth rates are limited by the supply of iron (Fe) in approximately one third of the open ocean, with major implications for carbon dioxide sequestration and carbon (C) biogeochemistry. To date, understanding how alteration of Fe supply changes phytoplankton physiology has focused on traditional metrics such as growth rate, elemental composition, and biophysical measurements such as photosynthetic competence (Fv/Fm). Researchers have subsequently employed transcriptomics to probe relationships between changes in Fe supply and phytoplankton physiology. Recently, studies have investigated longer-term (i.e. following acclimation) responses of phytoplankton to various Fe conditions. In the present study, the coastal diatom, Thalassiosira pseudonana, …
Dinitrogen Fixation In Aphotic Oxygenated Marine Environments,
2013
Old Dominion University
Dinitrogen Fixation In Aphotic Oxygenated Marine Environments, Eyal Rahav, Edo Bar-Zeev, Sarah Ohayon, Hila Elifantz, Natalia Belkin, Barak Herut, Margaret R. Mulholland, Iiana Berman-Frank
OES Faculty Publications
We measured N2 fixation rates from oceanic zones that have traditionally been ignored as sources of biological N2fixation; the aphotic, fully oxygenated, nitrate (NO¯3)-rich, waters of the oligotrophic Levantine Basin (LB) and the Gulf of Aqaba (GA). N2 fixation rates measured from pelagic aphotic waters to depths up to 720 m, during the mixed and stratified periods, ranged from 0.01 nmol N L-1 d-1 to 0.38 nmol N L-1 d-1. N2 fixation rates correlated significantly with bacterial productivity and heterotrophic diazotrophs were identified from aphotic as well as …
Development And Deployment Of A Point-Source Digital Inline Holographic Microscope For The Study Of Plankton And Particles To A Depth Of 6000 M,
2013
Old Dominion University
Development And Deployment Of A Point-Source Digital Inline Holographic Microscope For The Study Of Plankton And Particles To A Depth Of 6000 M, Alexander B. Bochdansky, Manfred H. Jericho, Gerhard J. Herndl
OES Faculty Publications
Bochdansky, A. B., Jericho, M. H., & Herndl, G. J. (2013). Development and deployment of a point-source digital inline holographic microscope for the study of plankton and particles to a depth of 6000 m. Limnology and Oceanography: Methods, 11, 28-40. doi: 10.4319/lom.2013.11.28
Effect Of Laser Ablation Depth In Otolith Life History Scans,
2013
Old Dominion University
Effect Of Laser Ablation Depth In Otolith Life History Scans, Renée R. Hoover, Cynthia M. Jones
OES Faculty Publications
Life history scans of fish otoliths are bringing new insight into the structure, connectivity, and movement of fish populations. Data obtained from such scans, however, possess in-herent limitations that have not yet been fully addressed or understood. For example, several investigators have noted delays in otolith elemental uptake that do not appear to reflect habitat exposure. We hypothesized that the 3-dimensional structure of otoliths may produce sampling artifacts in the results obtained from laser ablation scans. To test this hypothesis, we sampled sagittal otoliths from juvenile Atlantic croaker Micropogonias undulatus with laser ablation inductively coupled plasma mass spectrometry to obtain …
Distributions Of Particulate Heme B In The Atlantic And Southern Oceans- Implications For Electron Transport In Phytoplankton,
2013
Old Dominion University
Distributions Of Particulate Heme B In The Atlantic And Southern Oceans- Implications For Electron Transport In Phytoplankton, Martha Gledhill, Eric P. Achterberg, David J. Honey, Maria C. Nielsdottir, Micha J.A. Rijkenberg
OES Faculty Publications
Concentrations of heme b, the iron-containing component of b-type hemoproteins, ranged from b concentrations were enhanced in the photic zone and decreased with depth. Heme b concentrations correlated positively with chlorophyll a (chl a) in the TNA (r=0.41, pb did not correlate with chl a in the IB or SS. In the IB and SS, stations with high-chlorophyll and low-nutrient (Fe and/or Si) concentrations exhibited low heme bconcentrations relative to particulate organic carbon (< 0.1 μmolmol-1, and high chl a:heme b ratios (> 500). High chl a:heme b ratios resulted from relative decreases in …
Isotopic (Δ13c, Δ14c) Analysis Of Organic Acids In Marine Samples Using Wet Chemical Oxidation,
2013
University of South Carolina - Columbia
Isotopic (Δ13c, Δ14c) Analysis Of Organic Acids In Marine Samples Using Wet Chemical Oxidation, Susan Q. Lang, G. L. Früh-Green, S. M. Bernasconi, L. Wacker
