Efficient implementation of the Metropolis-Hastings algorithm, with application to the Cormack-Jolly-Seber model
W.A. Link, R. J. Barker
2008, Conference Paper, Environmental and Ecological Statistics
Judicious choice of candidate generating distributions improves efficiency of the Metropolis-Hastings algorithm. In Bayesian applications, it is sometimes possible to identify an approximation to the target posterior distribution; this approximate posterior distribution is a good choice for candidate generation. These observations are applied to analysis of the Cormack-Jolly-Seber model and...
Multidecadal climate-induced variability in microseisms
R.C. Aster, D.E. McNamara, P.D. Bromirski
2008, Seismological Research Letters (79) 194-202
Microseisms are the most ubiquitous continuous seismic signals on Earth at periods between approximately 5 and 25 s (Peterson 1993; Kedar and Webb 2005). They arise from atmospheric energy converted to (primarily) Rayleigh waves via the intermediary of wind-driven oceanic swell and occupy a period band that is uninfluenced by...
Investigation of bioaerosols released from swine farms using conventional and alternative waste treatment and management technologies
G. Ko, O. D. Simmons III, C.A. Likirdopulos, L. Worley-Davis, Murray Williams, M.D. Sobsey
2008, Environmental Science & Technology (42) 8849-8857
Microbial air pollution from concentrated animal feeding operations (CAFOs) has raised concerns about potential public health and environmental impacts. We investigated the levels of bioaerosols released from two swine farms using conventional lagoon-sprayfield technology and ten farms using alternative waste treatment and management technologies in the United States. In total,...
Characteristics of mangrove swamps managed for mosquito control in eastern Florida, USA
B. Middleton, D. Devlin, E. Proffitt, Karen McKee, K.F. Cretini
2008, Marine Ecology Progress Series (371) 117-129
Manipulations of the vegetation and hydrology of wetlands for mosquito control are common worldwide, but these modifications may affect vital ecosystem processes. To control mosquitoes in mangrove swamps in eastern Florida, managers have used rotational impoundment management (RIM) as an alternative to the worldwide practice of mosquito ditching. Levees surround...
More than 400 million years of evolution and some plants still can't make it on their own: Plant stress tolerance via fungal symbiosis
R. Rodriguez, R. Redman
2008, Conference Paper, Journal of Experimental Botany
All plants in natural ecosystems are thought to be symbiotic with mycorrhizal and/or endophytic fungi. Collectively, these fungi express different symbiotic lifestyles ranging from parasitism to mutualism. Analysis of Colletotrichum species indicates that individual isolates can express either parasitic or mutualistic lifestyles depending on the host genotype colonized. The endophyte...
Late-stage sulfides and sulfarsenides in Lower Cambrian black shale (stone coal) from the Huangjiawan mine, Guizhou Province, People's Republic of China
H. E. Belkin, K. Luo
2008, Mineralogy and Petrology (92) 321-340
The Ni-Mo Huangjiawan mine, Guizhou Province, People's Republic of China, occurs in Lower Cambrian black shale (stone coal) in an area where other mines have recently extracted ore from the same horizon. Detailed electron microprobe (EMPA) and scanning electron microscope (SEM) analyses of representative thin sections have revealed a complex...
Creation of a continent recorded in zircon zoning
D.E. Moser, J. R. Bowman, J. Wooden, J.W. Valley, F. Mazdab, N. Kita
2008, Geology (36) 239-242
We have discovered a robust microcrystalline record of the early genesis of North American lithosphere preserved in the U-Pb age and oxygen isotope zoning of zircons from a lower crustal paragneiss in the Neoarchean Superior province. Detrital igneous zircon cores with ??18O values of 5.1???-7.1??? record creation of primitive to...
Broadband seismic measurements of degassing activity associated with lava effusion at Popocatépetl Volcano, Mexico
Alejandra Arciniega-Ceballos, Bernard A. Chouet, Phillip Dawson, Guenter Asch
2008, Journal of Volcanology and Geothermal Research (170) 12-23
From November 1999 through July 2000, a broadband seismic experiment was carried out at Popocatépetl Volcano to record seismic activity over a wide period range (0.04–100 s). We present an overview of the seismicity recorded during this experiment and discuss results of analyses of long-period (LP) and very-long-period (VLP) seismic signals...
