6,023 research outputs found

    A volcano's pulse

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    Before the 1995 Soufrière Hills eruption began, there had been seismic crises approximately every 30 years since the late 1890s; each crisis lasted months to years and involved thousands of small earthquakes. In 1935, some earthquakes were large enough to cause damage to buildings in the capital Plymouth and there was real concern that an eruption was imminent. These seismic crises were later interpreted as pulses of magma trying, but failing, to reach the surface. A final seismic crisis began in 1992, and by November 1995 fresh lava had reached the surface and began to form a dome in the volcano’s summit crater. The eruption has since been characterised by pulsatory activity on a range of different timescales

    Evaluative criteria in written language for elementary grades

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    Thesis (Ed.M.)--Boston UniversityThis thesis has been developed to help set up criteria to evaluate the writLen language area of an elementary school. The criteria consist of specific statements indicating desirable conditions and procedures in the written language area of the elementary school program. Such statements should furnish a means for teachers to examine and evaluate the effectiveness of their own work

    Incidental Catch of Marine Mammals by Foreign and Joint Venture Trawl Vessels in the U.S. EEZ of the North Pacific, 1973-88

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    During 1973-88, 3,661 marine mammals of 17 species were reported as incidental catch by U.S. fishery observers aboard foreign and joint venture trawl vessels in the U.S. Exclusive Economic Zone in the North Pacific Ocean and the Bering Sea. Northern sea lions (Eumetopias jubatus) accounted for 90% of the reported incidental mortality in the Gulf of Alaska and eastern Bering Sea. Nearly half of these sea lions were taken in trawl nets in the Shelikof Strait, Alaska, joint venture fishery during 1982-84. However, high incidental mortality rates (>25 sea lions per 10,000 metric tons of groundfish catch) also occurred in the foreign fisheries near Kodiak Island and in the Aleutian Islands area in earlier years. Estimated annual mortality of incidentally caught northern sea lions in Alaska declined from 1,000 to 2,000 animals per year during the early 1970s and 1982 to fewer than 100 animals in 1988. In the Bering Sea most sea lions incidentally caught were males, while in the Gulf of Alaska females were more frequently caught. Females may also have been dominant in the incidental catch of sea lions in the Aleutian Islands area, but age and sex composition data are limited. Incidental mortality of adult female sea lions by foreign trawl fisheries in these areas could have partially contributed to the reported declines in northern sea lion populations in Alaska during the 1970s, but it cannot alone account for the present decline in population size. (PDF file contains 64 pages.

    An Accounting of the Sources of Steller Sea Lion, Eumetopias jubatus, Mortality

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    During 1991–2000, the west-are additional mortalities that fueled the ern stock of Steller sea lions, Eumetopias decline. We tabulated the levels of reported jubatus, declined at 5.03% (SE = 0.25%) anthropogenic sources of mortality (sub- per year, statistically significant rates (P 8.2% partition the various sources of “additional” per year). Using a published correction mortalities as anthropogenic and as addifactor, we estimated the total non-pup pop-tional mortality including some predation. ulation size in Alaska of the western stock We classified 436 anthropogenic mortalities of Steller sea lions to be about 33,000 ani-and 769 anthropogenic plus some predation mals. Based on a published life table and mortalities as “mortality above replace-the current rate of decline, we estimate that ment”; this accounted for 26% and 46% of the total number of mortalities of non-pup the estimated total level of “mortality above Steller sea lions during 1991–2000 was replacement”, respectively. The remaining about 6,383 animals; of those, 4,718 (74%) mortality (74% and 54%, respectively) was are mortalities that would have occurred if not attributed to a specific cause and may be the population were stable, and 1,666 (26%) the result of nutritional stress

    Trends and Potential Interactions Between Pinnipeds and Fisheries of New England and the U.S. West Coast

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    Long-term trends in the abundance and distribution of several pinniped species and commercially important fisheries of New England and the contiguous U.S. west coast are reviewed, and their actual and potential interactions discussed. Emphasis is on biological interactions or competition. The pinnipeds include the western North Atlantic stock of harbor seals, Phoca vitulina concolor; western North Atlantic gray seals, Halochoerus grypus; the U.S. stock of California sea lions, Zalophus californianus californianus; the eastern stock of Steller sea lions, Eumetopias jubatus; and Pacific harbor seals, Phoca vitulina richardii. Fisheries included are those for Atlantic cod, Gadus morhua; silver hake, Merluccius bilinearis; Atlantic herring, Clupea harengus; the coastal stock of Pacific whiting, Merluccius productus; market squid, Loligo opalescens; northern anchovy, Engraulis mordax; Pacific her-ring, Clupea pallasi; and Pacific sardine, Sardinops sagax. Most of these pinniped populations have grown exponentially since passage of the U.S. Marine Mammal Protection Act in 1972. They exploit a broad prey assemblage that includes several commercially valuable species. Direct competition with fisheries is therefore possible, as is competition for the prey of commercially valuable fish. The expanding pinniped populations, fluctuations in commercial fish biomass, and level of exploitation by the fisheries may affect this potential for competition. Concerns over pinnipeds impacting fisheries (especially those with localized spawning stocks or at low biomass levels) are more prevalent than concerns over fisheries’ impacts on pinnipeds. This review provides a framework to further evaluate potential biological interactions between these pinniped populations and the commercial fisheries with which they occur

    Identifying environmental drivers of fungal non-pollen palynomorphs in the montane forest of the eastern Andean flank, Ecuador

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    Samples taken from sedimentary archives indicate that fungal non-pollen palynomorphs (NPPs) can be used to provide information on forest cover, fire regime, and depositional environment in the eastern Andean flank montane forest of Ecuador. Within the 52 samples examined, 54 fungal NPP morphotypes are reported, of which 25 were found to be previously undescribed. Examination of fungal NPPs over a gradient of forest cover (2–64%) revealed three distinct assemblages: (1) low (Neurospora, IBB-16, HdV-201, OU-102, and OU-110 indicative of an open degraded landscape; (2) medium (8–32%) forest cover Cercophora-type 1, Xylariaceae, Rosellinia-type, Kretzschmaria deusta, Amphirosellinia, Sporormiella, and Glomus suggestive of a forested landscape disturbed by herbivores and soil erosion; and (3) high (32–63%) forest cover Anthostomella fuegiana, OU-5, OU-101, OU-108, and OU-120. Environmental variables for forest cover (forest pollen), available moisture (aquatic remains), regional fire regime (microcharcoal), and sediment composition (organic carbon) were found to explain ~40% of the variance in the fungal NPP data set. Fire was found to be the primary control on fungal NPP assemblage composition, with available moisture and sediment composition the next most important factors

    Droit politique

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    This paper, a revised version of lectures given in Paris in 2016, examines the contribution that French jurists have made to the development of political jurisprudence. It argues that that contribution can most concisely be presented by examining the manner in which the distinctive concept of "droit politique" was devised and has evolved in French legal and political thought. The paper considers the pioneering contributions of Bodin, Montesquieu and Rousseau, examines the role the concept performed in revolutionary debates, and explains its subsequent development in the nineteenth and twentieth centuries
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