Universiẗat, Diss., 2002--Heidelberg.

Konstanz, Univ., Diplomarbeit, 2008.

Introduction The National Superconducting Cyclotron Laboratory (NSCL) is a national nuclear physics facility in which heavy ion beams are fragmented to produce exotic nuclei. In this process of fragmentation many nuclei are created, however, only one isotope is selected for experimentation. The remaining isotopes that are created go unused. The future upgrade of the NSCL to the Facility for Rare Isotope Beams (FRIB) will increase the incident energy of these heavy ion beams and amplify the current by three orders of magnitude. An aqueous beam dump will be created to collect the unused isotopes created in the process of fragmentation. Several of these isotopes are of interest for many applications including nuclear security, medical imaging, and therapy and are not currently available or are only available in very limited supply. Harvesting these isotopes from the aqueous beam dump could provide a consistent supply of these im-portant isotopes as an ancillary service to the existing experimental program. Material and Methods A liquid water target system was designed and tested to serve as a mock beam dump for exper-iments at the NSCL1. A 25 pnA 130 MeV/u 76Ge beam was fragmented using a 493 mg/cm2 thick beryllium production target. After fragmentation the beam was separated using the A1900 frag-ment separator2 set up for maximum 67Cu pro-duction using a 240 mg/cm2 aluminum wedge and a 2% momentum acceptance. The secondary beam was collected for four hours in the liquid water target system before being transferred to a collection vessel. Four additional four hour collections were made before finally shipping the five collections to Washington University and Hope College for chemical separation. Four of the five samples were separated using a two part separation scheme. First they were passed through and 3M Empore iminodiacetic acid functionalized chelation disk in a 1.25M ammonium acetate solution at pH 5. The flow through was collected and analyzed using an HPGe detector. Then 10mL of 6M HCl acid was passed through the chelation disk to remove the 2+ transition metals. The 10mL of 6M HCl acid was collected after passing through the disk and added to an anion-exchange column with 2.5 g AG1-X8 resin. The eluate was collected and then an additional 10mL of 6M HCl was passed through the column to remove the nickel. The 67Cu was then collected by passing 10mL of 0.5M HCl and the eluate was collected in 1mL fractions each analyzed by HPGe for 67Cu concentration and purity. The two highest 67Cu fractions were heated to dryness and reconstituted in 50 μL 0.1M ammonium acetate pH 5.5. 2 μL of 7.9 mg/mL NOTA-Bz-Trastuzumab was added to 45 μL of 67Cu and 3 μL 0.1M ammonium acetate pH 5.5. This solution was placed in a shaking incubator at 37 °C for twenty minutes and then analyzed by radio-instant thin layer chromatography in order to determine the per-cent of 67Cu bound to the antibody. Results and Conclusion 67Cu was collected into the liquid water target system with an average efficiency of 85 ± 5 %. The secondary beam was 73 % pure with the impurities, half-lives greater than 1 minute, listed in TABLE 1. Separation of 67Cu from the impurities resulted in an average recovery of 88 ± 3 % for a total recovery of 67Cu from the beam and separation of 75 ± 4 %. No detectable radioactive impurities were found in the final samples when analyzed using an HPGe detector. TABLE 2 shows the amount of 67Cu collected from the beam and the amount recovered decay corrected to end of bombardment. Labeling NOTA-Bz-Trastuzumab with 67Cu resulted in > 95 % radiochemical yield. Collection of the 73 % pure 67Cu beam in water and the resulting separation proved successful. These results demonstrate that radioisotopes can be collected from fragmented heavy ion beams and isolated in usable quantities and purity for many radiochemical applications. Further experimentation with an unpurified beam to better simulate conditions in the beam dump at the Facility for Rare Isotope Beams will be performed in the near future.

München, Techn. Univ., Diss., 2009.

Darmstadt, Techn. Univ., Diss., 2004. / Dateien im PDF-Format

Der Beitrag beschäftigt sich damit, in welcher Weise Reinigungsarbeit - als ein typischer Bereich sogenannter "Einfacharbeit" - in den vergangenen Jahrzehnten von Auslagerungen betroffen war und wie sie davon geprägt wurde. Er stellt aktuelle Branchencharakteristika und Beschäftigungsbedingungen zur Reinigungsbranche in Österreich im internationalen Kontext dar und argumentiert, dass die mit der Auslagerung verbundenen Veränderungen der Reinigungsarbeit problematische Arbeits- und Beschäftigungsbedingungen verstärken. So tragen insbesondere die verbreiteten Arbeitszeiten an den Tagesrändern zu einer Unsichtbarmachung der Arbeit bei, die einer mangelnden Anerkennung weiter Vorschub leistet. Die Tendenz zur gesellschaftlichen Unsichtbarmachung spiegelt sich daneben auch in der wissenschaftlichen und gesellschaftlichen (Nicht-)Zuwendung zu "Einfachdienstleistungen" und der Reinigung im Speziellen wider. Der Beitrag geht weiters auf die Rolle des Wohlfahrtsstaates in der Gestaltung der Arbeits- und Lebensbedingungen von in "Einfachdienstleistungen" Beschäftigten ein. Abschließend weist er auf Ansatzpunkte für Verbesserungen auf unterschiedlichen Ebenen hin.

