Eukaryotic 2-Cys peroxiredoxins (Prx) are abundant antioxidant enzymes whose thioredoxin peroxidase activity plays an important role in protecting against oxidative stress, aging, and cancer. Paradoxically, this thioredoxin peroxidase activity is highly sensitive to inactivation by peroxide-induced Prx hyperoxidation. However, any possible advantage in preventing Prx from removing peroxides under oxidative stress conditions has remained obscure. Here we demonstrate that, in cells treated with hydrogen peroxide, the Prx Tpx1 is a major substrate for thioredoxin in the fission yeast Schizosaccharomyces pombe and, as such, competitively inhibits thioredoxin-mediated reduction of other oxidized proteins. Consequently, we reveal that the hyperoxidation of Tpx1 is critical to allow thioredoxin to act on other substrates ensuring repair of oxidized proteins and cell survival following exposure to toxic levels of hydrogen peroxide. We conclude that the inactivation of the thioredoxin peroxidase activity of Prx is important to maintain thioredoxin activity and cell viability under oxidative stress conditions.

aging ͉ Caenorhabditis elegans ͉ oxidative stress ͉ signaling ͉ chaperone

In a systematic review and meta-analysis of 27 controlled trials, we found TNF antagonists to be effective for induction and maintenance of perianal fistula response and remission. There are few data on the effects on internal fistulae. Further studies are needed, particularly for ustekinumab, vedolizumab, and stem cell therapies, in patients with fistulizing CD.

SummaryH2O2 can cause oxidative damage associated with age-related diseases such as diabetes and cancer but is also used to initiate diverse responses, including increased antioxidant gene expression. Despite significant interest, H2O2-signaling mechanisms remain poorly understood. Here, we present a mechanism for the propagation of an H2O2 signal that is vital for the adaptation of the model yeast, Schizosaccharomyces pombe, to oxidative stress. Peroxiredoxins are abundant peroxidases with conserved antiaging and anticancer activities. Remarkably, we find that the only essential function for the thioredoxin peroxidase activity of the Prx Tpx1(hPrx1/2) in resistance to H2O2 is to inhibit a conserved thioredoxin family protein Txl1(hTxnl1/TRP32). Thioredoxins regulate many enzymes and signaling proteins. Thus, our discovery that a Prx amplifies an H2O2 signal by driving the oxidation of a thioredoxin-like protein has important implications, both for Prx function in oxidative stress resistance and for responses to H2O2.

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Community-managed landscapes have valuable conservation potential. In particular, indigenous community management has slowed deforestation. However, globalized agriculture is an underlying driver of changes to indigenous community-managed landscapes. Our objective is to explain a hypothesized global-to-local causal pathway that stems from processes of globalized agriculture and changes to indigenous community-managed landscapes. The global-to-local pathway involves a nested hierarchy of political–economic processes, specifically land and natural resource privatization, commodification, and acquisition. At the local landscape level, we focus on changes to land tenure, livelihoods, land use, and land cover. Changes to land tenure involve a shift away from community and toward individual ownership and management. Concurrently, livelihoods shift away from subsistence and toward market-oriented activities. Subsequently, land use shifts away from small-scale extensive and toward large-scale intensive crop cultivation, away from diverse crop cultivation and toward monocropping, and away from crop toward livestock farming. Ultimately, land cover shifts away from diverse agro-forested and toward homogeneous deforested lands. We illustrate our approach using ejidos, a type of community-managed lands, in Yucatán, México as an exploratory example. We use descriptive statistics to initially assess the shift in ejido land tenure, from community to individually parcelized systems, and the shift in a principal subsistence livelihood and land use activity, from maize cultivation to cattle rearing. We highlight that individually parceled areas within ejidos are more deforested than community-managed areas. In all, we urge landscape conservation scientists to more fully consider not just local actions but also impacts stemming from globalized agriculture and to advance the breadth and depth of more extensive studies and analyses.

Purpose -The purpose of this review is to provide a comprehensive summary of current research on the health risks and benefits associated with coffee drinking. Design/methodology/approach -This review includes up-to-date information from the original literature on coffee drinking and health and presents findings in a manner accessible to both experts and non-experts. Findings -Coffee contains caffeine, antioxidants, and other phytochemicals, all of which affect disease risks. There is evidence that coffee drinking may not be suitable for certain individuals. Overall, however, coffee drinking seems to be a non-harmful habit for those who drink it regularly and in moderation, and recent studies indeed suggest that it may even be beneficial for most people. The most currently available evidence suggests that coffee drinking can help reduce the risk of several diseases, most notably type 2 diabetes, Alzheimer's disease, and Parkinson's disease, although the underlying mechanisms for this effect are still being investigated. Practical implications -Current studies suggest that coffee drinkers can help protect themselves from neurodegenerative and other diseases by drinking an average of two cups of regular, filtered coffee per day. Originality/value -This article provides accessible and comprehensive information to researchers, nutritionists, and consumers who are interested in the potential health risks and benefits of regular and moderate coffee drinking.

Collaboration has been a hallmark of applied anthropology for as long as anthropologists have been putting anthropology to use. The very process of applying anthropological methods and theories to real‐world problems requires an understanding of the needs of the people experiencing the problem. Collaboration also has a long history in both archaeology and ethnography in Mesoamerica. This article explores the relationship between collaboration and applied anthropology in the context of a volunteer tourism program in rural Yucatan, Mexico. Tourism—and especially archaeological tourism—is a driving force in the region's economy. Increasingly, volunteer tourism initiatives provide visitors with the opportunity to contribute to the local community as part of their travel experience. I argue that the conceptual framework of what constitutes meaningful collaboration offers us a way to examine the interactions and power dynamics surrounding the encounter between volunteer, host, and even ethnographer. Specifically, the article questions whether contributions of various sorts are a requisite for achieving actual collaboration in these encounters.