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Full-Text Articles in Physical Sciences and Mathematics
A Porpoise, Australophocaena Dioptrica, Previously Identified As Phocoena Spinipinnis, From Heard Island, Robert L. Brownell Jr., John Heyning, William Perrin
A Porpoise, Australophocaena Dioptrica, Previously Identified As Phocoena Spinipinnis, From Heard Island, Robert L. Brownell Jr., John Heyning, William Perrin
United States Department of Commerce: Staff Publications
Guiler, Burton and Gales (1987) reported a cranium (Tasmanian Museum No. A141 1) they identified as belonging to Burmeister’s porpoise, Phocoena spinipinnis Burmeister, 1865 from Heard Island (53°S 73°30’E). They noted that P. spinipinnis was previously known only from the cold-temperate coastal waters of South America and claimed that this cranium was evidence that the species has a much wider distribution than previously known. We have examined the photographs and details of their specimen and re-identify it here as Australophocaena dioptrica (Lahille, 1912) (family Phocoenidae).
Barnes (1985) listed several features that distinguish the skulls of species within the subfamily Phocoenoidinae …
Protected Species – Research Permits And The Value Of Basic Research, Katherine Ralls, Robert L. Brownell Jr.
Protected Species – Research Permits And The Value Of Basic Research, Katherine Ralls, Robert L. Brownell Jr.
United States Department of Commerce: Staff Publications
The complexities involved in obtaining permits for field research using protected species continue to increase. In October 1988, Congress amended the Marine Mammal Protection Act (MMPA) to increase the documentation required to obtain a scientific research permit (PL 100-711). Applicants for scientific research permits must now submit “information indicating that the taking is required to further a bona fide scientific purpose and does not involve unnecessary duplication of research.”
The Plight Of The ‘Forgotten’ Whales, Robert L. Brownell Jr., Katherine Ralls, William F. Perrin
The Plight Of The ‘Forgotten’ Whales, Robert L. Brownell Jr., Katherine Ralls, William F. Perrin
United States Department of Commerce: Staff Publications
The “Save the Whales” movement, the most successful wildlife crusade in history, has greatly influenced government policies in a number of countries, including the United States. Thanks in large part to the movement’s dedicated members, the fight to save the great whales has been largely won. Yet all but ignored in this victory has been the plight of smaller cetaceans, which continues to worsen.
Estimates Of Macroinvertebrate Biomass In Lake Michigan, Thomas F. Nalepa
Estimates Of Macroinvertebrate Biomass In Lake Michigan, Thomas F. Nalepa
United States Department of Commerce: Staff Publications
To obtain updated, more accurate estimates of macroinvertebrate standing stocks in Lake Michigan, benthic biomass (ash-free dry weight) was determined at 40 stations in the southern end of the lake in 1980 and 1981. Biomass generally increased as sampling depth increased from 16 to 30 m, peaked at depths of 30-40 m, and then declined at depths greater than 40 m. Mean total biomass at the 16-30 m, 31-50 m, 51-90, and> 90 m depth intervals was 4.9, 7.8, 4.2, and 1.9 g m-2, respectively. Oligochaetes (46%) and Pontoporeia hoyi (44%) accounted for most of the biomass at …
Effects Of Track Structure On Neutron Microdosimetry And Nanodosimetry, Randall S. Caswell
Effects Of Track Structure On Neutron Microdosimetry And Nanodosimetry, Randall S. Caswell
United States Department of Commerce: Staff Publications
The process by which neutrons transfer their energy to tissue is described, including the deposition of energy by secondary charged particle tracks in small sites; that is, microdosimetry and nanodosimetry. Three approximations are considered in order of increasing amounts of information on track structure: the continuous slowing-down approximation (CSDA), the straggling approximation, and the delta-ray approximation. Although simple approximations sometimes work quite well, much work remains to be done for very small sites, and for the inclusion of the effects of "passers" in the calculations.