Modelling and control of product life-cycles

iv+176hlm.;24c

Cannon-Thurston Maps for Kleinian Groups

We show that Cannon-Thurston maps exist for degenerate free groups without parabolics, i.e. for handlebody groups. Combining these techniques with earlier work proving the existence of Cannon-Thurston maps for surface groups, we show that Cannon-Thurston maps exist for arbitrary finitely generated Kleinian groups without parabolics, proving conjectures of Thurston and McMullen. We also show that point pre-images under Cannon-Thurston maps for degenerate free groups without parabolics correspond to end-points of leaves of an ending lamination in the Masur domain, whenever a point has more than one pre-image. This proves a conjecture of Otal. We also prove a similar result for point pre-images under Cannon-Thurston maps for arbitrary finitely generated Kleinian groups without parabolics.Comment: 39 pgs 1 fig. Final version incorporating referee comments. To appear in Forum of Mathematics, P

Intercultural crisis communication: cultural background and the formation of perception

Crisis communication is a fairly new research discipline that originated in the Unites States in the late 1980s. Most of the research in the field has been focused on a senderfocused strategy with the organisation in mind and neglected the audience perspective. In particular, little is known about how cultural background influences crisis message perception and how then perception influences organisational reputation. The importance of the crisis communicator, his/her capabilities and his/her unique deliverance of the crisis message to a multicultural audience has not received much attention in spite of such a significant role in informing the public and therefore in shaping the public image of the organisation. This research aimed to study crisis communication from an intercultural perspective and thus expand the field and fill gaps by investigating how cultural background truly influences perception of crisis messages and subsequently organisational reputation. Further, the study looked at how the proven benefits of multimodality in other fields can be used in crisis communication to better understand the perception creation process. The study utilised an exploratory mixed method approach, following on from an earlier pilot study. Participants were shown two short excerpts from the crisis press conferences of Germanwings U9525 and Malaysia Airlines MH370. The research included in-depth surveys with an open-ended section and was taken by 181 participants from 6 home country groups in the summer of 2016. The data was analysed utilising descriptive statistics as well as a thematic content analysis. The study concluded that cultural background is the decisive component when evaluating crisis messages and determining organisational reputation. Evidence were found to show significant impact in regard to the following three integral parts of crisis communication: Language Used for Crisis Communication, Crisis Information Content (Names & Nationalities of Victims), Attribution of Responsibility. The use of multiple modes and the introduction of multimodality into this study has also raised awareness for the inherent cultural features of crisis communicators. This analysis has provided indicators that significantly shape audiences’ perception. Those were: standing vs. sitting, speed of speaking, eye contact with audience, physical appearance, and facial expression. Finally, the study argued for a departure from the current generic approach in crisis communication to a situation-based crisis handling approach which is underpinned by social constructionism and appropriate and responsive to audiences and crisis context

Intercultural crisis communication: cultural background and the formation of perception

Crisis communication is a fairly new research discipline that originated in the Unites States in the late 1980s. Most of the research in the field has been focused on a senderfocused strategy with the organisation in mind and neglected the audience perspective. In particular, little is known about how cultural background influences crisis message perception and how then perception influences organisational reputation. The importance of the crisis communicator, his/her capabilities and his/her unique deliverance of the crisis message to a multicultural audience has not received much attention in spite of such a significant role in informing the public and therefore in shaping the public image of the organisation. This research aimed to study crisis communication from an intercultural perspective and thus expand the field and fill gaps by investigating how cultural background truly influences perception of crisis messages and subsequently organisational reputation. Further, the study looked at how the proven benefits of multimodality in other fields can be used in crisis communication to better understand the perception creation process. The study utilised an exploratory mixed method approach, following on from an earlier pilot study. Participants were shown two short excerpts from the crisis press conferences of Germanwings U9525 and Malaysia Airlines MH370. The research included in-depth surveys with an open-ended section and was taken by 181 participants from 6 home country groups in the summer of 2016. The data was analysed utilising descriptive statistics as well as a thematic content analysis. The study concluded that cultural background is the decisive component when evaluating crisis messages and determining organisational reputation. Evidence were found to show significant impact in regard to the following three integral parts of crisis communication: Language Used for Crisis Communication, Crisis Information Content (Names & Nationalities of Victims), Attribution of Responsibility. The use of multiple modes and the introduction of multimodality into this study has also raised awareness for the inherent cultural features of crisis communicators. This analysis has provided indicators that significantly shape audiences’ perception. Those were: standing vs. sitting, speed of speaking, eye contact with audience, physical appearance, and facial expression. Finally, the study argued for a departure from the current generic approach in crisis communication to a situation-based crisis handling approach which is underpinned by social constructionism and appropriate and responsive to audiences and crisis context

