Artificial Parthenogenesis in Rana Pipiens

This 9 page thesis attempts to prove that development of a frog\u27s egg may be initiated by a mechanical force alone, that this development is materially aided by a chemical agent, and to suggest the possible significance of each step to aid further investigation

Cold flow modelling of dual fluidised bed pyrolysis

High temperature pyrolysis at about 600-700°C of carbon containing waste materials (plastic waste, shredded old tires, biogenic residues, etc.) is an attractive technology for substitution of fossil fuels in industrial processes. A dual fluidized bed system is investigated in a scaled cold flow model. This model consists of a riser as combustion section and a bubbling fluidized bed as pyrolysis section. The pyrolysis section is aimed to convert the solid feed material into pyrolysis oil as well as permanent gas components. This gas stream can be directly used e.g. in rotary kilns at temperatures of 400-600°C with high tar content and therefore high heating value. The char is transported with the bed material to the riser to provide the energy for the pyrolysis, transported via the hot bed material. Moreover, the pyrolysing section will be used to separate unconvertable materials such as metal pieces, stones, etc. from the process. For certain feed materials the pyrolysing section could be built as circulating fluidized bed to perform a classification of the feed material. Thus different residence time in the pyrolyser can be achieved, depending on the fuel particle size and fluidization. The results are displayed inside a regime map of gas-solid fluidized beds. Bed material residence times as well as residence times of model particles of the feedstock are given. The investigations lead to a design of a system to be applicable for various feedstock materials as input for industrial processes

Cold flow modelling of dual fluidised bed pyrolysi

High temperature pyrolysis at about 600-700°C of carbon containing waste materials (plastic waste, shredded old tires, biogenic residues, etc.) is an attractive technology for substitution of fossil fuels in industrial processes. A dual fluidized bed system is investigated in a scaled cold flow model. This model consists of a riser as combustion section and a bubbling fluidized bed as pyrolysis section. The pyrolysis section is aimed to convert the solid feed material into pyrolysis oil as well as permanent gas components. This gas stream can be directly used e.g. in rotary kilns at temperatures of 400-600°C with high tar content and therefore high heating value. The char is transported with the bed material to the riser to provide the energy for the pyrolysis, transported via the hot bed material. Moreover, the pyrolysing section will be used to separate unconvertable materials such as metal pieces, stones, etc. from the process. For certain feed materials the pyrolysing section could be built as circulating fluidized bed to perform a classification of the feed material. Thus different residence time in the pyrolyser can be achieved, depending on the fuel particle size and fluidization. The results are displayed inside a regime map of gas-solid fluidized beds. Bed material residence times as well as residence times of model particles of the feedstock are given. The investigations lead to a design of a system to be applicable for various feedstock materials as input for industrial processes

Code Generation from UML Models

Creating a generic, object-oriented, component-based, transactional business system, which covers the whole lifecycle, is possible only with the integration of commercial tools, component technologies, newly developed class libraries and by using code generators. Most of the recently used tools for development techniques are focusing on only one of the layers of the model from the code generation point of view. As a consequence, the inter-layer connections are lost in the generated code. In this article, we describe a code generator technique which uses a UML model as a starting point and generates several layers directly. While generating the code, it preserves the original interlayer relationships originated in the model. Based on our experiences with 4GL systems it is obvious that there is a need to provide customisation in the generated code. We offer a multi-paradigm approach [1] to let the developer choose the appropriate solution for her or his implementation

