907 resultados para logic and contingency in history


Relevância:

100.00% 100.00%

Publicador:

Resumo:

How and when the Americas were populated remains contentious. Using ancient and modern genome-wide data, we found that the ancestors of all present-day Native Americans, including Athabascans and Amerindians, entered the Americas as a single migration wave from Siberia no earlier than 23 thousand years ago (ka) and after no more than an 8000-year isolation period in Beringia. After their arrival to the Americas, ancestral Native Americans diversified into two basal genetic branches around 13 ka, one that is now dispersed across North and South America and the other restricted to North America. Subsequent gene flow resulted in some Native Americans sharing ancestry with present-day East Asians (including Siberians) and, more distantly, Australo-Melanesians. Putative “Paleoamerican” relict populations, including the historical Mexican Pericúes and South American Fuego-Patagonians, are not directly related to modern Australo-Melanesians as suggested by the Paleoamerican Model.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In view of ongoing debates about the future of TBLT in EFL contexts (Thomas & Reinders, 2015; Zheng & Borg, 2014), we present a detailed case study of teacher beliefs and practices regarding TBLT conducted in a secondary school in mainland China with a long history of communicative and task-based teaching approaches. We used a mixed-methods approach to gather a broad range of triangulated data, combining individual interviews, material analysis and observations coded using a novel task-focused version of the COLT scheme (Littlewood, 2011; Spada & Fröhlich, 1995). Quantitative and qualitative findings revealed positive beliefs about TBLT principles in general, reflecting strong institutional support for communicative teaching. However, there was marked variability between beliefs and practices in using tasks, especially with beginner-level learners. Most teachers demonstrated an intrinsic lack of confidence in using tasks as more than a communicative ‘add-on’ to standard form-focused teaching. We argue this demonstrates a need for building teacher autonomy (Aoki, 2002; Benson, 2007), in implementing TBLT, even in supportive settings, to support successful authentic contextualising TBLT principles in different EFL contexts.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Aim We present a molecular phylogenetic analysis of Brotogeris (Psittacidae) using several distinct and complementary approaches: we test the monophyly of the genus, delineate the basal taxa within it, uncover their phylogenetic relationships, and finally, based on these results, we perform temporal and spatial comparative analyses to help elucidate the historical biogeography of the Neotropical region. Location Neotropical lowlands, including dry and humid forests. Methods Phylogenetic relationships within Brotogeris were investigated using the complete sequences of the mitochondrial genes cyt b and ND2, and partial sequences of the nuclear intron 7 of the gene for Beta Fibrinogen for all eight species and 12 of the 17 taxa recognized within the genus (total of 63 individuals). In order to delinetae the basal taxa within the genus we used both molecular and plumage variation, the latter being based on the examination of 597 skin specimens. Dates of divergence and confidence intervals were estimated using penalized likelihood. Spatial and temporal comparative analyses were performed including several closely related parrot genera. Results Brotogeris was found to be a monophyletic genus, sister to Myiopsitta. The phylogenetic analyses recovered eight well-supported clades representing the recognized biological species. Although some described subspecies are diagnosably distinct based on morphology, there was generally little intraspecific mtDNA variation. The Amazonian species had different phylogenetic affinities and did not group in a monophyletic clade. Brotogeris diversification took place during the last 6 Myr, the same time-frame as previously found for Pionus and Pyrilia. Main conclusions The biogeographical history of Brotogeris implies a dynamic history for South American biomes since the Pliocene. It corroborates the idea that the geological evolution of Amazonia has been important in shaping its biodiversity, argues against the idea that the region has been environmentally stable during the Quaternary, and suggests dynamic interactions between wet and dry forest habitats in South America, with representatives of the Amazonian biota having several independent close relationships with taxa endemic to other biomes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this study, we provide phylogenetic and biogeographic evidence that the Trypanosomo cruzi lineages T. cruzi I (TCI) and T. cruzi IIa (TCIIa) circulate amongst non-human primates in Brazilian Amazonia, and are transmitted by Rhodnius species in overlapping arboreal transmission cycles, sporadically infecting humans. TO presented higher prevalence rates, and no lineages other than TCI and TCIIa were found in this study in wild monkeys and Rhodnius from the Amazonian region. We characterised TO and TCIIa from wild primates (16 TO and five TCIIa), Rhodnius spp, (13 TCI and nine TCIIa), and humans with Chagas disease associated with oral transmission (14 TO and five TCIIa) in Brazilian Amazonia. To our knowledge, TCIIa had not been associated with wild monkeys until now. Polymorphisms of ssrDNA, cytochrome b gene sequences and randomly amplified polymorphic DNA (RAPD) patterns clearly separated TCIIa from TCIIb-e and TCI lineages, and disclosed small intra-lineage polymorphisms amongst isolates from Amazonia. These data are important in understanding the complexity of the transmission cycles, genetic structure, and evolutionary history of T cruzi populations circulating in Amazonia, and they contribute to both the unravelling of human infection routes and the pathological peculiarities of Chagas disease in this region. (C) 2008 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper presents the results of a new investigation of the Guarani Aquifer System (SAG) in Sao Paulo state. New data were acquired about sedimentary framework, flow pattern, and hydrogeochemistry. The flow direction in the north of the state is towards the southwest and not towards the west as expected previously. This is linked to the absence of SAG outcrop in the northeast of Sao Paulo state. Both the underlying Piramboia Formation and the overlying Botucatu Formation possess high porosity (18.9% and 19.5%, respectively), which was not modified significantly by diagenetic changes. Investigation of sediments confirmed a zone of chalcedony cement close to the SAG outcrop and a zone of calcite cement in the deep confined zone. The main events in the SAG post-sedimentary history were: (1) adhesion of ferrugineous coatings on grains, (2) infiltration of clays in eodiagenetic stage, (3) regeneration of coatings with formation of smectites, (4) authigenic overgrowth of quartz and K-feldspar in advanced eodiagenetic stage, (5) bitumen cementation of Piramboia Formation in mesodiagenetic stage, (6) cementation by calcite in mesodiagenetic and telodiagenetic stages in Piramboia Formation, (7) formation of secondary porosity by dissolution of unstable minerals after appearance of hydraulic gradient and penetration of the meteoric water caused by the uplift of the Serra do Mar coastal range in the Late Cretaceous, (8) authigenesis of kaolinite and amorphous silica in unconfined zone of the SAG and cation exchange coupled with the dissolution of calcite at the transition between unconfined and confined zone, and (9) authigenesis of analcime in the confined SAG zone. The last two processes are still under operation. The deep zone of the SAG comprises an alkaline pH, Na-HCO(3) groundwater type with old water and enriched delta(13)C values (<-3.9), which evolved from a neutral pH, Ca-HCO(3) groundwater type with young water and depleted delta(13)C values (>-18.8) close to the SAG outcrop. This is consistent with a conceptual geochemical model of the SAG, suggesting dissolution of calcite driven by cation exchange, which occurs at a relatively narrow front recently moving downgradient at much slower rate compared to groundwater flow. More depleted values of delta(18)O in the deep confined zone close to the Parana River compared to values of relative recent recharged water indicate recharge occur during a period of cold climate. The SAG is a ""storage-dominated"" type of aquifer which has to be managed properly to avoid its overexploitation. (C) 2011 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This article presents a study of how contemporary Swedish lower secondary school textbooks present the emergence of the Cold War and how 10 active lower secondary school history teachers interpreted a quotation that was ambiguous in relation to the general narrative in the studied Swedish textbooks, seeking to analyse textbooks both from the perspectives of content and reception. Applying a theoretical framework of uses of history, the study finds that the narratives presented in the studied textbooks are what could be called traditional in the sense that they do not acknowledge perspective and representation in history. While the interviewed teachers generally acknowledged that textbook narratives are representations of history and contingent on perspective, few teachers extended this to include how their own views affect their interpretations, suggesting an intermediary appreciation of the contextual contingency of historical narratives.

