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2015

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Articles 391 - 420 of 1152

Full-Text Articles in Earth Sciences

Modification Of Traffic-Related Respiratory Response By Asthma Control In A Population Of Car Commuters, Maria C. Mirabelli, Rachel Golan, Roby Greenwald, Amit U. Raysoni, Fernando Holguin, Priya Kewada, Andrea Winquist, W Dana Flanders, Jeremy A. Sarnat Jul 2015

Modification Of Traffic-Related Respiratory Response By Asthma Control In A Population Of Car Commuters, Maria C. Mirabelli, Rachel Golan, Roby Greenwald, Amit U. Raysoni, Fernando Holguin, Priya Kewada, Andrea Winquist, W Dana Flanders, Jeremy A. Sarnat

School of Earth, Environmental, & Marine Sciences Faculty Publications

Background: Effects of traffic-related exposures on respiratory health are well documented, but little information is available about whether asthma control influences individual susceptibility. We analyzed data from the Atlanta Commuter Exposure study to evaluate modification of associations between rush-hour commuting, in- vehicle air pollution, and selected respiratory health outcomes by asthma control status.

Methods: Between 2009 and 2011, 39 adults participated in Atlanta Commuter Exposure, and each conducted two scripted rush-hour highway commutes. In-vehicle particulate components were measured during all commutes. Among adults with asthma, we evaluated asthma control by questionnaire and spirometry. Exhaled nitric oxide, forced expiratory volume in …


Preliminary Isotope Assessment, La Grange Groundwater Area, Glenn A. Harrington Jul 2015

Preliminary Isotope Assessment, La Grange Groundwater Area, Glenn A. Harrington

Natural resources commissioned reports

The Department of Agriculture and Food, Western Australia (DAFWA) is currently undertaking a Royalties for Regions funded project in the La Grange Groundwater Area south of Broome. The focus is on providing improved confidence about soil suitability and water availability for potential expansion of irrigated agriculture in the region. Groundwater in the Broome Sandstone Aquifer (BSA) is the target water resource, however before the La Grange project commenced little was known about the physical and chemical attributes of the aquifer. This report provides the results of estimated groundwater recharge and residence times using environmental tracer techniques.

Sampling of 12 existing …


Short-Term Response Of Holcus Lanatus L. (Common Velvetgrass) To Chemical And Manual Control At Yosemite National Park, Usa, Laura J. Jones, Steven M. Ostoja, Matthew L. Brooks, Martin Hutten Jul 2015

Short-Term Response Of Holcus Lanatus L. (Common Velvetgrass) To Chemical And Manual Control At Yosemite National Park, Usa, Laura J. Jones, Steven M. Ostoja, Matthew L. Brooks, Martin Hutten

United States Geological Survey: Staff Publications

One of the highest priority invasive species at both Yosemite and Sequoia and Kings Canyon national parks is Holcus lanatus L. (common velvetgrass), a perennial bunchgrass that invades mid-elevation montane meadows. Despite velvetgrass being a high priority species, there is little information available on control techniques. The goal of this project was to evaluate the short-term response of a single application of common chemical and manual velvetgrass control techniques. The study was conducted at three montane sites in Yosemite National Park. Glyphosate spotspray treatments were applied at 0.5, 1.0, 1.5, and 2.0% concentrations, and compared with hand pulling to evaluate …


Long-Term Effects Of Alternative Residue Management Practices On Near-Surface Soil Properties And Soybean Production In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Christopher Ryan Norman Jul 2015

Long-Term Effects Of Alternative Residue Management Practices On Near-Surface Soil Properties And Soybean Production In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Christopher Ryan Norman

