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2009

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Articles 5191 - 5220 of 7615

Full-Text Articles in Physical Sciences and Mathematics

Do Monk Seals Exert Top-Down Pressure In Subphotic Ecosystems?, Frank Parrish Jan 2009

Do Monk Seals Exert Top-Down Pressure In Subphotic Ecosystems?, Frank Parrish

United States Department of Commerce: Staff Publications

Patterns of subphotic fish assemblages on seamounts in the Northwestern Hawaiian Islands were identified and compared for potential structuring influences, including the bottom-up effects of regional oceanic productivity and top-down predation pressure exerted by visiting monk seals (Monachus schauinslandi). Patterns in fish size, density, and biomass were evaluated at the deep extreme (350–500 m) of the seals feeding range to avoid confounding effects of diverse shallow habitats (e.g., coral reefs). Fish number and size were used to calculate biomass density of the seamount fish assemblages that were then compared to the independent variables of summit depth, substrate type, …


Blubber Testosterone: A Potential Marker Of Male Reproductive Status In Short-Beaked Common Dolphins, Nicholas Kellar, Marisa Trego, Corina Marks, Susan Chivers, Kerri Danil, Frederick Archer Jan 2009

Blubber Testosterone: A Potential Marker Of Male Reproductive Status In Short-Beaked Common Dolphins, Nicholas Kellar, Marisa Trego, Corina Marks, Susan Chivers, Kerri Danil, Frederick Archer

United States Department of Commerce: Staff Publications

A novel molecular technique was used to measure blubber testosterone (BT) in 114 male short-beaked common dolphins, Delphinus delphis, collected from incidental fishery bycatch and strandings. When these concentrations were compared across maturity states, the mean (± SEM) BT levels of mature D. delphis (14.3 ± 3.0 ng/g) were significantly higher than those of pubertal (2.5 ± 0.5 ng/g, P = 0.006) and immature animals (2.2 ± 0.3 ng/g, P < 0.0001). BT concentrations in mature males were significantly higher in summer months (53.9 ± 2.0 ng/g) than during the rest of the year (7.9 ± 0.69 ng/g, P < 0.0001), indicating reproductive seasonality. An analysis of BT in different anatomical locations showed that hormone concentrations were not homogenous throughout the body; the levels in the dorsal fin were significantly lower than in most other areas (F = 5.39, P = 0.043). Conversely, we found no significant differences in BT concentration with respect to subepidermal depth (F = 2.09, P = 0.146). Finally, testosterone levels in biopsies from 138 free-swimming male D. delphis, of unknown maturity state, sampled off California were found to be of concentrations similar to those from the fishery bycatch and stranding samples and revealed an …


Treatment Of Northern Fur Seal (Callorhinus Ursinus) Pups With Ivermectin Reduces Hookworm-Induced Mortality, Robert Delong, Anthony Orr, Ryan Jenkinson, Eugene T. Lyons Jan 2009

Treatment Of Northern Fur Seal (Callorhinus Ursinus) Pups With Ivermectin Reduces Hookworm-Induced Mortality, Robert Delong, Anthony Orr, Ryan Jenkinson, Eugene T. Lyons

United States Department of Commerce: Staff Publications

A breeding population of approximately 8,000–10,000 northern fur seals (Callorhinus ursinus) is located at San Miguel Island in the California Channel Islands. The population is increasing and produces about 2,500 pups annually (Melin et al. 2008). Pup mortality has increased during the past 10 yr and has reached 50% or more in some recent years. Although we have not completed studies to describe the causes of this pup mortality, it appears that hookworm disease has been a major cause (Lyons et al. 2001).


Contrasting Patterns Of Genetic Diversity At Three Different Genetic Markers In A Marine Mammal Metapopulation, J. I. Hoffman, K. K. Dasmahapatra, W. Amos, C. D. Phillips, T. S. Gelatt, J . W. Bickham Jan 2009

Contrasting Patterns Of Genetic Diversity At Three Different Genetic Markers In A Marine Mammal Metapopulation, J. I. Hoffman, K. K. Dasmahapatra, W. Amos, C. D. Phillips, T. S. Gelatt, J . W. Bickham