Eruption dynamics at Mount St. Helens imaged from broadband seismic waveforms: Interaction of the shallow magmatic and hydrothermal systems
G.P. Waite, B. A. Chouet, P.B. Dawson
2008, Journal of Geophysical Research B: Solid Earth (113)
The current eruption at Mount St. Helens is characterized by dome building and shallow, repetitive, long-period (LP) earthquakes. Waveform cross-correlation reveals remarkable similarity for a majority of the earthquakes over periods of several weeks. Stacked spectra of these events display multiple peaks between 0.5 and 2 Hz that are common...
Temporal downscaling of decadal sediment load estimates to a daily interval for use in hindcast simulations
N. K. Ganju, N. Knowles, D. H. Schoellhamer
2008, Journal of Hydrology (349) 512-523
In this study we used hydrologic proxies to develop a daily sediment load time-series, which agrees with decadal sediment load estimates, when integrated. Hindcast simulations of bathymetric change in estuaries require daily sediment loads from major tributary rivers, to capture the episodic delivery of sediment during multi-day freshwater flow pulses....
Contribution of sediment fluxes and transformations to the summer nitrogen budget of an Upper Mississippi River backwater system
W.F. James, W. B. Richardson, D.M. Soballe
2008, Hydrobiologia (598) 95-107
Routing nitrate through backwaters of regulated floodplain rivers to increase retention could decrease loading to nitrogen (N)-sensitive coastal regions. Sediment core determinations of N flux were combined with inflow-outflow fluxes to develop mass balance approximations of N uptake and transformations in a flow-controlled backwater of the Upper Mississippi River (USA)....
Methane hydrate formation in turbidite sediments of northern Cascadia, IODP Expedition 311
M.E. Torres, A.M. Trehu, N. Cespedes, M. Kastner, U.G. Wortmann, J.-H. Kim, P. Long, A. Malinverno, J. W. Pohlman, M. Riedel, T. Collett
2008, Earth and Planetary Science Letters (271) 170-180
Expedition 311 of the Integrated Ocean Drilling Program (IODP) to northern Cascadia recovered gas-hydrate bearing sediments along a SW-NE transect from the first ridge of the accretionary margin to the eastward limit of gas-hydrate stability. In this study we contrast the gas gas-hydrate distribution from two sites drilled ~ 8??km...
Gender identification of Caspian Terns using external morphology and discriminant function analysis
Joshua T. Ackerman, John Y. Takekawa, J.D. Bluso, J.L. Yee, Collin A. Eagles-Smith
2008, Wilson Journal of Ornithology (120) 378-383
Caspian Tern (Sterna caspia) plumage characteristics are sexually monochromatic and gender cannot easily be distinguished in the field without extensive behavioral observations. We assessed sexual size dimorphism and developed a discriminant function to assign gender in Caspian Terns based on external morphology. We collected and measured Caspian Terns in San...
Evidence for fish dispersal from spatial analysis of stream network topology
N.P. Hitt, P. L. Angermeier
2008, Journal of the North American Benthological Society (27) 304-320
Developing spatially explicit conservation strategies for stream fishes requires an understanding of the spatial structure of dispersal within stream networks. We explored spatial patterns of stream fish dispersal by evaluating how the size and proximity of connected streams (i.e., stream network topology) explained variation in fish assemblage structure and how...
Are fractal dimensions of the spatial distribution of mineral deposits meaningful?
G. L. Raines
2008, Natural Resources Research (17) 87-97
It has been proposed that the spatial distribution of mineral deposits is bifractal. An implication of this property is that the number of deposits in a permissive area is a function of the shape of the area. This is because the fractal density functions of deposits are dependent on the...
Representing general theoretical concepts in structural equation models: The role of composite variables
J.B. Grace, K.A. Bollen
2008, Environmental and Ecological Statistics (15) 191-213
Structural equation modeling (SEM) holds the promise of providing natural scientists the capacity to evaluate complex multivariate hypotheses about ecological systems. Building on its predecessors, path analysis and factor analysis, SEM allows for the incorporation of both observed and unobserved (latent) variables into theoretically-based probabilistic models. In this paper we...
