Ocorrencia de afideos causando danos em mangueira (Mangifera indica L.), no Vale do Sao Francisco.

Observaram-se em pomares de mangueiras (Mangifera iondica L.), no semi-arido nordestino, altas infestacoes de afideos causando danos as folhas novas e brotacao da planta. Diversas amostras foram coletadas, tendo sido identificadas tres especies: Aphis craccivora, Aphis gossypii e Toxoptera aurantii. As duas primeiras especies estao sendo relatadas pela primeira vez como pragas, em mangueiras, no Brasil. Especimes de referencia encontram-se depositados no Laboratorio de Entomologia da Embrapa Semi-Arido, localizada em Petrolina-PE

ESTIMATION OF RADIONUCLIDES IN SOILS -A COMPARISON OF METHODS FOR ANNUAL DOSE IN LUMINESCENCE DATING

Abstract. A study was made in order to compare and test the performance of several methods for the annual radiation dose determination in luminescence dating. The following techniques were used: instrumental neutron activation, high resolution gamma ray spectrometry and alpha spectrometry. Detailed analysis was carried out through gamma spectrometry, the activities of different nuclides ( Tl) in the uranium and thorium series being measured, as well as 40 K. The potential of this method in checking the occurrence of radioactive disequilibrium in the series was investigated. The assumption that radium disequilibrium caused by the percolation of groundwater in soils can be encountered was supported by our finds. The consistency of the results obtained through the three different methods indicate the reliability of using high resolution gamma ray spectrometry as a fast and accurate method for measuring natural radionuclides concentrations in luminescence dating and as well for purposes of environmental monitoring

Grambank reveals the importance of genealogical constraints on linguistic diversity and highlights the impact of language loss

While global patterns of human genetic diversity are increasingly well characterized, the diversity of human languages remains less systematically described. Here we outline the Grambank database. With over 400,000 data points and 2,400 languages, Grambank is the largest comparative grammatical database available. The comprehensiveness of Grambank allows us to quantify the relative effects of genealogical inheritance and geographic proximity on the structural diversity of the world's languages, evaluate constraints on linguistic diversity, and identify the world's most unusual languages. An analysis of the consequences of language loss reveals that the reduction in diversity will be strikingly uneven across the major linguistic regions of the world. Without sustained efforts to document and revitalize endangered languages, our linguistic window into human history, cognition and culture will be seriously fragmented.Genealogy versus geography Constraints on grammar Unusual languages Language loss Conclusio