308 research outputs found

    Managing (Un)certainty in the Japanese Antique Art Trade - How Economic and Social Factors Shape a Market

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    Market actors are commonly faced with solving three distinct coordination problems as sources of uncertainty. How should they value the objects of their trade, how can they shield themselves from the competition, and with whom and how do they cooperate? This article investigates how Japanese antique art dealers confront these issues. While offering a rich description and analysis of a hitherto understudied Japanese market, the article shows how economic and social issues are closely intertwined. It contributes to our understanding of behaviour in a Japanese market in three ways: Firstly, it underscores how inclusion/exclusion, status, reputation, networks and hierarchies constitute a field that allows market exchanges to exist in the first place, while also channelling, and being impacted by these market exchanges. Secondly, contrary to neoclassical economic theory, where the idea of value has largely been abandoned, the findings highlight the importance of distinguishing between notions of value and price in the understanding of markets. Thirdly, the article shows how market actors actively shape market arrangements to address the specific challenges of their domain. In the case of the Japanese antique art market these challenges include high risks of fakes, a limited quantity of high quality material, market outsiders, and dealers with deep pockets

    Loss of DNMT1o Disrupts Imprinted X Chromosome Inactivation and Accentuates Placental Defects in Females

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    The maintenance of key germline derived DNA methylation patterns during preimplantation development depends on stores of DNA cytosine methyltransferase-1o (DNMT1o) provided by the oocyte. Dnmt1omat-/- mouse embryos born to Dnmt1Δ1o/Δ1o female mice lack DNMT1o protein and have disrupted genomic imprinting and associated phenotypic abnormalities. Here, we describe additional female-specific morphological abnormalities and DNA hypomethylation defects outside imprinted loci, restricted to extraembryonic tissue. Compared to male offspring, the placentae of female offspring of Dnmt1Δ1o/Δ1o mothers displayed a higher incidence of genic and intergenic hypomethylation and more frequent and extreme placental dysmorphology. The majority of the affected loci were concentrated on the X chromosome and associated with aberrant biallelic expression, indicating that imprinted X-inactivation was perturbed. Hypomethylation of a key regulatory region of Xite within the X-inactivation center was present in female blastocysts shortly after the absence of methylation maintenance by DNMT1o at the 8-cell stage. The female preponderance of placental DNA hypomethylation associated with maternal DNMT1o deficiency provides evidence of additional roles beyond the maintenance of genomic imprints for DNA methylation events in the preimplantation embryo, including a role in imprinted X chromosome inactivation. © 2013 McGraw et al

    Epigenetic perturbations in the pathogenesis of mustard toxicity; hypothesis and preliminary results

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    Among the most readily available chemical warfare agents, sulfur mustard (SM), also known as mustard gas, has been the most widely used chemical weapon. SM causes debilitating effects that can leave an exposed individual incapacitated for days to months; therefore delayed SM toxicity is of much greater importance than its ability to cause lethality. Although not fully understood, acute toxicity of SM is related to reactive oxygen and nitrogen species, oxidative stress, DNA damage, poly(ADP-ribose) polymerase (PARP) activation and energy depletion within the affected cell. Therefore several antioxidants and PARP inhibitors show beneficial effects against acute SM toxicity. The delayed toxicity of SM however, currently has no clear mechanistic explanation. One third of the 100,000 Iranian casualties are still suffering from the detrimental effects of SM in spite of the extensive treatment. We, therefore, made an attempt whether epigenetic aberrations may contribute to pathogenesis of mustard poisoning. Preliminary evidence reveals that mechlorethamine (a nitrogen mustard derivative) exposure may not only cause oxidative stress, DNA damage, but epigenetic perturbations as well. Epigenetic refers to the study of changes that influence the phenotype without causing alteration of the genotype. It involves changes in the properties of a cell that are inherited but do not involve a change in DNA sequence. It is now known that in addition to mutations, epimutations contribute to a variety of human diseases. Under light of preliminary results, the current hypothesis will focus on epigenetic regulations to clarify mustard toxicity and the use of drugs to correct possible epigenetic defects
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