Winter Observations of Mammals and Birds, St. Matthew Island

Remore and uninhabited St. Matthew Island, lying 60 30 N, 172 30 W, on the continental shelf of the Bering Sea, is infrequently visited in summer and very rarely seen in the winter. The only signs of past human habitation are the wind-torn remains of a World War II naval observation station and the rectangular depressions of a couple of Eskimo house pits, of undetermined age, on the southwest side of the island. The last known visit to the island was during the summer of 1966. Our opportunity came on 6 and 7 February 1970, as a result of an oceanographic cruise aboard the U.S. Coast Guard icebreaker Northwind to study winter conditions in the ice-covered Bering Sea. At that time the island was covered with crusted, wind-glazed snow and locked in sea ice, with open water only along the south shore where large leads had opened up in the lee of the island. The weather was cold and very windy, temperatures ranging from 10°F to -20°F with a wind velocity averaging 30 to 40 knots, from the north. The afternoon of the 6th was clear, permitting a helicopter survey of the entire island. Most of the daylight hours of the 7th were occupied by ground investigations of the island under worsening weather conditions (overcast sky and 40-knot wind). The mammal population of the island is sparse .... We saw only arctic fox and reindeer, with no evidence of small mammals though they are known to exist there. ... Species observed on or in the vicinity of St. Matthew: Arctic Fox (Alopex lagopus), Reindeer (Rangifer tarandus), Walrus (Odobenus rosmarus), Ringed Seal (Phoca hispida,) Snowy Owl (Nyctea scandiaca), Thick-billed Murre (Uria lomvia), Harlequin (Histrionicus histrionicus), Common Eider (Somateria mollissima), King Eider (Somateria spectabilis), Old squaw (Clangula hyemalis), Pelagic Cormorant (Phalacrocorax pelagicus), Slaty-backed Gull (Larus schistisagus), Glaucous-winged Gull (Larus glaucescens), Glaucous Gull (Larus hyperboreus), Ivory Gull (Pagophila eburnea). We found a single herd of 32 reindeer at the southeast corner of the island. The animals were large and appeared to be in good condition, with impressive antlers. They are the remnant of a reindeer population introduced in 1944 that experienced a spectacular increase to 6,000 animals before crashing to 42 in the winter of 1963-64. Klein visited St. Matthew in the summer of 1966 to study the remaining reindeer and collected 10 animals, including the last male. He left 32 animals, all thought to be female, and all of which survived the intervening three and a half years up to the time of our arrival on the island. The observed marine mammal populations in the vicinity of St. Matthew proved to be disappointing. ... Ringed and bearded seals and walrus were observed some distance to the east of St. Matthew, in the edge of the sea ice in Bristol Bay; walrus were seen in large numbers north of the island, in the vicinity of St. Lawrence, so it seems likely that there should be marine mammals present in the area. ... The bird fauna of St. Matthew and vicinity was more diverse than that of the mammal. Twelve species were seen around the island, all of which, with the exception of a snowy owl, were marine and were observed in the leads and polynyas of the sea ice. Most common were murres, harlequins, and oldsquaws. ... As the ship proceeded westward from St. Matthew toward the Siberian coast, murres, black guillemots, and 4 species of gulls were seen. Several slaty-backed and glaucous-winged gulls were seen, and 3 glaucous and 2 ivory gulls observed near 60°N, 175°W. [Interestingly] ... of all the gulls seen, the slaty-back was by far the most common. This species is not considered common in Alaska

Amino Acid Substitutions in the S2 Subunit of Mouse Hepatitis Virus Variant V51 Encode Determinants of Host Range Expansion

We previously described mouse hepatitis virus (MHV) variant V51 derived from a persistent infection of murine DBT cells with an expanded host range (R. S. Baric, E. Sullivan, L. Hensley, B. Yount, and W. Chen, J. Virol. 73:638-649, 1999). Sequencing of the V51 spike gene, the mediator of virus entry, revealed 13 amino acid substitutions relative to the originating MHV A59 strain. Seven substitutions were located in the amino-terminal S1 cleavage subunit, and six were located in the carboxy-terminal S2 cleavage subunit. Using targeted RNA recombination, we constructed a panel of recombinant viruses to map the mediators of host range to the six substitutions in S2, with a subgroup of four changes of particular interest. This subgroup maps to two previously identified domains within S2, a putative fusion peptide and a heptad repeat, both conserved features of class I fusion proteins. In addition to an altered host range, V51 displayed altered utilization of CEACAM1a, the high-affinity receptor for A59. Interestingly, a recombinant with S1 from A59 and S2 from V51 was severely debilitated in its ability to productively infect cells via CEACAM1a, while the inverse recombinant was not. This result suggests that the S2 substitutions exert powerful effects on the fusion trigger that normally passes from S1 to S2. These novel findings play against the existing data that suggest that MHV host range determinants are located in the S1 subunit, which harbors the receptor binding domain, or involve coordinating changes in both S1 and S2. Mounting evidence also suggests that the class I fusion mechanism may possess some innate plasticity that regulates viral host range

A Conceptual Model of Natural and Anthropogenic Drivers and Their Influence on the Prince William Sound, Alaska, Ecosystem

Prince William Sound (PWS) is a semi-enclosed fjord estuary on the coast of Alaska adjoining the northern Gulf of Alaska (GOA). PWS is highly productive and diverse, with primary productivity strongly coupled to nutrient dynamics driven by variability in the climate and oceanography of the GOA and North Pacific Ocean. The pelagic and nearshore primary productivity supports a complex and diverse trophic structure, including large populations of forage and large fish that support many species of marine birds and mammals. High intra-annual, inter-annual, and interdecadal variability in climatic and oceanographic processes as drives high variability in the biological populations. A risk-based conceptual ecosystem model (CEM) is presented describing the natural processes, anthropogenic drivers, and resultant stressors that affect PWS, including stressors caused by the Great Alaska Earthquake of 1964 and the Exxon Valdez oil spill of 1989. A trophodynamic model incorporating PWS valued ecosystem components is integrated into the CEM. By representing the relative strengths of driver/stressors/effects, the CEM graphically demonstrates the fundamental dynamics of the PWS ecosystem, the natural forces that control the ecological condition of the Sound, and the relative contribution of natural processes and human activities to the health of the ecosystem. The CEM illustrates the dominance of natural processes in shaping the structure and functioning of the GOA and PWS ecosystems

ARGUER: Using Argument Schemas for Argument Detection and Rebuttal in Dialogs

This paper presents a computational method for argumentation on the basis of a declarative characterizatio

Symbiotic Cellulose Degradation in Green Turtles, \u3cem\u3eChelonia mydas\u3c/em\u3e L

A postgastric, fermentative breakdown of structural plant tissue was demonstrated for green turtles. About 90% cellulose was hydrolyzed. Bacterial and protozoan numbers compared with those of the rumen