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Full-Text Articles in Physical Sciences and Mathematics

Behavioral Enhancement Of Onshore Transport By Postlarval Caribbean Spiny Lobster (Panulirus Argus), Jason S. Goldstein, Mark J. Butler Iv Sep 2009

Behavioral Enhancement Of Onshore Transport By Postlarval Caribbean Spiny Lobster (Panulirus Argus), Jason S. Goldstein, Mark J. Butler Iv

Biological Sciences Faculty Publications

We conducted a series of laboratory experiments to examine the orientation, settlement, and metamorphosis of Caribbean spiny lobster (Panulirus argus) pueruli (postlarvae) in response to cues characteristic of their nursery in back-reef tropical lagoons. Our results suggest that pueruli were attracted to coastal water sources and the metabolites of red macroalgae (Laurencia spp.) when compared with oceanic water and artificial seawater treatments. Pueruli were not attracted to waterborne cues from sea grass, were repelled by hypersaline or hyposaline water, and discerned coastal cues from water collected as far as 30 km offshore from the reef. We also conducted experiments to …


Theoretical Studies Of 2,3 -Sigmatropic Rearrangements Of Allylic Selenoxides And Selenimides, Craig A. Bayse, Sonia Antony Sep 2009

Theoretical Studies Of 2,3 -Sigmatropic Rearrangements Of Allylic Selenoxides And Selenimides, Craig A. Bayse, Sonia Antony

Chemistry & Biochemistry Faculty Publications

Density-functional theory is used to model the endo and exo transition states for [2,3]-sigmatropic rearrangement of allylic aryl-selenoxides and -selenimides. The endo transition state is generally preferred for selenoxides if there is no substitution at the 2 position of the allyl group. Based upon the relative energies of the endo and exo transition states, enantioselectivity of rearrangements is expected to be greatest for molecules with substitutions at the 1- or (E)-3- position of the allyl group. Ortho substitution of a nitro group on the ancillary selenoxide phenyl ring reduces the activation barriers, increases the difference between the endo and exo …


Optics And Remote Sensing Of Bahamian Carbonate Sediment Whitings And Potential Relationship To Wind-Driven Langmuir Circulation, H. M. Dierssen, Richard C. Zimmerman, David J. Burdige Mar 2009

Optics And Remote Sensing Of Bahamian Carbonate Sediment Whitings And Potential Relationship To Wind-Driven Langmuir Circulation, H. M. Dierssen, Richard C. Zimmerman, David J. Burdige

OES Faculty Publications

Regions of milky white seas or "whitings" periodically occur to the west of Andros Island along the Great Bahama Bank where the bottom sediment consists of fine-grained aragonite mud. We present measurements of inherent optical properties within a sediment whiting patch and discuss the potential for monitoring the frequency, extent, and quantity of suspended matter from ocean colour satellite imagery. Sea spectral reflectance measured in situ and remotely from space revealed highly reflective waters elevated across the visible spectrum (i.e., "whitened") with a peak at 490 nm. Particulate backscattering was an order of magnitude higher than that measured at other …


Dc Electrokinetic Transport Of Cylindrical Cells In Straight Microchannels, Ye Ai, Ali Beskok, David T. Gauthier, Sang W. Joo, Shizhi Qian Jan 2009

Dc Electrokinetic Transport Of Cylindrical Cells In Straight Microchannels, Ye Ai, Ali Beskok, David T. Gauthier, Sang W. Joo, Shizhi Qian

Biological Sciences Faculty Publications

Electrokinetic transport of cylindrical cells under dc electric fields in a straight microfluidic channel is experimentally and numerically investigated with emphasis on the dielectrophoretic (DEP) effect on their orientation variations. A two-dimensional multiphysics model, composed of the Navier-Stokes equations for the fluid flow and the Laplace equation for the electric potential defined in an arbitrary Lagrangian-Eulerian framework, is employed to capture the transient electrokinetic motion of cylindrical cells. The numerical predictions of the particle transport are in quantitative agreement with the obtained experimental results, suggesting that the DEP effect should be taken into account to study the electrokinetic transport of …