Regenerative potential of human adipose-derived stromal cells of various origins

AbstractIn regenerative concepts, the potential of adult stem cells holds great promise concerning an individualized therapeutic approach. These cells provide renewable progenitor cells to replace aged tissue, and play a significant role in tissue repair and regeneration.In this investigation, the characteristics of different types of adipose tissue are analysed systematically with special attention to their proliferation and differentiation potential concerning the angiogenic and osteogenic lineage. Tissue samples from subcutaneous, visceral, and omental fat were processed according to standard procedures. The cells were characterized and cultivated under suitable conditions for osteogenic and angiogenic cell culture. The development of the different cell cultures as well as their differentiation were analysed morphologically and immunohistochemically from cell passages P1 to P12. Harvesting and isolation of multipotent cells from all three tissue types could be performed reproducibly. The cultivation of these cells under osteogenic conditions led to a morphological and immunohistochemical differentiation; mineralization could be detected. The most stable results were observed for the cells of subcutaneous origin. An osteogenic differentiation from adipose-derived cells from all analysed fatty tissues can be achieved easily and reproducibly. In therapeutic concepts including angiogenic regeneration, adipose-derived cells from subcutaneous tissue provide the optimal cellular base

CAD/CAP: Rechnergestützte Montagefeinplanung

Falling quantities, shorter product life cycles, increasing variety of variants and the need to react quickly (dates) and flexibly to market requirements make deployment more effective Planning tools for production ahead. Automated or computer-controlled manufacturing and assembly systems, in particular, require careful planning and optimization due to their high investment costs. The trend towards using computer-aided methods and procedures at the design and planning level will therefore intensify in the next few years. Using the example of task-oriented planning and programming of assembly cells, it can be shown how the effort and benefits in relation to conventional methods in the quality behave. Shorter planning and programming times contrast with larger amounts of data and increased use of hardware. The shortened learning phase can be explained by the fact that previously, specialists with IT and control skills were required to program automated assembly systems. With task-oriented programming techniques, the existing engineering knowledge of the planner can be efficiently supported based on familiar working techniques. Data formats (codes) and control details do not need to interest the operator when learning the system functions. Figure 106 summarizes the economic and qualitative advantages of using CAP tools in detailed assembly planning. However, these advantages mentioned have to be bought through an effort that is often not to be underestimated. In this context, effort means: o investments in hardware and software, o high running costs (maintenance / service contracts), o New hiring and / or training of qualified employees. o additional costs (premises, air conditioning, etc.), o Costs in the start-up phase (installation, adjustment, Disruptions of processes). For small and medium-sized companies, these costs usually represent insurmountable hurdles. However, due to falling hardware prices and the qualified personnel who will emerge from the university in a few years, a turnaround is also emerging here. Students in production engineering chairs are already being intensively prepared for the use of modern planning tools. Today, every graduate of the production technology course has gained experience in using 'CTechniques' or even participated in their development. Nevertheless, a further penetration of the use of computers in the planning can only take place if the technical problems of these tools have been eliminated. Planning tools in assembly are currently still the subject of research and development. The main problems are: o too simple models, o large amounts of data, o long response times, o