GEOMORPHIC RECORDS OF LITHOSPHERIC PROCESSES: CASE STUDIES IN THE NORTH AND SOUTH AMERICAN CORDILLERA

2018 ◽  
Author(s):  
Brian J. Yanites ◽  
◽  
Nathaniel Mitchell ◽  
Brigid M. Lynch
2020 ◽  
Author(s):  
Barbara Carrapa ◽  
◽  
Andrea Stevens Goddard ◽  
Scott Meek ◽  
Peter G. DeCelles

2021 ◽  
Vol 10 (11) ◽  
pp. e44101118992
Author(s):  
Edson Oliveira Pereira ◽  
Bernardino Vitoy ◽  
Daniel Ignacchiti Lacerda ◽  
Damaris Silveira

There are indigenous people on the North and South American continents who dwelled there before the Portuguese, Spanish, French, English, or Dutch invasions. With the European colonization, much of the indigenous population was enslaved, Christianized, and decimated almost completely. Presently, besides everyday challenges, such as rights and access to the homeland, agribusiness clashes, and other threats, there is a precariousness in the management and provision of healthcare provided to the Amerindians. This paper aims to draw a timeline on the state of health of Brazilian indigenous people, identifying its subjects, assessing its contexts, and discussing the legal milestones. Indigenous health policies hold (or at least should hold) a central position in the provision of healthcare to the indigenous population wherein they offer integral, universal, and equanimous healthcare services. Despite this, the urge to recognize some fragility restrains the management and provision of the health policies for the indigenous people.


2021 ◽  
pp. 1035-1057
Author(s):  
Pekka Hämäläinen

This chapter re-examines the powerful nomadic-equestrian societies in the North and South American grasslands and makes the case for a distinctive imperial formation, the kinetic empire. Kinetic empires were shape-shifting, action-based regimes that turned mobility into an imperial strategy and revolved around mobile activities: long-distance raiding, seasonal expansions, transnational diplomatic missions, semi-permanent trade fairs, recurring political assemblies, and control over shifting nodes. Their governing systems were light and flexible, and they rose and stayed in power by capitalizing on their superior capacity to access and connect political and economic centers around them. The Comanche and Lakota Indians created the Western Hemisphere’s most prominent examples of kinetic empires in the North American Great Plains. In South America the Araucanians frustrated European colonizing efforts, commanded a large and expanding territory, and pulled other Native groups on their orbit, but lacked the Comanches’ and Lakotas’ strong collective identities and political unity.


1998 ◽  
Vol 76 (10) ◽  
pp. 1812-1817 ◽  
Author(s):  
Sue Porebski ◽  
Paul M Catling

To improve the intraspecific classification of Fragaria chiloensis (L.) Duchesne, 35 plants including 5 North American ssp. lucida, 15 North American ssp. pacifica, and 15 South American ssp. chiloensis were analysed using random amplified polymorphic DNA (RAPDs). From 100 primers screened, 12 were selected providing 62 scorable polymorphic bands. The phenogram (cophenetic correlation, r = 0.99) based on UPGMA clustering of Jaccard's coefficients revealed a clear division between North American and South American plants, but only partial separation was shown between the two North American subspecies. This is the first comprehensive molecular evidence for major genetic divergence between the North American and South American subspecies of F. chiloensis and suggests greater genetic variation within the Canadian material of the North American ssp. pacifica than within the South American ssp.chiloensis. These findings strongly support protection and utilization of wild Canadian Fragaria germplasm for crop improvement.Key words: strawberry, Fragaria chiloensis, ssp. chiloensis, ssp. pacifica, ssp. lucida, RAPD, variation, germplasm, Canada, United States, Chile.


2021 ◽  
Author(s):  
Weliton D Silva ◽  
Lawrence M Hanks ◽  
Judith A Mongold-Diers ◽  
Anna C Grommes ◽  
José Maurício S Bento ◽  
...  

Abstract An increasing body of evidence indicates that cerambycid beetles native to different continents may share pheromone components, suggesting that these compounds arose as pheromone components early in the evolution of the family. Here, we describe the identification and field testing of the pheromone blends of two species in the subfamily Cerambycinae that share 2-nonanone as an important component of their male-produced aggregation-sex pheromones, the South American Stizocera consobrina Gounelle (tribe Elaphidiini) and the North American Heterachthes quadrimaculatus Haldeman (tribe Neoibidionini). Along with 2-nonanone, males of S. consobrina also produce 1-(1H-pyrrol-2-yl)-1,2-propanedione, whereas males of H. quadrimaculatus produce 10-methyldodecanol. Field bioassays conducted in Brazil (targeting S. consobrina) and Illinois (targeting H. quadrimaculatus) demonstrated that adults of both species were attracted only by the blends of both their pheromone components, and not to the individual components. The use of the pyrrole as a critical component for the former species is further evidence that this compound is a common pheromone structure among cerambycines in different biogeographical regions of the world.


2016 ◽  
Vol 12 (4) ◽  
pp. 20160062 ◽  
Author(s):  
Kieren J. Mitchell ◽  
Sarah C. Bray ◽  
Pere Bover ◽  
Leopoldo Soibelzon ◽  
Blaine W. Schubert ◽  
...  

