Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus (L.)
A.-R.A. El Gamal, K. B. Davis, J.A. Jenkins, Torrans E. Les
1999, Journal of the World Aquaculture Society (30) 269-275
Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus, was investigated by heat shock, cold shock, hydrostatic pressure, and/or chemicals (cytochalasin A, B, and D). Additionally, efficacy of combined protocols was determined. Heat shock 10 min after fertilization induced triploidy when incubation temperature was 24 C but not when incubation...
International trends in university education for wildlife conservation and management
W.B. Kessler, S. Csanyi, R. Field
1999, Wildlife Society Bulletin (26) 927-936
[No abstract available]...
The factors controlling species density in herbaceous plant communities: An assessment
J.B. Grace
1999, Perspectives in Plant Ecology, Evolution and Systematics (2) 1-28
This paper evaluates both the ideas and empirical evidence pertaining to the control of species density in herbaceous plant communities. While most theoretical discussions of species density have emphasized the importance of habitat productivity and disturbance regimes, many other factors (e.g. species pools, plant litter accumulation, plant morphology) have been...
Amount of gas hydrate estimated from compressional- and shear-wave velocities at the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well
Myung W. Lee
1999, Bulletin of the Geological Survey of Canada 313-322
The amount of in situ gas hydrate concentrated in the sediment pore space at the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well was estimated by using compressional-wave (P-wave) and shear-wave (S-wave) downhole log measurements. A weighted equation developed for relating the amount of gas hydrate concentrated in the pore space...
U.S. geological survey measurement programs and models pertinent to ocean and coastal prediction modeling
J. P. Bennett
1999, Marine Technology Society Journal (33) 88-92
No abstract available. ...
NEOCHIM: An electrochemical method for environmental application
R. W. Leinz, D.B. Hoover, A. L. Meier
1999, Journal of Geochemical Exploration (64) 421-434
Ion migration and electroosmosis are the principal processes underlying electrokinetic remediation of hazardous wastes from soils. These processes are a response of charged species to an applied electrical current and they are accompanied by electrolysis of water at the electrodes through which the current is applied. Electrolysis results in the...
Ventifacts at the Pathfinder landing site
N.T. Bridges, R. Greeley, A. F. C. Haldemann, Kenneth E. Herkenhoff, M. Kraft, T. J. Parker, A. W. Ward
1999, Journal of Geophysical Research E: Planets (104) 8595-8615
About half of the rocks at the Mars Pathfinder Ares Vallis landing site appear to be ventifacts, rocks abraded by windborne particles. Comparable resolution images taken by the Imager for Mars Pathfinder (IMP) camera and the Viking landers show that ventifacts are more abundant at the Pathfinder site. The ventifacts...
Evaluating data worth for ground-water management under uncertainty
B.J. Wagner
1999, Journal of Water Resources Planning and Management (125) 281-288
A decision framework is presented for assessing the value of ground-water sampling within the context of ground-water management under uncertainty. The framework couples two optimization models-a chance-constrained ground-water management model and an integer-programing sampling network design model-to identify optimal pumping and sampling strategies. The methodology consists of four steps: (1)...
Alaska resource data file: Big Delta quadrangle
Cameron Rombach
1999, Open-File Report 99-354
No abstract available....
Influence of various water quality sampling strategies on load estimates for small streams
Dale M. Robertson, Eric D. Roerish
1999, Water Resources Research (35) 3747-3759
Extensive streamflow and water quality data from eight small streams were systematically subsampled to represent various water‐quality sampling strategies. The subsampled data were then used to determine the accuracy and precision of annual load estimates generated by means of a regression approach (typically used for big rivers) and to determine...
Newly recognized faunal diversity within the Hamburg Klippe, Pennsylvania, U.S.A.: Implications for interpreting the history of the klippe
J.E. Repetski, G.R. Ganis, H. S. Williams
1999, Conference Paper, Acta Universitatis Carolinae, Geologica
[No abstract available]...
The geodesy and mapping program of the United States geological survey in Antarctica
J.L. Mullins, C.A. Hallam, L.D. Hothem, J.-C. Thomas
1999, Photogrammetric Engineering and Remote Sensing (65) 1340-1341
[No abstract available]...
The initial subevent of the 1994 Northridge, California, earthquake: Is earthquake size predictable?
Debi Kilb, J. Gomberg
1999, Journal of Seismology (3) 409-420
We examine the initial subevent (ISE) of the M 6.7, 1994 Northridge, California, earthquake in order to discriminate between two end-member rupture initiation models: the ‘preslip’ and ‘cascade’ models. Final earthquake size may be predictable from an ISE's seismic signature in the preslip model but not in the cascade model....
Birds associated with black-tailed prairie dog colonies in southern shortgrass prairie
V.A. Barko, J.H. Shaw, David M. Leslie Jr.
1999, Southwestern Naturalist (44) 484-489
We conducted a census of avifaunal richness and abundance on black-tailed prairie dog (Cynomys ludovicianus) colonies and uncolonized shortgrass prairie in the Oklahoma panhandle in July 1995 and April-June 1996. Five black-tailed prairie dog colonies were paired with five uncolonized prairie sites having similar topography and soil structure. Data were...
