Effects of marine reserves and urchin disease on southern Californian rocky reef communities
Michael D. Behrens, Kevin D. Lafferty
2004, Marine Ecology Progress Series (279) 129-139
While the species level effects of marine reserves are widely recognized, community level shifts due to marine reserves have only recently been documented. Protection from fishing of top predators may lead to trophic cascades, which have community-wide implications. Disease may act in a similar manner, regulating population levels of dominant...
Pyroclastic flow hazard at Volcán Citlaltépetl
Michael F. Sheridan, Bernard E. Hubbard, Gerardo Carrasco-Nunez, Claus Siebe
2004, Natural Hazards (33) 209-221
Volcán Citlaltépetl (Pico de Orizaba) with an elevation of 5,675 m is the highest volcano in North America. Its most recent catastrophic events involved the production of pyroclastic flows that erupted approximately 4,000, 8,500, and 13,000 years ago. The distribution of mapped deposits from these eruptions gives an approximate guide...
Using macroinvertebrates to identify biota-land cover optima at multiple scales in the Pacific Northwest, USA
R. W. Black, M.D. Munn, R.W. Plotnikoff
2004, Journal of the North American Benthological Society (23) 340-362
Macroinvertebrate assemblages and environmental variables were evaluated at 45 stream sites throughout the Puget Sound Basin, Washington, USA. Environmental variables were measured at 3 spatial scales: reach, local, and whole watershed. Macroinvertebrate distributions were related to environmental variables using canonical correspondence analysis to determine which variables and spatial scales best...
Winter survival of lesser scaup in east-central Florida
G. Herring, J.A. Collazo
2004, Journal of Wildlife Management (68) 1082-1087
The North American continental population of lesser scaup (Aythya affinis) has been declining since the mid-1980s. Seasonal survival estimates may provide insights about the ecological basis for this decline, but such data are not available. We estimated post-harvest winter survival of lesser scaup in east-central Florida, USA, where 62% of...
Measurement of clay surface areas by polyvinylpyrrolidone (PVP) sorption and its use for quantifying illite and smectite abundance
A.E. Blum, D. D. Eberl
2004, Clays and Clay Minerals (52) 589-602
A new method has been developed for quantifying smectite abundance by sorbing polyvinylpyrrolidone (PVP) on smectite particles dispersed in aqueous solution. The sorption density of PVP-55K on a wide range of smectites, illites and kaolinites is ~0.99 mg/m2, which corresponds to ~0.72 g of PVP-55K per gram of montmorillonite. Polyvinylpyrrolidone...
Habitat use and home range of the Laysan Teal on Laysan Island, Hawaii
M.H. Reynolds
2004, Waterbirds (27) 183-192
The 24-hour habitat use and home range of the Laysan Teal (Anas laysanensis), an endemic dabbling duck in Hawaii, was studied using radio telemetry during 1998-2000. Radios were retained for a mean of 40 days (0-123 d; 73 adult birds radio-tagged). Comparisons of daily habitat use were made for birds...
Improved calibration procedures and new standards for U - Pb and Th - Pb dating of Phanerozoic xenotime by ion microprobe
I.R. Fletcher, N.J. McNaughton, J.A. Aleinikoff, B. Rasmussen, S.L. Kamo
2004, Chemical Geology (209) 295-314
Xenotime is a widely occurring mineral that is amenable to U-Pb and Th-Pb dating but often is found as micrometre-sized crystals that can only be dated by in situ microanalytical techniques. Determining accurate ages for Phanerozoic samples, and assessing concordance in older samples, requires accurate determination of Pb/U and Pb/Th;...
Lunar highland meteorite Dhofar 026 and Apollo sample 15418: Two strongly shocked, partially melted, granulitic breccias
B. A. Cohen, O.B. James, L.A. Taylor, M.A. Nazarov, L.D. Barsukova
2004, Meteoritics and Planetary Science (39) 1419-1447
Studies of lunar meteorite Dhofar 026, and comparison to Apollo sample 15418, indicate that Dhofar 026 is a strongly shocked granulitic breccia (or a fragmental breccia consisting almost entirely of granulitic breccia clasts) that experienced considerable post-shock heating, probably as a result of diffusion of heat into the rock from...