Understanding How Disease And Environment Combine To Structure Resistance In Estuarine Bivalve Populations, Eileen E. Hofmann, David Bushek, Susan E. Ford, Ximing Guo, Dale Haidvogel, Dennis Hedgecock, John M. Klinck, Coren Milbury, Diego Narvaez, Eric Powell, Yongping Wang, Zhiren Wang, Liusuo Zhang Jan 2009

Understanding How Disease And Environment Combine To Structure Resistance In Estuarine Bivalve Populations, Eileen E. Hofmann, David Bushek, Susan E. Ford, Ximing Guo, Dale Haidvogel, Dennis Hedgecock, John M. Klinck, Coren Milbury, Diego Narvaez, Eric Powell, Yongping Wang, Zhiren Wang, Liusuo Zhang

CCPO Publications

Delaware Bay oyster (Crassostrea virginica) populations are influenced by two lethal parasites that cause Dermo and MSX diseases. As part of the US National Science Foundation Ecology of Infectious Diseases initiative, a program developed for Delaware Bay focuses on understanding how oyster population genetics and population dynamics interact with the environment and these parasites to structure he host populations, and how these interactions might modified by climate change. Laboratory and field studies undertaken during this program include identifying genes related to MSX and Dermo disease resistance, potential regions for refugia and the mechanisms that allow them to exist, …


Enso And Variability Of The Antarctic Peninsula Pelagic Marine Ecosystem, Valerie J. Loeb, Eileen E. Hofmann, John M. Klinck, Osmund Holm-Hansen, Warren B. White Jan 2009

Enso And Variability Of The Antarctic Peninsula Pelagic Marine Ecosystem, Valerie J. Loeb, Eileen E. Hofmann, John M. Klinck, Osmund Holm-Hansen, Warren B. White

CCPO Publications

The West Antarctic Peninsula region is an important source of Antarctic krill (Euphausia superba) in the Southern Ocean. From 1980-2004 abundance and concentration of phytoplankton and zooplankton, krill reproductive and recruitment success and seasonal sea ice extent here were significantly correlated with the atmospheric Southern Oscillation Index and exhibited three- to five-year frequencies characteristic of El Nino-Southern Oscillation (ENSO) variability. This linkage was associated with movements of the Southern Antarctic Circumpolar Current Front and Boundary, a changing influence of Antarctic Circumpolar Current and Weddell Sea waters, and eastward versus westward flow and mixing processes that are consistent with forcing by …


Patterns Of Larval Atlantic Croaker Ingress Into Chesapeake Bay, Usa, Jason J. Schaffler, Christian S. Reiss, Cynthia M. Jones Jan 2009

Patterns Of Larval Atlantic Croaker Ingress Into Chesapeake Bay, Usa, Jason J. Schaffler, Christian S. Reiss, Cynthia M. Jones

OES Faculty Publications

We compared ingress patterns of Atlantic croaker Micropogonias undulatus larvae into Chesapeake Bay, USA, with published ingress patterns through barrier island inlets, the accepted model for larval fish ingress. This model asserts that larvae ingress on night flood tides at the flooddominated side of the inlet and at all depths. At the Chesapeake Bay mouth and in the adjacent coastal waters, we compared the distribution of abundance, size, age, and growth rates of croaker prior to ingress, In contrast to the barrier island inlet model, croaker larvae were more abundant at depth than closer to the surface regardless of location. …


Cross-Basin Comparison Of Phosphorus Stress And Nitrogen Fixation In Trichodesmium, Annette M. Hynes, P. Dreux Chappell, Sonya T. Dyhrman, Scott C. Doney, Eric A. Webb Jan 2009

Cross-Basin Comparison Of Phosphorus Stress And Nitrogen Fixation In Trichodesmium, Annette M. Hynes, P. Dreux Chappell, Sonya T. Dyhrman, Scott C. Doney, Eric A. Webb

