Measuring the degree of virtualization. An empirical analysis in two Austrian industries.

Strategic management literature suggests that especially in young and dynamic industries Virtual Corporations are more likely to emerge, as this type of organization is flexible enough to deal with rapidly changing environments. This paper challenges the proposition that environ-mental uncertainty and technological change lead to organizational adaptation towards virtual structures. We analyzed companies of two Austrian industries, data processing and engineering, which are characterized by different rates of innovation and environmental uncertainty, and compare their strategic, structural, and process characteristics by measuring their Degree of Virtualization. Results indicate almost no difference in the Degree of Virtualization. From these findings, we draw implications for the theoretical concept of Virtual Corpora-tions as well as for empirical research. (author's abstract)Series: Report Series SFB "Adaptive Information Systems and Modelling in Economics and Management Science

Basics of Multibody Systems: Presented by Practical Simulation Examples of Spine Models

Computer modeling is a widely used method to determine the biomechanical behavior of a system. The aim of our biomechanical multibody simulation computer modeling is to consider the characteristics of a musculoskeletal system through the use of knowledge from the fields of mechanics, anatomy, and physiology in the model in an appropriate manner, in order to obtain as accurately as possible a realistic simulation of the biomechanical behavior of the system. Various application examples of a lumbar spine model that takes the spinal structures with their specific material properties into account are presented: effects of different spine alignments in standing position, effects of overweight on the spinal biomechanics, and application possibilities of biomechanical computer models in medicine

Computational Simulation as an Innovative Approach in Personalized Medicine

Background: Statistical analyses show that both the spine curvature and the morphological properties of the vertebral bodies can differ considerably. Therefore, the best outcome of a surgery for the individual patient could be achieved by developing patient specific implants to prevent inadequate anchorage of implants that don?t optimally fit to the anatomy and can cause damages of spinal structures

Die Potentiale von e-business in der Wertschöpfungskette

Unsere Gesellschaft macht sich auf den Weg zur sogenannten Informationsgesellschaft. Im ökonomischen Bereich zeigt sich dieser Trend durch die verstärkte Anwendung von Internet-Technologien. Der Trend der letzten Jahre zeigt deutlich, daß die Verbreitung des Internet und deren wirtschaftliche Nutzung nicht mehr aufzuhalten sind. Wir befinden uns inmitten einer tiefgreifenden Umgestaltung des wirtschaftlichen Lebens. Dieser Entwicklung können sich auch Unternehmen nicht entziehen. Das Internet und die damit verbundenen Anwendungen bringen bei einem immer stärker werdenden Wettbewerbs- und Kostendruck Chancen mit sich, Unternehmensabläufe neu zu gestalten, um sich so von Konkurrenten zu differenzieren und somit Wettbewerbsvorteilen zu erzielen. Integrierte Informationssysteme, die mit Hilfe des Internet arbeiten, machen es möglich, die Wertschöpfungskette zwischen Angestellten, Kunden, Lieferanten und Händlern neu zu gestalten und somit Kosten zu sparen, kundenfreundlich zu agieren und für alle Beteiligten Vorteile zu erzielen. Das weitreichende Potential des Internet ermöglicht gar eine komplette Neustrukturierung der Wertschöpfungskette eines Unternehmens und hat somit Auswirkungen auf alle Unternehmensbereiche. Die klassischen Grenzen der Unternehmung beginnen sich nach innen wie nach außen zu verändern, teilweise auch aufzulösen. Viele Unternehmen nutzen die Potentiale des Internet jedoch nur in Teilbereichen und schöpfen nicht das gesamte Spektrum der Möglichkeiten aus. Insbesondere die internen Wertschöpfungsprozesse, die große Chancen beinhalten, werden häufig vernachlässigt

Measurement of convective heat transfer for various checker systems

The heat transfer properties of six different checkerworks were studied using a special test equipment. The temperature was deliberately limited to 300 C in order to measure the local temperature distribution of the air for the first time. The flow in the regenerator channels shows a considerable non-symmetrical appearance and local strands. Its enthalpy can not be determined by the measurement of only one temperature. The heat transfer depends not only on the velocity of the flow (forced convection) but also on the temperature differences and resulting density differences of the fluid (free convection). In consequence of the low operating temperature and the necessity to measure the air temperature at many points, sufficiently accurate values for the coefficient of heat transfer could only be achieved for a part of the parameter range of industrial regenerators

Coevolutionary dynamics and geographic mosaics in the Social Parasite Harpagoxenus sublaevis and its two Host Species