Ad Duwayhi, Saudi Arabia: Geology and geochronology of a neoproterozoic intrusion-related gold system in the Arabian shield
Jeff L. Doebrich, S.G. Zahony, J.D. Leavitt, J.S. Portacio Jr., A.A. Siddiqui, Joseph L. Wooden, Robert J. Fleck, Holly J. Stein
2004, Economic Geology (99) 713-741
The Ad Duwayhi gold deposit, located in the east-central part of the Arabian shield, is the newest gold discovery in Saudi Arabia. Exploration to date has identified a gold resource of greater than 1 million ounces (oz) with significant potential for expansion. Gold mineralization was closely associated, in time...
Wrightwood and the earthquake cycle: What a long recurrence record tells us about how faults work
R. Weldon, K. Scharer, T. Fumal, G. Biasi
2004, GSA Today (14) 4-10
The concept of the earthquake cycle is so well established that one often hears statements in the popular media like, "the Big One is overdue" and "the longer it waits, the bigger it will be." Surprisingly, data to critically test the variability in recurrence intervals, rupture displacements, and relationships between...
Anchor and visible implant elastomer tag retention by hatchery rainbow trout stocked into an Ozark stream
M. G. Walsh, D.L. Winkelman
2004, North American Journal of Fisheries Management (24) 1435-1439
As part of a study to evaluate the stocking of rainbow trout Oncorhynchus mykiss in an Oklahoma Ozark stream, we tagged 2,542 hatchery-reared rainbow trout (123-366 mm total length) with individually numbered Floy FD-68B anchor tags and visible implant fluorescent elastomer (VIE) tags. We experimentally stocked double-marked rainbow trout into...
Habitat disturbance and the diversity and abundance of ants (Formicidae) in the Southeastern Fall-Line Sandhills
J.H. Graham, H.H. Hughie, S. Jones, K. Wrinn, A.J. Krzysik, J.J. Duda, D. Carl Freeman, J.M. Emlen, J.C. Zak, D.A. Kovacic, C. Chamberlin-Graham, H. Balbach
2004, Journal of Insect Science (4) 1-15
We examined habitat disturbance, species richness, equitability, and abundance of ants in the Fall-Line Sandhills, at Fort Benning, Georgia. We collected ants with pitfall traps, sweep nets, and by searching tree trunks. Disturbed areas were used for military training; tracked and wheeled vehicles damaged vegetation and soils. Highly disturbed sites...
Seasonal movement of brown trout in the Clinch River, Tennessee
J.M. Bettinger, P.W. Bettoli
2004, North American Journal of Fisheries Management (24) 1480-1485
We used radiotelemetry to monitor the seasonal movements of trophy-size brown trout Salmo trutta in the Clinch River below Norris Dam, Tennessee, to determine whether establishing a special-regulation reach to reduce fishing mortality was a viable management option. Fifteen brown trout (size range, 430-573 mm total length) collected from the...
Metabolism of niclosamide in sediment and water systems
P.W. Graebing, J.S. Chib, T.D. Hubert, W.H. Gingerich
2004, Journal of Agricultural and Food Chemistry (52) 5924-5932
A series of experiments analyzed the kinetics and mechanisms of [ 14C]niclosamide degradation. The aerobic aquatic metabolism of [ 14C]niclosamide was studied in nonsterile river water/sediment mixtures. Test systems, maintained under aerobic conditions, were treated with niclosamide and incubated in the dark at 25.0 ?? 1.0 ??C for 30 days....
Geophysical and isotopic mapping of preexisting crustal structures that influenced the location and development of the San Jacinto fault zone, southern California
V.E. Langenheim, R.C. Jachens, D. M. Morton, R. W. Kistler, J. C. Matti
2004, Geological Society of America Bulletin (116) 1143-1157
We examine the role of preexisting crustal structure within the Peninsular Ranges batholith on determining the location of the San Jacinto fault zone by analysis of geophysical anomalies and initial strontium ratio data. A 1000-km-long boundary within the Peninsular Ranges batholith, separating relatively mafic, dense, and magnetic rocks of the...
Sorption of 99mTc radiopharmaceutical compounds by soils
S. Jurisson, J. Gawenis, E. R. Landa
2004, Health Physics (87) 423-428
Study of the sorption of 99mTc radiopharmaceutical compounds by soils has assessed the fate of these compounds in the event of a surface spill and examined the potential of these compounds as hydrologic tracers. Sorption from deionized water, filtered Missouri River water, and artificial seawater by five surface soils was...