The fragmentation of natural habitat caused by anthropogenic land use changes is one of the main drivers of the current rapid loss of biodiversity. In face of this threat, ecological research needs to provide predictions of communities' responses to fragmentation as a prerequisite for the effective mitigation of further biodiversity loss. However, predictions of communities' responses to fragmentation require a thorough understanding of ecological processes, such as species dispersal and persistence. Therefore, this thesis seeks an improved understanding of community dynamics in fragmented landscapes. In order to approach this overall aim, I identified key questions on the response of plant diversity and plant functional traits to variations in species' dispersal capability, habitat fragmentation and local environmental conditions. All questions were addressed using spatially explicit simulations or statistical models. In chapter 2, I addressed scale-dependent relationships between dispersal capability and species diversity using a grid-based neutral model. I found that the ratio of survey area to landscape size is an important determinant of scale-dependent dispersal-diversity relationships. With small ratios, the model predicted increasing dispersal-diversity relationships, while decreasing dispersal-diversity relationships emerged, when the ratio approached one, i.e. when the survey area approached the landscape size. For intermediate ratios, I found a U-shaped pattern that has not been reported before. With this study, I unified and extended previous work on dispersal-diversity relationships. In chapter 3, I assessed the type of regional plant community dynamics for the study area in the Southern Judean Lowlands (SJL). For this purpose, I parameterised a multi-species incidence-function model (IFM) with vegetation data using approximate Bayesian computation (ABC). I found that the type of regional plant community dynamics in the SJL is best characterized as a set of isolated “island communities” with very low connectivity between local communities. Model predictions indicated a significant extinction debt with 33% - 60% of all species going extinct within 1000 years. In general, this study introduces a novel approach for combining a spatially explicit simulation model with field data from species-rich communities. In chapter 4, I first analysed, if plant functional traits in the SJL indicate trait convergence by habitat filtering and trait divergence by interspecific competition, as predicted by community assembly theory. Second, I assessed the interactive effects of fragmentation and the south-north precipitation gradient in the SJL on community-mean plant traits. I found clear evidence for trait convergence, but the evidence for trait divergence fundamentally depended on the chosen null-model. All community-mean traits were significantly associated with the precipitation gradient in the SJL. The trait associations with fragmentation indices (patch size and connectivity) were generally weaker, but statistically significant for all traits. Specific leaf area (SLA) and plant height were consistently associated with fragmentation indices along the precipitation gradient. In contrast, seed mass and seed number were interactively influenced by fragmentation and precipitation. In general, this study provides the first analysis of the interactive effects of climate and fragmentation on plant functional traits. Overall, I conclude that the spatially explicit perspective adopted in this thesis is crucial for a thorough understanding of plant community dynamics in fragmented landscapes. The finding of contrasting responses of local diversity to variations in dispersal capability stresses the importance of considering the diversity and composition of the metacommunity, prior to implementing conservation measures that aim at increased habitat connectivity. The model predictions derived with the IFM highlight the importance of additional natural habitat for the mitigation of future species extinctions. In general, the approach of combining a spatially explicit IFM with extensive species occupancy data provides a novel and promising tool to assess the consequences of different management scenarios. The analysis of plant functional traits in the SJL points to important knowledge gaps in community assembly theory with respect to the simultaneous consequences of habitat filtering and competition. In particular, it demonstrates the importance of investigating the synergistic consequences of fragmentation, climate change and land use change on plant communities. I suggest that the integration of plant functional traits and of species interactions into spatially explicit, dynamic simulation models offers a promising approach, which will further improve our understanding of plant communities and our ability to predict their dynamics in fragmented and changing landscapes. / Die Fragmentierung von Landschaften umfasst die Zerschneidung und den Verlust von Flächen mit natürlicher Vegetationsentwicklung und ist eine der Hauptursachen für den gegenwärtigen drastischen Verlust an Biodiversität. Diese Dissertation soll zu einem besseren Verständnis der Vegetationsdynamik in fragmentierten Landschaften beitragen. Damit verbunden ist das Ziel, Vorhersagen über die Reaktion von Pflanzengemeinschaften auf Fragmentierung zu verbessern. Diese Vorhersagen sind notwendig, um gezielte Naturschutzmaßnahmen zur Verminderung eines weiteren Verlustes an Biodiversität umsetzen zu können. In Kapitel 2 der Dissertation wird mit einem Simulationsmodell untersucht, wie sich die Ausbreitungsdistanz von Samen auf die lokale Artenzahl von Pflanzengemeinschaften auswirkt. Dabei zeigte sich, dass längere Ausbreitungsdistanzen die lokale Artenvielfalt sowohl erhöhen, als auch verringern können. Der wichtigste Einflussfaktor war dabei die Artenvielfalt der über-geordneten Pflanzengemeinschaft, in der die betrachtete lokale Gemeinschaft eingebettet war. Im dritten Kapitel wird die Konnektivität zwischen Pflanzengemeinschaften in Habitat-fragmenten, d.h. der Austausch von Arten und Individuen durch Samenausbreitung, im Unter-suchungsgebiet in Israel analysiert. Dafür wurde ein zweites räumliches Simulationsmodell mit statistischen Verfahren an Felddaten angepasst. Der Vergleich des Modells mit den Daten wies auf eine sehr geringe Konnektivität zwischen den Habitatfragmenten hin. Das Modell sagte vorher, dass innerhalb von 1000 Jahren 33% - 60% der Arten aussterben könnten. In Kapitel 4 wird zuerst analysiert, welche Prozesse die Verteilung von funktionellen Eigenschaften in Pflanzengemeinschaften bestimmen. In einem zweiten Schritt wird dann unter-sucht, wie sich funktionelle Eigenschaften von Pflanzengemeinschaften mit dem Niederschlag und der Fragmentierung im Untersuchungsgebiet in Israel verändern. Der Zusammenhang zwischen den Eigenschaften Pflanzenhöhe, sowie spezifischer Blattfläche und der Fragmentierung änderte sich nicht entlang des Niederschlagsgradienten. Im Gegensatz dazu, änderte sich der Zusammenhang zwischen der Samenmasse bzw. der Samenzahl und der Fragmentierung mit dem Niederschlag. Aus den Ergebnissen der ersten Teilstudie wird deutlich, dass Naturschutzmaßnahmen, die natürliche Habitate stärker vernetzen sollen, die Diversität, sowie die Zusammensetzung der übergeordneten Artengemeinschaft berücksichtigen müssen, um Verluste an Biodiversität zu vermeiden. Die Verknüpfung eines räumlichen Simulationsmodells mit Felddaten in der zweiten Teilstudie stellt einen neuen und vielversprechenden Ansatz für die Untersuchung der Auswirkungen verschiedener Management-Szenarien dar. Die dritte Teilstudie ist die erste Analyse der gemeinsamen Auswirkungen von Klima und Fragmentierung auf funktionelle Pflanzen-eigenschaften und zeigt die hohe Bedeutung der Untersuchung von Synergie-Effekten verschiedener Umweltfaktoren. Für zukünftige Forschung legt diese Dissertation nahe, funktionelle Eigenschaften und Konkurrenz zwischen Arten in räumlichen Simulationsmodellen zu berücksichtigen, um das Verständnis von Artengemeinschaften in fragmentierten Landschaften noch weiter zu verbessern.

