991 resultados para Indians of North America -- Antiquities


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An exemination of a series of indicators of economic integration in the western hemisphere (Canada-USA-Latin America) indicates that it is proceeding under the influence of formal trade agreements and informal forces including technological change, multinational firm rationalization and location strategies, etc.

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Common Loon (Gavia immer) is considered an emblematic and ecologically important example of aquatic-dependent wildlife in North America. The northern breeding range of Common Loon has contracted over the last century as a result of habitat degradation from human disturbance and lakeshore development. We focused on the state of New Hampshire, USA, where a long-term monitoring program conducted by the Loon Preservation Committee has been collecting biological data on Common Loon since 1976. The Common Loon population in New Hampshire is distributed throughout the state across a wide range of lake-specific habitats, water quality conditions, and levels of human disturbance. We used a multiscale approach to evaluate the association of Common Loon and breeding habitat within three natural physiographic ecoregions of New Hampshire. These multiple scales reflect Common Loon-specific extents such as territories, home ranges, and lake-landscape influences. We developed ecoregional multiscale models and compared them to single-scale models to evaluate model performance in distinguishing Common Loon breeding habitat. Based on information-theoretic criteria, there is empirical support for both multiscale and single-scale models across all three ecoregions, warranting a model-averaging approach. Our results suggest that the Common Loon responds to both ecological and anthropogenic factors at multiple scales when selecting breeding sites. These multiscale models can be used to identify and prioritize the conservation of preferred nesting habitat for Common Loon populations.

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Understanding and predicting changes in storm tracks over longer time scales is a challenging problem, particularly in the North Atlantic. This is due in part to the complex range of forcings (land–sea contrast, orography, sea surface temperatures, etc.) that combine to produce the structure of the storm track. The impact of land–sea contrast and midlatitude orography on the North Atlantic storm track is investigated through a hierarchy of GCM simulations using idealized and “semirealistic” boundary conditions in a high-resolution version of the Hadley Centre atmosphere model (HadAM3). This framework captures the large-scale essence of features such as the North and South American continents, Eurasia, and the Rocky Mountains, enabling the results to be applied more directly to realistic modeling situations than was possible with previous idealized studies. The physical processes by which the forcing mechanisms impact the large-scale flow and the midlatitude storm tracks are discussed. The characteristics of the North American continent are found to be very important in generating the structure of the North Atlantic storm track. In particular, the southwest–northeast tilt in the upper tropospheric jet produced by southward deflection of the westerly flow incident on the Rocky Mountains leads to enhanced storm development along an axis close to that of the continent’s eastern coastline. The approximately triangular shape of North America also enables a cold pool of air to develop in the northeast, intensifying the surface temperature contrast across the eastern coastline, consistent with further enhancements of baroclinicity and storm growth along the same axis.

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It is widely accepted, based on data from the last few decades and on model simulations, that anthropogenic climate change will cause increased fire activity. However, less attention has been paid to the relationship between abrupt climate changes and heightened fire activity in the paleorecord. We use 35 charcoal and pollen records to assess how fire regimes in North America changed during the last glacial–interglacial transition (15 to 10 ka), a time of large and rapid climate changes. We also test the hypothesis that a comet impact initiated continental-scale wildfires at 12.9 ka; the data do not support this idea, nor are continent-wide fires indicated at any time during deglaciation. There are, however, clear links between large climate changes and fire activity. Biomass burning gradually increased from the glacial period to the beginning of the Younger Dryas. Although there are changes in biomass burning during the Younger Dryas, there is no systematic trend. There is a further increase in biomass burning after the Younger Dryas. Intervals of rapid climate change at 13.9, 13.2, and 11.7 ka are marked by large increases in fire activity. The timing of changes in fire is not coincident with changes in human population density or the timing of the extinction of the megafauna. Although these factors could have contributed to fire-regime changes at individual sites or at specific times, the charcoal data indicate an important role for climate, and particularly rapid climate change, in determining broad-scale levels of fire activity.

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Land cover maps at different resolutions and mapping extents contribute to modeling and support decision making processes. Because land cover affects and is affected by climate change, it is listed among the 13 terrestrial essential climate variables. This paper describes the generation of a land cover map for Latin America and the Caribbean (LAC) for the year 2008. It was developed in the framework of the project Latin American Network for Monitoring and Studying of Natural Resources (SERENA), which has been developed within the GOFC-GOLD Latin American network of remote sensing and forest fires (RedLaTIF). The SERENA land cover map for LAC integrates: 1) the local expertise of SERENA network members to generate the training and validation data, 2) a methodology for land cover mapping based on decision trees using MODIS time series, and 3) class membership estimates to account for pixel heterogeneity issues. The discrete SERENA land cover product, derived from class memberships, yields an overall accuracy of 84% and includes an additional layer representing the estimated per-pixel confidence. The study demonstrates in detail the use of class memberships to better estimate the area of scarce classes with a scattered spatial distribution. The land cover map is already available as a printed wall map and will be released in digital format in the near future. The SERENA land cover map was produced with a legend and classification strategy similar to that used by the North American Land Change Monitoring System (NALCMS) to generate a land cover map of the North American continent, that will allow to combine both maps to generate consistent data across America facilitating continental monitoring and modeling

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We estimate crustal structure and thickness of South America north of roughly 40 degrees S. To this end, we analyzed receiver functions from 20 relatively new temporary broadband seismic stations deployed across eastern Brazil. In the analysis we include teleseismic and some regional events, particularly for stations that recorded few suitable earthquakes. We first estimate crustal thickness and average Poisson`s ratio using two different stacking methods. We then combine the new crustal constraints with results from previous receiver function studies. To interpolate the crustal thickness between the station locations, we jointly invert these Moho point constraints, Rayleigh wave group velocities, and regional S and Rayleigh waveforms for a continuous map of Moho depth. The new tomographic Moho map suggests that Moho depth and Moho relief vary slightly with age within the Precambrian crust. Whether or not a positive correlation between crustal thickness and geologic age is derived from the pre-interpolation point constraints depends strongly on the selected subset of receiver functions. This implies that using only pre-interpolation point constraints (receiver functions) inadequately samples the spatial variation in geologic age. The new Moho map also reveals an anomalously deep Moho beneath the oldest core of the Amazonian Craton.

