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Articles 1 - 23 of 23
Full-Text Articles in Fresh Water Studies
Niche Of Harmful Alga Aureococcus Anophagefferens Revealed Through Ecogenomics, Christopher Gobler, Dianna Berry, Sonya Dyhrman, Steven Wilhelm
Niche Of Harmful Alga Aureococcus Anophagefferens Revealed Through Ecogenomics, Christopher Gobler, Dianna Berry, Sonya Dyhrman, Steven Wilhelm
Steven Wilhelm
Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking, because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements showed that the harmful alga Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the genome of A. anophagefferens and compared its gene complement with those of six competing phytoplankton species identified through metaproteomics. …
Determining Rates Of Virus Production In Aquatic Systems By The Virus Reduction Approach,, M.G. Weinbauer, J.M. Rowe, Steven Wilhelm
Determining Rates Of Virus Production In Aquatic Systems By The Virus Reduction Approach,, M.G. Weinbauer, J.M. Rowe, Steven Wilhelm
Steven Wilhelm
The reduction approach to assess virus production and the prokaryotic mortality by viral lysis stops new infection by reducing total virus abundance (and thus virus–host contacts). This allows for easy enumeration of viruses that originate from lysis of already infected cells due to the decreased abundance of free virus particles. This reoccurrence can be quantified and used to assess production and cell lysis rates. Several modifications of the method are presented and compared. The approaches have great potential for elucidating trends in virus production rates as well as for making generalized estimates of the quantitative effects of viruses on marine …
The Construction And Analysis Of Marker Gene Libraries, S.M. Short, F. Chen, Steven Wilhelm
The Construction And Analysis Of Marker Gene Libraries, S.M. Short, F. Chen, Steven Wilhelm
Steven Wilhelm
Marker genes for viruses are typically amplified from aquatic samples to determine whether specific viruses are present in the sample, or to examine the diversity of a group of related viruses. In this chapter, we will provide an overview of common methods used to amplify, clone, sequence, and analyze virus marker genes, and will focus our discussion on viruses infecting algae, bacteria, and heterotrophic flagellates. Within this chapter, we endeavor to highlight critical aspects and components of these methods. To this end, instead of providing a detailed experimental protocol for each of the steps involved in examining virus marker gene …
The Southeastern Coastal Plain: An Overview, Lee J. Florea, H L. Vacher
The Southeastern Coastal Plain: An Overview, Lee J. Florea, H L. Vacher
Lee J Florea, PhD, P.G.
Florida enjoys the highest density of large springs in North America (Scott et al., 2004); Silver Springs is just one of the 33 first-magnitude springs (mean flow greater than 100 cfs (2.8 m3/s), and there are hundreds of smaller springs (Fig. 6.2; see Meinzer, 1927, and Scott et al., 2004). They are supplied by spectacular underwater caves that are internationally recognized in the cave-diving community. Less well known are the many air-filled caves of the region (see Florea, 2006; Moore, 2006; Lane 1986). Though generally smaller than their aquatic counterparts, their beauty can rival the world’s best show caves. This …
The Cumberland Plateau Of Eastern Kentucky, Larry C. Simpson, Lee J. Florea
The Cumberland Plateau Of Eastern Kentucky, Larry C. Simpson, Lee J. Florea
Lee J Florea, PhD, P.G.
Eastern Kentucky contains almost the same Mississippian limestones that appear at Mammoth Cave in south-central Kentucky (Chapter 3). To the east these strata dip below the Appalachian Basin and reappear as the Greenbrier Group in the Virginias. The limestone outcrop in eastern Kentucky follows the western margin of the Cumberland Plateau and forms a ragged ribbon of karst that is continuous from southeastern Ohio through Kentucky and Tennessee and into northern Alabama. There are more than 2,000 documented caves comprising over 470 km of surveyed passage in the Kentucky segment of the Cumberland Plateau (Fig. 2.115). At least 14 are …
Caves And Karst Of West-Central Florida, Lee J. Florea, David Budd, Robert Brinkmann
Caves And Karst Of West-Central Florida, Lee J. Florea, David Budd, Robert Brinkmann
Lee J Florea, PhD, P.G.