United States Department of Commerce: Staff Publications

Many studies use genetic markers to explore population structure and variability within species. However, only a minority use more than one type of marker and, despite increasing evidence of a link between heterozygosity and individual fitness, few ask whether diversity correlates with population trajectory. To address these issues, we analyzed data from the Steller’s sea lion, Eumetiopias jubatus, where three stocks are distributed over a vast geographical range and where both genetic samples and detailed demographic data have been collected from many diverse breeding colonies. To previously published mitochondrial DNA(mtDNA) and microsatellite data sets,we have added new data for …


Paedomorphic Ossification In Porpoises With An Emphasis On The Vaquita (Phocoena Sinus), Liliana Mellor, Lisa Noelle Cooper, Jorge Torre, Robert L. Brownell Jr. Jan 2009

Paedomorphic Ossification In Porpoises With An Emphasis On The Vaquita (Phocoena Sinus), Liliana Mellor, Lisa Noelle Cooper, Jorge Torre, Robert L. Brownell Jr.

United States Department of Commerce: Staff Publications

Heterochrony, the change in timing of developmental processes, is thought to be a key process shaping the numerous limb morphologies of tetrapods. Through a delayed offset in digit development, all cetaceans (i.e., whales, dolphins, and porpoises) have evolved supernumary phalanges (hyperphalangy). Moreover, some toothed cetaceans further alter digital morphologies by delayed endochondral and perichondral ossification of individual elements. In the harbor porpoise (Phocoena phocoena), these paedomorphic patterns have created poorly ossified phalangeal elements. However, no studies have addressed this morphology in other porpoise taxa. This study documents the timing of carpal and digital epiphyseal ossification in the poorly …


Indo-Pacific Bottlenose Dolphin Assessment Workshop Report, R.R. Reeves, R. L. Brownell Jr. Jan 2009

Indo-Pacific Bottlenose Dolphin Assessment Workshop Report, R.R. Reeves, R. L. Brownell Jr.

United States Department of Commerce: Staff Publications

A workshop on the assessment of Indo-Pacific bottlenose dolphins (Tursiops aduncus), with the Solomon Islands as a case study, took place from 21-23 August 2008 in Apia, Samoa. It was planned and organized under the auspices of the Cetacean Specialist Group and attended by 19 invited participants from eight countries. Financial support was provided by WWF (International), The Ocean Conservancy, Animal Welfare Institute, Humane Society of the United States, Whale and Dolphin Conservation Society, U.S. Marine Mammal Commission and U.S. National Oceanic and Atmospheric Administration. The workshop was hosted by the Secretariat of the Pacific Regional Environment Program …


Insights Into The Population Structure Of Blue Whales In The Eastern North Pacific From Recent Sightings And Photographic Identification, John Calambokidis, Jay Barlow, John K. B. Ford, Todd E. Chandler, Annie B. Douglas Jan 2009

Insights Into The Population Structure Of Blue Whales In The Eastern North Pacific From Recent Sightings And Photographic Identification, John Calambokidis, Jay Barlow, John K. B. Ford, Todd E. Chandler, Annie B. Douglas

United States Department of Commerce: Staff Publications

Blue whales were widely distributed in the North Pacific prior to the primary period of modern commercial whaling in the early 1900s. Despite concentrations of blue whale catches off British Columbia and in the Gulf of Alaska, there had been few documented sightings in these areas since whaling for blue whales ended in 1965. In contrast, large concentrations of blue whales have been documented off California and Baja California and in the eastern tropical Pacific since the 1970s, but it was not known if these animals were part of the same population that previously ranged into Alaskan waters. We document …


Feedback Between Zebra Mussel Selective Feeding And Algal Composition Affects Mussel Condition: Did The Regime Changer Pay A Price For Its Success?, Henry A. Vanderploeg, Thomas H. Johengen, James R. Liebig Jan 2009

Feedback Between Zebra Mussel Selective Feeding And Algal Composition Affects Mussel Condition: Did The Regime Changer Pay A Price For Its Success?, Henry A. Vanderploeg, Thomas H. Johengen, James R. Liebig

United States Department of Commerce: Staff Publications

1. We investigated the role of algal composition on pumping, clearance, assimilation, pseudofaeces and faeces production, feeding time budgets, and condition of zebra mussels from spring to autumn at two sites in Saginaw Bay (Lake Huron) and one site in western Lake Erie. Size-fractioned chlorophyll was used to distinguish between feeding on small (<53 >µm) and large (>53 µm) size fractions, and mussel feeding behaviour was quantified by video observations.

