Archaeogenetic perspectives on the hunter-gatherers and prehistoric farmers of the Mediterranean

I applied state-of-the-art ancient DNA (aDNA) approaches to recover highly degraded DNA molecules from post-glacial hunter-gatherers and early farmers from the Mediterranean to investigate the demographic processes that underlie archaeological transitions after the Ice Age and during the expansion of farming practises. I placed a particular emphasis on examining the genomic evidence for crossings of the Mediterranean Sea, as was proposed by archaeologists based on similarities in material culture. Each of the manuscripts contributes crucial genomic reference points for Mediterranean areas where human occupation locally persisted during the Ice Age, or with some of the earliest indications for farming. In Manuscript A, I report the oldest ancient genome-wide data for Africa to date retrieved from nine ~15,000 calBP microlithic Iberomaurusian hunter-gatherers from the Mediterranean coast in Morocco (Van de Loosdrecht et al. 2018. Science). In Manuscript B, I report a genomic transect of ten individuals from the Iberian Peninsula from various sites with Upper Palaeolithic to Middle Neolithic occupations (~13,000-6,000 calBP) (Villalba-Mouco et al. 2019. Curr. Biol). In Manuscript C, I explore the multi-disciplinary potential of archaeogenetics, and jointly report genomic and isotopic data for dietary inference for a transect of 19 Mesolithic foragers and Early Neolithic farmers from Sicily (~10,700-7,200 calBP) (Van de Loosdrecht et al. 2020. BioRxiv). In the discussion I provide archaeogenetic perspectives on topics long been debated by scholars of Mediterranean prehistory: 1) the origin of the Iberomaurusian industry in Northwest Africa; 2) the admixture dynamics of European foragers after the Ice Age; 3) the genomic evidence for direct population interactions across the Mediterranean Sea; 4) the demographic processes underlying the transition from foraging to farming in the Mediterranean; and 5) the southern Mediterranean Neolithic expansion route.1. Introduction 1.1. The ancient DNA revolution: current state-of-the-art 1.2. The ~10,000-year trajectory from foraging to farming in the Mediterranean region 1.2.1. Northwestern Africa during and after the last Ice Age 1.2.2. Europe during and after the last Ice Age 1.2.3. The Neolithic Revolution: sedentary farming communities expand into the Mediterranean 2. Aims and objectives 3. Overview of manuscripts 3.1. Manuscript A 3.2. Manuscript B 3.3. Manuscript C 4. Author contributions 5. Manuscript A 6. Manuscript B 7. Manuscript C 8. Discussion 8.1. Archaeogenetic perspectives on the repopulation of northern Africa and Europe after the Last Glacial Maximum 8.1.1. Northwestern Africa 8.1.2. Europe 8.2. Is there genomic evidence that prehistoric Mediterranean peoples were in direct contact across the Mediterranean Sea? 8.3. Limitations of ancestry inferences using ancient DNA 8.4. Conclusion 8.5. Outloo

Raman signatures of charge ordering in K0.3WO3

We present polarization- and temperature-dependent Raman spectroscopic study of hexagonal tungsten bronze, K0.3WO3. The observed asymmetry in phonon line shapes indicate the presence of strong lattice anharmonicity arising due to the nonstoichiometry of the material. We observed a broad multipeak Raman feature at low frequency due to the local modes of K atoms known as local structural excitations. The observed vibrational features indicate a second-order phase transition around T=200 K accompanied by a frequency softening of low-frequency phonon modes. The observed phonon anomalies hint a physical picture involving a continuous symmetry change toward a charge-ordered state below 200 K. These observations indicate that K0.3WO3 may exhibit a weak charge-density-wave ground state at low temperatures.

Dynamic simulation of N2O emissions from a full-scale partial nitritation reactor

This study deals with the potential and the limitations of dynamic models for describing and predicting nitrous oxide (N2O) emissions associated with biological nitrogen removal from wastewater. The results of a three-week monitoring campaign on a full-scale partial nitritation reactor were reproduced through a state-of-the-art model including different biological N2O formation pathways. The partial nitritation reactor under study was a SHARON reactor treating the effluent from a municipal wastewater treatment plant sludge digester. A qualitative and quantitative comparison between experimental data and simulation results was performed to identify N2O formation pathways as well as for model identification. Heterotrophic denitrifying bacteria and ammonium oxidizing bacteria (AOB) were responsible for N2O formation under anoxic conditions, whereas under aerated conditions the AOB were the most important N2O producers. Relative to previously proposed models, hydroxylamine (NH2OH) had to be included as a state variable in the AOB conversions in order to describe potential N2O formation by AOB under anoxic conditions. An oxygen inhibition term in the corresponding reaction kinetics was required to fairly represent the relative contribution of the different AOB pathways for N2O production. Nevertheless, quantitative prediction of N2O emissions with models remains a challenge, which is discussed

Static magnetic susceptibility, crystal field and exchange interactions in rare earth titanate pyrochlores

The experimental temperature dependence (T = 2–300 K) of single crystal bulk and site susceptibilities of rare earth titanate pyrochlores R2Ti2O7 (R = Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) is analyzed in the framework of crystal field theory and a mean field approximation. Analytical expressions for the site and bulk susceptibilities of the pyrochlore lattice are derived taking into account long range dipole–dipole interactions and anisotropic exchange interactions between the nearest neighbor rare earth ions. The sets of crystal field parameters and anisotropic exchange coupling constants have been determined and their variations along the lanthanide series are discussed.