Faculty Publications
We present a method for the isolation and off-line isotope analysis of formate and acetate in marine samples. Organic acids are separated by high performance liquid chromatography and collected in glass Exetainer® screw-capped vials that have been prespiked with an oxidant and flushed with helium. The vials are subsequently heated to convert the organic compounds to CO2 for radiocarbon and δ13C analysis. Small aliquots are sampled for measurement of δ13C by isotope ratio mass spectrometry, whereas the majority of the CO2 is saved for radiocarbon analysis by accelerator mass spectrometry using a gas ion …
Inertial Oscillations In The Gulf Of Mexico During 2005 Hurricane Season,
2013
Louisiana State University and Agricultural and Mechanical College
Inertial Oscillations In The Gulf Of Mexico During 2005 Hurricane Season, Fan Zhang
LSU Master's Theses
Near Inertial Oscillations (NIOs) are widely observed in ocean current data after severe weather. In this work, we analyzed the NIOs in the Central Gulf of Mexico (GoM) associated with 6 hurricanes/tropical storms in 2005, including Katrina and Rita, based on the deep ocean mooring from Coastal Studies Institute (CSI), LSU. The basic characteristics of the NIOs, such as phase speed, group speed, frequency, energy were discussed. The phase speed ranged from 0.56 cm/s to 2 cm/s above the thermocline for the NIOs during Hurricane Katrina and Rita, while the group velocity varied from 0.047 cm/s above the thermocline to …
Acoustic Biomass Of Fish Associated With An Oil And Gas Platform Before, During, And After "Reefing" It In The Northern Gulf Of Mexico,
2013
Louisiana State University and Agricultural and Mechanical College
Acoustic Biomass Of Fish Associated With An Oil And Gas Platform Before, During, And After "Reefing" It In The Northern Gulf Of Mexico, Grace Elizabeth Harwell
LSU Master's Theses
With over ~2600 oil and gas platforms (platforms) remaining in the northern Gulf of Mexico (Gulf), the Gulf States have access to one of the most unique fisheries in the world. Because of high abundances of game fishes around platform legs and the popular belief that platforms enhance fish stocks, both Louisiana and Texas have created artificial reef programs based upon the decommissioning of platforms. As oil and gas fields continue to be retired, oil and gas companies may find that “reefing” or toppling a platform may be a more economically viable alternative to complete removal of material. Questions remain …
Information Content Of Seasonal Forecasts In A Changing Climate,
2012
CUNY City College
Information Content Of Seasonal Forecasts In A Changing Climate, Nir Krakauer, Michael D. Grossberg, Irina Gladkova, Hannah Aizenman
Publications and Research
We study the potential value to stakeholders of probabilistic long-term forecasts, as quantified by the mean information gain of the forecast compared to climatology. We use as a case study the USA Climate Prediction Center (CPC) forecasts of 3-month temperature and precipitation anomalies made at 0.5-month lead time since 1995. Mean information gain was positive but low (about 2% and 0.5% of the maximum possible for temperature and precipitation forecasts, resp.) and has not increased over time. Information-based skill scores showed similar patterns to other, non-information-based, skill scores commonly used for evaluating seasonal forecasts but tended to be smaller, suggesting …
Use Of International Hydrographic Organization Tidal Data For Improved Tidal Prediction,
2012
Portland State University
Use Of International Hydrographic Organization Tidal Data For Improved Tidal Prediction, Songwei Qi
Dissertations and Theses
Tides are the rise and fall of water level caused by gravitational forces exerted by the sun, moon and earth. Understanding sea level variation and its impact currents is very important especially in coastal regions. With knowledge of the tide-generating force and boundary conditions, hydrodynamic models can be used to predict or model tides in coastal regions. However, these models are not sufficiently accurate, and in-situ tide gauge data may be used to improve them in coastal regions. The International Hydrographic Organization (IHO) tidal data bank consists of over 4000 tide gauge stations scattered all around the globe, most of …
Nursing Females Are More Prone To Heat Stress: Demography Matters When Managing Flying-Foxes For Climate Change,
2012
Macquarie University