Während des programmierten Zelltods (=Apoptose) kommt es zur Bildung von DNA-Fragmenten unterschiedlicher Größe. Ziel der vorliegenden Arbeit war es, die Fragmentierung des Chromatins während der Apoptose zu untersuchen, um Erkenntnisse über den zeitlichen und räumlichen Ablauf und die Zusammenhänge zwischen der Apoptose-bedingten Chromatinfragmentierung und der Chromatinstruktur zu gewinnen. Zur Untersuchung der Apoptose-bedingten Fragmentierung des Chromatins wurden verschiedene Zellinien, Induktoren mit Wirkung auf die verschiedenen Apoptose-Signalwege, die Anreicherung von apoptotischen Zellen durch magnetische Separation, die Induktion der Apoptose auf verschiedenen Stufen des Signalwegs, "in vitro"-Assays mit isolierten Kernen sowie die vorherige Synchronisierung der Zellen in Kombination mit einem Zellzyklus-Phasen-spezifischen Apoptose-Induktor getestet, etabliert und optimiert. Die Fragmentierung der DNA wurde sowohl im Vergleich funktionell verschiedener Chromatinregionen (Zentromer/Telomer/LINE/SINE-Elemente), als auch im Detail in einer Modellregion, dem Histongencluster auf Chromosom 6 untersucht.