2. Mussel pumping, clearance and assimilation rates varied among sites, particularly during summer, when phytoplankton composition varied considerably among sites. Lowest values were seen at the inner-bay site of …


Techniques For Consecutive Tem And Atom Probe Tomography Analysis Of Nanowires, D. R. Diercks, B. P. Gorman, Chin Li Cheung, G. Wang Jan 2009

Techniques For Consecutive Tem And Atom Probe Tomography Analysis Of Nanowires, D. R. Diercks, B. P. Gorman, Chin Li Cheung, G. Wang

Chemistry Department: Faculty Publications

Nanowires show great promise for development in many technological applications including electronics, photonics, and displays . Due to the fine scale of nanowires, transmission electron microscopy (TEM) and atom probe tomography (APT) are among a limited number of techniques that can measure the crystallographic and chemical nature of these structures which ultimately define their performance.


Quantum Mechanical/Molecular Mechanical/Continuum Style Solvation Model: Linear Response Theory, Variational Treatment, And Nuclear Gradients, Hui Li Jan 2009

Quantum Mechanical/Molecular Mechanical/Continuum Style Solvation Model: Linear Response Theory, Variational Treatment, And Nuclear Gradients, Hui Li

Chemistry Department: Faculty Publications

Linear response and variational treatment are formulated for Hartree–Fock (HF) and Kohn–Sham density functional theory (DFT) methods and combined discrete-continuum solvation models that incorporate self-consistently induced dipoles and charges. Due to the variational treatment, analytic nuclear gradients can be evaluated efficiently for these discrete and continuum solvation models. The forces and torques on the induced point dipoles and point charges can be evaluated using simple electrostatic formulas as for permanent point dipoles and point charges, in accordance with the electrostatic nature of these methods. Implementation and tests using the effective fragment potential (EFP, a polarizable force field) method and the …


Smooth Potential Energy Surface For Cavitation, Dispersion, And Repulsion Free Energies In Polarizable Continuum Model, Yali Wang, Hui Li Jan 2009

Smooth Potential Energy Surface For Cavitation, Dispersion, And Repulsion Free Energies In Polarizable Continuum Model, Yali Wang, Hui Li

Chemistry Department: Faculty Publications

The fixed points with variable areas [FIXPVA (Ref. 1)] tessellation scheme is used to obtain smooth potential energy surfaces for the cavitation Gcav, dispersion Gdis, and repulsion Grep free energies in the polarizable continuum model (PCM). It is shown that FIXPVA can reproduce the standard GEPOL (Ref. 4) results to within 1 kcal/mol.


A New Peroxide Fragmentation: Efficient Chemical Generation Of 1O2 In Organic Media, Patrick Dussault, Prasanta Ghorai Jan 2009

A New Peroxide Fragmentation: Efficient Chemical Generation Of 1O2 In Organic Media, Patrick Dussault, Prasanta Ghorai

Chemistry Department: Faculty Publications

Monoactivated derivatives of 1,1-dihydroperoxides undergo an unprecedented base-promoted fragmentation to efficiently generate singlet oxygen (1O2) in anhydrous organic solvents.


Seasonality, Estrous Cycle Characterization, Estrus Synchronization, Semen Cryopreservation, And Artificial Insemination In The Pacific White-Sided Dolphin (Lagenorhynchus Obliquidens), T. R. Robeck, K. J. Steinman, M. Greenwell, K. Ramirez, W. Van Bonn, M. Toshioka, E. Katsumata, L. Dalton, S. Osborn, J. K. O'Brien Jan 2009

Seasonality, Estrous Cycle Characterization, Estrus Synchronization, Semen Cryopreservation, And Artificial Insemination In The Pacific White-Sided Dolphin (Lagenorhynchus Obliquidens), T. R. Robeck, K. J. Steinman, M. Greenwell, K. Ramirez, W. Van Bonn, M. Toshioka, E. Katsumata, L. Dalton, S. Osborn, J. K. O'Brien

United States Department of Commerce: Staff Publications

The reproductive physiology of the Pacific white-sided dolphin, Lagenorhynchus obliquidens, was characterized to facilitate the development of artificial insemination (AI) using cryopreserved spermatozoa. Specific objectives were to: 1) describe reproductive seasonality of the Pacific white sided dolphins; 2) describe urinary LH and ovarian steroid metabolites during the estrous cycle; 3) correlate LH and ovarian steroidal metabolite patterns to ultrasound-monitored follicular growth and ovulation; and 4) assess the efficacy of synchronizing estrus, sperm collection/cryopreservation, and intrauterine insemination. Ovulations (64%, n=37) and conceptions (83%, n=18) occurred from August to October. Peak mean serum testosterone (24 ng/ml), cross-sectional testicular area (41.6 cm …


N-[4-(Morpholinodiazen­Yl)Phen­Yl]Acetamide, Ralph Isovitsch, Taylor Chin, Frank R. Fronczek Jan 2009

N-[4-(Morpholinodiazen­Yl)Phen­Yl]Acetamide, Ralph Isovitsch, Taylor Chin, Frank R. Fronczek

Chemistry

No abstract provided.