Nursing Females Are More Prone To Heat Stress: Demography Matters When Managing Flying-Foxes For Climate Change, Stephanie T. Snoyman, Jasmina Munich, Culum Brown
Ecological Impacts of Climate Change Collection
Determining the underlying mechanisms responsible for species-specific responses to climate change is important from a species management perspective. The grey-headed flying-fox, Pteropus poliocephalus, is listed as vulnerable but it also a significant pest species for orchardists and thereby presents an interesting management conundrum. Over the last century, the abundance of the grey-headed flying-fox, P. poliocephalus, in Australia has decreased due to a variety of threatening processes but has increased in abundance in urban areas. These flying-foxes are highly susceptible to extreme heat events which are predicted to increase in the future under climate change scenarios. Exceptionally hot days result in …
Influence Of Tidal Cycles On Movements Of Atlantic Bottlenose Dolphins (Tursiops Truncatus) In South Carolina Coastal Environments,
2012
Coastal Carolina University
Influence Of Tidal Cycles On Movements Of Atlantic Bottlenose Dolphins (Tursiops Truncatus) In South Carolina Coastal Environments, Lauren Albrittain
Honors Theses
When studying estuarine environments that are directly fed by the ocean tides, the impact of the changing tide is vital in studying the migration and travel behaviors of organisms within those environments. This study was aimed at determining the influence of the daily tidal currents on movement with or against the tides by Atlantic bottlenose dolphins (Tursiops truncatus). Data collection occurred from March to October 2012, at three study sites: the ACE River Basin National Wildlife Refuge, the Hilton Head estuary, and the Cape Romain National Wildlife Refuge. Photo identification transect surveys were conducted to observe resident Atlantic bottlenose dolphins …
The Tsunami Of March 11, 2011 As Observed By The Network Of Tide Gauges Of French Polynesia,
2012
Observatoire Géodésique de Tahiti, Université de Polynésie française.
The Tsunami Of March 11, 2011 As Observed By The Network Of Tide Gauges Of French Polynesia, Jean-Pierre Barriot, Jonathan Serafini, Lydie Sichoix, Dominique Reymond, Olivier Hyvernaud
Journal of Marine Science and Technology–Taiwan
We present here the network of tide gauges spanning French Polynesia, and the set of records made by this network of the tsunami wave of March 11, 2011 (Tōhoku earthquake). We also outline the least-squares procedure used to separate the tsunami signal from the oceanic tides signal.
Interannual Variability Of Wintertime Sea Surface Temperatures In The Eastern Taiwan Strait,
2012
Department of Environmental Biology and Fisheries Science, National Taiwan Ocean University, Keelung, Taiwan, R.O.C.
Interannual Variability Of Wintertime Sea Surface Temperatures In The Eastern Taiwan Strait, Mu-Tun Tzeng, Kuo-Wei Lan, Jui-Wen Chan
Journal of Marine Science and Technology–Taiwan
Using Advanced Very High Resolution Radiometer (AVHRR) sea surface temperatures (SSTs) at a 1.1-km spatial resolution, we investigated the long-term SST variability in winter in the eastern Taiwan Strait (TS) in 1995~2008. We performed an empirical orthogonal function (EOF) analysis of spatial and time series variances for 15-day mean images. The first three modes in the EOF analysis respectively accounted for 25.9%, 16.61% and 4.59% of variances. In the first mode, the spatial amplitude showed positive values in the northeastern TS and negative values south of Chang-Yuen Rise (CYR). This suggests that warmer water occurred south of the CYR and …
Open Source Remote Sensing:Introspect And Prospect,
2012
Department of Information Systems Engineering, Hansung University, Seoul, Korea.
Open Source Remote Sensing:Introspect And Prospect, Sanggoo Kang, Hee Young Yoo, Kiwon Lee
Journal of Marine Science and Technology–Taiwan
It is noteworthy that open source applications have been developed and studied in various fields as well as remote sensing field. Open sources for GIS have long history related to open standards over three decades, but those of remote sensing do relatively short. Moreover, there are still no summary reports for open sources for remote sensing. In this study, we summarized characteristics of open source applications for remotely sensed image processing and discussed their strengths and weaknesses at first. Based on the summary, two open source applications for InSAR Processing and Geographic Object-Based Image Analysis are practically implemented to introspect …
