The Political Economy of Universal Pensions in Bolivia

While non-contributory pensions are spreading around the globe, Bolivia is still the only Latin American country with a universal old-age pension scheme. Originally designed twenty years ago and contested more than once, the benefit survived a political regime change from neo-liberalism to new developmentalism and features an interesting political economy. With the commodities boom coming to an end, progressive neo-extractivism and thus, Bolivia’s universal pension, face new challenges.Während nicht beitragsfinanzierte Renten eine weltweite Konjunktur erleben, ist Bolivien nach wie vor das einzige lateinamerikanische Land mit einer universellen Altersrente, obwohl diese bereits vor zwanzig Jahren entwickelt wurde. Zwischen- zeitlich wurde die Grundrente mehrmals infrage gestellt, überlebte aber den politi- schen Regimewechsel vom Neoliberalismus zum neuen Desarrollismus. Ein Blick auf die politische Ökonomie dieser Transferleistung ist lohnenswert, zumal sich der pro- gressive Neo-Extraktivismus – und damit auch Boliviens Grundrente – nach dem Ende des Ressourcenbooms neuen Herausforderungen gegenüber sieht

The sorption of uranium(VI) and neptunium(V) onto surfaces of selected metal oxides and alumosilicates studied by in situ vibrational spectroscopy

