Grundwassercharakterisierung mit Umwelttracern: Erkundung des Grundwassers der Odenwald-Region sowie Implementierung eines neuen Edelgas-Massenspektrometersystems

Der erste Teil dieser Arbeit beschäftigt sich mit der Charakterisierung des Grundwassers der Odenwaldregion unter Verwendung stabiler und radioaktiver Isotope (2H, 18O, 3H) sowie verschiedener Datierungsmethoden (SF6, 3H-3He) und verschiedener Edelgase (He, Ne, Ar, Kr und Xe). Insbesondere wurden Fragestellungen in Hinblick auf Grundwasserneubildung, -zuflüsse, -mischung und Aufenthaltszeiten der Grundwässer untersucht. Anhand der stabilen Isotope 2H und 18O zeigt sich, dass die Grundwasserneubildung über das Jahr gleichverteilt stattfindet mit einer leichten Erhöhung im Winterhalbjahr. Weiterhin ermöglichen die stabilen Isotope eine Identifizierung des Grundwassers der verschiedenen Regionen, so dass gezeigt werden kann, dass Grundwasser des Hessischen Rieds teilweise (0-100%) im Kristallinen Odenwald neugebildet wird. Die Datierung des Grundwassers zeigt robuste 3H-3He-Alter von wenigen Jahren in Regionen potentieller Grundwasserneubildung bis hin zu nicht mehr datierbaren Grundwässern (>45 Jahre) im Bereich des Hessischen Rieds. Teilweise findet man hohe Mischunsgverhältnisse von altem (tritiumfreiem) und jungem (tritiumtragendem) Wasser. Die Datierung des Grundwassers mit Hilfe von SF6 ist dahingegen nicht möglich, da eine terrigene (natürliche) SF6-Quelle in Regionen kristalliner Lithologie identifiziert werden kann. Die Korrelation von hohen SF6-Konzentrationen mit hohen Radonkonzentrationen und radiogenen Heliumkonzentrationen weist darauf hin, dass die Produktion von SF6 durch den Zerfall radioaktiver Elemente im Boden begünstigt wird. In Anbetracht der Ergebnisse der stabilen Isotope und der Verteilung der Grundwasser-Verweilzeiten konnte eine obere Grenze der Zufluss- bzw. Neubildungsrate von Wasser aus dem Kristallin in das Hessische Ried von <(90+-23)l/(s km2) abgeschätzt werden. Im zweiten Teil der Arbeit wird das Edelgasmesssystem des Institutes für Umweltphysik Heidelberg im Detail beschrieben. Das System erlaubt die präzise Analyse von Edelgasen sowie deren Isotopenverhältnisse aus Wasser- oder Gasproben verschiedenster Herkunft. Typische Messgenauigkeiten der 3He, 4He, Ne, Ar, Kr und Xe Konzentrationen sind +-2,4%, +-0,38%, +-0,41%, +-0,43%, +-1,02% und +-1,01%

Investigation of a cold-based ice apron on a high-mountain permafrost rock wall using ice texture analysis and micro-14C dating : a case study of the Triangle du Tacul ice apron (Mont Blanc massif, France)

This study is part of the ANR 14-CE03-0006 VIP Mont Blanc and the EU ALCOTRA AdaPT Mont Blanc project.The current paper studies the dynamics and age of the Triangle du Tacul (TDT) ice apron, a massive ice volume lying on a steep high-mountain rock wall in the French side of the Mont-Blanc massif at an altitude close to 3640 m a.s.l. Three 60 cm long ice cores were drilled to bedrock (i.e. the rock wall) in 2018 and 2019 at the TDT ice apron. Texture (microstructure and lattice-preferred orientation, LPO) analyses were performed on one core. The two remaining cores were used for radiocarbon dating of the particulate organic carbon fraction (three samples in total). Microstructure and LPO do not substantially vary with along the axis of the ice core. Throughout the core, irregularly shaped grains, associated with strain-induced grain boundary migration and strong single maximum LPO, were observed. Measurements indicate that at the TDT ice deforms under a low strain-rate simple shear regime, with a shear plane parallel to the surface slope of the ice apron. Dynamic recrystallization stands out as the major mechanism for grain growth. Micro-radiocarbon dating indicates that the TDT ice becomes older with depth perpendicular to the ice surface. We observed ice ages older than 600 year BP and at the base of the lowest 30 cm older than 3000 years.Publisher PDFPeer reviewe