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A look at the role that symbolism plays in the novel. In this case, as it is in many other great novels, we see that symbolism is used to enhance the mood and the atmosphere of the novel rather than adding anything of importance to the plot.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Customer participation has been studied for decades; however, it gained a postmodern perspective around the year 2000. Customers have become co-creators of personalized experiences, moving from the audience to the stage. In the educational context, students must take responsibility for their learning process and participate in the production of the service. This changing is providing opportunities and challenges for higher education institutions (HEIs) to redefine their relationship with stakeholders, especially with students. This study is based on the service dominant logic (SDL) perspective because students are assumed to take the role of co-creators of knowledge in the educational setting. The research uses adapted frameworks and concepts applied in organizational, knowledge-intensive business services (KIBS) and also medical studies to advance the understanding of value co-creation in the HEI context. The current study addresses a lack of research in the higher education context focusing on defining students’ participation and students’ empowerment in higher education context. An empirical investigation was developed with traditional schools in Brazil. This investigation allowed the description of the constructs in the specific context. The description of student participation in HEIs context reflects the relevance of three dimensions – information sharing, personal interaction and responsible behavior. In the Brazilian context, responsible behavior is the weakest dimension in the construct, because the responsibilities are unbalanced between students and professors. The main reasons identified for this unbalanced relation were cultural issues and local regulation. Student empowerment was described as composed by four dimensions – meaningfulness, competence, impact and choice; however, one of them – choice – was identified as the weakest dimension, facing cultural and bureaucratic barriers for implementation in the Brazilian educational context. Moreover, interviewees spontaneously cited the idea of trust in the faculty as an important antecedent of student participation that must be considered when analyzing student participation and empowerment mechanisms. An additional contribution was the proposal of a theory-based framework for understanding the service dominant logic perspective in the HEI context, in which student participation and student empowerment were explored as mechanisms leading to positive student behavior toward institution.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The marsh deer is the largest neotropical cervid with morphological and ecological adaptations to wetlands and riparian habitats. Historically, this now endangered species occupied habitats along the major river basins in South America, ranging from southern Amazonia into northern Argentina to the Parana river delta. This particularly close association with wetlands makes marsh deer an excellent species for studying the effects of Pleistocene climatic changes on their demographic and phylogeographic patterns. We examined mitochondrial DNA variation in 127 marsh deer from 4 areas distributed throughout the Rio de]a Plata basin. We found 17 haplotypes in marsh deer from Brazil, Bolivia and Argentina that differed by 1-8 substitutions in a 601 bp fragment of mitochondrial control region sequence, and 486 bp of cytochrome b revealed only 3 variable sites that defined 4 haplotypes. Phylogeny and distribution of control region haplotypes suggest that populations close to the Pantanal area in central Brazil underwent a rapid population expansion and that this occurred approximately 28,000-25,000 years BP. Paleoclimatic data from this period suggests that there was a dramatic increase for precipitation in the medium latitudes in South America and these conditions may have fostered marsh deer's population growth.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This article analyzes how Latin American history was interpreted by two eminent historians, the Argentine Ricardo Levene and the Spaniard Rafael Altamira. It discusses how their paths crossed in the advocacy of Hispano-Americanism as a political project and interpretive horizon of Iberian and American history.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper describes a novel approach for mapping lightning processes using fuzzy logic. The estimation process is carried out using a fuzzy system based on Sugeno's architecture. Simulation results confirm that proposed approach can be efficiently used in these types of problem.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This article examines the challenges involved in the process of police militarization and implementation of police discipline in the State of São Paulo during the First Brazilian Republic (1889 to 1930). The implementation of a militarized police model, initiated by the 1906 French Military Mission, was not fully able to deal with indiscipline issues among policemen. Beyond creating problems of its own, such as fostering a corporatist culture and strengthening rigid hierarchies, military discipline prevented police forces to address new issues that would affect its practices. Documents in the São Paulo State Public Archive provides a window to the daily violence, the personal compromises, the institutional conflicts and the political meddling that was part of police life in the State of São Paulo at the turn of the century.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)