The Wodaabe of Niger, traditionally mobile cattle nomads, are undergoing significant changes as they shift towards agro-pastoralism and urban migration. This book explores the spatial transformations linked to urban migration and the sedentarization of rural proto-villages. It delves into the implications of these changes for social group formation and collective identity, highlighting the challenges and adaptations faced as they integrate into the broader structures of modern society and the nation-state.
High-Precision Measurements of Bound-Electron g-Factors of Highly Charged Ions
This thesis presents the first isotope-shift measurement of bound-electron g-factors of highly charged ions and determines the most precise value of the electron mass in atomic mass units, which exceeds the value in the literature by a factor of 13. As the lightest fundamental massive particle, the electron is one of nature’s few central building blocks. A precise knowledge of its intrinsic properties, such as its mass, is mandatory for the most accurate tests in physics - the Quantum Electrodynamics tests that describe one of the four established fundamental interactions in the universe. The underlying measurement principle combines a high-precision measurement of the Larmor-to-cyclotron frequency ratio on a single hydrogen-like carbon ion studied in a Penning trap with very accurate calculations of the so-called bound-electron g-factor. For the isotope-shift measurement, the bound-electron g-factors of two lithium-like calcium isotopes have been measured with relative uncertainties of a few 10^{-10}, constituting an as yet unrivaled level of precision for lithium-like ions.