OES Faculty Publications

We investigated the phosphorus (P) status and N2 fixation rates of Trichodesmium populations from the North Pacific, western South Pacific, and western North Atlantic. Colonies of Trichodesmium were collected and analyzed for endogenous alkaline phosphatase (AP) activity using enzyme-labeled fluorescence ( ELF) and for nitrogenase activity using acetylene reduction. AP hydrolyzes dissolved inorganic phosphate (DIP) from dissolved organic phosphorus and is active in Trichodesmium colonies experiencing P stress. Across multiple stations in the subtropical North and South Pacific, there was low to moderate ELF labeling in Trichodesmium, although labeling was present in other taxa. In contrast, Trichodesmium ELF …


Thin Layer Formation During Runaway Stratification In The Tidally Dynamic San Francisco Estuary, Alexander B. Bochdansky, Stephen M. Bollens Jan 2009

Thin Layer Formation During Runaway Stratification In The Tidally Dynamic San Francisco Estuary, Alexander B. Bochdansky, Stephen M. Bollens

OES Faculty Publications

During the course of a year, we repeatedly collected high-resolution vertical fluorometer data timed to coincide with a specific state during the tidal cycle. The time (end of the ebb during neap tide) and the location (a deep channel half-way between the Golden Gate and the point of tidally averaged bottom salinity of 2 psu) were chosen with the goal to observe runaway stratification. We consistently found at least one pronounced chlorophyll peak in the water column; however, the vertical location of these peaks varied within three types including surface, bottom and subsurface maxima. Our results showed that heterogeneity of …


Regional Characterisation Of Hard-Bottom Nursery Habitat For Juvenile Caribbean Spiny Lobster (Panulirus Argus) Using Rapid Assessment Techniques, Rodney D. Bertelsen, Mark J. Butler Iv, William F. Herrnkind, John H. Hunt Jan 2009

Regional Characterisation Of Hard-Bottom Nursery Habitat For Juvenile Caribbean Spiny Lobster (Panulirus Argus) Using Rapid Assessment Techniques, Rodney D. Bertelsen, Mark J. Butler Iv, William F. Herrnkind, John H. Hunt

Biological Sciences Faculty Publications

Shallow, hard-bottom habitat constitutes approximately 30% of the coastal waters of south Florida, United States, yet it is a chronically understudied feature of the marine seascape in this region. In this study, we characterised the general biogeographic and structural features of shallow benthic hard-bottom communities in the Florida Keys, and related those to the abundance of juvenile Caribbean spiny lobster (Panulirus argus), the target of one of Florida's most economically valuable fisheries. We used rapid assessment techniques to survey more than 100 hard-bottom sites in the Florida Keys to estimate the percentage bottom coverage of vegetation (seagrass and …


Is Seagrass An Important Nursery Habitat For The Caribbean Spiny Lobster, Panulirus Argus, In Florida?, Donald C. Behringer, Mark J. Butler Iv, William Herrnkind, John H. Hunt, Charles A. Acosta, William C. Sharp Jan 2009

Is Seagrass An Important Nursery Habitat For The Caribbean Spiny Lobster, Panulirus Argus, In Florida?, Donald C. Behringer, Mark J. Butler Iv, William Herrnkind, John H. Hunt, Charles A. Acosta, William C. Sharp

Biological Sciences Faculty Publications

Caribbean spiny lobster (Panulirus argus) settle preferentially in macroalgal-covered hard-bottom habitat, but seagrass is more prevalent in Florida (United States) and the Caribbean, so even low settlement of lobsters within seagrass could contribute substantially to recruitment if post-settlement survival and growth were high. We tested the role of seagrass and hard-bottom habitats for P. argus recruitment in three ways. We first explored possible density-dependent regulation of early benthic juvenile lobster survival within cages deployed in seagrass and hard-bottom habitats. Second, we compared settlement and survival of P. argus in both habitats, by comparing the recovery of microwire-tagged early …