A Robust, Multisite Holocene History Of Drift Ice Off Northern Iceland: Implications For North Atlantic Climate, John T. Andrews, Dennis Darby, Dennis Eberle, Anne E. Jennings, Matthias Moros, Astrid Ogilvie Jan 2009

A Robust, Multisite Holocene History Of Drift Ice Off Northern Iceland: Implications For North Atlantic Climate, John T. Andrews, Dennis Darby, Dennis Eberle, Anne E. Jennings, Matthias Moros, Astrid Ogilvie

United States Geological Survey: Staff Publications

An important indicator of Holocene climate change is provided by evidence for variations in the extent of drift ice. A proxy for drift ice in Iceland waters is provided by the presence of quartz. Quantitative xray diffraction analysis of the < 2 mm sediment fraction was undertaken on 16 cores from around Iceland. The quartz weight (wt.)% estimates from each core were integrated into 250-yr intervals between −0.05 and 11.7 cal. ka BP. Median quartz wt.% varied between 0.2 and 3.4 and maximum values ranged between 2.8 and 11.8 wt.%. High values were attained in the early Holocene and minimum values were reached 6–7 cal. ka BP. Quartz wt.% then rose steadily during the late Holocene. Our data exhibit no correlation with counts on haematite-stained quartz (HSQ) grains from VM129-191 west of Ireland casting doubt on the ice-transport origin. A pilot study on the provenance of Fe oxide grains in two cores that cover the last 1.3 and 6.1 cal. ka BP indicated a large fraction of the grains between 1 and 6 cal. ka BP were from either Icelandic or presently unsampled sources. However, there was a dramatic increase in Canadian and Russian sources from the Arctic Ocean ~1 cal. ka BP. These data may indicate the beginning of an Arctic Oscillation-like climate mode.


Toxicity Of Polybrominated Diphenyl Ethers (De-71) In Chicken (Gallus Gallus), Mallard (Anas Platyrhynchos), And American Kestrel (Falco Sparverius) Embryos And Hatchlings, Moira A. Mckernan, Barnett A. Rattner, Robert C. Hales, Mary Ann Ottinger Jan 2009

Toxicity Of Polybrominated Diphenyl Ethers (De-71) In Chicken (Gallus Gallus), Mallard (Anas Platyrhynchos), And American Kestrel (Falco Sparverius) Embryos And Hatchlings, Moira A. Mckernan, Barnett A. Rattner, Robert C. Hales, Mary Ann Ottinger

United States Geological Survey: Staff Publications

Embryonic survival, pipping and hatching success, and sublethal biochemical, endocrine, and histological endpoints were examined in hatchling chickens (Gallus gallus), mallards (Anas platyrhynchos), and American kestrels (Falco sparverius) following air cell administration of a pentabrominated diphenyl ether (penta-BDE; DE-71) mixture (0.01–20 µg/g egg) or polychlorinated biphenyl (PCB) congener 126 (3,3’,4,4’,5-pentachlorobiphenyl; 0.002 µg/g egg). The penta-BDE decreased pipping and hatching success at concentrations of 10 and 20 µg/g egg in kestrels but had no effect on survival endpoints in chickens or mallards. Sublethal effects in hatchling chickens included ethoxyresorufin-O-dealkylase (EROD) induction and histological …


Geochemical Evidence For African Dust And Volcanic Ash Inputs To Terra Rossa Soils On Carbonate Reef Terraces, Northern Jamaica, West Indies, Daniel R. Muhs, James R. Budahn Jan 2009

Geochemical Evidence For African Dust And Volcanic Ash Inputs To Terra Rossa Soils On Carbonate Reef Terraces, Northern Jamaica, West Indies, Daniel R. Muhs, James R. Budahn

United States Geological Survey: Staff Publications

The origin of red or reddish-brown, clay-rich, ‘‘terra rossa’’ soils on limestone has been debated for decades. A traditional qualitative explanation for their formation has been the accumulation of insoluble residues as the limestone is progressively dissolved over time. However, this mode of formation often requires unrealistic or impossible amounts of carbonated is solution. Therefore, where this mechanism is not viable and where local fluvial or colluvial inputs can be ruled out, an external source or sources must be involved in soil formation.