unpredictable malfunctions in real operation, o limited computer graphics, o poor communication. Commercially available 'C systems' offer very simple data models. For the programming of robots, this means e.g. strong deviations between calculated and real time and positioning behavior. Due to limited communication between planning and operation, a lot of information that has already been entered is lost (insufficient interfaces). Research laboratories in industry and universities are working intensively on these problems. The present work provides the foundation for the expansion of existing tools and provides information on how these can be effectively integrated.Sinkende Stückzahlen, kürzere Produktlebenszyklen, steigende Variantenvielfalt und die Notwendigkeit, schnell (Termine) und flexibel auf Markterfordernisse zu reagieren, setzen den Einsatz effektiver Planungswerkzeuge für die Produktion voraus. Besonders automatisierte oder rechnergeführte Fertigungs- und Montagesysteme bedürfen aufgrund ihrer hohen Investitionskosten einer sorgfältigen Planung und Optimierung. Der Trend, rechnergestützte Methoden und Verfahren in der Konstruktions- und Planungsebene einzusetzen, wird sich deshalb in den nächsten Jahren verstärken. Am Beispiel der aufgabenorientierten Planung und Programmierung von Montagezellen läßt sich zeigen, wie sich Aufwand und Nutzen gegenüber herkömmlichen Methoden in der Planung qualitativ verhalten. Kürzere Planungs- und Programmierzeiten stehen hierbei größeren Datenmengen und verstärktem Hardwareeinsatz gegenüber. Die verkürzte Einlernphase läßt sich dadurch erklären, daß zur Programmierung von automatisierten Montageanlagen bisher Spezialisten mit Informatik- und Steuerungskenntnissen erforderlich waren. Mit aufgabenorientierten Programmiertechniken kann das vorhandene Ingenieurwissen des Planers aufgrund gewohnter Arbeitstechniken effizient unterstützt werden. Datenformate (Codes) und steuerungstechnische Details brauchen den Bediener beim Erlernen der Systemfunktionen nicht zu interessieren. In Bild 106 werden die wirtschaftlichen und qualitativen Vorteile beim Einsatz von CAP-Werkzeugen in der Montagefeinplanung zusammengefaßt. Diese genannten Vorteile müssen allerdings durch einen, häufig nicht zu unterschätzenden Aufwand, erkauft werden. Aufwand bedeutet in diesem Zusammenhang: o Investitionen in Hard- und Software, o hohe laufende Kosten (Wartungs- / Serviceverträge), o Neueinstellung und/oder Schulung von qualifizierten Mitarbeitern. o Nebenkosten (Räumlichkeiten, Klimaanlagen, usw.), o Kosten in der Anlaufphase (Installations-, Anpassungsaufwand, Störungen von Abläufen). Für kleine und mittlere Unternehmen stellen diese genannten Kosten meist unüberwindliche Hürden dar. Durch sinkende Hardwarepreise und durch das in einigen Jahren aus dem Hochschulbereich dringende qualifizierte Personal, zeichnet sich aber auch hier eine Wende ab. Studenten an fertigungstechnischen Lehrstühlen werden heute bereits intensiv auf den Einsatz moderner Planungswerkzeuge vorbereitet. So hat heute jeder Absolvent des Studiengangs Produktionstechnik Erfahrung im Umgang mit 'CTechniken' gesammelt oder sich sogar an deren Entwicklung beteiligt. Dennoch kann eine weitere Durchdringung des Rechnereinsatzes in der Planung nur dann erfolgen, wenn die technischen Probleme dieser Werkzeuge beseitigt sind. Planungswerkzeuge in der Montage sind derzeit immer noch Gegenstand von Forschung und Entwicklung. Probleme machen vor allem: o zu einfache Modelle, o große Datenmengen, o lange Antwortzeiten, o nicht planbare Störungen im Realbetrieb, o eingeschränkte Computergraphik, o mangelhafte Kommunikation. Käufliche 'C-Systeme' bieten sehr einfache Datenmodelle an. Für die Programmierung von Robotern bedeutet dies z.B. starke Abweichungen zwischen berechnetem und realem Zeit- und Positionierverhalten. Durch eingeschränkte Kommunikation zwischen Planung und Betrieb gehen zudem viele Informationen verloren, die bereits einmal eingegeben worden sind (unzureichende Schnittstellen). Forschungslaboratorien der Industrie und der Hochschulen arbeiten intensiv an diesen Problemen. Die vorliegende Arbeit liefert das Fundament für den Ausbau bestehender Werkzeuge und gibt Hinweise, wie diese effektiv integriert werden können