Graduate Theses and Dissertations

Adoption of management practices that maintain or increase soil organic matter (SOM), which contains 58% carbon (C) on average, may help to mitigate climate change by sequestering atmospheric C. Therefore, the main objective of this study was to determine the long-term trends in SOM, soil C and nitrogen (N), bulk density, various soil chemical properties (i.e., pH, electrical conductivity [EC], and Mehlich-3-extractable nutrients) in the top 10 cm, and soybean yield as affected by residue burning (burning and non-burning), tillage (conventional and no-tillage), irrigation (irrigated and non-irrigated), and N-fertilization/residue level (high and low) in a wheat (Triticum aestivum L.)-soybean [Glycine …


Lithologic Controls On Bedrock Channel Morphology In The Buffalo River Basin, Evan A. Thaler Jul 2015

Lithologic Controls On Bedrock Channel Morphology In The Buffalo River Basin, Evan A. Thaler

Graduate Theses and Dissertations

The longevity of high relief terrains in passive margin systems remains an explained phenomenon in geomorphology. Current landscape evolution models assume an equilibrium state between rock uplift rates and erosion rates. However, analysis of chi gradients of bedrock channels across several lithologies in the Buffalo River Basin reveals disequilibrium in the basin controlled by the presence of a thick interval of Pennsylvanian sandstone that caps many of the plateaus in the basin. Headwater channels beneath the caprock tend to have higher chi gradient values in all lithologies than headwater channels in basins where the sandstone caprock is absent. High chi …


Metal Mobilization In Groundwater, Bauxite, Ar, Steven Alexander Hamlin Jul 2015

Metal Mobilization In Groundwater, Bauxite, Ar, Steven Alexander Hamlin

Graduate Theses and Dissertations

The Wilcox Aquifer of Bauxite, AR contains bauxite ore deposits that may contribute heavy metals to groundwater. Twenty-four wells were sampled for aluminum, iron, manganese, zinc, lead, barium, nitrate, sulfate, sodium, alkalinity, calcium, magnesium, chloride, pH, total organic carbon, and total dissolved solids. A Wilcoxon Rank-Sum compared the similarity of the three geographic areas covered in the study. All parameters for wells in Bauxite and Sardis failed to reject the null hypothesis, signifying that wells all occupy the Saline Formation. 2/3rds of the parameters from BFI261 and the Bauxite region did not agree, suggesting the two areas do not occupy …


Paleoclimate Implications From Stable Isotope Analysis Of Sedimentary Organic Carbon And Vertebrate Fossils From The Cedar Mountain Formation, Ut, U.S.A., Garrett Andrew Hatzell Jul 2015

Paleoclimate Implications From Stable Isotope Analysis Of Sedimentary Organic Carbon And Vertebrate Fossils From The Cedar Mountain Formation, Ut, U.S.A., Garrett Andrew Hatzell

Graduate Theses and Dissertations

Oxygen and carbon isotopic compositions of fossilized vertebrate teeth and bone were analyzed to determine isotopic values of vertebrate faunal diet from the early Cretaceous Cedar Mountain Formation of Utah. Results for δ18O of PO4 (δ18Op) (Suarez et al., 2014) from the same data set have been compared to the δ18O of CO3 (δ18Oc) portion of teeth and turtle shell to determine if diagenetic alteration of the isotopes has occurred by plotting the line of best fit equation that models the relationship between unaltered δ18OP and δ18OC of modern mammals from Iacumin et al., 1996. Results indicate slight diagenesis of …


The Functional And Distributional Ecology Of Mycetozoans Under Changing Edaphic And Climatic Dynamics, Geoffrey Lloyd Zahn Jul 2015

The Functional And Distributional Ecology Of Mycetozoans Under Changing Edaphic And Climatic Dynamics, Geoffrey Lloyd Zahn

Graduate Theses and Dissertations

Investigations into the distribution and ecosystem functions of fruiting amoebae revealed that local-scale environmental conditions can largely explain broad biogeographical patterns in species assemblage, the way in which amoeboid predators shape bacterial communities and how this top-down influence may affect global biogeochemical processes in a changing climate. The distribution and assemblage of protosteloid amoebae on the islands of New Zealand and Hawaii did not yield any expected patterns of island biogeography, and conformed to other global regions studied. The strongest predictor of species richness in a given region was sampling effort and these species do not appear to have any …