Taxonomy Of Quaternary Deep-Sea Ostracods From The Western North Atlantic Ocean, Moriaki Yasuhara, Hisayo Okahashi, Thomas M. Cronin Jan 2009

Taxonomy Of Quaternary Deep-Sea Ostracods From The Western North Atlantic Ocean, Moriaki Yasuhara, Hisayo Okahashi, Thomas M. Cronin

United States Geological Survey: Staff Publications

Late Quaternary sediments from Ocean Drilling Program (ODP) Hole 1055B, Carolina Slope, western North Atlantic (32°47.041’ N, 76°17.179’ W; 1798 m water depth) were examined for deep-sea ostracod taxonomy. A total of 13 933 specimens were picked from 207 samples and c. 120 species were identified. Among them, 87 species were included and illustrated in this paper. Twenty-eight new species are described. The new species are: Ambocythere sturgio, Argilloecia abba, Argilloecia caju, Argilloecia keigwini, Argilloecia robinwhatleyi, Aversovalva carolinensis, Bythoceratina willemvandenboldi, Bythocythere eugeneschornikovi, Chejudocythere tenuis, Cytheropteron aielloi, Cytheropteron demenocali, Cytheropteron didieae, Cytheropteron richarddinglei, Cytheropteron fugu, Cytheropteron guerneti, Cytheropteron richardbensoni, Eucytherura hazeli, …


Mineralogy Of Mine Waste At The Vermont Asbestos Group Mine, Belvidere Mountain, Vermont, Denise M. Levitan, Jane M. Hammarstrom, Mickey E. Gunter, Robert R. Seal Ii, I-Ming Chou, Nadine M. Piatak Jan 2009

Mineralogy Of Mine Waste At The Vermont Asbestos Group Mine, Belvidere Mountain, Vermont, Denise M. Levitan, Jane M. Hammarstrom, Mickey E. Gunter, Robert R. Seal Ii, I-Ming Chou, Nadine M. Piatak

United States Geological Survey: Staff Publications

Samples from the surfaces of waste piles at the Vermont Asbestos Group mine in northern Vermont were studied to determine their mineralogy, particularly the presence and morphology of amphiboles. Analyses included powder X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and Raman spectroscopy. Minerals identified by XRD were serpentine-group minerals, magnetite, chlorite, quartz, olivine, pyroxene, and brucite; locally, mica and carbonates were also present. Raman spectroscopy distinguished antigorite and chrysotile, which could not be differentiated using XRD. Long-count, short-range XRD scans of the (110) amphibole peak showed trace amounts of amphibole in most samples. Examination …


Microseismicity At The North Anatolian Fault In The Sea Of Marmara Offshore Istanbul, Nw Turkey, Fatih Bulut, Marco Bohnhoff, William L. Ellsworth, Mustafa Aktar, Georg Dresen Jan 2009

Microseismicity At The North Anatolian Fault In The Sea Of Marmara Offshore Istanbul, Nw Turkey, Fatih Bulut, Marco Bohnhoff, William L. Ellsworth, Mustafa Aktar, Georg Dresen

United States Geological Survey: Staff Publications

The North Anatolian Fault Zone (NAFZ) below the Sea of Marmara forms a ‘‘seismic gap’’ where a major earthquake is expected to occur in the near future. This segment of the fault lies between the 1912 Ganos and 1999 İzmit ruptures and is the only NAFZ segment that has not ruptured since 1766. To monitor the microseismic activity at the main fault branch offshore of Istanbul below the Çınarcık Basin, a permanent seismic array (PIRES) was installed on the two outermost Prince Islands, Yassiada and Sivriada, at a few kilometers distance to the fault. In addition, a temporary network of …