Spatial Variation In Otolith Chemistry Of Atlantic Croaker Larvae In The Mid-Atlantic Bight, Jason J. Schaffler, Christian S. Reiss, Cynthia M. Jones Jan 2009

Spatial Variation In Otolith Chemistry Of Atlantic Croaker Larvae In The Mid-Atlantic Bight, Jason J. Schaffler, Christian S. Reiss, Cynthia M. Jones

OES Faculty Publications

Larval Atlantic croaker Micropogonias undulatus (1 to 7 mm in standard length) were collected on the east coast of the United States from North Carolina to Delaware during 2000. We defined 3 water-mass boundaries for potential groups of spawning Atlantic croaker using temperature and salinity measured at each sampling station. We tested the hypothesis that distinct otolith chemistries existed among 3 groups of larval Atlantic croaker collected from these water masses using solution-based inductively coupled plasma-mass spectrometry. Multivariate analysis of variance indicated that otolith chemistry differed significantly among water masses. Using a quadratic discriminant function, we were able to correctly …


Phytoplankton Blooms: Their Occurence And Composition Within Virginia's Tidal Tributaries, Harold G. Marshall, Todd A. Egerton Jan 2009

Phytoplankton Blooms: Their Occurence And Composition Within Virginia's Tidal Tributaries, Harold G. Marshall, Todd A. Egerton

Biological Sciences Faculty Publications

Sporadic algal bloom development within a 10 year monitoring program in Virginia tidal tributaries of Chesapeake Bay is reviewed. These blooms were common events, characteristically producing a color signature to the surface water, typically short lived, occurring mainly from spring into autumn throughout different salinity regions of these rivers, and were produced primarily by dinoflagellates. The abundance threshold levels that would identify bloom status from a non-bloom presence were species specific, varied with the taxon's cell size, and ranged from ca. 10 to 10(4) cells mL(-1). Among the most consistent sporadic bloom producers were the dinoflagellates Akashiwo sanguinea, Cochlodinium …


Multiple Imputation To Correct For Measurement Error In Admixture Estimates In Genetic Structured Association Testing, Miguel A. Padilla, Jamin Divers, Laura K. Vaughan, David B. Allison, Hemant K. Tiwari Jan 2009

Multiple Imputation To Correct For Measurement Error In Admixture Estimates In Genetic Structured Association Testing, Miguel A. Padilla, Jamin Divers, Laura K. Vaughan, David B. Allison, Hemant K. Tiwari

Psychology Faculty Publications

Objectives: Structured association tests ( SAT), like any statistical model, assumes that all variables are measured without error. Measurement error can bias parameter estimates and confound residual variance in linear models. It has been shown that admixture estimates can be contaminated with measurement error causing SAT models to suffer from the same afflictions. Multiple imputation (MI) is presented as a viable tool for correcting measurement error problems in SAT linear models with emphasis on correcting measurement error contaminated admixture estimates. Methods: Several MI methods are presented and compared, via simulation, in terms of controlling Type I error rates for both …


Pressure-Driven Transport Of Particles Through A Converging-Diverging Microchannel, Ye Ai, Sang W. Joo, Xiangchun Xuan, Shizhi Qian Jan 2009

Pressure-Driven Transport Of Particles Through A Converging-Diverging Microchannel, Ye Ai, Sang W. Joo, Xiangchun Xuan, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

Pressure-driven transport of particles through a symmetric converging-diverging microchannel is studied by solving a coupled nonlinear system, which is composed of the Navier-Stokes and continuity equations using the arbitrary Lagrangian-Eulerian finite-element technique. The predicted particle translation is in good agreement with existing experimental observations. The effects of pressure gradient, particle size, channel geometry, and a particle's initial location on the particle transport are investigated. The pressure gradient has no effect on the ratio of the translational velocity of particles through a converging-diverging channel to that in the upstream straight channel. Particles are generally accelerated in the converging region and then …


