Ozone depletion and UVB radiation: Impact on plant DNA damage in southern South America

The primary motivation behind the considerable effort in studying stratospheric ozone depletion is the potential for biological consequences of increased solar UVB (280–315 nm) radiation. Yet, direct links between ozone depletion and biological impacts have been established only for organisms of Antarctic waters under the influence of the ozone “hole;” no direct evidence exists that ozone-related variations in UVB affect ecosystems of temperate latitudes. Indeed, calculations based on laboratory studies with plants suggest that the biological impact of ozone depletion (measured by the formation of cyclobutane pyrimidine dimers in DNA) is likely to be less marked than previously thought, because UVA quanta (315–400 nm) may also cause significant damage, and UVA is unaffected by ozone depletion. Herein, we show that the temperate ecosystems of southern South America have been subjected to increasingly high levels of ozone depletion during the last decade. We found that in the spring of 1997, despite frequent cloud cover, the passages of the ozone hole over Tierra del Fuego (55° S) caused concomitant increases in solar UV and that the enhanced ground-level UV led to significant increases in DNA damage in the native plant Gunnera magellanica. The fluctuations in solar UV explained a large proportion of the variation in DNA damage (up to 68%), particularly when the solar UV was weighted for biological effectiveness according to action spectra that assume a sharp decline in quantum efficiency with increasing wavelength from the UVB into the UVA regions of the spectrum.

Biogeographic range expansion into South America by Coccidioides immitis mirrors New World patterns of human migration

Long-distance population dispersal leaves its characteristic signature in genomes, namely, reduced diversity and increased linkage between genetic markers. This signature enables historical patterns of range expansion to be traced. Herein, we use microsatellite loci from the human pathogen Coccidioides immitis to show that genetic diversity in this fungus is geographically partitioned throughout North America. In contrast, analyses of South American C. immitis show that this population is genetically depauperate and was founded from a single North American population centered in Texas. Variances of allele distributions show that South American C. immitis have undergone rapid population growth, consistent with an epidemic increase in postcolonization population size. Herein, we estimate the introduction into South America to have occurred within the last 9,000–140,000 years. This range increase parallels that of Homo sapiens. Because of known associations between Amerindians and this fungus, we suggest that the colonization of South America by C. immitis represents a relatively recent and rapid codispersal of a host and its pathogen.

Emergence of a new epidemic/epizootic Venezuelan equine encephalitis virus in South America.

One of the most important questions in arbovirology concerns the origin of epidemic Venezuelan equine encephalitis (VEE) viruses; these viruses caused periodic, extensive epidemics/epizootics in the Americas from 1938-1973 (reaching the United States in 1971) but had recently been presumed extinct. We have documented the 1992 emergence of a new epidemic/epizootic VEE virus in Venezuela. Phylogenetic analysis of strains isolated during two outbreaks indicated that the new epidemic/epizootic virus(es) evolved recently from an enzootic VEE virus in northern South America. These results suggest continued emergence of epizootic VEE viruses; surveillance of enzootic viruses and routine vaccination of equines should therefore be resumed.

Climatic evolution of eastern South America during the last deglaciation: a paleoceanographic approach

