Meta-analysis of Genome-Wide Association Studies for Extraversion: Findings from the Genetics of Personality Consortium

Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion

Variações espaço-temporais no estoque de sementes do solo na floresta amazônica

A dispersão eficiente, a longevidade e a capacidade das sementes de permanecer em estado latente a espera de condições adequadas de germinação no banco de sementes do solo da floresta garantem a presença de espécies arbóreas pioneiras nas áreas perturbadas. As variações estacionais e espaciais na densidade e na composição florística do banco de sementes em Florestas Tropicais Úmidas são assuntos ainda pouco compreendidos. Este trabalho verificou a existência de modificações espaço-temporais do banco de sementes presente em áreas de Floresta Tropical úmida localizadas próximas a Manaus, AM. Em cada uma das seis áreas estudadas, foram coletadas 40 amostras circulares de solo superficial (10 cm de diâmetro e 2 cm de profundidade) ao acaso. Essas amostras foram coletadas a cada dois meses, entre agosto/2004 e junho/2005,. As amostras de solo foram distribuídas em bandejas em casa de vegetação e a emergência das sementes presentes no solo foi acompanhada por 4 meses. Houve uma redução significativa (H: 14,09, p < 0,05) na densidade média de sementes no solo em junho (início da estação seca) em relação a fevereiro (meio da estação chuvosa). Houve também diferença significativa (H: 188,72, p < 0,05) na densidade média de sementes do solo presente nas diferentes áreas amostradas. Assim como para outras áreas de florestas tropicais, o banco de sementes permanente da floresta foi dominado por espécies pioneiras, principalmente da família Melastomataceae, enquanto as espécies típicas da Floresta Tropical madura foram raras no solo florestal

Chemical composition and antioxidant and antifungal properties of Mentha x piperita L. (peppermint) and Mentha arvensis L. (cornmint) samples

Essential oils and infusions from commercial peppermint sachets (CPS), and non-commercial genuine peppermint (NCP) and cornmint (NCC) samples were analyzed by GC/MS and LC/MS. Minimum inhibitory concentration (MIC) of mint oils against Fusarium moniliforme, Aspergillus niger and Aspergillus fumigates was determined. Antioxidant potential was monitored by total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and soybean oil oxidation tests. CPS and NCC oils had lower menthofuran content than NCP. Mint oils did not show a uniform standard of antifungal activity and they had the modest reducing ability. CPS and NCC infusions showed higher IC50 and lower TPC than NCP ones. In the soybean oxidation test, mint oils presented prooxidant behavior. CPS infusions showed antioxidant potential significantly (P<0.05, Tukey) lower than that from NCC and NCP infusions. NCP infusions were more efficient in delaying propagation reaction than NCC ones. This may be attributed to higher amount of rosmarinic acid and hesperidin in NCP