Rolling-circle transposons in eukaryotes

All eukaryotic DNA transposons reported so far belong to a single category of elements transposed by the so-called “cut-and-paste” mechanism. Here, we report a previously unknown category of eukaryotic DNA transposons, Helitron, which transpose by rolling-circle replication. Autonomous Helitrons encode a 5′-to-3′ DNA helicase and nuclease/ligase similar to those encoded by known rolling-circle replicons. Helitron-like transposons have conservative 5′-TC and CTRR-3′ termini and do not have terminal inverted repeats. They contain 16- to 20-bp hairpins separated by 10–12 nucleotides from the 3′-end and transpose precisely between the 5′-A and T-3′, with no modifications of the AT target sites. Together with their multiple diverged nonautonomous descendants, Helitrons constitute ≈2% of both the Arabidopsis thaliana and Caenorhabditis elegans genomes and also colonize the Oriza sativa genome. Sequence conservation suggests that Helitrons continue to be transposed.

cemA homologue essential to CO2 transport in the cyanobacterium Synechocystis PCC6803.

We have isolated mutants of Synechocystis PCC6803 that grew very slowly in a low-sodium medium, which is unfavorable for HCO3(-) transport, and examined two of these mutants (SC1 and SC2) for their ability to take up CO2 and HCO3(-) in the light. The CO2 transport activity of SC1 and SC2 was much lower than that of the wild type (WT), whereas there was no difference between the mutants and the WT in their activity of HCO3(-) transport. A clone containing a 3.9-kilobase-pair insert DNA that transforms both mutants to the WT phenotype was isolated from a genomic library of WT Synechocystis. Sequencing of the insert DNA in the region of mutations in SC1 and SC2 revealed an open reading frame (designated cotA), which showed significant amino-acid sequence homology to cemA encoding a protein found in the inner envelope membrane of chloroplasts. The cotA gene is present in a single copy and was not cotranscribed with any other gene(s). cotA encodes a protein of 247 amino acids containing four transmembrane domains. There was substitution of a single base in SC1 and two bases in SC2 in their cotA genes. A possible role of the cotA gene product in CO2 transport is discussed.

Invited commentary: Gender regimes in health systems

In short, what Elisa Chilet has found in her recent thesis dissertation entitled 'Gender bias in clinical research, pharmaceutical marketing and the prescription of drugs', a review of which is published in this issue of the journal, is a significant amount of gender bias.

The laws of Harvard College, 1767

Leather hardcover volume containing a draft of the 1767 College Laws with portions crossed out and edited. The volume appears to be a working copy and includes page references in the front of the volume and additional notes inserted between pages.

[ Book of predictions] : manuscript, 1785-1812

Book of yearly predictions about the sultan, his family, ministers, grand mufti, etc. Records for years 1199-1227 AH [1785-1812 AD]. Year run from nevrūz to nevrūz (beginning of spring). Predictions concern political affairs and state of health of various individuals. Predictions about weather conditions and the eclipses also included. Separate section at end of each year's entry breaks down predictions into months. Manuscript apparently the author's working copy and probably the sole copy.

Risālat al-Surūr fī ḥaqq wālidayhi ʻalayhi al-salām : manuscript, 1737

Title from f. 1r.

Sporting guide to Michigan.

Contains information about recreational activities and the automobile industry in Michigan, and selective directory of journalists and General Motors managers and their hobbies.

Maps, &c. of the mineral region of Lake Superior.

Cover title.

Water resources of the Detroit area, Michigan /

4 folded maps in pocket.

Canoe trails of Michigan.

One folded map inside envelope attached to back cover.

Fables. : de l'académie franc̜oise, de celles de Madrid, Florence, etc. ....

Page [66] misnumbered 6.

Sir Isaac Newtonʾs Principia

"Finding that all the editions of the Principia are now out of print, we have been induced to reprint Newtonʾs last edition without note or comment, only introducing the "Corrigenda" of the old copy and correcting typographical errors."--Editorsʾ notice.

Official awards.

Title varies slightly.