Intelligente Werkstoffe - Vom Makromolekül zum intelligenten Material

Sensitive polymers change their conformation in response to even a little change in the environmental conditions, e. g. temperature, pH value, concentration of a second component, or light. Crosslinking of these polymers and their swelling in water forms smart hydrogels (intelligent hydrogels). Different shapes and dimensions are possible: bulk gel, thin layers, intraor intermolecular crosslinked globular particles. Smart hydrogels display two important properties: Their volume (swelling degree) depends on the environment and can be switched between two states. The gels can thus be used as actuators. As the change in the gel properties is stimulated by changes in the environment, the gels can also be used as sensors. Smart hydrogels are suitable for applications in microsystems, and gel particles are potential carriers for drugs in the human body.Umgebungssensitive Polymere ändern in Abhängigkeit von Umgebungsbedingungen, wie zum Beispiel dem Licht, der Temperatur, dem pH-Wert oder der Konzentration einer zweiten Komponente neben dem Polymer, drastisch ihre Molekülgestalt. Vernetzt und in Wasser gequollen, bilden sie sogenannte smarte Hydrogele. Dabei werden die Besonderheiten eines Makromoleküls, dessen Eigenschaften durch die Umgebung beeinflusst werden, auf ein polymeres Material übertragen. Dies kann ein großer Körper, eine dünne Schicht oder ein Nanopartikel sein. Das Volumen der smarten Hydrogele kann zwischen zwei Zuständen geschaltet werden. Dabei können die Hydrogele wie Aktoren eine Kraft ausüben. Da das Schalten durch die Umgebung stimuliert wird, sind sie als Sensoren verwendbar. Die Polymerstrukturen sind miniaturisierbar, sodass smarte Hydrogele als Komponenten in Mikrosystemen angewendet werden können. Zum Beispiel werden die Partikel zur kontrollierten Abgabe von Arzneimittelwirkstoffen verwendet

Mediterranean radiocarbon offsets and calendar dates for prehistory

A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean for five decades, setting the time frame for prehistory. However, as measurement precision increases, there is mounting evidence for some small but substantive regional (partly growing season) offsets in same-year radiocarbon levels. Controlling for interlaboratory variation, we compare radiocarbon data from Europe and the Mediterranean in the second to earlier first millennia BCE. Consistent with recent findings in the second millennium CE, these data suggest that some small, but critical, periods of variation for Mediterranean radiocarbon levels exist, especially associated with major reversals or plateaus in the atmospheric radiocarbon record. At high precision, these variations potentially affect calendar dates for prehistory by up to a few decades, including, for example, Egyptian history and the much-debated Thera/Santorini volcanic eruption

Seroprevalence of Measles-, Mumps-, and Rubella-specific antibodies in the German adult population – cross-sectional analysis of the German Health Interview and Examination Survey for Adults (DEGS1)

Background: The WHO European Region targets the elimination of measles, rubella, and the congenital rubella syndrome and welcomes mumps elimination via the joint MMR vaccine. In a push towards this elimination goal, Germany introduced a recommendation on MMR vaccination for adults in 2010 to prevent increasing numbers of measles cases among adults and to strengthen herd immunity. Methods: The prevalence of anti-measles, -mumps, and -rubella IgG antibodies was analysed in 7,115 participants between the ages of 18 and 79 years in the German Health Interview and Examination Survey. Risk factors of seronegativity of adults born 1970 or later were determined. Findings: The seroprevalence of anti-measles IgG antibodies was more than 97% in adults born before 1965 and less than 90% in adults born afterwards. Prevalence and GMTs declined with later years of birth. Seronegativity was associated with two-sided migration background and region of residence in East Germany. For anti-mumps IgG antibodies, the seroprevalence was less than 90% in almost all age groups. Prevalence and GMTs declined with later years of birth. Seronegativity was not associated with any socio-demographic factor. Anti-rubella IgG seropositivity was found in more than 90% of adults born before 1985. GMTs declined in younger age groups. Seronegativity was associated with birth between 1980 and 1993 and male gender. High socio-economic status lowered the odds of being seronegative. Interpretation: These data reinforce the implementation of the vaccination recommendation for adults and provide the basis for further evaluation of this measure. Funding: The Federal Ministry of Health, Germany.Peer Reviewe

Rewriting the Central European Early Bronze Age Chronology: Evidence from Large-Scale Radiocarbon Dating

The transition from the Neolithic to the Early Bronze Age in Central Europe has often been considered as a supra-regional uniform process, which led to the growing mastery of the new bronze technology. Since the 1920s, archaeologists have divided the Early Bronze Age into two chronological phases (Bronze A1 and A2),which were also seen as stages of technical progress. On the basis of the early radiocarbon dates from the cemetery of Singen, southern Germany, the beginning of the Early Bronze Age in Central Europe was originally dated around 2300/2200 BC and the transition to more complex casting techniques (i.e.,Bronze A2) around 2000 BC. On the basis of 140 newly radiocarbon dated human remains from Final Neolithic, Early and Middle Bronze Age cemeteries south of Augsburg (Bavaria) and a re-dating of ten graves from the cemetery of Singen, we propose a significantly different dating range, which forces us to re-think the traditional relative and absolute chronologies as well as the narrative of technical development. We are now able to date the beginning of the Early Bronze Age to around 2150 BC and its end to around 1700 BC. Moreover, there is no transition between Bronze (Bz) A1 and Bronze (Bz) A2, but a complete overlap between the type objects of the two phases from 1900-1700 BC. We thus present a revised chronology of the assumed diagnostic type objects of the Early Bronze Age and recommend a radiocarbon-based view on the development of the material culture. Finally, we propose that the traditional phases Bz A1 and Bz A2 do not represent a chronological sequence, but regionally different social phenomena connected to the willingness of local actors to appropriate the new bronze technology