Solubility And Detectability Of Hydrocarbons On The Surface Of Titan, Sandeep Singh Jul 2015

Solubility And Detectability Of Hydrocarbons On The Surface Of Titan, Sandeep Singh

Graduate Theses and Dissertations

Titan’s thick atmosphere is enriched with organic compounds and its surface holds reservoirs of hydrocarbons. This makes Titan the only other candidate in our solar system (apart from Earth) to have stable liquid at the surface. The stability and characteristics of liquid and ices on the surface of Titan are of high importance in understanding its surface-atmosphere interactions. Titan’s hydrological cycle is similar to what we see on Earth, with the exception of methane (CH4) and ethane (C2H6) taking the place of water. The smoggy atmosphere veils the surface of Titan from the view of Cassini spacecraft, except at seven …


U.S. Drought Monitor, June 30, 2015, Brian Fuchs Jun 2015

U.S. Drought Monitor, June 30, 2015, Brian Fuchs

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for June 30, 2015 (6/30/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


Defining The Terroir Of The Columbia Gorge Wine Region, Oregon And Washington, Usa Using Geographic Information Systems (Gis), Hilary Whitney Jun 2015

Defining The Terroir Of The Columbia Gorge Wine Region, Oregon And Washington, Usa Using Geographic Information Systems (Gis), Hilary Whitney

Dissertations and Theses

The Columbia Gorge Wine Region (CGWR) is an emerging wine producing area that extends for about 100km along the Columbia River in Oregon and Washington State in which the number of vineyards, wineries and physical terroir conditions have yet to be defined. To better understand the physical factors affecting Oregon and Washington wine, this project analyzes climate, topography, geology and soil at vineyards in the CGWR. This was accomplished using Geographic Information Systems, existing earth science databases and field work. The region, which includes the Columbia Gorge American Viticulture Area (AVA) and the southwest portion of the Columbia Valley AVA, …


Nutrient Addition Effects On Tropical Dry Forests: A Mini-Review From Microbial To Ecosystem Scales, Jennifer S. Powers, Kristen K. Becklund, Maria G. Gei, Siddharth B. Iyengar, Rebecca Meyer, Christine S. O'Connell, Erik M. Schilling, Christina M. Smith, Bonnie G. Waring, Leland K. Werden Jun 2015

Nutrient Addition Effects On Tropical Dry Forests: A Mini-Review From Microbial To Ecosystem Scales, Jennifer S. Powers, Kristen K. Becklund, Maria G. Gei, Siddharth B. Iyengar, Rebecca Meyer, Christine S. O'Connell, Erik M. Schilling, Christina M. Smith, Bonnie G. Waring, Leland K. Werden

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Humans have more than doubled inputs of reactive nitrogen globally and greatly accelerated the biogeochemical cycles of phosphorus and metals. However, the impacts of increased element mobility on tropical ecosystems remain poorly quantified, particularly for the vast tropical dry forest biome. Tropical dry forests are characterized by marked seasonality, relatively little precipitation, and high heterogeneity in plant functional diversity and soil chemistry. For these reasons, increased nutrient deposition may affect tropical dry forests differently than wet tropical or temperate forests. Here, we review studies that investigated how nutrient availability affects ecosystem and community processes from the microsite to ecosystem scales …


U.S. Drought Monitor, June 23, 2015, Richard Tinker Jun 2015

U.S. Drought Monitor, June 23, 2015, Richard Tinker

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for June 23, 2015 (6/23/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


Resonance Of Relativistic Electrons With Electromagnetic Ion Cyclotron Waves, Richard Denton, K. Jordanova, J. Bortnik Jun 2015

Resonance Of Relativistic Electrons With Electromagnetic Ion Cyclotron Waves, Richard Denton, K. Jordanova, J. Bortnik