Assessing the potential for fish predation to impact zebra mussels (Dreissena polymorpha): Insight from bioenergetics models
M.A. Eggleton, L.E. Miranda, J.P. Kirk
2004, Ecology of Freshwater Fish (13) 85-95
Rates of annual food consumption and biomass were modeled for several fish species across representative rivers and lakes in eastern North America. Results were combined to assess the relative potential of fish predation to impact zebra mussels (Dreissena polymorpha). Predicted annual food consumption by fishes in southern waters was over...
Paleoseismology and neotectonics of the Shivwits section of the Hurricane Fault, northwestern Arizona
L. Amoroso, P. A. Pearthree, J.R. Arrowsmith
2004, Bulletin of the Seismological Society of America (94) 1919-1942
The Shivwits section of the Hurricane Fault in northwestern Arizona has been largely ignored in evaluating the seismic hazard posed to the rapidly growing populations of southwestern Utah. To assess this hazard, we conducted studies along the Shivwits section using field observations and geomorphic modeling to understand the Quaternary tectonism...
Precipitation and the occurrence of lyme disease in the Northeastern United States
G.J. McCabe, J.E. Bunnell
2004, Vector-Borne and Zoonotic Diseases (4) 143-148
The occurrence of Lyme disease is a growing concern in the United States, and various studies have been performed to understand the factors related to Lyme disease occurrence. In the United States, Lyme disease has occurred most frequently in the northeastern United States. Positive correlations between the number of cases...
Roosevelt elk density and social segregation: Foraging behavior and females avoiding larger groups of males
F. Weckerly, K. McFarland, M. Ricca, K. Meyer
2004, American Midland Naturalist (152) 386-399
Intersexual social segregation at small spatial scales is prevalent in ruminants that are sexually dimorphic in body size. Explaining social segregation, however, from hypotheses of how intersexual size differences affects the foraging process of males and females has had mixed results. We studied whether body size influences on forage behavior,...
The Anarraaq Zn-Pb-Ag and barite deposit, northern Alaska: Evidence for replacement of carbonate by barite and sulfides
K.D. Kelley, Julie A. Dumoulin, S. Jennings
2004, Economic Geology (99) 1577-1591
The Anarraaq deposit in northern Alaska consists of a barite body, estimated to be as much as 1 billion metric tons, and a Zn-Pb-Ag massive sulfide zone with an estimated resource of about 18 Mt at 18 percent Zn, 5.4 percent Pb, and 85 g/t Ag. The barite and sulfide...
Timing of Precambrian melt depletion and Phanerozoic refertilization events in the lithospheric mantle of the Wyoming Craton and adjacent Central Plains Orogen
R. W. Carlson, A.J. Irving, D.J. Schulze, B. C. Hearn Jr.
2004, LITHOS (77) 453-472
Garnet peridotite xenoliths from the Sloan kimberlite (Colorado) are variably depleted in their major magmaphile (Ca, Al) element compositions with whole rock Re-depletion model ages generally consistent with this depletion occurring in the mid-Proterozoic. Unlike many lithospheric peridotites, the Sloan samples are also depleted in incompatible trace elements, as shown...
U-Pb zircon constraints on the tectonic evolution of southeastern Tibet, Namche Barwa area
A.L. Booth, P.K. Zeitler, W.S.F. Kidd, J. Wooden, Yajing Liu, B. Idleman, M. Hren, C. P. Chamberlain
2004, American Journal of Science (304) 889-929
The eastern syntaxis of the Himalayas is expressed in the crust as a pronounced southward bend in the orogen. The change in strike of geologic features coincides with the high topography of the Namche Barwa region, the exposure of granulite-grade metamorphic rocks, and a 180-degree bend in the Yalu Tsangpo....
Encounter history modeling of joint mark-recapture, tag-resighting and tag-recovery data under temporary emigration
R. J. Barker, K.P. Burnham, Gary C. White
2004, Statistica Sinica (14) 1037-1055
We describe a joint analysis of mark-recapture, tag-resight and tag-recovery data that directly models the encounter history of an animal. The probability of the encounter history for each animal is partitioned into survival, recapture, resighting, and recovery components, and a component for the probability that the animal is never encountered...
Modeling interpopulation dispersal by banner-tailed kangaroo rats
J.L. Skvarla, J.D. Nichols, J.E. Hines, P.M. Waser
2004, Ecology (85) 2737-2746
Many metapopulation models assume rules of population connectivity that are implicitly based on what we know about within-population dispersal, but especially for vertebrates, few data exist to assess whether interpopulation dispersal is just within-population dispersal "scaled up." We extended existing multi-stratum mark-release-recapture models to incorporate the robust design, allowing us...
