Canister cryogenic system for cooling germanium semiconductor detectors in borehole and marine probes
G. R. Boynton
1975, Nuclear Instruments and Methods (123) 599-603
High resolution intrinsic and lithium-drifted germanium gamma-ray detectors operate at about 77–90 K. A cryostat for borehole and marine applications has been designed that makes use of prefrozen propane canisters. Uses of such canisters simplifies cryostat construction, and the rapid exchange of canisters...
Calculated geochronology and stress field orientations along the Hawaiian chain
E.D. Jackson, H. R. Shaw, K.E. Bargar
1975, Earth and Planetary Science Letters (26) 145-155
A new method has been discovered for calculating ages of the main shield building stages of volcanoes along the Hawaiian chain from Kilauea to the Hawaiian-Emperor bend. The method is based on a graphical technique for hypothetical subtraction of distance intervals that...
Mercury distribution in ancient and modern sediment of northeastern Bering Sea
C.H. Nelson, D.E. Pierce, Kam Leong, F.F.H. Wang
1975, Marine Geology (18) 91-104
Reconnaissance sampling of surface and subsurface sediment to a maximum depth of 80 m below the sea floor shows that typical values of 0.03 p.p.m. and anomalies of 0.2-1.3 p.p.m. mercury have been present in northeastern Bering Sea since Early Pliocene time. Values are highest in modern beach (maximum 1.3...
Thermomagnetic analysis of meteorites, 2. C2 chondrites
D.E. Watson, E.E. Larson, J.M. Herndon, M.W. Rowe
1975, Earth and Planetary Science Letters (27) 101-107
Samples of all eighteen of the known C2 chondrites have been analyzed thermomagnetically. For eleven of these, initial Fe3O4 content is low (generally <1%) and theJs-T curves are irreversible. The heating curves show variable greater (up to 10 times) than it is initially. This...
Some aspects of the breeding biology of the upland sandpiper in North Dakota
K.F. Higgins, L.M. Kirsch
1975, The Wilson Bulletin (87) 96-102
Abstract has not been submitted...
Survival of wood duck and mallard broods in north-central Minnesota
I.J. Ball, D.S. Gilmer, L.M. Cowardin, J. H. Riechmann
1975, Journal of Wildlife Management (39) 776-780
Duckling survival in wood duck (Aix sponsa) and mallard (Anas platyrhynchos) broods was estimated from data obtained from 71 radio-marked brood hens on a study area in north-central Minnesota. Radio-marked hens produced 30 broods during the study, and 41 hens already leading broods were captured and radio-marked. Production estimates based...
Fitting Richards' curve to data of diverse origins
Douglas H. Johnson, A.B. Sargeant, S.H. Allen
1975, Growth (39)
Published techniques for fitting data to nonlinear growth curves are briefly reviewed, most techniques require knowledge of the shape of the curve. A flexible growth curve developed by Richards (1959) is discussed as an alternative when the shape is unknown. The shape of this curve is governed by a specific...
A spring aerial census of red foxes in North Dakota
A.B. Sargeant, W.K. Pfeifer, S.H. Allen
1975, Journal of Wildlife Management (39) 30-39
Systematic aerial searches were flown on transects to locate adult red foxes (Vulpes vulpes), pups, and rearing dens on 559.4 km2 (six townships) in eastern North Dakota during mid-May and mid-June each year from 1969 through 1973 and during mid-April 1969 and early May 1970. The combined sightings of foxes...
Age determination of female redhead ducks
C.W. Dane, Douglas H. Johnson
1975, Journal of Wildlife Management (39) 256-263
Eighty-seven fall-collected wings from female redhead ducks (Aythya americana) were assigned to the adult or juvenile group based on 'tertial' and 'tertial covert' shape and wear. To obtain spring age-related characters from these fall-collected groupings, we considered parameters of flight feathers retained until after the first breeding season. Parameters measured...
Death feigning by ducks in response to predation by red foxes (Vulpes fulva)
Alan B. Sargeant, L. E. Eberhardt
1975, American Midland Naturalist (94) 108-119
Predation by captive red foxes (Vulpes fulva) on approximately 50 ducks comprised of five species was observed in tests conducted at the Northern Prairie Wildlife Research Center, Jamestown, North Dakota. Most ducks were attacked from a rear or lateral position and seized in the cervical or thoracic region. All birds...
Leech (Hirudinea) infestations among waterfowl near Yellowknife, Northwest Territories
James C. Bartonek, David L. Trauger
1975, Canadian Field-Naturalist (89) 234-243
Fourteen species of aquatic birds, including 11 species of ducks, were infested with leeches Theromyzon rude and Placobdella ornata near Yellowknife, Northwest Territories. Leeches infested 88% of 41 American Wigeon (Anas americana) and 31% of 86 Lesser Scaup (Aythya affinis) examined after death. Lesser Scaup captured by drive-trapping contained significantly...
Use of elevated nest baskets by ducks
Harold A. Doty, F.B. Lee, A.D. Kruse
1975, Wildlife Society Bulletin (3) 68-73
Open-top nest baskets were mounted on upright metal poles in various wetlands to assess the value of baskets as a potential technique for increasing duck nest success. Observations were made from 1966-1968 in North and South Dakota, Minnesota, and Wisconsin and were continued through 1973 in North Dakota. Baskets were...
