Convergence of Broadcast and New Telecom Networks

The demand of the new telecom industry for cost efficient provision of mobile multimedia services is faced with the reality of scarce radio resources. The requirement of spectrum efficiency has driven the development of various digital radio technologies that have been optimized for specific services, namely for broadcast or for mobile communication. However, existing and emerging multimedia services exhibit challenging requirements in terms of asymmetry, interactivity, real-time, and multicast communication. This paper describes an IP based multi-radio infrastructure that enables the co-operation of existing radio networks to combine their capabilities to ensure a spectrum efficient provision of high-quality mobile multimedia services. Further the need for a dynamic allocation of spectrum to radio services is motivated. The basic functionality and the architecture of a multi-radio system is outlined, with a special emphasis on the cooperation between different radio systems. Further an evolution path for the convergence of broadcast and new telecom is desribed, starting from today's systems and leading to a fully coordinated system.     

FAK Shutdown: Consequences on Epithelial Morphogenesis and Biomarker Expression Involving an Innovative Biomaterial for Tissue Regeneration

By employing an innovative biohybrid membrane, the present study aimed at elucidating the mechanistic role of the focal adhesion kinase (FAK) in epithelial morphogenesis in vitro over 4, 7, and 10 days. The consequences of siRNA-mediated FAK knockdown on epithelial morphogenesis were monitored by quantifying cell layers and detecting the expression of biomarkers of epithelial differentiation and homeostasis. Histologic examination of FAK-depleted samples showed a significant increase in cell layers resembling epithelial hyperplasia. Semiquantitative fluorescence imaging (SQFI) revealed tissue homeostatic disturbances by significantly increased involucrin expression over time, persistence of yes-associated protein (YAP) and an increase of keratin (K) 1 at day 4. The dysbalanced involucrin pattern was underscored by ROCK-II^Ser1366 activity at day 7 and 10. SQFI data were confirmed by quantitative PCR and Western blot analysis, thereby corroborating the FAK shutdown-related expression changes. The artificial FAK shutdown was also associated with a significantly higher expression of filaggrin at day 10, sustained keratinocyte proliferation, and the dysregulated expression of K19 and vimentin. These siRNA-induced consequences indicate the mechanistic role of FAK in epithelial morphogenesis by simultaneously considering prospective biomaterial-based epithelial regenerative approaches.     

Parkhaus “Am Gericht” in Frankfurt am Main – Eine Sanierung mit kathodischem Korrosionsschutz

Parking garage “Am Gericht” in Frankfurt am Main – a refurbishment with cathodic corrosion protection. After several decades in use a refurbishment is often necessary for the bearing structure of reinforced concrete parking garages due to chlorides, which have been brought into concrete by road salt, and the resulting corrosion of the reinforcement, which may lead to a serious decrease of the bearing capacity. With the system of the cathodic protection of the reinforcement exists a cost‐effective and reliable technique as an alternative to common solutions. An intensive investigation of the structure, the knowledge of the reasonable limits of the system, excellent design and execution of the construction work and the monitoring of the working system are nevertheless required, which is illustrated by the example of the parking garage “Am Gericht” in Frankfurt am Main.     

Polymer-based fabrication techniques for enclosed microchannels in biomedical applications

Investigations and analyses of body fluids like serum or whole blood are essential tasks in biomedical research in order to understand and diagnose diseases, to conduct pharmacological tests or to culture cells. Therefore, microfluidic systems provide a favorable tool for processing fluid samples as they allow downscaling of sample volumes and handling of single fluid components such as cells or proteins. For this reason, we present simple fabrication techniques for microchannel systems using polymer materials only. The demonstrated fabrication procedures are based on combinations of acrylic glass and the photo resists SU-8 and PerMX3020. On the one hand, these materials are low-priced compared to conventional silicon or glass. On the other hand, they have not shown any interaction with blood or other cell suspensions within the frame of our study. Furthermore, their transparency guarantees an easy observability of all processes within the system. Depending on the channel dimensions, different adhesion bonding techniques for closing of the systems are applied, whereas the fluidic interfaces are included by mechanical drilling. Summing up, we provide complete fabrication processes for fluidic systems which are simpler and more cost-effective than conventional methods and yet cope with all essential requirements for microfluidic applications.     