Candida spp. and Oxidative Stress Response in Innate Immune Cells

In dieser Arbeit wurde der „Oxidative Burst“ des angeborenen Immunsystems in der Interaktion mit Candida albicans untersucht. Das klinische Spektrum des opportunistischen Pathogens C. albicans reicht von mucokutanen Infektionen bis hin zu lebensbedrohlichen, systemischen Krankheiten in immunsupprimierten Patienten. Eine der ersten Reaktionen der Zellen des angeborenen Immunsystems, sogenannte Phagozyten, ist die Produktion von Reaktiven Oxygen Spezies (ROS) wenn sie auf Pathogene stoßen. ROS spielen eine wichtige Rolle bei Entzündungsreaktionen, zum Beispiel zerstören sie eindringende Krankheitserreger. Durch eine Überproduktion von ROS kann aber auch das Endothel beschädigt werden. Frühere Studien haben gezeigt, dass Zymosan, eine Zellwand Aufbereitung von Saccharomyces cerevisiae, und C. albicans die ROS Produktion in Makrophagen aktivieren. Das C. albicans Genom codiert sechs Superoxid Dismutasen (SOD1 bis SOD6), die an der Zersetzung von ROS beteiligt sind, SOD1 bis SOD3 sind intrazellular und SOD4 bis SOD6 sind wahrscheinlich an der Zellwand von C. albicans lokalisiert. Diese Arbeit zeigt, dass die Co-Kultur von Makrophagen oder myeloischen dendritischen Zellen mit C. albicans denen Sod5 genetisch entfernt wurde zu einer massiven extrazellulären Anhäufung von ROS in vitro führt. Diese ROS Akkumulierung ist in der Interaktion mit Makrophagen noch höher wenn C. albicans weder Sod4 noch Sod5 haben. Weiteres werden C. albicans Sod5 und Sod4 Mutanten von Makrophagen in vitro besser getötet als Wildtyp C. albicans. Makrophagen, die einen Defekt im Oxidativen Burst haben weil ihnen das gp91Phox Gen fehlt, können diese Mutanten nicht mehr töten, dies zeigt eine ROS-abhängige Eliminierung von pathogenen Pilzen durch Makrophagen. Diese Daten zeigen die physiologische Rolle der C. albicans Zellwand SODs bei der Entgiftung von ROS und weisen auf einen Mechanismus, mit dem C. albicans das Immunsystems in vivo überlistet, hin. Im zweiten Teil dieser Arbeit wurden potentielle Rezeptor(en) untersucht, durch die Makrophagen C. albicans erkennen, um den oxidative Burst zu induzieren. Die Toll Like Rezeptor-Familie und das intrazelluläre MyD88 Adapter-Protein sind nicht an der ROS-Produktion durch Zymosan oder C. albicans Stimulation beteiligt. Wenn der C-Typ-Lectin-Rezeptor Dectin-1 mit Zymosan oder Hitze-getöteter C. albicans stimuliert wird, induziert Dectin-1 die ROS Antwort indem die Src und Syk-Kinase aktiviert wird. Darüber hinaus aktiviert Zymosan auch die ERK1/2 MAP-Kinasen via Dectin-1. Im Gegensatz dazu ist Dectin-1 nur mäßig an der Aktivierung von ROS und ERK1 beteiligt wenn die Makrophagen mit lebenden C. albicans stimuliert werden. Interessanterweise ist die Aktivierung der Src und Syk-Kinasen auch wichtig für ROS Induktion durch Stimulierung mit lebender C. albicans. Dies führt zu dem Schluss, dass ein Rezeptor oder Adapter-Protein mit einem ITAM Motif an der Induktion von ROS beteiligt ist. Ein siRNA-basierendes knock-down-Experiment zeigt, dass das ITAM Adapter-Protein DAP12 für die ROS Produktion durch C. albicans und Zymosan mitverantwortlich ist.In this work the oxidative burst of the innate immune system in response to Candida albicans infection was investigated. The clinical spectrum of the human opportunistic pathogen C. albicans ranges from mucocutaneous infections to systemic life-threatening diseases in immunocompromised patients. One of the immediate early responses of cells of the innate immune system on encountering microbial pathogens is the production of reactive oxygen species (ROS) by phagocytes. ROS play important roles in inflammatory reactions by destroying invading pathogens. However, overproduction of ROS may also cause endothelial damage, and excessive inflammation. Previous studies have shown that zymosan, a cell wall preparation of Saccharomyces cerevisiae, as well as C. albicans in the yeast form, strongly induce ROS in macrophages. The C. albicans genome harbours six superoxide dismutases (SOD1-6) involved in ROS degradation; SOD1 to SOD3 are intracellular and SOD4 to SOD6 are located in the cell wall. This work demonstrates that co-culture of macrophages or myeloid dendritic cells with C. albicans cells lacking Sod5 leads to massive extracellular ROS accumulation in vitro. ROS accumulation was further increased in co-culture with fungal cells lacking both Sod4 and Sod5. Survival experiments show that C. albicans Sod5 and Sod4 double mutants exhibit a severe loss of viability in the presence of macrophages in vitro. The reduced viability of the mutants relative to wild type is not evident with macrophages from gp91phox-/- mice defective in the oxidative burst activity, demonstrating a ROS-dependent killing activity of macrophages targeting fungal pathogens. These data show a physiological role for cell surface SODs in detoxifying ROS, and suggest a mechanism whereby C. albicans can evade host immune surveillance in vivo. The second part of this thesis aims to identify putative receptor(s) by which macrophages recognise C. albicans and induce the oxidative burst. The Toll-like receptor family and its MyD88 adaptor protein are not involved in ROS production due to zymosan or C. albicans stimulation. The c-type lectin receptor Dectin-1 can induce the ROS response via activation of Syk kinase with its immunoreceptor tyrosine-based activation motif (ITAM)-like domain upon zymosan or heat-killed C. albicans stimulation. Furthermore, zymosan also activates extracellular signal related kinase ERK1/2 MAPK dependent on Dectin-1. In contrast, Dectin-1 is only moderately involved in activation of ROS and ERK1/2 when stimulated with live C. albicans. Interestingly, activation of Src and Syk kinases is essential to induce the ROS response by live C. albicans. This leads us to conclude that an ITAM-containing receptor or adaptor protein is involved in the recognition of live C. albicans. Using a siRNA-based knock-down assay, we found that one ITAM-containing adaptor protein, DAP12, may contribute to the ROS response upon fungal pathogens such as C. albicans

