A EDUCAÇÃO A PARTIR DAS VOZES DA JUVENTUDE CATARINENSE

Esse artigo discute o trabalho realizado pelo Instituto Catarinense da Juventude (ICJ) com uma parcela da juventude catarinense. O objetivo do estudo é relacionar o processo de escuta dos jovens, pelos pesquisadores do ICJ, no que diz respeito ao que eles pensam acerca da educação. A metodologia utilizada foi a análise documental do livro “Vozes da juventude catarinense: rodas de conversa”. Como categorias de análise foram utilizados: conceito de juventude e Roda de Conversa. Além dessas categorias, o livro Retratos da Juventude Brasileira permitiu realizar comparações sobre a pesquisa do ICJ e a pesquisa de Abramo e Branco (2005). A juventude de Santa Catarina na pesquisa do ICJ (2014) falou de suas ansiedades, desejos e sonhos diante da educação escolar e não descolou o papel da educação do mundo do trabalho.

A Educação a Partir das Vozes da Juventude Catarinense

Esse artigo discute o trabalho realizado pelo Instituto Catarinense da Juventude (ICJ) com uma parcela da juventude catarinense. O objetivo do estudo é relacionar o processo de escuta dos jovens, pelos pesquisadores do ICJ, no que diz respeito ao que eles pensam acerca da educação. A metodologia utilizada foi a análise documental do livro “Vozes da juventude catarinense: rodas de conversa”. Como categorias de análise foram utilizados: conceito de juventude e Roda de Conversa. Além dessas categorias, o livro Retratos da Juventude Brasileira permitiu realizar comparações sobre a pesquisa do ICJ e a pesquisa de Abramo e Branco (2005). A juventude de Santa Catarina na pesquisa do ICJ (2014) falou de suas ansiedades, desejos e sonhos diante da educação escolar e não descolou o papel da educação do mundo do trabalho.

Tree rings reveal globally coherent signature of cosmogenic radiocarbon events in 774 and 993 CE

This study was funded by the WSL-internal COSMIC project (5233.00148.001.01), the ETHZ (Laboratory of Ion Beam Physics), the Swiss National Science Foundation (SNF Grant 200021L_157187/1), and as the Czech Republic Grant Agency project no. 17-22102s.Though tree-ring chronologies are annually resolved, their dating has never been independently validated at the global scale. Moreover, it is unknown if atmospheric radiocarbon enrichment events of cosmogenic origin leave spatiotemporally consistent fingerprints. Here we measure the 14C content in 484 individual tree rings formed in the periods 770–780 and 990–1000 CE. Distinct 14C excursions starting in the boreal summer of 774 and the boreal spring of 993 ensure the precise dating of 44 tree-ring records from five continents. We also identify a meridional decline of 11-year mean atmospheric radiocarbon concentrations across both hemispheres. Corroborated by historical eye-witness accounts of red auroras, our results suggest a global exposure to strong solar proton radiation. To improve understanding of the return frequency and intensity of past cosmic events, which is particularly important for assessing the potential threat of space weather on our society, further annually resolved 14C measurements are needed.Publisher PDFPeer reviewe

Ranking of tree-ring based temperature reconstructions of the past millennium

Tree-ring chronologies are widely used to reconstruct high-to low-frequency variations in growing season temperatures over centuries to millennia. The relevance of these timeseries in large-scale climate reconstructions is often determined by the strength of their correlation against instrumental temperature data. However, this single criterion ignores several important quantitative and qualitative characteristics of tree-ring chronologies. Those characteristics are (i) data homogeneity, (ii) sample replication, (iii) growth coherence, (iv) chronology development, and (v) climate signal including the correlation with instrumental data. Based on these 5 characteristics, a reconstruction-scoring scheme is proposed and applied to 39 published, millennial-length temperature reconstructions from Asia, Europe, North America, and the Southern Hemisphere. Results reveal no reconstruction scores highest in every category and each has their own strengths and weaknesses. Reconstructions that perform better overall include N-Scan and Finland from Europe, E-Canada from North America, Yamal and Dzhelo from Asia. Reconstructions performing less well include W-Himalaya and Karakorum from Asia, Tatra and S-Finland from Europe, and Great Basin from North America. By providing a comprehensive set of criteria to evaluate tree-ring chronologies we hope to improve the development of large-scale temperature reconstructions spanning the past millennium. All reconstructions and their corresponding scores are provided at www.blogs.uni-mainz.de/fb09climatology

