Patterns of modern pollen and plant richness across northern Europe

Sedimentary pollen offers excellent opportunities to reconstruct vegetation changes over past millennia. Number of different pollen taxa or pollen richness is used to characterise past plant richness. To improve the interpretation of sedimentary pollen richness, it is essential to understand the relationship between pollen and plant richness in contemporary landscapes. This study presents a regional-scale comparison of pollen and plant richness from northern Europe and evaluates the importance of environmental variables on pollen and plant richness. We use a pollen dataset of 511 lake-surface pollen samples ranging through temperate, boreal and tundra biomes. To characterise plant diversity, we use a dataset formulated from the two largest plant atlases available in Europe. We compare pollen and plant richness estimates in different groups of taxa (wind-pollinated vs. non-wind-pollinated, trees and shrubs vs. herbs and grasses) and test their relationships with climate and landscape variables. Pollen richness is significantly positively correlated with plant richness (r = 0.53). The pollen plant richness correlation improves (r = 0.63) when high pollen producers are downweighted prior to estimating richness minimising the influence of pollen production on the pollen richness estimate. This suggests that methods accommodating pollen-production differences in richness estimates deserve further attention and should become more widely used in Quaternary pollen diversity studies. The highest correlations are found between pollen and plant richness of trees and shrubs (r = 0.83) and of wind-pollinated taxa (r = 0.75) suggesting that these are the best measures of broad-scale plant richness over several thousands of square kilometres. Mean annual temperature is the strongest predictor of both pollen and plant richness. Landscape openness is positively associated with pollen richness but not with plant richness. Pollen richness values from extremely open and/or cold areas where pollen production is low should be interpreted with caution because low local pollen production increases the proportion of extra-regional pollen. Synthesis. Our results confirm that pollen data can provide insights into past plant richness changes in northern Europe, and with careful consideration of pollen-production differences and spatial scale represented, pollen data make it possible to investigate vegetation diversity trends over long time-scales and under changing climatic and habitat conditions

Trabalho, abuso de drogas e os aparelhos ideológicos de estado: um estudo com alunos do ensino médio e fundamental Work, drug addiction and apparatus of state: a study with students of elementary and secondary school

A pesquisa se baseia em trabalho de prevenção de dependência entre estudantes de 23 municípios de quatro regiões brasileiras. Foram analisados 68.210 questionários referentes a Região Norte (29.386 questionários / 7 cidades), Região Nordeste (17.971 questionários / 3 cidades), Região Sudeste (4.197 questionários / 4 cidades) e Região Sul (16.656 questionários / 9 cidades). Os questionários continham 25 perguntas, das quais oito foram estudadas. Encontraram-se respostas aproximadas em todas as regiões brasileiras. Observou-se ainda que não foi possível estabelecer uma relação entre o trabalho e a experiência de abuso de drogas. A Igreja e a escola se mostraram extremamente importantes na formação dos jovens. A escola se mostrou herdeira de um trabalho educativo antes restrito às famílias. O abuso de drogas foi encontrado, na Região Norte, em torno de 2%, sendo na Região Nordeste em torno de 6%, na Região Sudeste e Sul em cerca de 5%. A idade predominante para o primeiro uso se situou entre 11 e 15 anos em todas as regiões estudadas e o percentual maior foi de alunos do ensino fundamental. Encontrou-se alguma concordância com o trabalho de Althusser, no que se refere aos aparelhos ideológicos de Estado. A Igreja e a família tiveram uma importância muito grande para a busca de apoio ou esclarecimentos por parte desses jovens.<br>The research was based on a drug abuse prevent program among 68,210 students in Brazil. Questionnaires were applied in four Brazilian Regions: North (n = 29,386 in 7 cities); Northeast (n = 17,971 in 3 cities); Southeast (n = 4,197 in 4 cities) and South (n = 16,656 in 9 cities). This questionnaire included 25 questions and among then, eight were studied. Similar answers were found in all regions of the country. The main conclusions were: religion and school were pointed as an extreme importance as an educational aspect in the children's own lives. School replaced an educational role, that was a former family privilege. The experience of drug abuse in childhood was measured in: North (2%), Northeast (6%), South and Southeast (5%). The prevailing age of the first drug use was found between 11 and 15 years old in all the regions, during the fundamental school degree. Certain agreement with Althuser's work on ideological apparatus of State was found. Family and religion were important protection factors against drug abuse