Social parasites such as bees, wasps and ants parasitize complete insect societies. They take advantage of the brood care behaviour of other social insect species, and thus avoid the costs of parental care similar to avian brood parasites such as cuckoos and cowbirds. The European social parasite Harpagoxenus sublaevis is an obligate slavemaking ant species that exploits mainly two closely related host species of the genus Leptothorax. To found a new colony, a slavemaking queen invades a host colony, kills the resident queen and workers. The inseminated queen raises the alien brood and the later emerging host workers accept the parasite queen as their own and become slaves that carry out all necessary colony tasks. A year later, slavemaking workers emerge, which conduct regular slave raids on neighbouring host colonies for worker brood to replenish the labour force of the slavemaker nest. These slave raids can impose severe selection pressure on the hosts, as slavemaking colonies attack several host nests per year and raided host colonies often perish as a consequence of the attack. According to the geographical mosaic theory of coevolution, differences in the advance or trajectory of the coevolutionray process between local communities are predicted due to their composition and the strength of ecological selection pressures through competition and resource availability. In our study system, investigations of the impact of the slave making ant H. sublaevis at several geographic distant sites allow general conclusions on the virulence, the degree of reciprocal adaptation and specialization of the species, and the evolutionary trajectories within this host-parasite system. The European slave making ant H. sublaevis and its host species are good examples as parasites and hosts are widely distributed throughout Eurasia whereas other social parasites use host species with small or patchy populations, e.g. Myrmoxenus or Chalepoxenus, where selection should be strong to decrease their virulence. Furthermore H. sublaevis produces a large army of slave making workers indicating that this species remains highly virulent. In accordance with the assumption of a geographic mosaic in the interaction of H. sublaevis and its hosts, these studies have shown that parasite prevalence is a good predictor of the strength of reciprocal adaptation in different communities. In our genetic, chemical and behavioural studies we could show that H. sublaevis prefers the smaller host L. muscorum, which is more limited in dispersal than its larger competitor L. acervorum. Both hosts showed differences in defense strategies of which L. acervorum is the more aggressive host, while L. muscorum tend to flee when getting into contact with its parasite. Moreover for the genetic more variable parasite the chemical profile of L. muscorum may be easier to imitate as this host is more limited in gene flow than its counter part. Further explanation of the better resemblance of the parasite to its smaller host could be the easier acquisition of the more volatile shorter hydrocarbons. Also in the field manipulation study both host species showed different responses to the parasite pressure of H. sublaevis following the two strategies, investment in sexuals or in workforce. Moreover our crossfostering experiment indicated that the local parasite showed a greater impact on its hosts than the allopatric one. This led to the conclusion that coevolutionary trajectories differ between communities, asumed by different historical processes, community context and ecological conditons at each site which confirms the geographic mosaic theory of coevolution

The enrichment of Pluchea odorata anti-neoplastic activities and the analysis of underlying mechanisms