Exact methods for the resource levelling problem

We present a project scheduling problem subject to general temporal constraints where the utilization of a set of renewable resources has to be smoothed over time. For solving the NP-hard optimization problem, we point out some important structural properties and introduce a new enumeration scheme. Combining this enumeration scheme with some branch-and-bound techniques, we propose an appropriate solution procedure for the project scheduling problem at hand. To outline the practical importance of resource levelling, we sketch exemplary the optimization of mid-term planning schedules with regard to the resource requirements of IT projects. Finally, we present results from a comprehensive computational study on problem instances of the well-known rlp_j10 and rlp_j20 test sets devised by Kolisch et al. (Benchmark Instances for Project Scheduling Problems, Kluwer, Boston, 1999).     

Sicherung der Netzneutralität

Die Geschichte des Internets ist eine Erfolgsgeschichte. Dieser Erfolg beruht u.a. auf einer neutralen Datenübermittlung, die dadurch gekennzeichnet ist, dass Netzbetreiber Datenpakete von und an ihre Kunden unver?ndert und gleichberechtigt übertragen, unabh?ngig davon, woher diese stammen und welche Anwendungen die Pakete generiert haben. In jüngster Zeit werden Forderungen nach Verkehrsregelungen im Internet lauter. Begründet wird diese Initiative mit einer drohenden Netzüberlastung, die durch die wachsende Popularit?t von Videoangeboten wie YouTube oder Streaming-Angeboten wie Hulu entsteht. Kritiker befürchten, dass durch den Einsatz neuer Netzwerkmanagementtechniken die Innovationsoffenheit und die freie Kommunikation im Internet gef?hrdet werden. Der Beitrag analysiert die M?glichkeiten und Grenzen der Gew?hrleistung von Netzneutralit?t durch das deutsche Telekommunikations- und Medienrecht.     

Curcumin-Induced Heme Oxygenase-1 Expression Prevents H2O2-Induced Cell Death in Wild Type and Heme Oxygenase-2 Knockout Adipose-Derived Mesenchymal Stem Cells

Mesenchymal stem cell (MSC) administration is a promising adjuvant therapy to treat tissue injury. However, MSC survival after administration is often hampered by oxidative stress at the site of injury. Heme oxygenase (HO) generates the cytoprotective effector molecules biliverdin/bilirubin, carbon monoxide (CO) and iron/ferritin by breaking down heme. Since HO-activity mediates anti-apoptotic, anti-inflammatory, and anti-oxidative effects, we hypothesized that modulation of the HO-system affects MSC survival. Adipose-derived MSCs (ASCs) from wild type (WT) and HO-2 knockout (KO) mice were isolated and characterized with respect to ASC marker expression. In order to analyze potential modulatory effects of the HO-system on ASC survival, WT and HO-2 KO ASCs were pre-treated with HO-activity modulators, or downstream effector molecules biliverdin, bilirubin, and CO before co-exposure of ASCs to a toxic dose of H₂O₂. Surprisingly, sensitivity to H₂O₂-mediated cell death was similar in WT and HO-2 KO ASCs. However, pre-induction of HO-1 expression using curcumin increased ASC survival after H₂O₂ exposure in both WT and HO-2 KO ASCs. Simultaneous inhibition of HO-activity resulted in loss of curcumin-mediated protection. Co-treatment with glutathione precursor N-Acetylcysteine promoted ASC survival. However, co-incubation with HO-effector molecules bilirubin and biliverdin did not rescue from H₂O₂-mediated cell death, whereas co-exposure to CO-releasing molecules-2 (CORM-2) significantly increased cell survival, independently from HO-2 expression. Summarizing, our results show that curcumin protects via an HO-1 dependent mechanism against H₂O₂-mediated apoptosis, and likely through the generation of CO. HO-1 pre-induction or administration of CORMs may thus form an attractive strategy to improve MSC therapy.