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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
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Removal of ash from plankton samples concentrated by ignition
No abstract available.
Authors
K. N. Sachs
Resource understanding: a challenge to aerial methods
Aerial survey methods are speeding acquisition of survey data needed to provide and manage the nation's resources. These methods have been applied to topographic mapping for a number of years and the record clearly shows their advantages in terms of cost and speed in contrast to the ground methods that have been historically employed. Limited use is now being made of aerial methods to assist cadas
Authors
Stewart L. Udall
Results of woodcock wing collections, 1959 to 1962
During hunting seasons from 1959 to 1962, age and sex determined from 45,444 wings were used to measure annual productivity of woodcocks (Philohela minor). Age of birds was determined by pattern and color of secondaries and by wear on primaries. Sex was determined by width and length of primaries. Overall age ratios, weighted by kill estimates, were the same each year and indicated no change in an
Authors
F.W. Martin, A. D. Geis, W. H. Stickel
Sarcocystis in a yellowthroat and a rusty blackbird
No abstract available.
Authors
L. N. Locke, J.O. Knisley
Servo-amplifiers for ion current measurement in mass spectrometry
A servo-voltmeter can provide a useful alternative to the d.c. amplifier or vibrating reed electrometer for the accurate measurement of mass spectrometer ion currents, and has some advantages which recommend its use in certain applications. A generalized analysis based on servomechanism theory is presented as an aid for understanding the design criteria for this type of device. Two existing system
Authors
J. S. Stacey, R.D. Russell, F. Kollar
Sex ratios and sexual dimorphism among recently transformed sea lampreys, Petromyzon marinus Linnaeus
The sex, length, and weight were determined of nearly all recently transformed sea lampreys migrating downstream in the Carp Lake River, Michigan, in the fall, winter, and spring of 1960-61. Similar data were collected from samples of an earlier run in the Carp Lake River and of runs in three other tributaries of Lakes Huron and Michigan. The sex ratio of the 1960-61 migrants in the Carp Lake Rive
Authors
Vernon C. Applegate, M.L.H. Thomas
Simple enrichment of commercial media for growth of Hemophilus piscium
No abstract available.
Authors
G. L. Bullock
Sixty-fifth Christmas Bird Count. 228. Southern Dorchester County, Md
No abstract available.
Authors
C.S. Robbins
Solution of rocks and refractory minerals by acids at high temperatures and pressures. Determination of silica after decomposition with hydrofluoric acid
A modified Morey bomb was designed which contains a removable nichromecased 3.5-ml platinium crucible. This bomb is particularly useful for decompositions of refractory samples for micro- and semimicro-analysis. Temperatures of 400–450° and pressures estimated as great as 6000 p.s.i. were maintained in the bomb for periods as long as 24 h. Complete decompositions of rocks, garnet, beryl, chrysober
Authors
I. May, J.J. Rowe
Some aspects of the geochemistry of yttrium and the lanthanides
Recent data on the relative abundances of the lanthanides and yttrium in meteorites, basaltic rocks, granitic rocks and sedimentary rocks are reviewed. It is shown that the data are inadequate to substantiate or to disprove Taylor's derivation from these data of a 1:1 abundance ratio of basaltic to granitic rocks in the continental crust. Graphs are given to illustrate the variation of lanthanides
Authors
Michael Fleischer
Some diseases and parasites of captive woodcocks
Observations were made concerning the diseases and parasites of a group of woodcocks (Philohela minor) caught in Massachusetts in the summer of 1960 and kept in captivity in Maryland, and of another group caught and kept in Louisiana in the winter of 1960-61. Bumblefoot, a granulomatous swelling of the foot caused by Micrococcus sp., is reported for woodcocks for the first time. Six of 31 woodco
Authors
L. N. Locke, W. H. Stickel, S.A. Geis
Some recent developments and applications of fish cell and tissue culture
No abstract available.
Authors
K. Wolf