Enzymatic and histopathologic biomarkers as indicators of contaminant exposure and effect in Asian clam (Potamocorbula amurensis)
S.J. Teh, S.L. Clark, C. L. Brown, S. N. Luoma, D.E. Hinton
1999, Biomarkers (4) 497-509
Enzymatic and histopathologic alterations of the digestive gland, gill, gonad, and kidney were studied in Asian clam (Potamocorbula amurensis) in April, 1997 from each of four United States Geological Survey (USGS) stations in the San Francisco Estuary. Stations were selected based on differing body burdens of metallic contaminants in clams...
Comment on "antiphasing between rainfall in Africa's rift valley and North America's great basin"
P. C. D. Milly
1999, Quaternary Research (51) 104-107
[No abstract available]...
Tidally generated sea-floor lineations in Bristol Bay, Alaska, USA
M. S. Marlow, A.J. Stevenson, H. Chezar, R.A. McConnaughey
1999, Geo-Marine Letters (19) 219-226
Highly reflective linear features occur in water depths of 20-30 m in northern Bristol Bay (Alaska, USA) and are, in places, over 600 m in length. Their length-to-width ratio is over 100:1. The lineations are usually characterized by large transverse ripples with wavelengths of 1-2 m. The lineations trend about...
Transect across the West Antarctic rift system in the Ross Sea, Antarctica
H. Trey, A. K. Cooper, G. Pellis, Vedova B. Della, G. Cochrane, Giuliano Brancolini, J. Makris
1999, Tectonophysics (301) 61-74
In 1994, the ACRUP (Antarctic Crustal Profile) project recorded a 670-km-long geophysical transect across the southern Ross Sea to study the velocity and density structure of the crust and uppermost mantle of the West Antarctic rift system. Ray-trace modeling of P- and S-waves recorded on 47 ocean bottom seismograph (OBS)...
Trace-element geochemistry of metabasaltic rocks from the Yukon-Tanana Upland and implications for the origin of tectonic assemblages in east-central Alaska
Cynthia Dusel-Bacon, K.M. Cooper
1999, Canadian Journal of Earth Sciences (36) 1671-1695
We present major- and trace- element geochemical data for 27 amphibolites and six greenstones from three structural packages in the Yukon-Tanana Upland of east-central Alaska: the Lake George assemblage (LG) of Devono-Mississippian augen gneiss, quartz-mica schist, quartzite, and amphibolite; the Taylor Mountain assemblage (TM) of mafic schist and gneiss, marble,...
Variations in water clarity and bottom albedo in Florida Bay from 1985 to 1997
R. P. Stumpf, M.L. Frayer, M.J. Durako, J. C. Brock
1999, Estuaries (22) 431-444
Following extensive seagrass die-offs of the late 1980s and early 1990s, Florida Bay reportedly had significant declines in water clarity due to turbidity and algal blooms. Scant information exists on the extent of the decline, as this bay was not investigated for water quality concerns before the die-offs and limited...
Vermiculite
M.J. Potter
1999, American Ceramic Society Bulletin (78) 145-146
[No abstract available]...
Biochemical and molecular typing of Streptococcus iniae isolated from fish and human cases
S.V. Dodson, J.J. Maurer, E.B. Shotts
1999, Journal of Fish Diseases (22) 331-336
Streptococcus iniae is an important bacterial pathogen of fish, causing up to 50% mortality in stocks, which has recently been associated with human infections. To determine whether S. iniae isolates from humans and fish are similar, the present authors examined the biochemical profiles and genetic relatedness of these...
Use of implantable pellets to administer low levels of methyl mercury to fish
B.S. Arnold, C. H. Jagoe, T. S. Gross
1999, Conference Paper, ASTM Special Technical Publication
Implantable pellets of methyl mercury chloride were tested in Nile Tilapia (Oreochromis niloticus) to appraise the effectiveness of the method for chronic studies of mercury. Two dosing regimes of 15 and 1.5 grams/CH3HgCl pellet (test 1) and 1 and 0.1 grams/pellet (test 2-3) of methyl mercury chloride were used in...
Nitrogen mineralization in a mature boreal forest, Isle Royale, Michigan
R. Stottlemyer, D. Toczydlowski
1999, Conference Paper, Journal of Environmental Quality
The 115-ha boreal Wallace Lake watershed, located on Isle Royale in the Lake Superior Basin, receives moderate anthropogenic atmospheric N inputs (3 kg ha-1 yr-1). Ecosystem response to atmospheric N inputs is, in part, determined by internal production and consumption of this limiting nutrient. The objectives of this 2-yr study...
From in situ coal to the final coal product: A case study of the Danville Coal Member (Indiana)
Maria Mastalerz, P.L. Padgett
1999, International Journal of Coal Geology (41) 107-123
A surface coal mine operation and preparation plant in southwestern Indiana was sampled to examine variations in coal quality and coal petrography parameters for the Danville Coal Member of the Dugger Formation (Pennsylvanian-Desmoinesian, Westphalian D). Representative samples from in situ coal, preparation plant feeds, and a final coal product were...
