Klimawandel und Lebenswirklichkeit

Der Klimawandel ist eine der größten Herausforderungen der menschlichen Gesellschaft. Die Naturwissenschaften haben die damit verbundenen Veränderungsprozesse hinlänglich untersucht und auf die damit verbundenen Risiken hingewiesen. Die Medien spielen eine große Rolle, um dem komplexen Phänomen der globalen Erwärmung einen sozialen Deutungsrahmen zu geben. In Deutschland gibt es zahlreiche Regionen, die auf ganz unterschiedliche Weise von den klimawandelbedingten Veränderungsprozessen betroffen sind. Ein stetig wachsender Teil der Bevölkerung hat in seiner lebensnahen Umwelt mittlerweile ganz eigene Erfahrungen mit den Auswirkungen des Klimawandels gemacht. Das vorliegende Buch gibt Einblick in das Verhältnis zwischen medienvermittelter Information zu primärer Umwelterfahrung und beleuchtet insbesondere die Relevanz des individuellen Wissensvorrates im Hinblick auf ein soziales Klimabewusstsein

In Vitro Formation of Urinary Stones : Generation of Spherulites of Calcium Phosphate in Gel and Overgrowth with Calcium Oxalate Using a New Flow Model of Crystallization

Calcium phosphate (CaP) has been detected in the majority of urinary stones containing predominantly calcium oxalate (CaOx). Therefore, crystal phases of CaP might play an important role with respect to the formation of urinary calcium stones in general. Very often, CaP found in stones or tissue of human kidney occurs in the shape of small spherulites. In this paper, we report on a new flow model of crystallization (FMCG), which has been used to generate spherulites of CaP in a gel matrix of 1% agar-agar at 37°C from a supersaturated, metastable solution continuously flowing over the gel surface. Scanning electron microscopy (SEM), X-ray diffraction and microscopic Fourier transformed infrared spectroscopy (FTIR) revealed that the particles formed (diameter: up to 200 μm) consisted of a poorly crystal-line core of carbonatoapatite which was partly surrounded by a well-crystallized shell of octacalcium phosphate (OCP) showing radially oriented sheet-like structures. Subsequently, CaOx was grown on these spherulites from a flow of a correspondingly supersaturated solution conducted over the gel matrix. It could be shown by SEM that growth of calcium oxalate monohydrate (COM) was characteristically induced by the OCP shell. Radial sheet-like forms of OCP were directly continued by COM showing a certain radial orientation. The model of crystallization in gel matrices applied here should be well-suited to simulate the process of urinary stone formation under in vitro conditions

Rollenerwartungen unterschiedlicher Berufsgruppen im OP

Zusammenfassung: Hintergrund: Ausdifferenzierte Rollenstrukturen haben den Vorteil, dass sie den Teammitgliedern vorgeben, welches Verhalten von ihnen erwartet wird bzw. welches Verhalten sie von den anderen Mitgliedern erwarten können. Die Entstehung einer solchen Rollenstruktur erfordert jedoch eine Vielzahl an Interaktionen der betreffenden Menschen und somit eine Mindestkontaktdauer. Im OP-Saal arbeiten die Teams meist in wechselnder Zusammensetzung. In diesen kurzfristig zusammengestellten Teams kann sich eine Rollenstruktur nicht ausdifferenzieren. In der vorliegenden Untersuchung wird der Frage nachgegangen, ob die Zugehörigkeit zu einer bestimmten Berufsgruppe die fehlende Möglichkeit zur häufigen Interaktion im OP-Bereich substituiert. Methode: Anhand eines 9-Item-Fragebogens zur sozialperspektivischen Imagepositionierung (Kurzform von SYMLOG) wurden in einer schriftlichen Befragung OP-Saal-Mitarbeiter aus zwei Krankenhäusern zu ihrer Einschätzung von professionsspezifischen Verhaltensmerkmalen bezüglich Einfluss, Sympathie und Zielorientierung befragt (n=179). Ergebnisse: Die jeweiligen Berufsgruppen beurteilen sich selbst in der Eigenbewertung in jeder der 3Dimensionen höher, als sie die beiden anderen Professionen in der Fremdbeurteilung bewerten. Die Fremdbewertungen können jedoch den Wert der Eigenbewertung übersteigen. Die Analyse der Rollenwahrnehmung zeigt auf, dass sich beide akademischen Berufsgruppen einen großen Einfluss und eine große Zielorientierung zuschreiben. Hieraus kann ein Führungsanspruch abgeleitet werden, der ein Konfliktpotenzial beinhalten könnte. Diskussion: Die Datenanalyse zeigt, dass im untersuchten Kollektiv eine ausdifferenzierte Rollenstruktur im OP-Saal nicht vorhanden war. Hieraus lassen sich Optimierungsmöglichkeiten ableiten, wie beispielsweise der verstärkte Einsatz eingespielter Teams oder die Implementierung Konflikt reduzierender Methode

Organizing Equity Exchanges

In the last years equity exchanges have diversified their operations into business areas such as derivatives trading, posttrading services, and software sales. Securities trading and post-trading are subject to economies of scale and scope. The integration of these functions into one institution ensures efficiency by economizing on transactions costs. Using balanced panel data from major equity exchanges over the period 2005-2007, we examine empirically the presence of economies of scale in securities trading. Moreover, we analyze the impact of vertical integration of trading, clearing, and settlement, the impact of the size of an exchange, and the impact of diversification on the profitability of exchanges. The evidence confirms that a large number of transactions leads to low costs per trade. The evidence shows that the profitability of equity exchanges is highest for vertically integrated exchanges and that diversification and size have a negative impact on their profitability