Representation of Thermal Information in the Antennal Lobe of Leaf-Cutting Ants

Insects are equipped with various types of antennal sensilla, which house thermosensitive neurons adapted to receive different parameters of the thermal environment for a variety of temperature-guided behaviors. In the leaf-cutting ant Atta vollenweideri, the physiology and the morphology of the thermosensitive sensillum coeloconicum (Sc) has been thoroughly investigated. However, the central projections of its receptor neurons are unknown. Here we selectively stained the three neurons found in single Sc and tracked their axons into the brain of Atta vollenweideri workers. Each of the three axons terminates in a single glomerulus of the antennal lobe (Sc-glomeruli). Two of the innervated glomeruli are adjacent to each other and are located laterally, while the third one is clearly separated and located medially in the antennal lobe. Using two-photon Ca2+ imaging of antennal lobe projection neurons, we studied where in the antennal lobe thermal information is represented. In the 11 investigated antennal lobes, we found up to 10 different glomeruli in a single specimen responding to temperature stimulation. Both, warm- and cold-sensitive glomeruli could be identified. The thermosensitive glomeruli were mainly located in the medial part of the antennal lobe. Based on the general representation of thermal information in the antennal lobe and functional data on the Sc-glomeruli we conclude that temperature stimuli received by Sc are processed in the medial of the three target glomeruli. The present study reveals an important role of the antennal lobe in temperature processing and links a specific thermosensitive neuron to its central target glomerulus

Neue Perspektiven auf Früherkennung und Therapie der Alzheimer-Erkrankung durch statistische Modellierung kognitiver Fähigkeiten

Die Alzheimer-Erkrankung ist die häufigste Ursache von Demenzen. Erste pathologische Veränderungen entwickeln sich bereits Jahrzehnte vor der Ausbildung einer Demenz und leichte kognitive und affektive Veränderungen treten Jahre vor der Demenzdiagnose auf. Dies eröffnet Möglichkeiten zur Früherkennung und Prävention. Da nicht alle Personen mit einer Alzheimer-Pathologie zu Lebzeiten eine Demenz entwickeln, stellt sich die Frage, welche weiteren Prozesse im Gehirn auftreten müssen, die aus einer Alzheimer-Erkrankung eine Demenz entstehen lassen. Ein Ziel der vorliegenden Arbeit ist es, Indikatoren dieser Prozesse im frühen symptomatischen Stadium der Alzheimer-Erkrankung zu identifizieren, um die Vorhersage des weiteren Verlaufs der kognitiven Entwicklung zu verbessern und so einen Beitrag zur Früherkennung von Personen mit hohem Demenzrisiko zu leisten. Ein weiteres Ziel ist es, Faktoren zu identifizieren, die mit einem langsameren Verlauf dieser Prozesse in Verbindung stehen und somit die Auswirkungen von Pathologie auf Kognition mindern. Dies könnte dazu beitragen, neue Therapieansätze der Alzheimer-Erkrankung zu entwickeln. Um diese Ziele zu erreichen, wurden im Rahmen von vier Studien unterschiedliche methodische Ansätze verfolgt und Hausarzt- und Gedächtnisambulanzstichproben untersucht. Zum einen wurden statistische Modellierungen, wie Strukturgleichungsmodelle, verwendet, um den Verlauf kognitiver Funktionen im Rahmen der Alzheimer-Erkrankung zu charakterisieren und Zusammenhänge mit dem subjektiven Erleben und den Lebenserfahrungen der untersuchten Personen zu beschreiben. Zum anderen wurden Längsschnittdaten zur kognitiven Entwicklung mit genetischen Informationen kombiniert, um das Zusammenspiel biologischer Prozesse mit dem symptomatischen Verlauf der Erkrankung zu untersuchen. In Studie I wurde die zeitliche Reihenfolge von subjektiver Wahrnehmung kognitiver Verschlechterung einerseits und depressiven Symptomen andererseits im Verlauf des kognitiven Abbaus untersucht. Studie II untersuchte die Assoziation eines genetischen Risikoscores mit der längsschnittlichen Entwicklung einer Demenz bei Personen aus der Allgemeinbevölkerung und Individuen mit leichten kognitiven Einschränkungen. In Studie III wurde die Assoziation zwischen der seltenen Variante p.P522R im Gen PLCG2 und dem kognitiven Abbau sowie Biomarkern der Alzheimer-Erkrankung bei Patienten mit leichten kognitiven Einschränkungen untersucht. Studie IV untersuchte die Assoziation zwischen beruflichen kognitiven Anforderungen im mittleren Lebensalter, Biomarkern der Alzheimer-Erkrankung und kognitiven Fähigkeiten im späteren Lebensalter. Durch die gemeinsame Betrachtung und Modellierung von psychologischen Variablen (kognitive Fähigkeiten, subjektives Erleben, lebenslange Erfahrungen) einerseits und von biologischen Faktoren (Genetik, Biomarker der Alzheimerpathologie) andererseits konnten die vier Studien einige Merkmale und Einflussgrößen von demenzbezogenen Prozessen neu identifizieren und in ihrem Zusammenwirken verständlich machen