Ceramide is a bioactive molecule involved in cellular responses to stress and inflammation. The major pathway for ceramide accumulation is via agonist-induced activation of cellular sphingomyelinases. It has also been shown that the ceramide level in circulating low density lipoprotein (LDL) increases during systemic inflammation, hence it is of importance to understand whether LDL-derived ceramide also contributes to the cellular ceramide homeostasis and affects cell functions. This article provides evidence of uptake of ceramideenriched LDL by human microvascular endothelial cells in a receptor-mediated fashion. This uptake can be competed by native LDL, indicating that the LDL-binding receptor may be involved. Following uptake, part of the LDL-derived ceramide is converted to sphingosine, but more importantly, part of it accumulates inside the cells (approximately 1.44 nmol/mg of cell protein). This accumulation of ceramide correlates with an increased incidence of apoptosis. The addition of tumor necrosis factor-␣ further enhances the accumulation of LDL-derived ceramide and the rate of apoptosis. In contrast, inhibitors of receptor-mediated endocytosis block both, the accumulation of LDL-derived ceramide and the concurrent increase in apoptosis. We also show that LDL-delivered ceramide is a more efficient inducer of apoptosis as compared with ethanol-delivered ceramide, the same apoptotic effect being achieved by substantially smaller increases in intracellular ceramide. Taken together, the presented data indicate that increases in lipoprotein ceramide concentration may result in changes in the bioactive properties of circulating lipoproteins such as the enhanced ability to induce apoptosis in the microvascular endothelium.The uptake and metabolism of modified low density lipoprotein (LDL) 1 are a pre-requisite for the formation of atherosclerotic plaques (1-7). Recent studies suggest that changes in the sphingolipid content of LDL also affect the development of atherosclerosis by promoting aggregation (8 -10) and oxidation (11) of LDL. These studies have focused on the role of secreted, zinc-dependent, sphingomyelinase (S-SMase), which hydrolyzes LDL sphingomyelin (SM) to ceramide. It is secreted mainly by endothelial cells in vitro in response to either TNF-␣ or interleukin-1␤ (12), as well as in response to lipopolysaccharide in vivo (13). Studies using bacterial SMase or recombinant S-SMase have shown that conversion of LDL-SM to ceramide leads to aggregation (8) and fusion (14) of the LDL particles, increases their retention in subintimal space (19), and can facilitate LDL oxidation (11). The possible role of SMase has been further emphasized by data showing that LDL extracted from advanced human aortic plaques has higher ceramide content than LDL extracted from circulation or from normal aorta (19). These findings indicate that changes in the SM/ceramide ratio of LDL affect their atherogenic properties, however, they do not distinguish between the effect of ceramide increase and that of SM depletion. ...

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The far right in the United States has gained international visibility and power by promulgating its ideas using multiple media sources. This paper considers contemporary right‐wing representations of John Dewey as found on English‐language internet websites. The author employs discourse analytic methods to address the questions—‘How is John Dewey constructed in right‐wing internet discourse?’ and ‘By what means has the Right come to construct Dewey in this way?’ Elements of the internet discourse are related to texts that helped shape it. The paper demonstrates that far right‐wing websites construct Dewey and his ideas as the antithesis of American values and as a political and existential threat of the highest order. In this discourse, Dewey is connected to Satan, communism and global conspiracy theories. The paper concludes with a discussion of the implications of these beliefs for current educational and political philosophy and praxis.

The purpose of this paper is to begin to excavate the unstated theoretical underpinnings of teacher evaluation systems as they exist in policy and practice and to explicitly consider how these evaluation systems might intersect theoretically with social learning theory. Research suggests that organizational leaders believe growth-based evaluation practices have yet-untapped potential to support teacher learning within teacher communities. However, models of teacher evaluation, as defined in federal and state policy and developed and implemented in practice, rarely make explicit the theoretical and conceptual frameworks upon which they are based. Further, evaluation models do not explicitly intersect with the conceptual frameworks for such learning, e.g., communities of practice (CoPs) and social learning theory. Rather, the role of teacher evaluation in social learning within and across educational organizations remains under-theorized. We argue for research examining potential connections in theory and practice between two existing conceptual frameworks: 1) social learning theory and 2) teacher evaluation systems (understood as policy, models, and practices).

This case study addressed effects of international student teaching on U.S. teacher candidates’ cross-cultural adaptability and perspectives on language, culture, and schooling. Interviews and the Cross-Cultural Adaptability Inventory were collected from 18 participants before and after 4 weeks student teaching internationally. Interviews were coded using the Cross-Cultural Adaptability Inventory dimensions and interpreted using Mezirow’s transformational learning theory. Findings suggested that increased cross-cultural adaptation aligns with transformational learning. Transformational learning led participants to question assumptions and consider incorporating different perspectives in future teaching.