Bridging clinical information systems and grid middleware: a Medical Data Manager

International audienceThis paper describes the effort to deploy a Medical Data Management service on top of the EGEE grid infrastructure. The most widely accepted medical image stan- dard, DICOM, was developed for fulfilling clinical practice. It is implemented in most medical image acquisition and analysis devices. The EGEE middleware is us- ing the SRM standard for handling grid files. Our prototype is exposing an SRM compliant interface to the grid middleware, transforming on the fly SRM requests into DICOM transactions. The prototype ensures user identification, strict file ac- cess control and data protection through the use of relevant grid services. This Medical Data Manager is easing the access to medical databases needed for many medical data analysis applications deployed today. It offers a high level data man- agement service, compatible with clinical practices, which encourages the migration of medical applications towards grid infrastructures. A limited scale testbed has been deployed as a proof of concept of this new service. The service is expected to be put into production with the next EGEE middleware generation

Studies in Health Technology and Informatics

Background: Standards have become available to share semantically encoded vital parameters from medical devices, as required for example by personal healthcare records. Standardised sharing of biosignal data largely remains open. Objectives: The goal of this work is to explore available biosignal file format and data exchange standards and profiles, and to conceptualise end-To-end solutions. Methods: The authors reviewed and discussed available biosignal file format standards with other members of international standards development organisations (SDOs). Results: A raw concept for standards based acquisition, storage, archiving and sharing of biosignals was developed. The GDF format may serve for storing biosignals. Signals can then be shared using FHIR resources and may be stored on FHIR servers or in DICOM archives, with DICOM waveforms as one possible format. Conclusion: Currently a group of international SDOs (e.g. HL7, IHE, DICOM, IEEE) is engaged in intensive discussions. This discussion extends existing work that already was adopted by large implementer communities. The concept presented here only reports the current status of the discussion in Austria. The discussion will continue internationally, with results to be expected over the coming years