Ziel dieser Diplomarbeit war die Anreicherung der anti-neoplastischen Aktivität der guatemalischen Pflanze Pluchea odorata (L.) Cass., Asteraceae, und die Untersuchung der zugrunde liegenden Mechanismen dieser Aktivität. Neueste Untersuchungsergebnisse zeigen die starke anti-neoplastische Aktivität der oberirdischen Pflanzenteile dieser traditionellen Heilpflanze, welche bei den Maya zur Behandlung schwerer Entzündungen eingesetzt wird [GRIDLING et al., 2008]. Auf Basis dieser Ergebnisse wurden zur Anreicherung aktiver Verbindungen, Bio-Assay unterstützte Fraktionierungen durchgeführt. Zu Beginn wurde das getrocknete, pulverisierte Pflanzenmaterial mit Hilfe der ASE (accelerated solvent extraction) extrahiert um das bioaktive P. odorata ASE - CH2Cl2 Extrakt zu erhalten. Darauf folgten die Fraktionierungsschritte durch (VLC) Vacuum liquid chromatography (PE,CHCl3-MeOH,MeOH-H2O in unterschiedlichem Mischungsverhältnis), durch (CC) Normal column chromatography (Chloroform-Methanol-Wasser Gradient) auf Silikagel KG60 und durch RP-18 (SPE) Solid phase extraction (CHCl3,MeOH,H2O in unterschiedlichem Mischungsverhältnis). Demzufolge ist die anti-proliferative Aktivität der P. odorata auf eine Fraktion zurückzuführen, welche hoch polare Bestandteile aufweist. Durch fünf aufeinander folgende Fraktionierungsschritte konnte eine 25-fache Anreicherung der anti-proliferativen Aktivität erreicht werden. Zur laufenden Überprüfung der anti-kanzerogenen Wirkung der erhaltenen Fraktionen wurde die Proliferationshemmung und die Induktion des Zelltodes in HL60 Zellen und MCF7 Zellen getestet. Die wirksamsten Fraktionen waren F2/11, F2/13 und F3/4, welche in der Folge mittels Western blot getestet wurden um zugrunde liegende Mechanismen aufzuzeigen. Die jeweils unterschiedliche Cyclin D1 Expression der einzelnen Fraktionen hat gezeigt, dass die Fraktion F2/11 schwächer wirksame Komponenten enthält als F2/13, und weist zugleich auf eine Aktivitätsanreicherung in Fraktion F3/4 hin. Die Inkubation der Zellen mit den Fraktionen F2/11, F2/13 und F3/4 löste eine Phosphorylierung von Chk2 am aktivierenden Thr68 aus, wobei Fraktion F2/11 die Chk2 Aktivierung zum frühesten Zeitpunkt auslöste. Die beobachtete Chk2 Aktivität untermauerte den Hinweis darauf, dass sich die aktiven Verbindungen in F2/11 und F2/13 unterschieden. Gleichzeitig zeigte sie deutlich, dass diese Verbindungen, welche vornehmlich in die Zellzyklus-Progression eingegriffen haben, in F3/4 angereichert wurden. Fraktion F2/11 und F3/4 wiesen die am stärksten pro-apoptotisch aktiven Verbindungen auf, wobei es durch die Fraktionierungsschritte zu einer 45-fachen Anreicherung in Fraktion F3/4 kam. Den Beweis der Genotoxizität der Fraktion F2/11 lieferte die rasch ausgelöste Phosphorylierung von H2AX. Offensichtlich ist in Fraktion F2/11 eine DNA-schädigende Komponente enthalten. Dahingegen fand die Induktion von γH2AX durch F2/13 und F3/4 in Folge der Aktivierung von Caspasen statt, was durch die Aufspaltung von PARP belegt wurde. Die Acetylierung des alpha-Tubulin hat gezeigt, dass die Mikrotubuli durch alle 3 Fraktionen stabilisiert wurden, und in der Folge mitotischen Arrest und Apoptose auslöste, was an den Mechanismus des Taxol erinnert. Fraktion F3/4 zeigte eine Steigerung der Tubulin-acetylierenden Wirkung. Somit haben wir die Auftrennung und Isolierung von zwei verschiedenen anti-neoplastisch wirksamen Komponenten oder Verbindungsgemischen aus dem P. odorata ASE – CH2Cl2 Extrakt erreicht.The aim of this diploma theses was to enrich the anti-neoplastic activities of Pluchea odorata (L.) Cass., Asteraceae, and analyse the underlying mechanisms. In recent investigations a strong anti-neoplastic activity was found from aerial parts of Pluchea odorata, a plant used by the Maya to treat severe inflammatory conditions [GRIDLING et al., 2008]. Hence, bioassay-guided fractionation was carried out to enrich the active compound(s). Initially the plant material was extracted by (ASE) accelerated solvent extraction obtaining the bioactive P. odorata ASE - CH2Cl2 extract. It was re-chromatographed by (VLC) vacuum liquid chromatography (PE,CHCl3-MeOH,MeOH-H2O in different ratios), normal (CC) column chromatography (chloroform-methanol-water gradient) on silica gel KG60 and RP-18 (SPE) solid phase extraction (CHCl3,MeOH,H2O in different ratios). The bioassay-guided fractionation indicated that the anti-proliferative activity of P. odorata is due to a fraction containing highly apolar constituents. As a result of five fractionation steps, an at least 25 fold enrichment of anti-proliferative activity was reached. To test the efficiency in anticancer effects the inhibition of proliferation and the induction of cell death were investigated in HL60 cells and MCF7 cells. The most potent fractions F2/11, F2/13 and F3/4 were tested by western blot to obtain evidence of underlying mechanisms. Differences between fractions in Cyclin D1 expression indicate, that F2/11 contains less potent principles than F2/13, but in F3/4 the activity was enriched. Chk2 was phosphorylated at the activating Thr68 site upon treatment with all three fractions tested. F2/11 induced activation of Chk2 as the earliest of the events. Chk2 activity supported the notion that different active principles were contained in F2/11 and in F2/13, and that those components that more specifically interfered with cell cycle progression, became enriched in F3/4. Fraction F2/11 and F3/4 were the most pro-apoptotic active ones and the pro-apoptotic properties were enriched at least by 45 fold in fraction F3/4. Genotoxicity of fraction F2/11 was indicated by rapidly inducing phosphorylation of H2AX. Apparently, there is a DNA damaging compound in F2/11, whereas induction of γH2AX is the consequence of the activation of caspases by F2/13 and F3/4 as evidenced by PARP cleavage, in which this property was enriched. The acetylation of alpha-tubulin implicated that all three fractions stabilized microtubule, reminiscent of the mechanism of taxol and therefore, trigger mitotic arrest and apoptosis. F3/4 showed an enrichment in the tubulin acetylation property. Thus, we could separate two very distinct anti-neoplastic properties in the fraction of the P. odorata ASE – CH2Cl2 extract