Dartmouth Scholarship

Relativistic electrons have been thought to more easily resonate with electromagnetic ion cyclotron (EMIC) waves if the total density is large. We show that, for a particular EMIC mode, this dependence is weak due to the dependence of the wave frequency and wave vector on the density. A significant increase in relativistic electron minimum resonant energy might occur for the H band EMIC mode only for small density, but no changes in parameters significantly decrease the minimum resonant energy from a nominal value. The minimum resonant energy depends most strongly on the thermal velocity associated with the field line motion …


Laser Vision: Lidar As A Transformative Tool To Advance Critical Zone Science, N. F. Glenn Jun 2015

Laser Vision: Lidar As A Transformative Tool To Advance Critical Zone Science, N. F. Glenn

Geosciences Faculty Publications and Presentations

Observation and quantification of the Earth’s surface is undergoing a revolutionary change due to the increased spatial resolution and extent afforded by light detection and ranging (lidar) technology. As a consequence, lidar-derived information has led to fundamental discoveries within the individual disciplines of geomorphology, hydrology, and ecology. These disciplines form the cornerstones of critical zone (CZ) science, where researchers study how interactions among the geosphere, hydrosphere, and biosphere shape and maintain the “zone of life”, which extends from the top of unweathered bedrock to the top of the vegetation canopy. Fundamental to CZ science is the development of transdisciplinary theories …


Using A High Altitude Balloon Platform To Observe And Measure Seasonal Ozone Flux Over Agricultural Landscapes, Cody Sabo Jun 2015

Using A High Altitude Balloon Platform To Observe And Measure Seasonal Ozone Flux Over Agricultural Landscapes, Cody Sabo

2017 Academic High Altitude Conference

The concentration of greenhouse gasses (GHGs) in the atmosphere has continued to rise since the industrial era. This issue has had a multitude of negative impacts on all living things. Among the major GHGs are carbon dioxide, methane, nitrous oxide, and ozone. Ozone is of particular importance because it not only has the ability to trap heat in the atmosphere, but it also directly impacts organisms by causing harm to both plants and humans. The damage that ozone causes to plants is most closely linked to ozone uptake rather than ozone concentration. So, measuring ozone uptake is becoming critical for …


Detection Of Small-Scale Rockfall Incidents Using Their Seismic Signature, Achilleas Tripolitsiotis, Antonis Daskalakis, Stelios Mertikas, Dionysios Hristopulos, Zacharias Agioutantis, Panagiotis Partsinevelos Jun 2015

Detection Of Small-Scale Rockfall Incidents Using Their Seismic Signature, Achilleas Tripolitsiotis, Antonis Daskalakis, Stelios Mertikas, Dionysios Hristopulos, Zacharias Agioutantis, Panagiotis Partsinevelos

Mining Engineering Faculty Publications

Several algorithms have been effectively used to identify the seismic signature of rockfall incidents, which constitute a significant threat for human lives and infrastructure especially when occurring along transportation networks. These algorithms have been mostly evaluated using data from large scale rockfall events that release a large amount of energy. However, low-energy rockfall events (< 100 Joules) triggered by small-sized individual rocks falling from small heights can be severely destructive. In this study, a three-parameter algorithm has been developed to identify low-energy rockfall events. An experimental setup was implemented to 1) validate the results obtained by this algorithm against visual inspection of seismic signals records, 2) define the optimal algorithm parameterization to minimize false alarms, and 3) investigate whether tri-axial vibration monitoring can be replaced by a uniaxial device in order to reduce the installation cost of a real-time rockfall monitoring system. It was found that the success rate of the proposed algorithm exceeds 80% independently of the parameters used, while event identification at a maximum distance with minimal false alarms was achieved when using mean ± 3σ as the threshold criterion and 6 ms and 4 ms as the trigger and event window parameters respectively. Finally, it was found that for the specific experimental setup, a uniaxial device could be used for rockfall event identification.