Adhesion of HVOF-sprayed WC-Co coatings on 316L substrates processed by SLM

Different studies have been demonstrated that the surface integrity of substrate bulk materials to be coated has a significant impact on the adhesion of thermally sprayed coatings. It is known that the surface integrity of parts processed by selective laser melting (SLM) differs from those obtained from bulk materials. Although 316L stainless steel is among the most investigated material for SLM, the adhesion of thermally sprayed coatings on 316L stainless steel substrates processed by SLM has not been studied yet. This study aims at evaluating the effect of various mechanical pre-treatments onto 316L stainless steel substrates processed by SLM and their effect on the adhesion of high velocity oxy-fuel (HVOF)-sprayed WC-Co coatings. To differentiate between topographical effects and residual stress-related phenomena, a stress-relief heat treatment of the SLM substrates served as a reference throughout the investigations. The differently pre-treated SLM substrates were investigated with regard to the surface roughness and residual stresses. For the HVOF-sprayed SLM composites, Vickers interfacial indentation tests were conducted to assess the resulting coating adhesion. The findings demonstrated that the HVOF-sprayed WC-Co coatings predominantly exhibit good adhesion to the SLM 316L substrates. However, it was found that the stress state in the SLM 316L substrate surface is more likely to affect the adhesion of the WC-Co coating, while the substrate surface roughness showed a marginal effect

Разработка ингибиторов коррозии сталей на основе тиомочевины и наночастиц металлов

Despite the essential role of the fibrinogen gamma-chain as a blood clotting factor, the fibrinogen gamma-chain contains a number of interaction sites to recruit other factors such as leukocytes important for prevention of pathogen entry and propagation of the repair process. Interleukin-6 (IL-6) is known as the major inducer of gamma-fibrinogen synthesis in hepatocytes, whereas IL-1beta has been shown to act as a potent inhibitor of gamma-fibrinogen expression. Studies on the rat fibrinogen gamma-chain promoter suggest that nuclear factor (NF)-kappaB replaces the signal transducer and activator of transcription (STAT) 3 from binding to overlapping NF-kappaB/STAT3 binding sites within the 5' regulatory region of the rat gamma-chain gene promoter. However, despite its physiological relevance, the underlying mechanism responsible for the inhibitory effect of IL-1beta in humans is still not understood and apparently more complex. In contrast to the mechanism described for the rat gene our results indicate that IL-1beta suppresses the IL-6-induced activation of the human gamma-fibrinogen gene particularly by blocking the late phase STAT3-tyrosine phosphorylation NF-kappaB-dependently but independent from de novo protein synthesis. Consequently, blocking NF-kappaB activation restores specifically late phase STAT3 activation as well as the induction of the human gamma-fibrinogen gene. In contrast, specifically early STAT3 activation could be restored by a block of the p38 mitogen-activated protein kinase (p38(MAPK)) pathway. In summary, our results indicate that expression of the gamma-fibrinogen gene is mainly controlled by the strength of late phase STAT3 activation, which in turn is negatively regulated by the extent of IL-1beta-mediated NF-kappaB activity

Collateral circulation: Past and present

Following an arterial occlusion outward remodeling of pre-existent inter-connecting arterioles occurs by proliferation of vascular smooth muscle and endothelial cells. This is initiated by deformation of the endothelial cells through increased pulsatile fluid shear stress (FSS) caused by the steep pressure gradient between the high pre-occlusive and the very low post-occlusive pressure regions that are interconnected by collateral vessels. Shear stress leads to the activation and expression of all NOS isoforms and NO production, followed by endothelial VEGF secretion, which induces MCP-1 synthesis in endothelium and in the smooth muscle of the media. This leads to attraction and activation of monocytes and T-cells into the adventitial space (peripheral collateral vessels) or attachment of these cells to the endothelium (coronary collaterals). Mononuclear cells produce proteases and growth factors to digest the extra-cellular scaffold and allow motility and provide space for the new cells. They also produce NO from iNOS, which is essential for arteriogenesis. The bulk of new tissue production is carried by the smooth muscles of the media, which transform their phenotype from a contractile into a synthetic and proliferative one. Important roles are played by actin binding proteins like ABRA, cofilin, and thymosin beta 4 which determine actin polymerization and maturation. Integrins and connexins are markedly up-regulated. A key role in this concerted action which leads to a 2-to-20 fold increase in vascular diameter, depending on species size (mouse versus human) are the transcription factors AP-1, egr-1, carp, ets, by the Rho pathway and by the Mitogen Activated Kinases ERK-1 and -2. In spite of the enormous increase in tissue mass (up to 50-fold) the degree of functional restoration of blood flow capacity is incomplete and ends at 30% of maximal conductance (coronary) and 40% in the vascular periphery. The process of arteriogenesis can be drastically stimulated by increases in FSS (arterio-venous fistulas) and can be completely blocked by inhibition of NO production, by pharmacological blockade of VEGF-A and by the inhibition of the Rho-pathway. Pharmacological stimulation of arteriogenesis, important for the treatment of arterial occlusive diseases, seems feasible with NO donors

Self-Organization and Regulation of Intrinsically Disordered Proteins with Folded N-Termini

How do mostly disordered proteins coordinate the specific assembly of very large signal transduction protein complexes? A newly emerging hypothesis may provide some clues towards a molecular mechanism