293 research outputs found

    Nutrient enrichment scarcely affects ecosystem impacts of a non-native herbivore in a spring-fed river

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    SUMMARY 1. Non-native invasive species (NNIS) are a global issue whose introduction into novel ecosystems can fundamentally alter nutrient recycling and storage. It is therefore important to understand factors that affect the abundance and distribution of NNIS and their effects on ecosystems. 2. We investigated how nutrient enrichment and herbivorous armoured catfish separately and in combination affect ecosystem processes in a subtropical spring-fed river (San Marcos, River, TX, U.S.A.). A replicated stream channel experiment in which nutrient enrichment was cross-classified with the presence and the absence of armoured catfish was conducted to evaluate how nutrient enrichment may affect the ecosystem and nutrient cycling effects of catfish. 3. The presence of catfish reduced periphyton biomass and altered detrital decomposition rates and, contrary to predictions, decreased periphyton N:P. In addition, the presence of catfish increased the severity of periphyton P-limitation. We found little evidence that adding nutrients altered the effects of armoured catfish on ecosystem dynamics. 4. Armoured catfish likely play an important role in the nutrient dynamics of the San Marcos River, but nutrient enrichment has little influence on determining the magnitude of ecosystem and nutrient cycling effects of this invasive and stoichiometrically unique consumer

    GMOs: Non-Health Issues

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    The controversy over genetically modified [GM] organisms is often framed in terms of possible hazards for human health. Articles in a previous volume of this *Encyclopedia* give a general overview of GM crops [@Mulvaney2014] and specifically examine human health [@Nordgard2014] and labeling [@Bruton2014] issues surrounding GM organisms. This article explores several other aspects of the controversy: environmental concerns, political and legal disputes, and the aim of "feeding the world" and promoting food security. Rather than discussing abstract, hypothetical GM organisms, this article explores the consequences of the GM organisms that have actually been deployed in the particular contexts that they have been deployed, on the belief that there is little point in discussing GM organisms in an idealized or context-independent way

    The three main monotheistic religions and gm food technology: an overview of perspectives

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    Abstract Background Public acceptance of genetically modified crops is partly rooted in religious views. However, the views of different religions and their potential influence on consumers' decisions have not been systematically examined and summarized in a brief overview. We review the positions of the Judaism, Islam and Christianity – the three major monotheistic religions to which more than 55% of humanity adheres to – on the controversies aroused by GM technology. Discussion The article establishes that there is no overarching consensus within the three religions. Overall, however, it appears that mainstream theology in all three religions increasingly tends towards acceptance of GM technology per se, on performing GM research, and on consumption of GM foods. These more liberal approaches, however, are predicated on there being rigorous scientific, ethical and regulatory scrutiny of research and development of such products, and that these products are properly labeled. Summary We conclude that there are several other interests competing with the influence exerted on consumers by religion. These include the media, environmental activists, scientists and the food industry, all of which function as sources of information and shapers of perception for consumers

    Effects of partner proteins on BCA2 RING ligase activity

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    Abstract Background BCA2 is an E3 ligase linked with hormone responsive breast cancers. We have demonstrated previously that the RING E3 ligase BCA2 has autoubiquitination activity and is a very unstable protein. Previously, only Rab7, tetherin, ubiquitin and UBC9 were known to directly interact with BCA2. Methods Here, additional BCA2 binding proteins were found using yeast two-hybrid and bacterial-II-hybrid screening techniques with Human breast and HeLa cDNA libraries. Co-expression of these proteins was analyzed through IHC of TMAs. Investigation of the molecular interactions and effects were examined through a series of in vivo and in vitro assays. Results Ten unique BCA2 interacting proteins were identified, two of which were hHR23a and 14-3-3sigma. Both hHR23a and 14-3-3sigma are co-expressed with BCA2 in breast cancer cell lines and patient breast tumors (n = 105). hHR23a and BCA2 expression was significantly correlated (P = \u3c 0.0001 and P = 0.0113) in both nucleus and cytoplasm. BCA2 expression showed a statistically significant correlation with tumor grade. High cytoplasmic hHR23a trended towards negative nodal status. Binding to BCA2 by hHR23a and 14-3-3sigma was confirmed in vitro using tagged partner proteins and BCA2. hHR23a and 14-3-3sigma effect the autoubiquitination and auto-degradation activity of BCA2. Ubiquitination of hHR23a-bound BCA2 was found to be dramatically lower than that of free BCA2, suggesting that hHR23a promotes the stabilization of BCA2 by inactivating its autoubiquitination activity, without degradation of hHR23a. On the other hand, phosphorylated BCA2 protein is stabilized by interaction with 14-3-3sigma both with and without proteasome inhibitor MG-132 suggesting that BCA2 is regulated by multiple degradation pathways. Conclusions The interaction between BCA2 and hHR23a in breast cancer cells stabilizes BCA2. High expression of BCA2 is correlated with grade in breast cancer, suggesting regulation of this E3 ligase is important to cancer progression

    Structural Basis for Specific Binding of Human MPP8 Chromodomain to Histone H3 Methylated at Lysine 9

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    . MPP8 binding to methylated H3K9 is suggested to recruit the H3K9 methyltransferases GLP and ESET, and DNA methyltransferase 3A to the promoter of the E-cadherin gene, mediating the E-cadherin gene silencing and promote tumor cell motility and invasion. MPP8 contains a chromodomain in its N-terminus, which is used to bind the methylated H3K9. HP1, a chromodomain containing protein that binds to methylated H3K9 as well. The structure also reveals that the human MPP8 chromodomain forms homodimer, which is mediated via an unexpected domain swapping interaction through two β strands from the two protomer subunits.Our findings reveal the molecular mechanism of selective binding of human MPP8 chromodomain to methylated histone H3K9. The observation of human MPP8 chromodomain in both solution and crystal lattice may provide clues to study MPP8-mediated gene regulation furthermore
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