The real west-central Florida is far from the “Sunshine State” image of white sand beaches and palm trees. Gently rolling hills, dense jungle-like forests, pine and palmetto scrublands, impenetrable cypress swamps, and alligator-laden rivers are more common. Numerous crystal-clear springs offer a glimpse of the hidden world below – a world that could challenge the most imaginative Disney artists (Fig. 6.17).
Masw Tests For Detection Of Decayed Buried Timber Within Railway Embankments, Barry A. Palynchuk Phd, Chris Bunce Phd, Steve Sather M.Eng
Masw Tests For Detection Of Decayed Buried Timber Within Railway Embankments, Barry A. Palynchuk Phd, Chris Bunce Phd, Steve Sather M.Eng
Barry A. Palynchuk PhD
No abstract provided.
Actinorhodopsin Genes Discovered Diverse In Freshwater Habitats And Among Cultivated Actinobacteria, A.K. Sharma, K. Sommerfeld, G.S. Bullerjahn, A.R. Matteson, Steven Wilhelm, J. Jezbera, U. Brandt, W.F. Doolittle, M.W. Hahn
Actinorhodopsin Genes Discovered Diverse In Freshwater Habitats And Among Cultivated Actinobacteria, A.K. Sharma, K. Sommerfeld, G.S. Bullerjahn, A.R. Matteson, Steven Wilhelm, J. Jezbera, U. Brandt, W.F. Doolittle, M.W. Hahn
Steven Wilhelm
Microbial rhodopsins are membrane proteins that utilize a retinal chromophore to harvest sunlight for energetic and photosensory functions. Recently, a group of novel rhodopsin sequences named ‘actinorhodopsins’ (ActRs) was hypothesized to exist among uncultured planktonic Actinobacteria. ActRs were discovered by mining metagenomic data obtained during the Venter Institute’s Global Ocean Sampling expedition, from a hypersaline lagoon, two estuaries and a freshwater lake. On the basis of these findings, and many studies that show Actinobacteria are common inhabitants of lakes, we predicted that ActR genes would likely be present in other freshwater habitats and among the genomes of cultivated Actinobacteria …
Identifying The Source Of Unknown Microcystin Genes And Predicting Microcystin Variants By Comparing Genes Within Uncultured Cyanobacterial Cells, C.J. Allender, G.R. Lecleir, J.M. Rinta-Kanto, R.L. Small, M.F. Satchwell, G.L. Boyer, Steven Wilhelm
Identifying The Source Of Unknown Microcystin Genes And Predicting Microcystin Variants By Comparing Genes Within Uncultured Cyanobacterial Cells, C.J. Allender, G.R. Lecleir, J.M. Rinta-Kanto, R.L. Small, M.F. Satchwell, G.L. Boyer, Steven Wilhelm
Steven Wilhelm
While multiple phylogenetic markers have been used in the culture independent study of microcystin producing cyanobacteria, in only a few instances have multiple markers been studied within individual cells, and in all cases these studies have been conducted with cultured isolates. Here, we isolate and evaluate large DNA fragments (> 6 kb) encompassing two genes involved in microcystin biosynthesis (mcyA2 and mcyB1) and use them to identify the source of gene fragments found in water samples. Further investigation of these gene loci from individual cyanobacterial cells allowed for improved analysis of the genetic diversity within microcystin producers as …
Distribution Of Calcifying And Silicifying Phytoplankton In Relation To Environmental And Biogeochemical Parameters During The Late Stages Of The 2005 North East Atlantic Spring Bloom, K. Leblanc, C.E. Hare, Y. Feng, G.M. Berg, G.R. Ditullio, A. Neeley, I. Benner, C. Sprengel, A. Beck, S.A. Sanudo-Wilhemy, U. Passow, K. Klinck, J.M. Rowe, Steven Wilhelm, C.W. Brown, D.A. Hutchins
