2,402,473 research outputs found
Comparative analysis of Mycobacterium tuberculosis pe and ppe genes reveals high sequence variation and an apparent absence of selective constraints.
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110619.pdf (Publisher’s version ) (Open Access)Mycobacterium tuberculosis complex (MTBC) genomes contain 2 large gene families termed pe and ppe. The function of pe/ppe proteins remains enigmatic but studies suggest that they are secreted or cell surface associated and are involved in bacterial virulence. Previous studies have also shown that some pe/ppe genes are polymorphic, a finding that suggests involvement in antigenic variation. Using comparative sequence analysis of 18 publicly available MTBC whole genome sequences, we have performed alignments of 33 pe (excluding pe_pgrs) and 66 ppe genes in order to detect the frequency and nature of genetic variation. This work has been supplemented by whole gene sequencing of 14 pe/ppe (including 5 pe_pgrs) genes in a cohort of 40 diverse and well defined clinical isolates covering all the main lineages of the M. tuberculosis phylogenetic tree. We show that nsSNP's in pe (excluding pgrs) and ppe genes are 3.0 and 3.3 times higher than in non-pe/ppe genes respectively and that numerous other mutation types are also present at a high frequency. It has previously been shown that non-pe/ppe M. tuberculosis genes display a remarkably low level of purifying selection. Here, we also show that compared to these genes those of the pe/ppe families show a further reduction of selection pressure that suggests neutral evolution. This is inconsistent with the positive selection pressure of "classical" antigenic variation. Finally, by analyzing such a large number of genes we were able to detect large differences in mutation type and frequency between both individual genes and gene sub-families. The high variation rates and absence of selective constraints provides valuable insights into potential pe/ppe function. Since pe/ppe proteins are highly antigenic and have been studied as potential vaccine components these results should also prove informative for aspects of M. tuberculosis vaccine design
Education and Sexualities
No full textBoth from the point of view of the experiences of different groups of students, and also with respect to the form that education about sexuality, sex, and relationships should take, education and sexuality raises complex questions and provokes heated―sometimes furious―debate. This four-volume collection offers an authoritative overview of key issues within this rapidly developing field. Under the editorship of Peter Aggleton (editor-in-chief of the international journal, Sex Education), the collection covers a wide range of contemporary issues and concerns, including: the sexualities curriculum; ‘politics and pleasure’; classroom processes and dynamics; sexual and gender diversity in the classroom; gender and sexual violence in schools and colleges; and bullying, victimization and abuse. Special attention is also given to enduring topics, such as the content and context of sexualtiy education; the age at which it should take place; faith and religion; politics and political controversies; and the science and ethics of sexualities education
A socio-ecological approach to understanding adolescent girls' engagement and experiences in the PE environment : a case study design
No full textAdolescence is known to be a period of increased risk for the development of unhealthy behaviours such as physical inactivity (Currie et al., 2011). Low physical activity (PA) levels are especially noted in girls, who typically engage in less PA than boys throughout the teenage years (Whitehead and Biddle 2008). In Scotland, evidence suggests there is a significant decline in PA among adolescent girls, with only 41% of 13−15 year olds achieving the current recommendations, compared with 56% of 11−12 year olds (Scottish Executive, 2011). In addition, a proportion of girls are not engaging with school PE classes (Niven et al., 2014; Kirby et al., 2012). In order to understand more about how and why this decline exists, a sample of 20 ‘disengaged’ 12−13-year-old girls (second year of secondary school) were recruited from four case study schools in Scotland. This study aims to explore the interaction between the social and physical environment, and how these affect disengaged girls’ experiences and engagement in PE. Girls were categorised as ‘disengaged’ from PE if they did not participate regularly and reported negative emotions about the subject. Girls took part in in-depth interviews to explore their experiences and engagement in PE. The theoretical framework is based on Welks (1999) Youth Physical Activity Promotion model (YPAP), a socio-ecological approach which conceptualises the influential correlates of PA as: individual-level predisposing and enabling factors, including personal attributes and environmental variables and reinforcing (social) factors. This model was applied within a Scottish education context to understand the importance of each component and also the interaction between these and the influence that one may have on another. The results indicate that although the type of activity offered in PE is important, it appears that perceptions of competence and the social environment these were delivered in, such as single-sex classes, had more of an influence on girls’ engagement in PE. For this group of Scottish adolescent girls, the wider psychosocial environment in which PE takes place may have a greater impact on levels of enjoyment and participation than the PA itself.Peer reviewe
czs108/PE-Packer: v1.0.0-beta
No full textPE-Packer is a simple packer for Windows PE files. The new PE file after packing can obstruct the process of reverse engineering.
It will do the following things when packing a PE file:
Transforming the original import table.
Encrypting sections.
Clearing section names.
Installing the shell-entry.
When running a packed PE file, the shell-entry will decrypt and load the original program as follows:
Decrypting sections.
Initializing the original import table.
Relocation.
Warning
This project is just a demo for beginners to study Windows PE Format and Assembly Language. It still has some compatibility problems and bugs that cannot be used in practice
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