Comparative study of transport processes of nitrogen, phosphorus, and herbicides to streams in five agricultural basins, USA
Joseph L. Domagalski, S. Ator, R. Coupe, K. McCarthy, D. Lampe, Mark W. Sandstrom, N. Baker
2008, Journal of Environmental Quality (37) 1158-1169
Agricultural chemical transport to surface water and the linkage to other hydrological compartments, principally ground water, was investigated at five watersheds in semiarid to humid climatic settings. Chemical transport was affected by storm water runoff, soil drainage, irrigation, and how streams were linked to shallow ground water systems. Irrigation practices...
Efficacy of algal metrics for assessing nutrient and organic enrichment in flowing waters
S. D. Porter, D. K. Mueller, N.E. Spahr, M.D. Munn, N. M. Dubrovsky
2008, Freshwater Biology (53) 1036-1054
1. Algal-community metrics were calculated for periphyton samples collected from 976 streams and rivers by the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Programme during 1993–2001 to evaluate national and regional relations with water chemistry and to compare whether algal-metric values differ significantly among undeveloped and developed land-use classifications. 2. Algal...
Density currents in the Chicago River: Characterization, effects on water quality, and potential sources
P.R. Jackson, C.M. Garcia, K. A. Oberg, K. K. Johnson, M.H. Garcia
2008, Science of the Total Environment (401) 130-143
Bidirectional flows in a river system can occur under stratified flow conditions and in addition to creating significant errors in discharge estimates, the upstream propagating currents are capable of transporting contaminants and affecting water quality. Detailed field observations of bidirectional flows were made in the Chicago River in Chicago, Illinois...
Sand composition and transport history on a fringing coral reef, Molokai, Hawaii
R.S. Calhoun, M.E. Field
2008, Conference Paper, Journal of Coastal Research
Composition of sand grains from the beaches, reef flat, and fore reef of south Molokai, Hawaii, provides key information about the origin and transport history of sediment on the reef and adjacent beach. The most common grain types include coralline algae, coral, chemically altered carbonate, and siliciclastic grains. Minor components...
Rainfall effects on rare annual plants
J.M. Levine, A. K. McEachern, C. Cowan
2008, Journal of Ecology (96) 795-806
Variation in climate is predicted to increase over much of the planet this century. Forecasting species persistence with climate change thus requires understanding of how populations respond to climate variability, and the mechanisms underlying this response. Variable rainfall is well known to drive fluctuations in annual plant populations, yet the...
Effects of climate and land management change on streamflow in the driftless area of Wisconsin
P. F. Juckem, R. J. Hunt, Marilyn P. Anderson, Dale M. Robertson
2008, Journal of Hydrology (355) 123-130
Baseflow and precipitation in the Kickapoo River Watershed, located in the Driftless Area of Wisconsin, exhibit a step increase around 1970, similar to minimum and median flows in many other central and eastern USA streams. Potential effects on streamflow due to climatic and land management changes were evaluated by comparing...
Three-dimensional P-wave velocity structure and precise earthquake relocation at Great Sitkin Volcano, Alaska
Jeremy Pesicek, Clifford H. Thurber, Heather R. DeShon, Stephanie G. Prejean, Haijiang Zhang
2008, Bulletin of the Seismological Society of America (98) 2428-2448
Waveform cross-correlation with bispectrum verification is combined with double-difference tomography to increase the precision of earthquake locations and constrain regional 3D P-wave velocity heterogeneity at Great Sitkin volcano, Alaska. From 1999 through 2005, the Alaska Volcano Observatory (AVO) recorded ∼1700 earthquakes in the vicinity of Great Sitkin, including two ML 4.3 earthquakes that...
Assigning king eiders to wintering regions in the Bering Sea using stable isotopes of feathers and claws
S. Oppel, A.N. Powell
2008, Marine Ecology Progress Series (373) 149-156
Identification of wintering regions for birds sampled during the breeding season is crucial to understanding how events outside the breeding season may affect populations. We assigned king eiders captured on breeding grounds in northern Alaska to 3 broad geographic wintering regions in the Bering Sea using stable carbon and nitrogen...
Aquatic macroinvertebrates associated with Schoenoplectus litter in a constructed wetland in California (USA)
S. M. Nelson, J.S. Thullen
2008, Ecological Engineering (33) 91-101
Culm processing characteristics were associated with differences in invertebrate density in a study of invertebrates and senesced culm packs in a constructed treatment wetland. Invertebrate abundance differed by location within the wetland and there were differences between the two study years that appeared to be related to water quality and...