The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear ( Tremarctos ornatus ), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears ( Tremarctos ), South American short-faced bears ( Arctotherium ) and North American short-faced bears ( Arctodus ) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears ( Arctodus and Arctotherium ), potentially as an adaptation to dominate competition for megafaunal carcasses.


TAPPI Journal ◽  
2012 ◽  
Vol 11 (3) ◽  
pp. 21-27 ◽  
Author(s):  
PETER W. HART

Several mills in North America have been successful in using xylanase enzymes expressed from Trichoderma reesei (a fungus) as part of their bleaching sequence for many years. These mills process hardwood and softwood species, with and without oxygen delignification. These mills also use three-, four-, and five-stage bleaching sequences. North American mills tend to report increased pulp brightness ceilings and decreased bleaching costs as benefits associated with the application of enzymes in the bleaching process. Laboratory testing suggests that eucalyptus pulp is highly susceptible to fungal- and bacterial-derived enzyme bleaching and should result in significant cost savings in South American mills. At least four different mills in South America have attempted to perform enzyme bleaching trials using bacterial-derived enzymes. Each of these mill trials resulted in significantly increased operating costs and/or unsustainable operating conditions. More recently, one of these South American mills performed a short trial using a commercially available, fungal-derived enzyme. This trial was technically successful. This report attempts to determine why the South American mill experiences with bacterial-derived enzymes have been poor, while North American mills and the one South American mill trial have had good results with fungal-derived enzymes. Operating conditions and trial goals for the North and South American mills also were examined.


1966 ◽  
Vol 44 (7) ◽  
pp. 899-928 ◽  
Author(s):  
Cecily Joseph ◽  
Margaret Heimburger

The American species of Anemone L. (section Eriocephalus Hook. f. & Thoms.) with tuberous rootstocks were studied by biosystematic methods. Anemone caroliniana Walt., A. heterophylla Nutt. ex Torr. & Gray, A. tuberosa Rydb., and A. edwardsiana Tharp (tentatively) are recognized from North America and A. decapetala Ard., A. triternata Vahl, and A. cicutifolia Johnst. from South America. Karyotypes of the diploid species (2n = 16), A. heterophylla, A. tuberosa, A. decapetala, and A. triternata are described. They resemble the karyotype of A. caroliniana published earlier. Anemone edwardsiana and A. cicutifolia are also presumed diploid from stomatal and pollen grain studies. A new taxon (2n = 32), of undecided status, was obtained from Chile. North American plants included by authors in A. decapetala are here referred to A. heterophylla. The North and South American species appear to form two separate groups, the species of each continent being more closely related among themselves than to those of the other continent. Fewer stomata, larger chromosome size, and higher DNA content are characteristic of the North American species. Additional support for the separation of the two groups derives from limited meiotic studies which indicate a larger number of inversion differences in inter- than in intra-continental hybrids.


2021 ◽  
Author(s):  
Peter Somkuti ◽  
Christopher O'Dell ◽  
Gregory McGarragh ◽  
Sean Crowell ◽  
Eric Burgh ◽  
...  

<p>Since its selection as a NASA Earth Venture mission in late 2016, the Geostationary Carbon Cycle Observatory (GeoCarb) has been in steady development. Launch is planned for 2024, and the instrument will be hosted on a commercial platform in geostationary orbit. Featuring a geostationary view over the western hemisphere, GeoCarb will be able to provide atmospheric total-column trace gas amounts to help answer scientific questions related to the carbon cycle of North and South America such as the quantification of regional- and urban-scale carbon dioxide emissions.</p><p>GeoCarb’s instrument design features a two-arm grating-type spectrometer with four separate bands at wavelengths 0.765 µm, 1.606 µm, 2.065 µm and 2.323 µm in order to measure atmospheric absorption features of oxygen (O2), carbon dioxide (CO2), methane (CH4) and carbon monoxide (CO). With the spacecraft position being fixed relative to Earth and the instrument’s scan mirror assembly, GeoCarb will be able to selectively point at locations visible from its position over the American continents. As a result, very different sampling strategies can be employed,  compared to polar orbiting instruments which are generally limited to revisit periods of days and weeks. For routine operations, the North and South American land masses will be scanned at least once per day – depending on the final choice of scanning strategy, large portions of the American continents could be measured twice per day. Thanks to the flexible scanning capability, there is also the possibility for special campaigns which can feature many repeated measurements over targets of special interest throughout a single day.</p><p>In this presentation, we summarize the most recent development status of the GeoCarb instrument and the various retrieval algorithms that will be used for data product generation. We will share updates on the impact of sub-slit scene inhomogeneity on retrieval results, and how a slit homogenizer can mitigate those effects. Further, we report on our analyses regarding the correction of the so-called keystone optical aberration. Finally, we provide a detailed overview of GeoCarb’s capabilities for the retrieval of solar-induced chlorophyll fluorescence.</p>


Sign in / Sign up

Export Citation Format

Share Document