Salt Separation Processes In Salt Cedar, Rudy Sookbirsingh Jan 2009

Salt Separation Processes In Salt Cedar, Rudy Sookbirsingh

Open Access Theses & Dissertations

Salt cedar (genus Tamarix, Family Tamaricaceae) is an exotic, invasive plant in southwestern North America; it has a poor reputation as a heavy-consumer of water and a threat to the landscape and ecology of the region. This study focuses upon saltseparation mechanisms in the salt cedar species Tamarix ramossissima (Ledeb.) which were investigated with a variety of microscopic techniques. The results indicate that this species can produce different salt crystal aggregates morphologies from its vesiculated trichomes, and may use variable mechanisms for separating anions and cations of various salts. It was additionally found that salt crystals aggregates in this species …


Runtime Assertion Checking For Jml On The Eclipse Platform Using Ast Merging, Amritam Sarcar Jan 2009

Runtime Assertion Checking For Jml On The Eclipse Platform Using Ast Merging, Amritam Sarcar

Open Access Theses & Dissertations

The Java Modeling Language (JML) is a formal behavioral interface specification language for Java. It is used for detailed design documentation of Java program modules such as classes and interfaces. JML has been used extensively by many researchers across various projects and has a large and varied spectrum of tool support. It extends from runtime assertion checking (RAC) to theorem proving.

Amongst these tools, RAC and ESC/Java has been used as a common tool for many research projects. RAC for JML is a tool that checks at runtime for possible violations of any specifications. However, lately there has been a …


Nutrient Dynamics In A Created Desert Wetland: Implications For The Rio Bosque Wetlands Park, Ruth Rodriguez Jan 2009

Nutrient Dynamics In A Created Desert Wetland: Implications For The Rio Bosque Wetlands Park, Ruth Rodriguez

Open Access Theses & Dissertations

Rio Bosque Wetland Park is an arid wetland currently under restoration, which primarily receives water inputs from the Bustamante Waste Water Treatment Plant (WWTP) during the non-irrigation season. Understanding the ability of a desert wetland to remove nutrients from the water column through uptake by primary producers or sediment transformations is key to justifying the protection and creation of other similar wetland sites. Nitrate concentrations tended to be reduced, relative to the inflow, near the outflow of the wetland.To further understand these trends, sediment nutrient release experiments and algal nutrient limitation experiments were completed. Sediment phosphorus release experiments indicated that …


A Characterization Of Pseudo-Orders In The Ring Zn, Jorge Ivan Vargas Jan 2009

A Characterization Of Pseudo-Orders In The Ring Zn, Jorge Ivan Vargas

Open Access Theses & Dissertations

Partially ordered sets are widely studied in algebra. The theory of lattice-ordered and partially-ordered rings is an important case. In this paper, we consider a more general relation: pseudo orders, which are relations that are reflexive and antisymmetric, but are not necessarily transitive. Analogously to partially-ordered rings, we study pseudo-ordered rings. We present a general characterization for pseudo-ordered rings, and then we focus on a specific structure: the ring Zn. Having the constraints of this ring, we are able to give the conditions under which Zn can be pseudo-ordered.


Fate Of Sulfamethoxazole, 4-Nonylphenol, And 17Β-Estradiol In Groundwater Contaminated By Wastewater Treatment Plant Effluent, Larry Barber, Steffanie Keefe, Dennis Leblanc, Paul Bradley, Francis Chapelle, Michael Meyer, Keith Lofton, Dana Kolpin, Fernando Rubio Jan 2009

Fate Of Sulfamethoxazole, 4-Nonylphenol, And 17Β-Estradiol In Groundwater Contaminated By Wastewater Treatment Plant Effluent, Larry Barber, Steffanie Keefe, Dennis Leblanc, Paul Bradley, Francis Chapelle, Michael Meyer, Keith Lofton, Dana Kolpin, Fernando Rubio

United States Geological Survey: Staff Publications

Organic wastewater contaminants (OWCs) were measured in samples collected from monitoring wells located along a 4.5- km transect of a plume of groundwater contaminated by 60 years of continuous rapid infiltration disposal of wastewater treatment plant effluent. Fifteen percent of the 212OWCs analyzed were detected, including the antibiotic sulfamethoxazole (SX), the nonionic surfactant degradation product 4-nonylphenol (NP), the solvent tetrachloroethene (PCE), and the disinfectant 1,4-dichlorobenzene (DCB). Comparison of the 2005 sampling results to data collected from the same wells in 1985 indicates that PCE and DCB are transported more rapidly in the aquifer than NP, consistent with predictions based on …