Para dar suporte ao atual debate sobre as consequências climáticas da liberação antropogênica de CO2 na atmosfera, o refinamento do conhecimento sobre mudanças climáticas e oceanográficas no passado é necessário. A Circulação de Revolvimento Meridional do Atlântico (CRMA) tem papel fundamental na oceanografia e clima das áreas sob influência do Oceano Atlântico, controlando diretamente a estratificação e distribuição de massas d\'água, a quantidade de calor transportada pelo oceano e os ciclo e armazenamento de compostos químicos, como o CO2 em mar profundo. A formação e circulação da Água Intermediária Antártica (AIA), envolvida no transporte de calor e sal para o giro subtropical do Hemisfério Sul e nas teleconexões climáticas entre altas e baixas latitudes, é componente importante do ramo superior da CRMA. A reconstrução de propriedades de massas de água intermediárias é, portanto, importante para a compreensão dos sistemas de retroalimentação entre oceano-clima. No entanto, informações quanto a evolução da AIA continuam limitadas. Oscilações da CRMA e consequentes mudanças na distribuição de calor tem implicações importantes para o clima Sul Americano, influenciando a disponibilidade de umidade para o Sistema de Monções Sul Americano (SMSA), via temperatura da superfície marinha e posicionamento da Zona de Convergência Intertropical. Neste trabalho nós reconstruímos a assinatura isotópica da AIA durante os estágios isotópicos marinhos 2 e 3 (41-12 cal ka AP) usando isótopos de carbono e oxigênio de foraminíferos bentônicos (gêneros Cibicidoides e Uvigerina) de um testemunho de sedimentos marinhos datados por radiocarbono (1100 m de profundidade e a 20°S na costa do Brasil). Concluímos que propriedades físicas e químicas da AIA mudaram durante os estadiais Heinrich 3 e 4, provavelmente como consequência de enfraquecimento da CRMA durante estes períodos. Também reconstruímos as condições continentais do leste brasileiro entre o último máximo glacial e a deglaciação (23-12 cal ka AP) baseadas em razões Ti/Ca de nosso testemunho de sedimentos marinhos como indicadoras de aporte terrígeno do Rio Doce. A maior parte da chuva que cai na Bacia do Rio Doce está relacionada a atividade do SMAS. Nosso registro de Ti/Ca em conjunto com \'\'delta\' POT.18\'O de espeleotemas da Caverna Lapa Sem Fim, também no leste do Brasil, sugere diminuição marcante da chuva durante o interestadial Bølling-Allerød, provavelmente relacionada a enfraquecimento do SMAS. Ademais comparamos as razões de Ti/Ca com dados de saída da rodada SYNTRACE do modelo climático CCSM3 com forçantes transientes para a última deglaciação. Os registros geoquímicos e a saída do modelo mostram resultados consistentes entre si e sugerem que o leste da América do Sul passou pelo seu período mais seco de toda a última deglaciação durante o interestadial Bølling-Allerød, provavelmente relacionado ao enfraquecimento do SMAS.

Mangrove, Crab and Shorebird Activity as Bioindicators to the Health Status of Mangrove Ecosystems along the Surinamese Coastline, South America

This study focused on the shorebird activity along the Surinamese coast in relation to the mangrove ecosystem health. The health of three estuarine mangrove areas was assessed using important bioindicators of the mangrove ecosystem: crabs, birds and mangroves. Mangrove vegetation was measured at Weg Naar Zee, Matapica canal delta and Coronie coast. Crab activity was measured by burrow and crab counts. Occurring shorebirds were also counted at these areas. The results show that mangrove regeneration and shorebird activity is significantly related to the health of the ecosystem. Weg Naar Zee was the most damaged and highest at risk. Matapica canal delta and the Coronie coast were the least damaged, with Coronie coast showing greatest health and biodiversity of the indicators.

Studies of fossil mammals of South America.

v.1:no.1(1930)

Catalogue of birds of the Americas and the adjacent islands in Field Museum of Natural History and including all species and subspecies known to occur in North America, Mexico, Central America, South America, the West Indies, and islands of the Caribbean Sea, the Galapagos Archipelago, and other islands which may properly be included on account of their faunal affinities.

v.13:pt.1:no.1(1942)

[ Portolan chart of eastern North and Central America and northern South America] : manuscript, 1659

Autograph (signed) map. Includes inscription: Made by Nicholas Comberford dwelling neare to the west end of the school house at the Sign of the Platt in Redcliffe. Anno 1659.

South America, 1807 (Image 2 of 7) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Colombia Prima or South America : in which it has been attempted to delineate the extent of our knowledge of that continent, extracted chiefly from the original manuscript maps of ... Pinto, likewise fom those of João Joaquin da Rocha, João da Costa Ferreira ... Francisco Manuel Sobreviela &c. and from the most authentic edited accounts of those countries, digested & constructed by ... Louis Stanislas D'Arcy Delarochette. It was published by William Faden geographer to His Majesty and to His Royal Highness the Prince of Wales in June 4th, 1807. Scale [ca. 1:3,000,000]. This layer is image 2 of 7 total images of the eight sheet map, representing the northern portion of the map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the South America Lambert Conformal Conic projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, mines, tribes, and more. Relief shown by hachures. Includes notes.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