Potential Export Of Unattached Benthic Macroalgae To The Deep Sea Through Wind Driven Langmuir Circulation, H. M. Dierssen, Richard C. Zimmerman, Lisa A. Drake, David J. Burdige Jan 2009

Potential Export Of Unattached Benthic Macroalgae To The Deep Sea Through Wind Driven Langmuir Circulation, H. M. Dierssen, Richard C. Zimmerman, Lisa A. Drake, David J. Burdige

OES Faculty Publications

Carbon export to the deep sea is conventionally attributed to the sinking of open ocean phytoplankton. Here, we report a Langmuir supercell event driven by high winds across the shallow Great Bahama Bank that organized benthic non-attached macroalgae, Colpomenia sp., into visible windrows on the seafloor. Ocean color satellite imagery obtained before and after the windrows revealed a 588 km2 patch that rapidly shifted from highly productive macroalgae to bare sand. We assess a number of possible fates for this macroalgae and contend that this event potentially transported negatively buoyant macroalgae to the deep Tongue of the Ocean …


Influence Of Irradiance And Iron On The Growth Of Colonial Phaeocystic Antarctica: Implications For Seasonal Bloom Dynamics In The Ross Sea, Antarctica, Nathan S. Garcia, Peter N. Sedwick, Giacomo R. Ditullio Jan 2009

Influence Of Irradiance And Iron On The Growth Of Colonial Phaeocystic Antarctica: Implications For Seasonal Bloom Dynamics In The Ross Sea, Antarctica, Nathan S. Garcia, Peter N. Sedwick, Giacomo R. Ditullio

OES Faculty Publications

Laboratory culture experiments were used to investigate the growth rate of colonial Phaeocystis anarctica as a function of irradiance and dissolved iron concentration. The experiments were conducted with a P. antarctica strain isolated from the southern Ross Sea, Antarctica, and made use of natural, low-iron (P. antarctica attained an average maximum cell-specific growth rate of 0.37 d-1at an irradiance of 68 μE m-2s-1, above which growth rates decreased to 0.27 d-1 at an irradiance of 314 μE m-2s-1. The dependence of growth rate on ambient dissolved iron concentration was …


Geobiology: Evidence For Early Life On Earth And The Search For Life On Other Planets, Sherry L. Cady, Nora Noffke Jan 2009

Geobiology: Evidence For Early Life On Earth And The Search For Life On Other Planets, Sherry L. Cady, Nora Noffke

OES Faculty Publications

Extensive research efforts in the subdisciplinary field of geobiology have focused on the interactions between Earth and life through time. As a consequence, gaps in our knowledge of Earth’s history are closing, and the search for life beyond Earth is expanding. A few examples of geobiology studies designed to advance our understanding of life on early Earth and to improve the chances of finding life on other planets are provided to highlight recent developments and research areas that are on the verge of new discoveries.


Synergistic Effects Of Iron And Temperature On Antarctic Phytoplankton And Microzooplankton Assemblages, J. M. Rose, Y. Feng, G. R. Ditullio, R. B. Dunbar, C. E. Hare, P. A. Lee, M. Lohan, M. Long, W. O. Smith Jr., B. Sohst, S. Tozzi, Y. Zhang, D. A. Hutchins Jan 2009

Synergistic Effects Of Iron And Temperature On Antarctic Phytoplankton And Microzooplankton Assemblages, J. M. Rose, Y. Feng, G. R. Ditullio, R. B. Dunbar, C. E. Hare, P. A. Lee, M. Lohan, M. Long, W. O. Smith Jr., B. Sohst, S. Tozzi, Y. Zhang, D. A. Hutchins

OES Faculty Publications

Iron availability and temperature are important limiting factors for the biota in many areas of the world ocean, and both have been predicted to change in future climate scenarios. However, the impacts of combined changes in these two key factors on microbial trophic dynamics and nutrient cycling are unknown. We examined the relative effects of iron addition (+1 nM) and increased temperature (+4° C) on plankton assemblages of the Ross Sea, Antarctica, a region characterized by annual algal blooms and an active microbial community. Increased iron and temperature individually had consistently significant but relatively minor positive effects on total phytoplankton …