Copyright Bites

Copyright Bites is a series of short videos that makes copyright law and policy easier to understand. With a distinctive visual vocabulary and style, the series explores the relationship between copyright and the public domain both of which are essential in fostering creativity and the creation of new work. It concerns how creators exploit and protect their work, as well as when it is okay to copy and re-use the work of others without having to ask for permission and without having to clear rights. Copyright is extremely important; but so too is the public domain.

Propriedades Psicométricas do Teste Stroop numa Amostra de Adultos da População Portuguesa: estudo preliminar

Objetivos: O presente estudo insere-se no Projeto - Estudos Normativos de Instrumentos Neuropsicologicos (ENIN) e tem por objetivo analisar as propriedades psicométricas do Teste Stroop, fornecendo dados normativos de uma amostra da População Portuguesa. Métodos: Selecionámos e inquirimos 671 sujeitos. As variáveis independentes estudadas foram idade, sexo, escolaridade e profissão. Foram utilizados vários testes neste estudo, contribuindo para a obtenção de validade convergente: Bateria de Avaliação Frontal-FAB, Figura Complexa de Rey-Osterrieth e Teste do Relógio. Foram estudadas a consistência interna e a estabilidade temporal do Teste Stroop. Resultados: A nossa amostra ficou constituída por 310 sujeitos (46,2%) do sexo masculino e 361 (53,8%) do sexo feminino, com idades compreendidas entre os 18 e 100 anos (M = 41,12; DP = 20,85). No que se refere ao nível de escolaridade (M = 5,71; DP = 1,45), este variou entre o 1º Ciclo do Ensino Básico e o Ensino Superior. As profissões, exercidas inseriram-se maioritariamente na categoria das profissões intelectuais (N = 281; 84,9%). Relativamente às variáveis sociodemográficas, verificámos que a idade, sexo, escolaridade e profissão influenciam nas provas de Leitura e Nomeação de Cor do Teste Stroop. No que diz respeito à validade convergente, observámos que a prova de Nomeação de Cor apresentou correlações positivas fracas com o FAB, Figura Complexa de Rey-Cópia (FCR-Cópia) e Teste do Relógio, e correlações positivas moderadas com a prova de Leitura. A consistência interna do Teste Stroop apresentou uma elevada confiabilidade (α = 0,99). A correlação teste-reteste apenas se mostrou significativa para a prova de Nomeação de Cor. Conclusão: Este estudo mostra que o Teste Stroop é promissoriamente confiável como instrumento de avaliação neuropsicológica, podendo potencialmente ser utilizado para qualquer faixa etária da população. Em estudos futuros são necessárias amostras com números mais elevados de participantes nas faixas etárias acima dos 30 anos, representativas dos níveis de escolaridade abaixo do 9ºano, a exercerem profissões manuais, e com residência noutras regiões geográficas para além do Centro. / Objectives: The present study is part of the Project - Estudos Normativos de Instrumentos Neuropsicologicos (ENIN) and aims to analyze the psychometric properties of the Stroop test. Methods: We have selected, and we also enquired 671 subjects. The independent variables studied were age, gender, education and profession. Several tests were used in this study for analysis of convergent validity: convergent validity: Frontal Assessment Battery-FAB, Complex Figure Rey-Osterrieth and the clock test. We also studied the internal consistency and the temporal stability of the Stroop test. Results: Our sample was composed of 310 subjects (46.2%) male and 361 (53.8%) females, with ages between 18 and 100 years (M = 41.12; SD = 20.85). The level of schooling (M = 5.71; SD = 1.45) ranged between the 1st cycle and the Higher Education. The professions were mainly intellectual ones (N = 281; 84.9%). On sociodemographic variables, we found that the age, sex, education and profession influenced reading and Color naming of Stroop test. Regarding convergent validity, Color naming showed weak positive correlations with the FAB, Complex Figure Rey-Copy, and the clock test. Color naming moderate positive correlations with the reading. The internal consistency of the Stroop test was high (α = 0.99). The test-retest correlation was significant only for Color naming. Conclusion: This study shows that the Stroop test is promissory reliable instrument of neuropsychological assessment and may potentially be used for any age range of the population. In future research, it is necessary to enroll samples with higher numbers of participants above 30 years, representative of the levels of schooling below the 9º grade, with more manual professions represented, and with residence in other geographic regions in addition to the Center region of Portugal.