South America, 1807 (Image 3 of 7) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Colombia Prima or South America : in which it has been attempted to delineate the extent of our knowledge of that continent, extracted chiefly from the original manuscript maps of ... Pinto, likewise fom those of João Joaquin da Rocha, João da Costa Ferreira ... Francisco Manuel Sobreviela &c. and from the most authentic edited accounts of those countries, digested & constructed by ... Louis Stanislas D'Arcy Delarochette. It was published by William Faden geographer to His Majesty and to His Royal Highness the Prince of Wales in June 4th, 1807. Scale [ca. 1:3,000,000]. This layer is image 3 of 7 total images of the eight sheet map, representing the eastern portion of the map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the South America Lambert Conformal Conic projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, mines, tribes, and more. Relief shown by hachures. Includes notes.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

South America, 1807 (Image 4 of 7) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Colombia Prima or South America : in which it has been attempted to delineate the extent of our knowledge of that continent, extracted chiefly from the original manuscript maps of ... Pinto, likewise fom those of João Joaquin da Rocha, João da Costa Ferreira ... Francisco Manuel Sobreviela &c. and from the most authentic edited accounts of those countries, digested & constructed by ... Louis Stanislas D'Arcy Delarochette. It was published by William Faden geographer to His Majesty and to His Royal Highness the Prince of Wales in June 4th, 1807. Scale [ca. 1:3,000,000]. This layer is image 4 of 7 total images of the eight sheet map, representing the northeast portion of the map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the South America Lambert Conformal Conic projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, mines, tribes, and more. Relief shown by hachures. Includes notes.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

South America, 1807 (Image 5 of 7) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Colombia Prima or South America : in which it has been attempted to delineate the extent of our knowledge of that continent, extracted chiefly from the original manuscript maps of ... Pinto, likewise fom those of João Joaquin da Rocha, João da Costa Ferreira ... Francisco Manuel Sobreviela &c. and from the most authentic edited accounts of those countries, digested & constructed by ... Louis Stanislas D'Arcy Delarochette. It was published by William Faden geographer to His Majesty and to His Royal Highness the Prince of Wales in June 4th, 1807. Scale [ca. 1:3,000,000]. This layer is image 5 of 7 total images of the eight sheet map, representing the southwest portion of the map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the South America Lambert Conformal Conic projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, mines, tribes, and more. Relief shown by hachures. Includes notes.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

South America, 1807 (Image 6 of 7) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Colombia Prima or South America : in which it has been attempted to delineate the extent of our knowledge of that continent, extracted chiefly from the original manuscript maps of ... Pinto, likewise fom those of João Joaquin da Rocha, João da Costa Ferreira ... Francisco Manuel Sobreviela &c. and from the most authentic edited accounts of those countries, digested & constructed by ... Louis Stanislas D'Arcy Delarochette. It was published by William Faden geographer to His Majesty and to His Royal Highness the Prince of Wales in June 4th, 1807. Scale [ca. 1:3,000,000]. This layer is image 6 of 7 total images of the eight sheet map, representing the western portion of the map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the South America Lambert Conformal Conic projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, mines, tribes, and more. Relief shown by hachures. Includes notes.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

South America, 1807 (Image 7 of 7) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Colombia Prima or South America : in which it has been attempted to delineate the extent of our knowledge of that continent, extracted chiefly from the original manuscript maps of ... Pinto, likewise fom those of João Joaquin da Rocha, João da Costa Ferreira ... Francisco Manuel Sobreviela &c. and from the most authentic edited accounts of those countries, digested & constructed by ... Louis Stanislas D'Arcy Delarochette. It was published by William Faden geographer to His Majesty and to His Royal Highness the Prince of Wales in June 4th, 1807. Scale [ca. 1:3,000,000]. This layer is image 7 of 7 total images of the eight sheet map, representing the southern portion of the map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the South America Lambert Conformal Conic projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, mines, tribes, and more. Relief shown by hachures. Includes notes.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.