Peptide Hydrolysis And The Uptake Of Dipeptides By Phytoplankton, Margaret R. Mulholland, Cindy Lee Jan 2009

Peptide Hydrolysis And The Uptake Of Dipeptides By Phytoplankton, Margaret R. Mulholland, Cindy Lee

OES Faculty Publications

Rates of peptide hydrolysis (using the fluorescent substrate, lucifer yellow anhydride-labeled tetra-alanine) and dipeptide uptake (using dually labeled, 15N and 13C, dialanine) were measured in phytoplankton cultures and in natural populations during algal blooms dominated by one or two taxa. During most sampling events, both peptide hydrolysis and dipeptide uptake were greatest in the size fraction containing the dominant phytoplankter, suggesting that phytoplankton contribute substantially to or may even dominate observed extracellular peptide hydrolysis and dipeptide uptake in the environment. These are the first data suggesting that dipeptides may be taken up directly by phytoplankton and this may …


The Effects Of Climate Change On Biodiversity: Pressing Issues And Research Priorities, Friedhelm Krupp, Lytton J. Musselman, Mohammed M.A. Kotb, Ilka Weidig Jan 2009

The Effects Of Climate Change On Biodiversity: Pressing Issues And Research Priorities, Friedhelm Krupp, Lytton J. Musselman, Mohammed M.A. Kotb, Ilka Weidig

Biological Sciences Faculty Publications

No abstract provided.


The Epidemiological Status Of Pav1, And The Effects Of Infection On Caribbean Spiny Lobster (Panulirus Argus) Condition, Olfaction, And Predation Risk, Donald C. Behringer, Mark J. Butler Iv, Jeffrey D. Shields Jan 2009

The Epidemiological Status Of Pav1, And The Effects Of Infection On Caribbean Spiny Lobster (Panulirus Argus) Condition, Olfaction, And Predation Risk, Donald C. Behringer, Mark J. Butler Iv, Jeffrey D. Shields

Biological Sciences Faculty Publications

No abstract provided.


Patterns Of Spiny Lobster (Panulirus Argus) Postlarval Recruitment In The Carribbean: A Crtr Project, Mark J. Butler Iv, Angela M. Mojica, Eloy Sosa-Cordero, Marines Millet, Paul Sanchez-Navarro, Miguel A. Maldonado, Juan Posada, Bladimir Rodriguez, Carlos M. Rivas, Adrian Oviedo, Marcio Arrone, Martha Prada, Nick Bach, Nilda Jimenez, Maria Del Carmen Garcia-Rivas, Kirah Forman, Donald C. Behringer Jr., Thomas Matthews, Claire Paris, Robert Cowen Jan 2009

Patterns Of Spiny Lobster (Panulirus Argus) Postlarval Recruitment In The Carribbean: A Crtr Project, Mark J. Butler Iv, Angela M. Mojica, Eloy Sosa-Cordero, Marines Millet, Paul Sanchez-Navarro, Miguel A. Maldonado, Juan Posada, Bladimir Rodriguez, Carlos M. Rivas, Adrian Oviedo, Marcio Arrone, Martha Prada, Nick Bach, Nilda Jimenez, Maria Del Carmen Garcia-Rivas, Kirah Forman, Donald C. Behringer Jr., Thomas Matthews, Claire Paris, Robert Cowen

Biological Sciences Faculty Publications

As part of the Coral Reef Targeted Research (CRTR) Program, a partnership between the Global Environment Facility and the World Bank, our research team examined the recruitment patterns of Caribbean spiny lobster (Panulirus argus) postlarvae among regions in the Caribbean, with a particular focus on Mesoamerica. Our goal was to collect comparable information on postlarval supply among regions and to provide data to test predictions of connectivity generated from a coupled biophysical oceanographic model of lobster larval dispersal. Here we present the results of the postlarval recruitment monitoring program. We monitored the catch of postlarvae on Witham-style collectors …