Variation in response of channel catfish to Henneguya sp. infections (Protozoa: Myxosporidea)
J. P. McCraren, M.L. Landolt, G. L. Hoffman, F. P. Meyer
1975, Journal of Wildlife Diseases (11) 2-7
Infections in channel catfish (Ictalurus punctatus, Rafinesque) induced by the sporozoan Henneguya (Protozoa: Myxosporidea) result in seven known and diverse disease manifestations. Most outstanding is an interlamellar branchial form responsible for significant losses among immature catfish, and a unique papillomatous form. The question of whether or not the species of Henneguya involved in these...
Effects of pH on toxicity of antimycin to fish
L. L. Marking
1975, Journal of the Fisheries Research Board of Canada (32) 769-773
Detoxification of antimycin at pH 9.5 was caused by two factors. The piscicide was biologically unavailable at the high pH, and this unavailability was reversed by decreasing the pH of water solutions. Simultaneously antimycin detoxified with time, and the resulting loss in toxicity was irreversible. The toxicity of antimycin was...
Environmental factors affecting the strength of walleye (Stizostedion vitreum vitreum) year-classes in western Lake Erie, 1960-70
Wolf-Dieter N. Busch, Russell L. Scholl, Wilbur L. Hartman
1975, Journal of the Fisheries Research Board of Canada (32) 1733-1743
Commercial production of walleyes (Stizostedion vitreum vitreum) from western Lake Erie declined from 5.9 million pounds in 1956 to 140,000 pounds by 1969. Since 1956, marked irregularity in year-class success has developed. Only four year-classes were considered good during 1959–70. The rate and regularity of water warming during the spring...
Predation by fish on walleye eggs on a spawning reef in western Lake Erie, 1969-71
David R. Wolfert, Wolf-Dieter N. Busch, Carl T. Baker
1975, Ohio Journal of Science (75) 118-125
Nearly 2,000 fish representing 21 species were captured with experimental gillnets on Kelleys Island Shoal during the spawning and incubation periods of walleyes (Stizostedion v. vitreum) in 1969-71. A total of 794 stomachs were examined. Four species contained walleye eggs: yellow perch (Perca flavescens), spottail shiner (Notropis hudsonius), stonecat (Noturus...
Annual contribution of carbon, nitrogen, and phosphorus by migrant Canada geese to a hardwater lake
Bruce A. Manny, Robert G. Wetzel, W.C. Johnson
1975, International Association of Theoretical and Applied Limnology (19) 949-951
Each year more than 6,000 migrant Canada geese (Branta canadensis interior Todd) rest for 3 to 10 days during the months of March, October, November, and December on Wintergreen Lake, a productive 15 ha (33 acre) hardwater lake in the W. K. Kellogg Bird Sanctuary of Michigan State University in...
Effects of agricultural burning on nesting waterfowl
E.K. Fritzell
1975, Canadian Field-Naturalist (89) 21-27
Agricultural burning in an intensively farmed region within Manitoba's pothole district is shown to affect the nesting activities of ground-nesting ducks. All species, except Blue-winged Teal (Anas discors), preferred unburned nest cover, although success was higher in burned areas, where predators may have exerted less influence. Attitudes of farmers, burning...
Dieldrin in the diet of channel catfish (Ictalurus punctatus): uptake and effect on growth
Ray L. Argyle, George C. Williams, Clara B. Daniel
1975, Journal of the Fisheries Research Board of Canada (32) 2197-2204
Fingerling channel catfish (Ictalurus punctatus) were given diets containing 0, 0.4, 0.8, or 4.0 I?g dieldrin/g of food (dry weight) for 210 days, followed by a dieldrin-free diet for 56 days. Catfish receiving 4.0 I?g dieldrin/g food gained about 17% less weight than the control fish in 210 days and...
Chemicals used most frequently for control of infectious diseases of fishes
S. F. Snieszko
1975, Fish Health News (4) 2-7
Thin-section electron microscopy of mature Myxosoma cerebralis (Myxosporidea) spores
P.D. Lunger, B.L. Rhoads, K. Wolf, M.E. Markiw
1975, Journal of Parasitology (61) 476-480
The morphology of purified, mature Myxosoma cerebralis spores was examined by thin-section electron microscopy. Surface architecture corresponded closely to that described in an earlier scanning electron microscopy study of this organism (Lom and Hoffman, 1971). A uniformly thick spore wall is composed of finely granular, electron-lucent material. Intrawall "valvoplasm" at...
Productivity and flowering of winter ephemerals in relation to Sonoran Desert shrubs
William L. Halvorson, Duncan T. Patten
1975, American Midland Naturalist (93) 311-319
Ephemeral plant biomass and density on a Sonoran Desert hill near Cave Creek, Arizona, vary relative to shrub canopy type and shrub density. Higher shrub density associated with increased elevation appears to decrease both ephemeral biomass productivity and density, while ephemeral growth is enhanced under a shrub canopy if it...
Longevity of nonsprouting Ceanothus
Jon E. Keeley
1975, American Midland Naturalist (93) 504-507
Evidence is presented indicating species of Ceanothus in the subgenus Cerastes are generally longer-lived than species in the subgenus Euceanothus. It is proposed that this is due, at least in part, to the unique stem morphology of the former. The stems of these plants have a ribbed appearance which arises...
Thoracic collapse as affected by the retia thoracica in the dolphin
Clifford A. Hui
1975, Respiration Physiology (25) 63-70
The carcass of a subadult female Delphinus was placed in a hyperbaric chamber and subjected to two simulated dives each equivalent to 69.7 m. In one dive the thorax was in its natural state, and in the other 100 ml of water had been injected into each pleural cavity. Various morphometric...
Mineral upplementation of diets containing soybean meal as a source of protein for rainbow trout
H. G. Ketola
1975, Progressive Fish-Culturist (37) 73-75
No abstract available....
