Alternative Nf-kb Signaling in Atherogenesis

Inflammatory processes mark all stages of atherogenesis. One of the key regulators of inflammation is the transcription factor nuclear factor kappa B (Nf-kb). Nf-kb is the general name for a whole family of dimeric transcription factors. One can distinguish between a classical and an alternative pathway with Rela/p50 (Nf-kb1) and Relb/p52 (Nf-kb2) representing the terminal transcription factors, respectively. Classical Nf-kb1 signaling has been associated with atherosclerotic lesion development many times, mainly because of its regulation of many pro-inflammatory proteins with an established role in atherogenesis. Recent studies provided evidence of crosstalk between classical Nf-kb1 and alternative Nf-kb2 signaling, implicating a potential role for Nf-kb2 in atherogenesis. The aim of the present study was to investigate the influence of Nf-kb2 on atherosclerotic lesion development in a knockout mouse model. Nfkb2 knockout (Nfkb2-/-) mice were generated on two different atherosclerosis sensible backgrounds, the Apoe- and Ldlr- deficient background. Quantification of atherosclerotic lesion development showed, that Nfkb2-/- mice developed significantly more atherosclerosis at the brachiocephalic artery than wild type controls, indicating a protective effect of Nf-kb2 on atherogenesis. Further expression analyses in bone marrow-derived macrophages (BMDM) revealed highly significant upregulation of matrix metalloproteinase 9 (Mmp9) in Nfkb2-/- mice. Overexpression of Mmp9 was associated with enhanced macrophage migration across extracellular matrix in vitro and an inflammatory plaque phenotype with advanced, macrophage-rich lesions. Accordingly, increased Mmp9 expression in Nfkb2-/- macrophages might have contributed to enhanced lesion development in these mice

Energy storage and dispersion of surface acoustic waves trapped in a periodic array of mechanical resonators

International audienceIt has been shown previously that surface acoustic waves can be efficiently trapped and slowed by steep ridges on a piezoelectric substrate, giving rise to two families of shear-horizontal and vertically polarized surface waves. The mechanisms of energy storage and dispersion are explored by using the finite element method to model surface acoustic waves generated by high aspect ratio electrodes. A periodic model is proposed including a perfectly matched layer to simulate radiation conditions away from the sources, from which the modal distributions are found. The ratio of the mechanical energy confined to the electrode as compared to the total mechanical energy is calculated and is found to be increasing for increasing aspect ratio and to tend to a definite limit for the two families of surface waves. This observation is in support of the interpretation that high aspect ratio electrodes act as resonators storing mechanical energy. These resonators are evanescently coupled by the surface. The dispersion diagram is presented and shows very low group velocities as the wave vector approaches the limit of the first Brillouin zone

Corporate communications and public relations in Asia: Context, status quo, and future challenges

This research paper offers insights into the status quo of corporate communications and public relations in Asia and analyzes the political, economic and cultural context in which practicioners operate. As a result of the economic upswing and political opening of Asian nations in the last decade, the fields of corporate communications and PR have experienced an expansion and professionalization. However, these developments differ from those in Western countries. Political and cultural particularities have led to specific characteristics of Asian corporate communications/PR like the importance of personal relationships and hierarchy. As Asian markets become increasingly important in terms of production and sales and with growning numvers of international companies establishing parts of their HQs and communication managers is/becomes essential. The paper discusses current topics, challenges and findings of recent empirical studies and outlines fields for future research that are importance to corporate practice.Der vorliegende Forschungsbericht gibt einen Überblick über den Staus Quo von Unternehmenskommunikation und Public Relations im asiatischen Raum und geht auf politische, wirtschaftliche und kulturelle Besonderheiten ein. Im Zuge des wirtschaftlichen Aufschwungs und der politischen Öffnung der asiatischen Nationen hat auch das Kommunikationsmanagement eine Expansion und Professionalisierung erfahren, die sich jedoch von den entsprechenden Entwicklungen in westlichen Nationen unterscheidet. Politische sowie kulturelle Einflüsse führen zu spezifischen Ausprägungen in der Kommunikationsarbeit. Kenntnisse hierüber sind für deutsche Kommunikationsmanager essentiell, da Asien nicht nur als Produktions- und Absatzmarkt, sondern auch als Unternehmensstandort immer wichtiger wird. Zahlreiche internationale Firmen haben in den vergangenen Jahren Teile ihrer Unternehmenszentralen sowie ihrer Kommunikationsabteilungen nach Asien verlagert. Der Bericht diskutiert heutige Herausforderungen und Themen und skizziert Ergebnisse aktueller empirischer Studien. Es werden zudem Fragestellungen für künftige Forschung aufgezeigt, die für die Unternehmenspraxis von Interesse sind

Host-pathogen interactions between the human innate immune system and Candida albicans—understanding and modeling defense and evasion strategies

The diploid, polymorphic yeast Candida albicans is one of the most important humanpathogenic fungi. C. albicans can grow, proliferate and coexist as a commensal on or within thehuman host for a long time. Alterations in the host environment, however, can render C. albicansvirulent. In this review, we describe the immunological cross-talk between C. albicans and thehuman innate immune system. We give an overview in form of pairs of human defense strategiesincluding immunological mechanisms as well as general stressors such as nutrient limitation,pH, fever etc. and the corresponding fungal response and evasion mechanisms. FurthermoreComputational Systems Biology approaches to model and investigate these complex interactionare highlighted with a special focus on game-theoretical methods and agent-based models. Anoutlook on interesting questions to be tackled by Systems Biology regarding entangled defenseand evasion mechanisms is given