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In a recent study we found that crania from South Amerindian populations on each side of the Andes differ significantly in terms of craniofacial shape. Western populations formed one morphological group, distributed continuously over 14,000 km from the Fuegian archipelago (southern Chile) to the Zulia region (northwestern Venezuela). Easterners formed another group, distributed from the Atlantic Coast up to the eastern foothills of the Andes. This differentiation is further supported by several genetic studies, and indirectly by ecological and archaeological studies. Some authors suggest that this dual biological pattern is consistent with differential rates of gene flow and genetic drift operating on both sides of the Cordillera due to historical reasons. Here we show that such East-West patterning is also observable in North America. We suggest that the ""ecological zones model"" proposed by Dixon, explaining the spread of the early Americans along a Pacific dispersal corridor, combined with the evolution of different population dynamics in both regions, is the most parsimonious mechanism to explain the observed patterns of within- and between-group craniofacial variability. (c) 2007 Elsevier Ltd. All rights reserved.

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Includes bibliography

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Includes bibliography

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In worldwide aviation operations, bird collisions with aircraft and ingestions into engine inlets present safety hazards and financial loss through equipment damage, loss of service and disruption to operations. The problem is encountered by all types of aircraft, both military and commercial. Modern aircraft engines have achieved a high level of reliability while manufacturers and users continually strive to further improve the safety record. A major safety concern today includes common-cause events which involve significant power loss on more than one engine. These are externally-inflicted occurrences, with the most frequent being encounters with flocks of birds. Most frequently these encounters occur during flight operations in the area on or near airports, near the ground instead of at cruise altitude conditions. This paper focuses on the increasing threat to aircraft and engines posed by the recorded growth in geese populations in North America. Service data show that goose strikes are increasing, especially in North America, consistent with the growing resident geese populations estimated by the United States Department of Agriculture (USDA). Airport managers, along with the governmental authorities, need to develop a strategy to address this large flocking bird issue. This paper also presents statistics on the overall status of the bird threat for birds of all sizes in North America relative to other geographic regions. Overall, the data shows that Canada and the USA have had marked improvements in controlling the threat from damaging birds - except for the increase in geese strikes. To reduce bird ingestion hazards, more aggressive corrective measures are needed in international air transport to reduce the chances of serious incidents or accidents from bird ingestion encounters. Air transport authorities must continue to take preventative and avoidance actions to counter the threat of birdstrikes to aircraft. The primary objective of this paper is to increase awareness of, and focus attention on, the safety hazards presented by large flocking birds such as geese. In the worst case, multiple engine power loss due to large bird ingestion could result in an off-airport forced landing accident. Hopefully, such awareness will prompt governmental regulatory agencies to address the hazards associated with growing populations of geese in North America.

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An important issue in both Canadian and United States immigration history has been the control of immigration, which includes possible quotas, immigration laws as well as denying entry, and finally, the deportation of immigrants. This paper is based on information that is available on the deportations of 167 people, most of them young adult males. Many assume politics was a key motivation for deportation. However, Finnish Americans were rarely deported for political activities. The paper discusses a few interesting cases of political deportations both during the interwar years, and after the Second World War. The information is mostly based on the correspondence between the authorities in Finland and the United States and Canada, available at the Foreign Ministry Archives in Helsinki, Finland. Special attention is directed to the social and political background of those people and of special interest are the specific reasons, social or health problems, which seem to be the basis of most deportation decisions.

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Corporate Social Responsibility (CSR) addresses the responsibility of companies for their impacts on society. The concept of strategic CSR is becoming increasingly mainstreamed in the forest industry, but there is, however, little consensus on the definition and implementation of CSR. The objective of this research is to build knowledge on the characteristics of CSR and to provide insights on the emerging trend to increase the credibility and legitimacy of CSR through standardization. The study explores how the sustainability managers of European and North American forest companies perceive CSR and the recently released ISO 26000 guidance standard on social responsibility. The conclusions were drawn from an analysis of two data sets; multivariate survey data based on one subset of 30 European and 13 North American responses, and data obtained through in-depth interviewing of 10 sustainability managers that volunteered for an hour long phone discussion about social responsibility practices at their company. The analysis concluded that there are no major differences in the characteristics of cross-Atlantic CSR. Hence, the results were consistent with previous research that suggests that CSR is a case- and company-specific concept. Regarding the components of CSR, environmental issues and organizational governance were key priorities in both regions. Consumer issues, human rights, and financial issues were among the least addressed categories. The study reveals that there are varying perceptions on the ISO 26000 guidance standard, both positive and negative. Moreover, sustainability managers of European and North American forest companies are still uncertain regarding the applicability of the ISO 26000 guidance standard to the forest industry. This study is among the first to provide a preliminary review of the practical implications of the ISO 26000 standard in the forest sector. The results may be utilized by sustainability managers interested in the best practices on CSR, and also by a variety of forest industrial stakeholders interested in the practical outcomes of the long-lasting CSR debate.