Distribution Of Calcifying And Silicifying Phytoplankton In Relation To Environmental And Biogeochemical Parameters During The Late Stages Of The 2005 North East Atlantic Spring Bloom, K. Leblanc, C.E. Hare, Y. Feng, G.M. Berg, G.R. Ditullio, A. Neeley, I. Benner, C. Sprengel, A. Beck, S.A. Sanudo-Wilhemy, U. Passow, K. Klinck, J.M. Rowe, Steven Wilhelm, C.W. Brown, D.A. Hutchins
Steven Wilhelm
The late stage of the North East Atlantic (NEA) spring bloom was investigated during June 2005 along a transect section from 45 to 66° N between 15 and 20° W in order to characterize the contribution of siliceous and calcareous phytoplankton groups and describe their distribution in relation to environmental factors. We measured several biogeochemical parameters such as nutrients, surface trace metals, algal pigments, biogenic silica (BSi), particulate inorganic carbon (PIC) or calcium carbonate, particulate organic carbon, nitrogen and phosphorus (POC, PON and POP, respectively), as well as transparent exopolymer particles (TEP). Results were compared with other studies undertaken in …
The Effects Of Increased Pco2 And Temperature On The North Atlantic Spring Bloom: I. The Phytoplankton Community And Biogeochemical Response, Y. Feng, C.E. Hare, K. Leblanc, J.M. Rose, Y Zhang, G.R. Ditullio, P. Lee, Steven Wilhelm, J.M. Rowe, J. Sun, N. Nemcek, C. Gueguen, U. Passow, I. Benner, C. Brown, D.A. Hutchins
The Effects Of Increased Pco2 And Temperature On The North Atlantic Spring Bloom: I. The Phytoplankton Community And Biogeochemical Response, Y. Feng, C.E. Hare, K. Leblanc, J.M. Rose, Y Zhang, G.R. Ditullio, P. Lee, Steven Wilhelm, J.M. Rowe, J. Sun, N. Nemcek, C. Gueguen, U. Passow, I. Benner, C. Brown, D.A. Hutchins
Steven Wilhelm
ABSTRACT: The North Atlantic spring bloom is one of the largest annual biological events in the ocean, and is characterized by dominance transitions from siliceous (diatoms) to calcareous (coccolithophores) algal groups. To study the effects of future global change on these phytoplankton and the biogeochemical cycles they mediate, a shipboard continuous culture experiment (Ecostat) was conducted in June 2005 during this transition period. Four treatments were examined: (1) 12°C and 390 ppm CO2 (ambient control), (2) 12°C and 690 ppm CO2 (high pCO2), (3) 16°C and 390 ppm CO2 (high temperature), and (4) 16°C and …
Effects Of Increased Pco2 And Temperature On The North Atlantic Spring Bloom: Iii. Dimethylsulfoniopropionate, P.A. Lee, J.R. Rudisill, A.R. Neeley, D.A. Hutchins, Y. Feng, C.E. Hare, K. Leblanc, J.M. Rose, Steven Wilhelm, J.M. Rowe, G.R. Ditullio
Effects Of Increased Pco2 And Temperature On The North Atlantic Spring Bloom: Iii. Dimethylsulfoniopropionate, P.A. Lee, J.R. Rudisill, A.R. Neeley, D.A. Hutchins, Y. Feng, C.E. Hare, K. Leblanc, J.M. Rose, Steven Wilhelm, J.M. Rowe, G.R. Ditullio
Steven Wilhelm
The CLAW hypothesis argues that a negative feedback mechanism involving phytoplankton-derived dimethylsulfoniopropionate (DMSP) could mitigate increasing sea surface temperatures that result from global warming. DMSP is converted to the climatically active dimethylsulfide (DMS), which is transferred to the atmosphere and photochemically oxidized to sulfate aerosols, leading to increases in planetary albedo and cooling of the Earth’s atmosphere. A shipboard incubation experiment was conducted to investigate the effects of increased temperature and pCO2 on the algal community structure of the North Atlantic spring bloom and their subsequent impact on particulate and dissolved DMSP concentrations (DMSPp and DMSPd). Under …
Geology And Hydrology Of Karst In West-Central And North-Central Florida, Lee J. Florea
Geology And Hydrology Of Karst In West-Central And North-Central Florida, Lee J. Florea
Lee J Florea, PhD, P.G.
