In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.
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Question: The twin-arginine translocation (Tat) protein export system is present in the cytoplasmic membranes of most bacteria and archaea and has the highly unusual property of transporting fully folded proteins. The system must therefore provide a transmembrane pathway that is large enough to allow the passage of structured macromolecular substrates of different sizes but that maintains the impermeability of the membrane to ions. In the Gram-negative bacterium Escherichia coli, this complex task can be achieved by using only three small membrane proteins: TatA, TatB and TatC. In this Review, we summarize recent advances in our understanding of how this remarkable machine operates.

Answer: The twin-arginine translocation (Tat) protein export pathway

Question: This paper examines the effect of one form of chronic stress--household crowding--on psychological well-being, as measured by multiple inverse indicators of psychological well-being. We rely on data from a large (n = 2017) random sample of households in Bangkok, Thailand, a context that has a higher level and broader range of crowding than typically found in the United States. Objective household crowding is found to be detrimental to psychological well-being, controlling for a number of background characteristics. The effect of objective crowding is mediated by subjective crowding, which has strong, consistent and direct detrimental effects on well-being. There is no evidence of a gender effect. Extended family households are not uncommon in Bangkok, but the effects of objective and subjective crowding are similar in both two- and three-generation households, as well as in one- and multiple-couple households. The argument that subjective crowding is an effect, rather than a cause, of psychological well-being is examined and rejected. The findings suggest that crowding, as a chronic source of stress, constitutes a major threat to psychological well-being. Although the empirical analyses are based on data from one city, we frame the issue of household crowding in a historical and theoretical context in order to suggest in which cultural settings household crowding is most likely to have detrimental effects on psychological well-being.

Answer: Chronic stress and psychological well-being: evidence from Thailand on household crowding.

Question: The process of aging results in a host of changes at the cellular and molecular levels, which include senescence, telomere shortening, and changes in gene expression. Epigenetic patterns also change over the lifespan, suggesting that epigenetic changes may constitute an important component of the aging process. The epigenetic mark that has been most highly studied is DNA methylation, the presence of methyl groups at CpG dinucleotides. These dinucleotides are often located near gene promoters and associate with gene expression levels. Early studies indicated that global levels of DNA methylation increase over the first few years of life and then decrease beginning in late adulthood. Recently, with the advent of microarray and next-generation sequencing technologies, increases in variability of DNA methylation with age have been observed, and a number of site-specific patterns have been identified. It has also been shown that certain CpG sites are highly associated with age, to the extent that prediction models using a small number of these sites can accurately predict the chronological age of the donor. Together, these observations point to the existence of two phenomena that both contribute to age-related DNA methylation changes: epigenetic drift and the epigenetic clock. In this review, we focus on healthy human aging throughout the lifetime and discuss the dynamics of DNA methylation as well as how interactions between the genome, environment, and the epigenome influence aging rates. We also discuss the impact of determining 'epigenetic age' for human health and outline some important caveats to existing and future studies.

Answer:
DNA methylation and healthy human aging