10,896 research outputs found

    Opposite Arrows of Time Can Reconcile Relativity and Nonlocality

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    We present a quantum model for the motion of N point particles, implying nonlocal (i.e., superluminal) influences of external fields on the trajectories, that is nonetheless fully relativistic. In contrast to other models that have been proposed, this one involves no additional space-time structure as would be provided by a (possibly dynamical) foliation of space-time. This is achieved through the interplay of opposite microcausal and macrocausal (i.e., thermodynamic) arrows of time.Comment: 12 pages, 4 figures; v5: section headlines adde

    Analysis of Arkansas Fur Harvest Records - 1942-1984: III. Harvest-Price Relationships

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    Correlation and linear regression analyses between mean annual pelt price and total harvest of 13 Arkansas furbearer species between 1965 and 1983 were performed for state and regions (Ozark Mountains, Ouachita Mountains, Gulf Coastal Plain, and Mississippi Delta). Statewide, strong correlations (r \u3e 0.80) were identified for bobcat (Felis rufus), coyote (Canis latrans), gray fox (Urocyon cinereoargenteus), mink (Mustela vison), nutria (Myocastor coypus), opossum (Didelphis virginiana), and raccoon (Procyonlotor). Moderate correlations (r = 0.55 - 0.79) were identified for eastern spotted skunk (Spilogale putorius), muskrat (Ondatra zibethicus), river otter (Lutra canadensis), and striped skunk (Mephitis mephitis). Nonsignificant correlations (r \u3c 0.468) were shown for beaver (Castor canadensis) and long-tailed weasel (Mustela frenata). Regional differences were noted for each species

    Analysis of Arkansas Fur Harvest Records - 1942-1984: II. Species Accounts

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    Fur harvest records were maintained by the Arkansas Game and Fish Commission on the following 16 furbearers: badger, beaver, bobcat, eastern spotted skunk (civet), coyote, gray fox, long-tailed weasel, mink, muskrat, nutria, opossum, raccoon, red fox, red wolf, river otter, and striped skunk. These harvest records were analyzed for each species in terms of mean pelt price and numbers of pelt sold by region (Ozark Mountains, Ouachita Mountains, Gulf Coastal Plain, and Mississippi Delta) per year. Historical or biological influences important in interpreting species accounts are presented

    Mentoring to reduce antisocial behaviour in childhood

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    The effects of social interventions need to be examined in real life situations as well as studie

    Analysis of Arkansas Fur Harvest Records - 1942-1984: I. State and Regional Accounts

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    Fur harvest records maintained by the Arkansas Game and Fish Commission from 1942-1984 summarized the number of pelts sold by region (Ozark Mountains, Ouachita Mountains, Gulf Coastal Plain, and Mississippi Delta) and the average price per pelt for 16 furbearers. Analysis of these records showed that in the 1979-80 trapping season (the record year for both harvest and value both in Arkansas and the nation), the value of the Arkansas fur harvest ranked 14th nationally (2.12% of total national value). Fur harvests in Arkansas were high in the 1940\u27s, declined in the 1950\u27s and 1960\u27s and then experienced a rapid increase in the 1970\u27s and into the 1980\u27s. In all decades, the Mississippi Delta has ranked first in both numbers of pelts harvested and total value. With the exception of the 1970\u27s, the Delta has been followed by the Ozark Mountains, the Gulf Coastal Plain, and the Ouachita Mountain Region

    Recurrent geomagnetic storms and relativistic electron enhancements in the outer magnetosphere: ISTP coordinated measurements

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    New, coordinated measurements from the International Solar-Terrestrial Physics (ISTP) constellation of spacecraft are presented to show the causes and effects of recurrent geomagnetic activity during recent solar minimum conditions. It is found using WIND and POLAR data that even for modest geomagnetic storms, relativistic electron fluxes are strongly and rapidly enhanced within the outer radiation zone of the Earth\u27s magnetosphere. Solar wind data are utilized to identify the drivers of magnetospheric acceleration processes. Yohkoh solar soft X-ray data are also used to identify the solar coronal holes that produce the high-speed solar wind streams which, in turn, cause the recurrent geomagnetic activity. It is concluded that even during extremely quiet solar conditions (sunspot minimum) there are discernible coronal holes and resultant solar wind streams which can produce intense magnetospheric particle acceleration. As a practical consequence of this Sun-Earth connection, it is noted that a long-lasting E\u3e1MeV electron event in late March 1996 appears to have contributed significantly to a major spacecraft (Anik E1) operational failure

    Contrasting geochemical signatures on land from the Middle and Late Permian extinction events

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    The end of the Palaeozoic is marked by two mass‐extinction events during the Middle Permian (Capitanian) and the Late Permian (Changhsingian). Given similarities between the two events in geochemical signatures, such as large magnitude negative ή 13 C anomalies, sedimentological signatures such as claystone breccias, and the approximate contemporaneous emplacement of large igneous provinces, many authors have sought a common causal mechanism. Here, a new high‐resolution continental record of the Capitanian event from Portal Mountain, Antarctica, is compared with previously published Changhsingian records of geochemical signatures of weathering intensity and palaeoclimatic change. Geochemical means of discriminating sedimentary provenance (Ti/Al, U/Th and La/Ce ratios) all indicate a common provenance for the Portal Mountain sediments and associated palaeosols, so changes spanning the Capitanian extinction represent changes in weathering intensity rather than sediment source. Proxies for weathering intensity chemical index of alteration, ∆ W and rare earth element accumulation all decline across the Capitanian extinction event at Portal Mountain, which is in contrast to the increased weathering recorded globally at the Late Permian extinction. Furthermore, palaeoclimatic proxies are consistent with unchanging or cooler climatic conditions throughout the Capitanian event, which contrasts with Changhsingian records that all indicate a significant syn‐extinction and post‐extinction series of greenhouse warming events. Although both the Capitanian and Changhsingian event records indicate significant redox shifts, palaeosol geochemistry of the Changhsingian event indicates more reducing conditions, whereas the new Capitanian record of reduced trace metal abundances (Cr, Cu, Ni and Ce) indicates more oxidizing conditions. Taken together, the differences in weathering intensity, redox and the lack of evidence for significant climatic change in the new record suggest that the Capitanian mass extinction was not triggered by dyke injection of coal‐beds, as in the Changhsingian extinction, and may instead have been triggered directly by the Emeishan large igneous province or by the interaction of Emeishan basalts with platform carbonates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108696/1/sed12117.pd

    Brief of Law Professors as \u3cem\u3eAmici Curiae\u3c/em\u3e in Support of Petitioner

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    Amici curiae respectfully submit this brief in support of Petitioner, Edward Lane, encouraging the reversal of the judgment of the Eleventh Circuit, because the judgment below is inconsistent with both the Court’s general historical approach to public employee speech and the specific approach to such speech that the Court adopted in Garcetti v. Ceballos, 547 U.S. 410 (2006). Amici are law professors who teach and write about the constitutional rights of public employees and have published a number of scholarly articles on these topics. Amici have no financial stake in the outcome of this case, and in this brief do not ask the Court to reconsider Garcetti. But we are troubled by the tendency in some courts of appeals to misread this Court’s decision in Garcettito articulate ever-broadening readings of the narrow exemption from First Amendment protection the Court carved out. We file this brief to urge this Court to correct these rulings by clarifying the narrow nature of the exemption it recognized
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