The state of Florida is blessed with the highest density of large springs in North America and hundreds of smaller springs where the water from limestone aquifers returns to the surface (Scott et al., 2004). Spectacular underwater caves supply water to these springs. Lesser known are the equally fantastic air-filled caves of Florida and South Georgia (Florea, 2006; Lane, 1986). This paper features these underwater and airfilled caves, explores the impact of changes in sea level on karst in this near-coastal environment, and establishes several geologic and hydrologic characteristics that distinguish karst in the limestones of the southeast from karst …
Visualization Of Groundwater Flow Within Touching-Vug And Matrix Porosity In An Eogenetic Karst Aquifer, Lee J. Florea, Kevin J. Cunningham, Stephen Altobelli
Visualization Of Groundwater Flow Within Touching-Vug And Matrix Porosity In An Eogenetic Karst Aquifer, Lee J. Florea, Kevin J. Cunningham, Stephen Altobelli
Lee J Florea, PhD, P.G.
In this study, we use an innovative, non-invasive technology, nuclear magnetic resonance imaging (NMRI), to visualize the direction and magnitude of groundwater flow in field samples of late Pleistocene limestone of the Biscayne aquifer. Specific goals of the first set of NMRI experiments are to map the advective velocity of water flowing at two rates of specific discharge (0.00025 and 0.00013 m/s) through a 10-cm-diameter cylindrical, epoxy-resin model. The model interior accurately reproduces a well-connected maze of ichnologically influenced, centimeter-scale, touching-vug macroporosity common within preferred flow zones in parts of the Biscayne aquifer. A second set of NMRI experiments investigates …
Focus Group On Karst Hydrology - Conceptual Models, Aquifer Characterization, And Numerical Modeling, Martin Sauter, Lee J. Florea, Others
Focus Group On Karst Hydrology - Conceptual Models, Aquifer Characterization, And Numerical Modeling, Martin Sauter, Lee J. Florea, Others
Lee J Florea, PhD, P.G.
No abstract provided.
Biogenic Porosity And Its Lattice Boltzmann Method Permeability In The Karst Biscayne Aquifer, Kevin Cunningham, Mike Sukop, Haibo Huang, Pedro Alvarez, Allen Curran, Michael Waker, Lee J. Florea, Robert Renken, Joann F. Dixon
Biogenic Porosity And Its Lattice Boltzmann Method Permeability In The Karst Biscayne Aquifer, Kevin Cunningham, Mike Sukop, Haibo Huang, Pedro Alvarez, Allen Curran, Michael Waker, Lee J. Florea, Robert Renken, Joann F. Dixon
Lee J Florea, PhD, P.G.
No abstract provided.
Morphologic Features Of Conduits And Aquifer Response In The Unconfined Floridan Aquifer System, West Central Florida, Lee J. Florea, H L. Vacher
Morphologic Features Of Conduits And Aquifer Response In The Unconfined Floridan Aquifer System, West Central Florida, Lee J. Florea, H L. Vacher
Lee J Florea, PhD, P.G.
Conduits within the unconfined Floridan Aquifer of west-central Florida include both horizontal and vertical components. In this paper, we investigate each and propose theories based upon cave survey data and a collection of over 300 Florida cave maps. First, we find that vertical portions of conduits visually correlate to fractures, and these fractures tend to be the dominant control of conduit directionality. Length-weighted rose diagrams of passage directions reveal a NW-SE and NE-SW pattern of conduit directions statistically similar to results found in remote sensing studies of photolinears. Secondly we note that horizontal elements of conduits occur at consistent horizons …
Le Voragini Catastrofiche Della Florida, Lee J. Florea, Robert Brooks, Tom Turner, Mario Parise
Le Voragini Catastrofiche Della Florida, Lee J. Florea, Robert Brooks, Tom Turner, Mario Parise
Lee J Florea, PhD, P.G.
The West-Central Florida landscape is worlds away from white-sand beaches and palm trees: gentle rolling hills, dense jungle-like forests, pine tree and palmetto scrub lands, impenetrable cypress swamps, and alligator-laden rivers. Numerous crystal-clear springs offer a glimpse of the hidden world below these wildly-diverse ecosystems. Internationally recognized in the cave diving community, Florida harbors some of the longest and most spectacular underwater cave systems. Lesser known are Florida’s “dry” caves, that rarely have large natural openings and, though often smaller than their aquatic counterparts, the beauty found within can rival the world’s best show-caves. Little was known about caves and …
Cave Levels, Marine Terraces, Paleoshorelines, And The Water Table In Peninsular Florida, Lee J. Florea, H L. Vacher
Cave Levels, Marine Terraces, Paleoshorelines, And The Water Table In Peninsular Florida, Lee J. Florea, H L. Vacher
Lee J Florea, PhD, P.G.