Quantitative Hermeneutics: Counting Forestructures On A Path From W.M. Davis To The Concept Of Multiple-Permeability Karst Aquifers, H. L. Vacher, Lee J. Florea Jun 2015

Quantitative Hermeneutics: Counting Forestructures On A Path From W.M. Davis To The Concept Of Multiple-Permeability Karst Aquifers, H. L. Vacher, Lee J. Florea

International Journal of Speleology

Hermeneutics is the theory of interpretation. One of its major components is recognizing prejudgments, or forestructures, that we bring to our objects of study. In this paper, we construct a historical narrative of the evolution of thinking about the role of caves in relation to groundwater flow in limestone, and we tabulate forestructures as they appear in the story. This account consists of three overlapping time periods: the before and after of an incident that repelled hydrogeologists and students of karst from each other in the middle of the 20th century; a period, up to around the turn of …


Representing Life In The Earth System With Soil Microbial Functional Traits In The Mimics Model, William R. Wieder, A. Stuart Grandy, Cynthia M. Kallenbach, P. G. Taylor, G. B. Bonan Jun 2015

Representing Life In The Earth System With Soil Microbial Functional Traits In The Mimics Model, William R. Wieder, A. Stuart Grandy, Cynthia M. Kallenbach, P. G. Taylor, G. B. Bonan

Faculty Publications

Projecting biogeochemical responses to global environmental change requires multi-scaled perspectives that consider organismal diversity, ecosystem processes, and global fluxes. However, microbes, the drivers of soil organic matter decomposition and stabilization, remain notably absent from models used to project carbon (C) cycle–climate feedbacks. We used a microbial trait-based soil C model with two physiologically distinct microbial communities, and evaluate how this model represents soil C storage and response to perturbations. Drawing from the application of functional traits used to model other ecosystems, we incorporate copiotrophic and oligotrophic microbial functional groups in the MIcrobial-MIneral Carbon Stabilization (MIMICS) model; these functional groups are …


U.S. Drought Monitor, June 16, 2015, Richard Tinker Jun 2015

U.S. Drought Monitor, June 16, 2015, Richard Tinker

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for June 16, 2015 (6/16/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


Lateral Dispersal And Foraging Behavior Of Entomopathogenic Nematodes In The Absence And Presence Of Mobile And Non-Mobile Hosts, Harit K. Bal, Parwinder Grewal Jun 2015

Lateral Dispersal And Foraging Behavior Of Entomopathogenic Nematodes In The Absence And Presence Of Mobile And Non-Mobile Hosts, Harit K. Bal, Parwinder Grewal

School of Earth, Environmental, & Marine Sciences Faculty Publications

Entomopathogenic nematodes have been classified into cruisers (active searchers) and ambushers (sit and wait foragers). However, little is known about their dispersal and foraging behavior at population level in soil. We studied lateral dispersal of the ambush foraging Steinernema carpocapsae (ALL strain) and cruise foraging Heterorhabditis bacteriophora (GPS11 strain) from infected host cadavers in microcosms (0.05 m2) containing Wooster silt-loam soil (Oxyaquic fragiudalf) and vegetation in the presence or absence of non-mobile and mobile hosts. Results showed that the presence of a non-mobile host (Galleria mellonella larva in a wire mesh cage) enhanced H. bacteriophora dispersal for up …


Dye Tracing To Determine Flow Properties Of Hydrocarbon-Polluted Rabots Glaciär, Kebnekaise, Sweden, Caroline C. Clason, C. Coch, J. Jarsjö, Keith A. Brugger, P. Jansson, G. Rosqvist Jun 2015

Dye Tracing To Determine Flow Properties Of Hydrocarbon-Polluted Rabots Glaciär, Kebnekaise, Sweden, Caroline C. Clason, C. Coch, J. Jarsjö, Keith A. Brugger, P. Jansson, G. Rosqvist