Climate-induced speleothem radiocarbon variability on Socotra Island from the Last Glacial Maximum to the Younger Dryas

In this study, the dead carbon fraction (DCF) variations in stalagmite M1-5 from Socotra Island in the western Arabian Sea were investigated through a new set of high-precision U-series and radiocarbon (14C) dates. The data reveal an extreme case of very high and also climate-dependent DCF. For M1-5, an average DCF of 56.2±3.4% is observed between 27 and 18kyrBP. Such high DCF values indicate a high influence of aged soil organic matter (SOM) and nearly completely closed-system carbonate dissolution conditions. Towards the end of the last glacial period, decreasing Mg/Ca ratios suggest an increase in precipitation which caused a marked change in the soil carbon cycling as indicated by sharply decreasing DCF. This is in contrast to the relation of soil infiltration and DCF as seen in stalagmites from temperate zones. For Socotra Island, which is influenced by the East African-Indian monsoon, we propose that more humid conditions and enhanced net infiltration after the Last Glacial Maximum (LGM) led to dense vegetation and thus lowered the DCF by increasing 14CO2 input into the soil zone. At the onset of the Younger Dryas (YD) a sudden change in DCF towards much higher, and extremely variable, values is observed. Our study highlights the dramatic variability of soil carbon cycling processes and vegetation feedback on Socotra Island manifested in stalagmite DCF on both long-term trends and sub-centennial timescales, thus providing evidence for climate influence on stalagmite radiocarbon. This is of particular relevance for speleothem studies that aim to reconstruct past atmospheric 14C (e.g., for the purposes of 14C calibration), as these would rely on largely climate-independent soil carbon cycling above the cave. © 2020 Copernicus GmbH. All rights reserved

Transcriptional signature of an adult brain tumor in Drosophila.

BACKGROUND: Mutations and gene expression alterations in brain tumors have been extensively investigated, however the causes of brain tumorigenesis are largely unknown. Animal models are necessary to correlate altered transcriptional activity and tumor phenotype and to better understand how these alterations cause malignant growth. In order to gain insights into the in vivo transcriptional activity associated with a brain tumor, we carried out genome-wide microarray expression analyses of an adult brain tumor in Drosophila caused by homozygous mutation in the tumor suppressor gene brain tumor (brat). RESULTS: Two independent genome-wide gene expression studies using two different oligonucleotide microarray platforms were used to compare the transcriptome of adult wildtype flies with mutants displaying the adult bratk06028 mutant brain tumor. Cross-validation and stringent statistical criteria identified a core transcriptional signature of brat(k06028) neoplastic tissue. We find significant expression level changes for 321 annotated genes associated with the adult neoplastic brat(k06028) tissue indicating elevated and aberrant metabolic and cell cycle activity, upregulation of the basal transcriptional machinery, as well as elevated and aberrant activity of ribosome synthesis and translation control. One fifth of these genes show homology to known mammalian genes involved in cancer formation. CONCLUSION: Our results identify for the first time the genome-wide transcriptional alterations associated with an adult brain tumor in Drosophila and reveal insights into the possible mechanisms of tumor formation caused by homozygous mutation of the translational repressor brat.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

The first directly dated cave bear from the Covoli di Velo Cave (Verona Province, Veneto, northern Italy) with some discussion of Italian Alps cave bears

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Pediatric in-hospital emergencies: real life experiences, previous training and the need for training among physicians and nurses

Objective: Pediatric emergencies challenge professional teams by demanding substantial cognitive effort, skills and effective teamwork. Educational designs for team trainings must be aligned to the needs of participants in order to increase effectiveness. To assess these needs, a survey among physicians and nurses of a tertiary pediatric center in Germany was conducted, focusing on previous experience, previous training in emergency care, and individual training needs. Results: Fifty-three physicians and 75 nurses participated. Most frequently experienced emergencies were respiratory failure, resuscitation, seizure, shock/sepsis and arrhythmia. Resuscitations were perceived as being particularly precarious. Team collaboration and communication were major issues arising from previous emergency situations, but perceptions differed between physicians and nurses. Regarding previous training, physicians were accustomed to self-directed learning, whereas nurses usually attended practical courses. Both physicians and nurses rated themselves as having moderate levels of knowledge and skills for pediatric emergencies, though residents reported the significantly lowest preparedness. Both professions reported a high need for training of basic procedures and emergency algorithms, physicians even more than nurses