Levels of passages are a common feature of many cave systems around the world. Likewise, coastal and marine terraces are common in coastal plain settings. This paper extends the discussion of cave levels from traditional research sites in the interior lowlands of the United States to the Atlantic Coastal Plains, namely peninsular Florida. Are there levels in Florida caves, and is there a link between the elevation of cave levels, marine terraces, paleoshorelines, and thus the water table, above and below present sea level in peninsular Florida?
Effects Of Experimental Greenhouse Warming On Phytoplankton And Zooplankton Communities In Fishless Alpine Ponds, Angela L. Strecker, Tyler P. Cobb, Rofl D, Vinebrooke
Effects Of Experimental Greenhouse Warming On Phytoplankton And Zooplankton Communities In Fishless Alpine Ponds, Angela L. Strecker, Tyler P. Cobb, Rofl D, Vinebrooke
Angela L. Strecker
The impacts of global warming on aquatic ecosystems are expected to be most pronounced at higher trophic levels in cold-water environments. Therefore, we hypothesized that wanning of fishless alpine ponds would suppress large-bodied consumers (e.g., cladocerans, copepods) and stimulate fast-growing microorganisms (e.g., phytoflagellates, rotifers), thereby altering the community composition and total abundance of zooplankton and phytoplankton. This hypothesis was tested using three blocks of four experimental mesocosms (1000-liter capacity) that were located next to alpine ponds in Banff National Park, Canada. Each block received unfiltered pond water and sediment from a pond following ice out in June 2000. A warming …
Light & Dark: The Hidden Wonders Of Buck Creek, Lee J. Florea
Light & Dark: The Hidden Wonders Of Buck Creek, Lee J. Florea
Lee J Florea, PhD, P.G.
As early morning mists rise from the banks of its supple waters, beams of light penetrate the Buck Creek valley illuminating its beauty. While light illuminates most of the land, there are secret places, nestled within the forest where darkness reigns supreme. Places beyond the touch of the sun, beyond the influence of seasons. Here time is measured not in cycles of light but by the flow of water and fall of rock. These are the caves, conduits for water past and present. Nestled in the hills of south-central Kentucky the caves along Buck Creek provide the lifeblood for a …
Solute Transport Through Laboratory-Scale Karstic Aquifers, Lee J. Florea, Carol M. Wicks
Solute Transport Through Laboratory-Scale Karstic Aquifers, Lee J. Florea, Carol M. Wicks
Lee J Florea, PhD, P.G.
Laboratory-scale models of branchwork and of network karstic aquifers were constructed to provide data needed for calibration of numerical models. The distribution and connectedness of the conduits and sinkholes were scaled similarly to those found in nature; however, the porosity of models (2 and 3%) and the recharge rate (80 cm/hr) could not be scaled appropriately. Pulses of 1-M NaCl were injected sequentially at ten locations on both models to determine transport parameters using QTRACER. For all experiments, the Reynolds numbers were <150, the Peclet numbers were >6, and the Froude numbers were ~0. The flow regime was laminar and subcritical and advective processes dominated …
Emergency Response Canadian Pacific Railway Canadian Main Line, Barry A. Palynchuk Phd, Michael J. Loehr, Robert W. Badger, Robert P. Conroy, Clive H. Mackay
Emergency Response Canadian Pacific Railway Canadian Main Line, Barry A. Palynchuk Phd, Michael J. Loehr, Robert W. Badger, Robert P. Conroy, Clive H. Mackay
Barry A. Palynchuk PhD
In late June 1998, a major storm event occurred in the Adirondack Mountains in the vicinity of Keeseville, New York about 150 miles north of Albany. This storm resulted in unprecedented damage to the Canadian Pacific Railway (CPR) Canadian Mainline along the shores of Lake Champlain. The storm caused 14 major embankment failures and washouts, numerous minor failures, severe bridge foundation scour and a major mainline derailment.