Response Of Sandhill Crane (Grus Canadensis Riverine Roosting Habitat To Changes In Stage And Sandbar Morphology, Paul Kinzel, Jonathan Nelson, Ashley Heckman Jan 2009

Response Of Sandhill Crane (Grus Canadensis Riverine Roosting Habitat To Changes In Stage And Sandbar Morphology, Paul Kinzel, Jonathan Nelson, Ashley Heckman

United States Geological Survey: Staff Publications

Over the past century, flow regulation and vegetation encroachment have reduced active channel widths along the central Platte River, Nebraska. During the last two decades, an annual program of in-channel vegetation management has been implemented to stabilize or expand active channel widths. Vegetation management practices are intended to enhance riverine habitats which include nocturnal roosting habitat for sandhill cranes. Evaluating the success of other management treatments such as streamflow modification requires an understanding of how flow shapes the sandbars in the river and how sandbar morphology interacts with flow to create crane habitat. These linkages were investigated along a 1-km …


Implications For The Dynamic Health Of A Glacier From Comparison Of Conventional And Reference-Surface Balances, W. D. Harrison, L. H. Cox, R. Hock, R. S. March, E. C. Pettit Jan 2009

Implications For The Dynamic Health Of A Glacier From Comparison Of Conventional And Reference-Surface Balances, W. D. Harrison, L. H. Cox, R. Hock, R. S. March, E. C. Pettit

United States Geological Survey: Staff Publications

Conventional and reference-surface mass-balance data from Gulkana and Wolverine Glaciers, Alaska, USA, are used to address the questions of how rapidly these glaciers are adjusting (or ‘responding’) to climate, whether their responses are stable, and whether the glaciers are likely to survive in today’s climate. Instability means that a glacier will eventually vanish, or at least become greatly reduced in volume, if the climate stabilizes at its present state. A simple non-linear theory of response is presented for the analysis. The response of Gulkana Glacier is characterized by a timescale of several decades, but its stability and therefore its survival …


Treatment Of Ro Concentrate Using Vsep Technology, Guillermo Guadalupe Delgado Jan 2009

Treatment Of Ro Concentrate Using Vsep Technology, Guillermo Guadalupe Delgado

Open Access Theses & Dissertations

The city of El Paso has the largest inland brackish desalination plant in the world. The Kay Bailey Hutchison (KBH) Desalting plant produces 15 million of permeate water every day. Due to the excellent quality of the water, the permeate water is blended with brackish water producing a final volume of 27.5 million gallons of water every day. With an average recovery rate of 80%, the KBH plant produces an average of 3 million gallons of concentrated brackish water that is disposed of via injection wells 23 miles from the plant.

Conventional reverse osmosis (RO) systems are not capable of …


Salsola Kali (Tumbleweed): A Possible Biomonitoring Device For The Detection Of Airborne Heavy Metals, Tenoch Benitez Jan 2009

Salsola Kali (Tumbleweed): A Possible Biomonitoring Device For The Detection Of Airborne Heavy Metals, Tenoch Benitez

Open Access Theses & Dissertations

Vehicular congestion generates particulate matter and contaminants such as lead, cadmium, copper, chromium, nickel, and zinc which have been detected in the U.S.-Mexico border region. To overcome the inconvenience of expensive sampling techniques, scientists started to assess air quality by using bioindicator plants, a technique called biomonitoring. Biomonitoring is an inexpensive and environmentally friendly approach to determine inorganic contaminants at trace levels. The purpose of this project was to determine the effectiveness of tumbleweed (Salsola kali) plants, sprayed with chelating agents, as a passive monitoring device to determine the possible presence of heavy metals in the ambient air around international …


Uptake Of Pahs And Metals By Plants In Arid Environment, Zarhelia Carlo Jan 2009

Uptake Of Pahs And Metals By Plants In Arid Environment, Zarhelia Carlo

Open Access Theses & Dissertations

Study of plant uptake of PAHs with the concurrent presence of metals in laboratory conditions was done with the aim to resemble specific combinations of natural environment. Toxicological response of seedlings was tested to define treatment conditions or possible interferences. The levels of PAHs and metals in the treatments were set up to have no toxic effect on plant growth. The complexity of concurrent contamination was demonstrated in a laboratory with soil. No visual differences were observed among various dose treatments of Cu and Zn with organics three PAHs, Phenanthrene (Phen), Acetoanthrancene, and Benzo(a)pyrene (BaP). The metal analysis by ICP/OES …