Introduction The National Superconducting Cyclotron Laboratory (NSCL) is a national nuclear physics facility in which heavy ion beams are fragmented to produce exotic nuclei. In this process of fragmentation many nuclei are created, however, only one isotope is selected for experimentation. The remaining isotopes that are created go unused. The future upgrade of the NSCL to the Facility for Rare Isotope Beams (FRIB) will increase the incident energy of these heavy ion beams and amplify the current by three orders of magnitude. An aqueous beam dump will be created to collect the unused isotopes created in the process of fragmentation. Several of these isotopes are of interest for many applications including nuclear security, medical imaging, and therapy and are not currently available or are only available in very limited supply. Harvesting these isotopes from the aqueous beam dump could provide a consistent supply of these im-portant isotopes as an ancillary service to the existing experimental program. Material and Methods A liquid water target system was designed and tested to serve as a mock beam dump for exper-iments at the NSCL1. A 25 pnA 130 MeV/u 76Ge beam was fragmented using a 493 mg/cm2 thick beryllium production target. After fragmentation the beam was separated using the A1900 frag-ment separator2 set up for maximum 67Cu pro-duction using a 240 mg/cm2 aluminum wedge and a 2% momentum acceptance. The secondary beam was collected for four hours in the liquid water target system before being transferred to a collection vessel. Four additional four hour collections were made before finally shipping the five collections to Washington University and Hope College for chemical separation. Four of the five samples were separated using a two part separation scheme. First they were passed through and 3M Empore iminodiacetic acid functionalized chelation disk in a 1.25M ammonium acetate solution at pH 5. The flow through was collected and analyzed using an HPGe detector. Then 10mL of 6M HCl acid was passed through the chelation disk to remove the 2+ transition metals. The 10mL of 6M HCl acid was collected after passing through the disk and added to an anion-exchange column with 2.5 g AG1-X8 resin. The eluate was collected and then an additional 10mL of 6M HCl was passed through the column to remove the nickel. The 67Cu was then collected by passing 10mL of 0.5M HCl and the eluate was collected in 1mL fractions each analyzed by HPGe for 67Cu concentration and purity. The two highest 67Cu fractions were heated to dryness and reconstituted in 50 μL 0.1M ammonium acetate pH 5.5. 2 μL of 7.9 mg/mL NOTA-Bz-Trastuzumab was added to 45 μL of 67Cu and 3 μL 0.1M ammonium acetate pH 5.5. This solution was placed in a shaking incubator at 37 °C for twenty minutes and then analyzed by radio-instant thin layer chromatography in order to determine the per-cent of 67Cu bound to the antibody. Results and Conclusion 67Cu was collected into the liquid water target system with an average efficiency of 85 ± 5 %. The secondary beam was 73 % pure with the impurities, half-lives greater than 1 minute, listed in TABLE 1. Separation of 67Cu from the impurities resulted in an average recovery of 88 ± 3 % for a total recovery of 67Cu from the beam and separation of 75 ± 4 %. No detectable radioactive impurities were found in the final samples when analyzed using an HPGe detector. TABLE 2 shows the amount of 67Cu collected from the beam and the amount recovered decay corrected to end of bombardment. Labeling NOTA-Bz-Trastuzumab with 67Cu resulted in > 95 % radiochemical yield. Collection of the 73 % pure 67Cu beam in water and the resulting separation proved successful. These results demonstrate that radioisotopes can be collected from fragmented heavy ion beams and isolated in usable quantities and purity for many radiochemical applications. Further experimentation with an unpurified beam to better simulate conditions in the beam dump at the Facility for Rare Isotope Beams will be performed in the near future.

The characterization of lipids is performed by mass spectrometry based on structure specific fragments or by accurate mass measurements of intact precursor ions. The latter method, termed ’top-down lipidomics’, is due to its robustness, simplicity and speed a valuable tool for medical research to elucidate the molecular background of lipid metabolic disorders. The current thesis aims to improve the established lipidomics methods. Therefore, a new top-down lipidomics method was introduced that increased the analysis throughput, lipidome coverage and accuracy of quantification, compared to previous approaches, by rapid successive acquisition of high resolution Fourier transform mass spectra in positive and negative ion modes. Furthermore, the characterization of molecular lipid species by utilizing high energy collisional dissociation was achieved on Orbitrap instruments. The mass accuracy of acquired MS/MS spectra increased the confidence in identification for unusual very-long chain polyunsaturated phosphatidylcholine species and a new lipid class, the maradolipids. Beyond that, effort was made to enhance the accuracy and comparability of MS/MS based bottom-up lipidomics data. In this respect, lipids with varying degree of unsaturation were analyzed and revealed discrete fragmentation properties. The technical refined lipidomics methods allowed insight into the lipid composition of lipoproteins and changes of the blood plasma induced by apheresis. Lipidomics screening of blood plasma uncovered an altered lipid pattern in consequence of impaired glucose metabolism and type 2 diabetes. The lipidomics characterization of islet allowed their quality assessment.