Thermal conductivity of anisotropic spin - 1/2 two leg ladder:Green's function approach

We study the thermal transport of a spin-1/2 two leg antiferromagnetic ladder in the direction of legs. The possible effect of spin-orbit coupling and crystalline electric field are investigated in terms of anisotropies in the Heisenberg interactions on both leg and rung couplings. The original spin ladder is mapped to a bosonic model via a bond-operator transformation where an infinite hard-core repulsion is imposed to constrain one boson occupation per site. The Green's function approach is applied to obtain the energy spectrum of quasi-particle excitations responsible for thermal transport. The thermal conductivity is found to be monotonically decreasing with temperature due to increased scattering among triplet excitations at higher temperatures. A tiny dependence of thermal transport on the anisotropy in the leg direction at low temperatures is observed in contrast to the strong one on the anisotropy along the rung direction, due to the direct effect of the triplet density. Our results reach asymptotically the ballistic regime of the spin - 1/2 Heisenberg chain and compare favorably well with exact diagonalization data

A critical review of resource recovery from municipal wastewater treatment plants : market supply potentials, technologies and bottlenecks

In recent decades, academia has elaborated a wide range of technological solutions to recover water, energy, fertiliser and other products from municipal wastewater treatment plants. Drivers for this work range from low resource recovery potential and cost effectiveness, to the high energy demands and large environmental footprints of current treatment-plant designs. However, only a few technologies have been implemented and a shift from wastewater treatment plants towards water resource facilities still seems far away. This critical review aims to inform decision-makers in water management utilities about the vast technical possibilities and market supply potentials, as well as the bottlenecks, related to the design or redesign of a municipal wastewater treatment process from a resource recovery perspective. Information and data have been extracted from literature to provide a holistic overview of this growing research field. First, reviewed data is used to calculate the potential of 11 resources recoverable from municipal wastewater treatment plants to supply national resource consumption. Depending on the resource, the supply potential may vary greatly. Second, resource recovery technologies investigated in academia are reviewed comprehensively and critically. The third section of the review identifies nine non-technical bottlenecks mentioned in literature that have to be overcome to successfully implement these technologies into wastewater treatment process designs. The bottlenecks are related to economics and value chain development, environment and health, and society and policy issues. Considering market potentials, technological innovations, and addressing potential bottlenecks early in the planning and process design phase, may facilitate the design and integration of water resource facilities and contribute to more circular urban water management practices

Dynamics in the dimerised and high field incommensurate phase of CuGeO3_3

Temperature ($2.3<T<40$\ K) and magnetic field ($0<B<17$\ T) dependent far infrared absorption spectroscopy on the spin-Peierls coumpound CuGeO$_3$\ has revealed several new absorption processes in both the dimerised and high field phase of CuGeO$_3$. These results are discussed in terms of the modulation of the CuGeO$_3$\ structure. At low fields this is the well known spin-Peierls dimerisation. At high fields the data strongly suggests a field dependent incommensurate modulation of the lattice as well as of the spin structure.Comment: 12 pages (revtex), 2 figures (eps), csh selfextracting .uu file, To appear in PRB-Rapid Com

Mapping the B,T phase diagram of frustrated metamagnet CuFeO2

The magnetic phase diagram of CuFeO2 as a function of applied magnetic field and temperature is thoroughly explored and expanded, both for magnetic fields applied parallel and perpendicular to the material's c-axis. Pulsed field magnetization measurements extend the typical magnetic staircase of CuFeO2 at various temperatures, demonstrating the persistence of the recently discovered high field metamagnetic transition up to Tn2 ~ 11 K in both field configurations. An extension of the previously introduced phenomenological spin model used to describe the high field magnetization process (Phys. Rev. B, 80, 012406 (2009)) is applied to each of the consecutive low-field commensurate spin structures, yielding a semi-quantitative simulation and intuitive description of the entire experimental magnetization process in both relevant field directions with a single set of parameters.Comment: 14 pages, 11 figures, submitted to Phys. Rev.

High-field recovery of the undistorted triangular lattice in the frustrated metamagnet CuFeO2

Pulsed field magnetization experiments extend the typical metamagnetic staircase of CuFeO2 up to 58 T to reveal an additional first order phase transition at high field for both the parallel and perpendicular field configuration. Virtually complete isotropic behavior is retrieved only above this transition, indicating the high-field recovery of the undistorted triangular lattice. A consistent phenomenological rationalization for the field dependence and metamagnetism crossover of the system is provided, demonstrating the importance of both spin-phonon coupling and a small field-dependent easy-axis anisotropy in accurately describing the magnetization process of CuFeO2.Comment: 4 pages, 4 figure