The migration behavior of actinides and other radioactive contaminants in the environment is controlled by prominent molecular phenomena such as hydrolysis and complexation reactions in aqueous solutions as well as the diffusion and sorption onto minerals present along groundwater flow paths. These reactions significantly influence the mobility and bioavailability of the metal ions in the environment, in particular at liquid-solid interfaces. Hence, for the assessment of migration processes the knowledge of the mechanisms occurring at interfaces is crucial. The required structural information can be obtained using various spectroscopic techniques. In the present study, the speciation of uranium(VI) and neptunium(V) at environmentally relevant mineral – water interfaces of oxides of titania, alumina, silica, zinc, and alumosilicates has been investigated by the application of attenuated total reflection Fourier-transform infrared (ATR FT-IR) spectroscopy. Moreover, the distribution of the hydrolysis products in micromolar aqueous solutions of U(VI) and Np(V/VI) at ambient atmosphere has been characterized for the first time, by a combination of ATR FT-IR spectroscopy, near infrared (NIR) absorption spectroscopy, and speciation modeling applying updated thermodynamic databases. From the infrared spectra, a significant change of the U(VI) speciation is derived upon lowering the U(VI) concentration from the milli- to the micromolar range, strongly suggesting the dominance of monomeric U(VI) hydrolysis products in the micromolar solutions. In contradiction to the predicted speciation, monomeric hydroxo species are already present at pH ≥ 2.5 and become dominant at pH 3. At higher pH levels (> 6), a complex speciation is evidenced including carbonate containing complexes. For the first time, spectroscopic results of Np(VI) hydrolysis reactions are provided in the submillimolar concentration range and at pH values up to 5.3, and they are comparatively discussed with U(VI). For both actinides, the formation of similar species is suggested at pH ≤ 4, whereas at higher pH, the infrared spectra evidence structurally different species. At pH 5, the formation of a carbonate-containing dimeric complex, that is (NpO2)2CO3(OH)3−, is strongly suggested, whereas carbonate complexation occurs only under more alkaline conditions in the U(VI) system. The results from the experiments of the sorption processes clearly demonstrate the formation of stable U(VI) surface complexes at all investigated mineral phases. This includes several metal oxides, namely TiO2, Al2O3, and SiO2, serving as model systems for the elucidation of more complex mineral systems, and several alumosilicates, such as kaolinite, muscovite and biotite. From a multiplicity of in situ experiments, the impact of sorbent characteristics and variations in the aqueous U(VI) system on the sorption processes was considered. A preferential formation of an inner-sphere complex is derived from the spectra of the TiO2 and SiO2 phases. In addition, since the in situ FT-IR experiments provide an online monitoring of the absorption changes of the sorption processes, the course of the formation of the U(VI) surface complexes can be observed spectroscopically. It is shown that after prolonged sorption time on TiO2, resulting in a highly covered surface, outer-sphere complexation predominates the sorption processes. The prevailing crystallographic modification, namely anatase and rutile, does not significantly contribute to the spectra, whereas surface specific parameters, e.g. surface area or porosity are important. A significant different surface complexation is observed for Al2O3. The formation of inner-spheric species is assumed at low U(VI) surface coverage which is fostered at low pH, high ionic strength and short contact times. At proceeded sorption the surface complexation changes. From the spectra, an outer-spheric coordination followed by surface precipitation or polymerization is deduced. Moreover, in contrast to TiO2, the appearance of ternary U(VI) carbonate complexes on the γ-Al2O3 surface is suggested. The first results of the surface reactions on more complex, naturally occurring minerals (kaolinite, muscovite and biotite) show the formation of U(VI) inner-sphere sorption complexes. These findings are supported by the spectral information of the metal oxide surfaces. In this work, first spectroscopic results from sorption of aqueous Np(V) on solid mineral phases are provided. It is shown that stable inner-sphere surface species of NpO2+ are formed on TiO2. Outer-sphere complexation is found to play a minor role due to the pH independence of the sorption species throughout the pH range 4 – 7.6. The comparative spectroscopic experiments of Np(V) sorption onto TiO2, SiO2, and ZnO indicate structurally similar bidentate surface complexes. The multiplicity of IR spectroscopic experiments carried out within this study yields a profound collection of spectroscopic data which will be used as references for future investigations of more complex sorption systems in aqueous solution. Furthermore, from a methodological point of view, this study comprehensively extends the application of ATR FT-IR spectroscopic experiments to a wide range in the field of radioecology. The results obtained in this work contribute to a better understanding of the geochemical interactions of actinides, in particular U(VI) and Np(V/VI), in the environment. Consequently, more reliable predictions of actinides migration which are essential for the safety assessment of nuclear waste repositories can be performed.Das Migrationsverhalten von Aktiniden und anderen radioaktiven Schadstoffen in der Umwelt wird von wichtigen molekularen Prozessen