RESUMO
OBJECTIVES: To identify and summarise the contextual factors associated with running demands in elite male Australian football (AF) gameplay that have been reported in the literature. DESIGN: Scoping review. METHODS: A contextual factor in sporting gameplay is a variable associated with the interpretation of results, yet is not the primary objective of gameplay. Systematic literature searches were performed in four databases to identify what contextual factors associated with running demands in elite male AF have been reported: Scopus, SPORTDiscus, Ovid Medline and CINAHL, for terms constructed around Australian football AND running demands AND contextual factors. The present scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and narrative synthesis was conducted. RESULTS AND CONCLUSION: A total of 36 unique articles were identified by the systematic literature search, which included 20 unique contextual factors. The most studied contextual factors were position (n = 13), time in game (n = 9), phases of play (n = 8), rotations (n = 7) and player rank (n = 6). Multiple contextual factors, such as playing position, aerobic fitness, rotations, time within a game, stoppages, and season phase appear to correlate with running demands in elite male AF. Many identified contextual factors have very limited published evidence and thus additional studies would help draw stronger conclusions.
RESUMO
Adenosine bases of RNA can be transiently modified by the deposition of a methyl-group to form N6-methyladenosine (m6A). This adenosine-methylation is an ancient process and the enzymes involved are evolutionary highly conserved. A genetic screen designed to identify suppressors of late flowering transgenic Arabidopsis plants overexpressing the miP1a microProtein yielded a new allele of the FIONA1 (FIO1) m6A-methyltransferase. To characterize the early flowering phenotype of fio1 mutant plants we employed an integrative approach of mRNA-seq, Nanopore direct RNA-sequencing and meRIP-seq to identify differentially expressed transcripts as well as differentially methylated RNAs. We provide evidence that FIO1 is the elusive methyltransferase responsible for the 3'-end methylation of the FLOWERING LOCUS C (FLC) transcript. Furthermore, our genetic and biochemical data suggest that 3'-methylation stabilizes FLC mRNAs and non-methylated FLC is a target for rapid degradation.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Regiões 3' não Traduzidas/genética , Adenosina/genética , Adenosina/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Histonas/genética , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Metilação , Metiltransferases/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Methylation of histone H3K9 is a hallmark of epigenetic silencing in eukaryotes. Nucleosome modifications often rely on positive feedback where enzymes are recruited by modified nucleosomes. A combination of local and global feedbacks has been proposed to account for some dynamic properties of heterochromatin, but the range at which the global feedbacks operate and the exact mode of heterochromatin propagation are not known. We investigated these questions in fission yeast. Guided by mathematical modeling, we incrementally increased the size of the mating-type region and profiled heterochromatin establishment over time. We observed exponential decays in the proportion of cells with active reporters, with rates that decreased with domain size. Establishment periods varied from a few generations in wild type to >200 generations in the longest region examined, and highly correlated silencing of two reporters located outside the nucleation center was observed. On a chromatin level, this indicates that individual regions are silenced in sudden bursts. Mathematical modeling accounts for these bursts if heterochromatic nucleosomes facilitate a deacetylation or methylation reaction at long range, in a distance-independent manner. A likely effector of three-dimensional interactions is the evolutionarily conserved Swi6HP1 H3K9me reader, indicating the bursting behavior might be a general mode of heterochromatin propagation.
Assuntos
Regulação Fúngica da Expressão Gênica , Inativação Gênica , Heterocromatina/metabolismo , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Genes Fúngicos Tipo Acasalamento , Heterocromatina/genética , Modelos Genéticos , Schizosaccharomyces , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismoRESUMO
Anthropologists have long noted that the use of ritual and magic is linked to conditions of risk and uncertainty. In this study, the authors examined how perceived task difficulty, participants' level of preparation, and the value of the outcome interact to influence the self-reporting of superstition and ritual. College students rated the likelihood of their using charms or rituals for various scenarios involving academic, artistic, and athletic performances. Reports of use of ritual increased as the stakes of the event increased and decreased with perceived expertise or level of preparation. Additional findings included participants' reporting frequent use of ritual while denying any causal effectiveness. The authors discuss results in terms of the rituals providing participants with an illusion of control.