Geology Publications

Over 11 000 L of kerosene was deposited on the surface of Rabots glaciär on the Kebnekaise Massif, northern Sweden, following the crash of a Royal Norwegian Air Force aircraft in March 2012. An environmental monitoring programme was subsequently commissioned, including a series of dye tracing experiments during the 2013 melt season, conducted to investigate the transport of pollutants through the glacier hydrological system. This experimental set-up provided a basis from which we could gain new insight into the internal hydrological system of Rabots glaciär. Results of dye tracing experiments reveal a degree of homogeneity in the topology of the …


Dramatic Loss Of Glacier Accumulation Area On The Tibetan Plateau Revealed By Ice Core Tritium And Mercury Records, S. Kang, F. Wang, U. Morgenstern, Y. Zhang, B. Grigholm, Susan D. Kaspari, M. Schwikowski, J. Ren, T. Yao, D. Qin, P. A. Mayewski Jun 2015

Dramatic Loss Of Glacier Accumulation Area On The Tibetan Plateau Revealed By Ice Core Tritium And Mercury Records, S. Kang, F. Wang, U. Morgenstern, Y. Zhang, B. Grigholm, Susan D. Kaspari, M. Schwikowski, J. Ren, T. Yao, D. Qin, P. A. Mayewski

All Faculty Scholarship for the College of the Sciences

Two ice cores were retrieved from high elevations (~5800 m a.s.l.) at Mt. Nyainqêntanglha and Mt. Geladaindong in the southern and central Tibetan Plateau region. The combined tracer analysis of tritium (3H), 210Pb and mercury, along with other chemical records, provided multiple lines of evidence supporting that the two coring sites had not received net ice accumulation since at least the 1950s and 1980s, respectively. These results implied an annual ice loss rate of more than several hundred millimeter water equivalent over the past 30–60 years. Both mass balance modeling at the sites and in situ data …


Slides: The Colorado River: Innovation In The Face Of Scarcity, Anne J. Castle Jun 2015

Slides: The Colorado River: Innovation In The Face Of Scarcity, Anne J. Castle

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Anne J. Castle, Stanford Woods Institute for the Environment

40 slides


Slides: Klamath Basin Agreements: Largest River Restoration Project In American History, Amy Cordalis Jun 2015

Slides: Klamath Basin Agreements: Largest River Restoration Project In American History, Amy Cordalis

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Amy Cordalis, Staff Attorney, Yurok Tribe

34 slides


Slides: The Blm And Colorado Dnr Mou: A Water-Based Partnership, Roy Smith Jun 2015

Slides: The Blm And Colorado Dnr Mou: A Water-Based Partnership, Roy Smith

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Roy Smith, Bureau of Land Management

19 slides


Slides: Never Let A Crisis Go To Waste, Lester Snow Jun 2015

Slides: Never Let A Crisis Go To Waste, Lester Snow

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Lester Snow, Executive Director, California Water Foundation

39 slides


Slides: Restoring The Acequias: Fixing What Wasn't Broken, Will Davidson Jun 2015

Slides: Restoring The Acequias: Fixing What Wasn't Broken, Will Davidson

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Will Davidson, Acequia Assistance Project

26 slides


Slides: Wrapping Up The Big Horn Adjudication: Lessons After 38 Years And 20,000 Claims, Ramsey L. Kropf Jun 2015

Slides: Wrapping Up The Big Horn Adjudication: Lessons After 38 Years And 20,000 Claims, Ramsey L. Kropf

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Ramsey L. Kropf, Deputy Solicitor for Water Resources, Office of the Solicitor, U.S. Department of the Interior

34 slides


Slides: The Columbia River Treaty, Barbara Cosens Jun 2015

Slides: The Columbia River Treaty, Barbara Cosens

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Barbara Cosens, Professor, University of Idaho College of Law and Waters of the West Graduate Program

22 slides