entlang der Grundwasserfließwege reguliert. Dazu gehören sowohl die Hydrolyse und Komplexierung in wässrigen Lösungen als auch Diffusion und Sorption der Schwermetalle an Mineralen. Diese Reaktionen beeinflussen entscheidend die Mobilität und Bioverfügbarkeit der Metallionen in der Umwelt, insbesondere an den fest-flüssig Grenzflächen. Genaue Kenntnisse über die an diesen Grenzflächen stattfindenden Mechanismen sind somit entscheidend, um Migrationsprozesse verlässlich abschätzen zu können. Die benötigten strukturellen Informationen können mit verschiedenen spektroskopischen Techniken ermittelt werden. Das Ziel der vorliegenden Arbeit war die Untersuchung der Speziation von Uran(VI) und Neptunium(V) an umweltrelevanten Grenzflächen von Oxiden des Titans, Aluminiums, Siliziums und Zinks und von Alumosilikaten mittels ATR FT-IR Spektroskopie. Des Weiteren wurde die Verteilung aquatischer Spezies in mikromolaren Lösungen des U(VI) und Np(V/VI) unter Normalbedingungen charakterisiert. Diese erstmalige Untersuchung wurde mit einer Kombination aus Speziationsmodellierung unter Anwendung aktueller thermodynamischer Daten und ATR FT-IR und NIR Absorptionsspektroskopie realisiert. Die Infrarotspektren zeigen eine deutliche Änderung der Speziesverteilung im Konzentrationsverlauf vom millimolaren zum mikromolaren Bereich. Dies verweist auf die Bildung monomerer U(VI) Hydrolyseprodukte. Im Gegensatz zu berechneten Speziationen werden diese monomeren Komplexe schon bei pH ≥ 2,5 gebildet und dominieren die Speziation bei pH 3. Bei höheren pH-Werten (> 6) konnte eine komplexe Speziesverteilung mit Anteilen von Karbonatkomplexen nachgewiesen werden. Erstmals konnten im Rahmen dieser Arbeit spektroskopische Befunde der Hydrolysereaktionen des Np(VI) im submillimolaren Konzentrationsbereich bis pH 5,3 erhalten werden. Diese wurden im Vergleich mit der U(VI) Speziation diskutiert. Obwohl im sauren Bereich (pH ≤ 4) die Bildung ähnlicher Komplexe nachgewiesen wurde, zeigen die bei höheren pH-Werten erhaltenen Spektren eine unterschiedliche Speziesverteilung. Im Gegensatz zum U(VI) bildet das Np(VI) schon bei pH 5 karbonathaltige aquatische Spezies wie (NpO2)2CO3(OH)3−. Die Ergebnisse der Sorptionsexperimente von U(VI) zeigen die Bildung stabiler Oberflächenkomplexe an allen untersuchten Mineralphasen. Dies umfasst mehrere als Modellsystem dienende Metalloxide wie TiO2, Al2O3 und SiO2, als auch komplexere Alumosilikate wie Kaolinit, Muskovit und Biotit. Für eine detaillierte Charakterisierung der Oberflächenkomplexe wurde eine Vielzahl von in situ Sorptionsexperimenten durchgeführt, die den Einfluss unterschiedlicher Parameter der mineralischen Phase als auch des wässrigen U(VI) Systems berücksichtigen. Die bevorzugte Bildung von innersphärischen Komplexen an TiO2 und SiO2 wird aus den spektroskopischen Daten abgeleitet. Da die in situ FT-IR Spektroskopie eine kontinuierliche Registrierung der Absorptionsänderungen während der ablaufenden Sorptionsprozesse erlaubt, kann somit der Verlauf dieser Prozesse quasi in Echtzeit spektroskopisch verfolgt werden. Es konnte gezeigt werden, dass mit fortschreitender Sorptionsdauer, d.h. bei hohen Beladungsdichten, die Bildung einer weiteren außersphärischen Spezies die Sorption dominert. Die vorliegende kristallographische Modifikation, Anatas und Rutil, ist nicht maßgeblich für das Auftreten unterschiedlicher Sorptionsprozesse verantwortlich, obwohl Parameter wie die spezifische Oberfläche und die Porosität für den Sorptionsprozess von Bedeutung sind. Deutlich verschiedene Oberflächenreaktionen werden für Al2O3 beobachtet. Aus den Spektren kann die Ausbildung einer innersphärischen Spezies bei sehr niedrigen U(VI) Beladungen, niedrigen pH-Werten, hohen Ionenstärken und kurzen Kontaktzeiten abgeleitet werden. Bei fortschreitender Sorption ändert sich die Art der Oberflächenkomplexe. Zunächst bilden sich außersphärische Spezies, während im weiteren Verlauf die Spektren auf eine beginnende Oberflächenausfällung bzw. Polymerisation hinweisen. Weiterhin wird das Auftreten von ternären U(VI) Karbonatkomplexen an γ-Al2O3 aus den spektroskopischen Daten abgeleitet. Die ersten Ergebnisse der Sorptionsexperimente an komplexeren, natürlich auftretenden Mineralphasen (Kaolinit, Muskovit und Biotit) zeigen eine bevorzugte Ausbildung von innersphärischen U(VI) Komplexen. Diese Resultate werden durch die spektralen Befunde der Experimente der Metalloxide gestützt. Erstmalig werden in dieser Arbeit spektroskopische Ergebnisse der Sorptionsprozesse von wässrigen Np(V) an verschiedenen Mineralphasen präsentiert. Wie U(VI) bildet Np(V) stabile innersphärische Oberflächenkomplexe an TiO2. Die Speziesverteilung an der TiO2 Oberfläche ist im pH Bereich 4 – 7,6 konstant. Daher ist zu erwarten, dass eine außersphärische Komplexierung hier nur eine untergeordnete Rolle spielt. Der Vergleich von Spektren der Np(V) Sorptionskomplexe an TiO2, SiO2 und ZnO weist auf die Bildung strukturell ähnlicher bidentater Komplexe hin. Die Vielzahl der hier vorgestellten infrarotspektroskopischen Experimente bietet eine fundierte Sammlung spektroskopischer Daten, die für zukünftige Untersuchungen komplexer aquatischer und mineralischer Systeme unerlässlich ist. Gleichzeitig wurde der Anwendungsbereich der ATR FT-IR Technik auf dem Gebiet der Radioökologie umfassend erweitert. Die im Rahmen dieser Arbeit gewonnenen Ergebnisse tragen zu einem besseren Verständnis der geochemischen Wechselwirkungen von Aktiniden, im Speziellen von U(VI) und Np(V) in der Umwelt bei. Damit unterstützen sie den Aufklärungsprozess der Migration von radioaktiven Kontaminationen und dienen als Grundlage für zuverlässige Prognosen für die Sicherheitsbewertung von Endlagern für nukleare Abfälle