Ranking of tree-ring based temperature reconstructions of the past millennium

Tree-ring chronologies are widely used to reconstruct high-to low-frequency variations in growing season temperatures over centuries to millennia. The relevance of these timeseries in large-scale climate reconstructions is often determined by the strength of their correlation against instrumental temperature data. However, this single criterion ignores several important quantitative and qualitative characteristics of tree-ring chronologies. Those characteristics are (i) data homogeneity, (ii) sample replication, (iii) growth coherence, (iv) chronology development, and (v) climate signal including the correlation with instrumental data. Based on these 5 characteristics, a reconstruction-scoring scheme is proposed and applied to 39 published, millennial-length temperature reconstructions from Asia, Europe, North America, and the Southern Hemisphere. Results reveal no reconstruction scores highest in every category and each has their own strengths and weaknesses. Reconstructions that perform better overall include N-Scan and Finland from Europe, E-Canada from North America, Yamal and Dzhelo from Asia. Reconstructions performing less well include W-Himalaya and Karakorum from Asia, Tatra and S-Finland from Europe, and Great Basin from North America. By providing a comprehensive set of criteria to evaluate tree-ring chronologies we hope to improve the development of large-scale temperature reconstructions spanning the past millennium. All reconstructions and their corresponding scores are provided at www.blogs.uni-mainz.de/fb09climatology. (C) 2016 Elsevier Ltd. All rights reserved.German Science Foundation [161/9-1]; National Natural Science Foundation of China [41325008]; [RNF 15-14-30011]Available online 10 June 2016. 24 month embargo.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

OS 10 ARTIGOS MAIS ACESSADOS NO ANO 2021

The 10 most accessed articles in 2021 of the magazine RECIMA21.Los 10 artículos más visitados en 2021 de la revista RECIMA21.Os 10 artigos mais acessados no ano de 2021 da Revista RECIMA21

Recent climate hiatus revealed dual control by temperature and drought on the stem growth of Mediterranean <i>Quercus ilex</i>

International audienceA better understanding of stem growth phenology and its climate drivers would improve projections of the impact of climate change on forest productivity. Under a Mediterranean climate, tree growth is primarily limited by soil water availability during summer, but cold temperatures in winter also prevent tree growth in evergreen forests. In the wide-spread Mediterranean evergreen tree species Quercus ilex, the duration of stem growth has been shown to predict annual stem increment, and to be limited by winter temperatures on the one hand, and by the summer drought onset on the other hand. We tested how these climatic controls of Q. ilex growth varied with recent climate change by correlating a 40-year tree ring record and a 30-year annual diameter inventory against winter temperature, spring precipitation, and simulated growth duration. Our results showed that growth duration was the best predictor of annual tree growth. We predicted that recent climate changes have resulted in earlier growth onset (-10 days) due to winter warming and earlier growth cessation (-26 days) due to earlier drought onset. These climatic trends partly offset one another, as we observed no significant trend of change in tree growth between 1968 and 2008. A moving-window correlation analysis revealed that in the past, Q. ilex growth was only correlated with water availability, but that since the 2000s, growth suddenly became correlated with winter temperature in addition to spring drought. This change in the climate-growth correlations matches the start of the recent atmospheric warming pause also known as the `climate hiatus'. The duration of growth of Q. ilex is thus shortened because winter warming has stopped compensating for increasing drought in the last decade. Decoupled trends in precipitation and temperature, a neglected aspect of climate change, might reduce forest productivity through phenological constraints and have more consequences than climate warming alone