Thirteen-Hundred-Year-Old Bead Adornments from Baar, Canton Zug, Switzerland

In the year 2000, an Early Medieval (7th-century) cemetery containing more than 200 burials with rich grave goods was discovered in Baar, Canton Zug, Switzerland. Thanks to the painstaking methods used in the excavation and recording of the 2,985 glass, amber, coral, and amethyst beads found with the female burials, it was possible to reconstruct the necklaces and sewn-on appliqués they were part of. Comparisons with mosaic depictions of famous women—such as the Empress Theodora in San Vitale in Ravenna, Italy—suggest that the people of Baar imitated southern Alpine Byzantine bead jewelry fashion

Palaeoseismological analyses of northern and central Germany

Northern Germany is an intraplate region and has been regarded as a low seismicity area for a long time. However, historic sources show the occurrence of several significant natural earthquakes in northern and central Germany since the 10th century. In recent years natural earthquakes as well as earthquakes in the vicinity of active gas fields, likely to have been associated with the recovery of hydrocarbons, have been repeatedly instrumentally recorded in northern Germany. In central Germany, which is exposed to a higher earthquake hazard than northern Germany, historically and instrumentally recorded earthquakes accumulate in a N-S trending zone. However, the seismic record of Germany is limited and solely goes back to the year 800 CE. Long periods of seismic quiescence alternating with fault activity for a short geological period of time can falsify the seismic hazard of an intraplate region. Seismic hazard can be underestimated because of seismic quiescence or overestimated because of the detection of periodical clustering, migrating and infrequent seismicity. Therefore, palaeoseismology is the missing link for an accurate assessment of the seismic hazard estimation of a continental low strain area like Germany. Northern and central Germany were repeatedly affected by glaciations and periglacial processes during the Pleistocene. The main difficulty is to distinguish the vast glaciotectonic deformation structures that are present in northern Germany from neotectonic deformation structures. Processes like cryoturbation, depositional loading in water saturated sediments and rapid rates of deposition can generate soft-sediment deformation structures that may also be mistaken for earthquake-induced structures. The analysis of neotectonic activity in northern and central Germany is challenging because recently observed vertical crustal movements along NWSE- striking faults do not commonly correspond to visible morphological features and fault scarps are rapidly destroyed by climatic conditions. Seven WNW-ESE trending major basement faults with a high potential for reactivation due to glacial isostatic adjustment were analysed with regard to neotectonic fault activity. In addition, in central Germany the controversially discussed seismically active part of the Regensburg-Leipzig-Rostock fault system between Leipzig and Cheb and surroundings was analysed with regard to pre-historic activity. Deformation bands and seismites in Palaeogene and Pleistocene deposits exposed in sand and gravel pits are indicators for neotectonic activity. Luminescence dating, shear-wave reflection seismics, electrical resistivity tomography and lineament analysis were applied to support neotectonic activity in the study area. Evidence for neotectonic movements, indicated by the occurrence of deformation bands in Middle to Late Pleistocene sediments, was identified along five of the seven major basement faults that were analysed in northern Germany. Evidence was found at the Aller Fault, the Halle Fault, the Harz Boundary Fault, the Steinhuder Meer Fault and the Osning Thrust. In the area around the Regensburg-Leipzig-Rostock fault system neotectonic movements are indicated by deformation bands in Palaeocene and Middle Pleistocene sediments at fault intersections of mainly NW-SE oriented faults like the Lusatian Thrust and the Finne-Gera-Jáchymov fault system and fault intersections of minor faults in the vicinity to the cities Leipzig and Dresden. It was possible to estimate the timing of neotectonic activity of faulted Pleistocene sediments by means of luminescence dating at two basement faults (Harz Boundary Fault, Steinhuder Meer Fault). The estimated ages of faulted debris-flow deposits at the Harz Boundary Fault (15.2 ± 0.8 and 14.2 ± 0.8 ka ka) point to fault movements after ~15 ka corresponding with the reactivation of the Osning Thrust. The estimated age of growth strata at the Steinhuder Meer Fault (189 ± 5 ka and 158 ± 4 ka) indicates fault movements in Middle Pleistocene Saalian times. At the Harz Boundary Fault shear-wave reflection seismic surveys and electrical resistivity tomography profiles support the neotectonic activity in the Lateglacial. The timing of fault movements implies that the seismicity in northern and parts of central Germany is likely induced by varying lithospheric stress conditions related to glacial isostatic adjustment. For the Harz Boundary Fault and the Osning Thrust this is supported by numerical simulations of Coulomb failure stress variations. Thus, the faults can be classified as glacially-induced faults. Along the Regensburg-Leipzig-Rostock fault system, focal mechanisms of deep-seated earthquakes partly show NW-SE trending nodal planes. The focal mechanisms indicate activity along NW-SE oriented faults that intersect the N-S striking Regensburg-Leipzig-Rostock fault system. This supports the seismotectonic importance of NWSE oriented faults and intersecting faults in the study area of northern and central Germany

Age-related changes of apoptotic cell death in human lymphocytes

Apoptosis seems to be involved in immunosenescence associated with aging. Moreover, in lymphocytes (PBL) of patients with Alzheimer's disease, an increased susceptibility to the apoptotic pathway has been described possibly due to impaired protection of oxidative stress. Accordingly, it seemed to be of particular interest to investigate the contribution of normal aging to the susceptibility from human lymphocytes to programmed cell death. We could show that PBL from elderly individuals (>60 years) accumulate apoptosing cells to a significant higher extent in spontaneous and activation-induced cell death compared to younger controls (<35 years). Treatment with the oxidative stressor 2-deoxy-D-ribose or with agonistic-CD95-antibody pronounced this effect even more implicating a higher sensitivity to reactive oxygen species and a higher functional CD95 expression, respectively. In addition, expression of the activation markers HLA-DR and CD95 was significantly increased in CD3+-cells of aged subjects, while expression of CD25 did not seem to be affected by age. Expression of Bcl-2 was increased in aging and correlated with the number of apoptotic cells

Interpretation of X-ray Absorption Spectroscopy in the Presence of Surface Hybridization

X-ray absorption spectroscopy yields direct access to the electronic and geometric structure of hybrid inorganic-organic interfaces formed upon adsorption of complex molecules at metal surfaces. The unambiguous interpretation of corresponding spectra is challenged by the intrinsic geometric flexibility of the adsorbates and the chemical interactions with the interface. Density-functional theory (DFT) calculations of the extended adsorbate-substrate system are an established tool to guide peak assignment in X-ray photoelectron spectroscopy (XPS) of complex interfaces. We extend this to the simulation and interpretation of X-ray absorption spectroscopy (XAS) data in the context of functional organic molecules on metal surfaces using dispersion-corrected DFT calculations within the transition potential approach. On the example of X-ray absorption signatures for the prototypical case of 2H-porphine adsorbed on Ag(111) and Cu(111) substrates, we follow the two main effects of the molecule/surface interaction on XAS: (1) the substrate-induced chemical shift of the 1s core levels that dominates in physisorbed systems and (2) the hybridization-induced broadening and loss of distinct resonances that dominates in more chemisorbed systems.Comment: 13 pages, 4 figure