Amid profoundly unstable and vulnerable times, conventional education systems continue to reflect the dominant ideology in modernity that has contributed to the current global polycrisis. This study explores how educators engage in vernacular pedagogical practices, locally grounded, relational and often situated outside standard curricula, that act as counterpoints to the conventional constraints using a Place-Based Education (PBE) approach. Drawing on semi-structured interviews with 14 educators from the Southeast Michigan Stewardship (SEMIS) Coalition, the research investigates how educators experience job satisfaction, define their roles and navigate tensions between dominant norms and community-rooted learning. Findings suggest that educators embrace indeterminism as a source of creativity, responsiveness and growth, weaving together interlaced strands of personal, cultural and ecological meaning in their vernacular pedagogical practices. Educators carve out alternative ways of knowing and relating, positioning PBE as a cultural stance that enables responsive, locally rooted reform amid today’s complex, uncertain and interconnected crises.

The Russian invasion of Ukraine in 2022, described by Chancellor Olaf Scholz as a Zeitenwende (turning point) triggered a fundamental rethinking of German foreign, security, and defence policy. This article conceptualises the invasion as a temporal shock to Germany’s ontological security. Building on the ‘temporal turn’ in International Relations, we argue that the war not only violated Ukraine’s national sovereignty and territorial integrity, but it also disrupted a broader sense of chronological continuity in European security, long defined by reduced defence spending and the assumption that interstate war was obsolete. Where previous studies have focused on the interrelationship of ontological security and temporality built around the concepts of biographical continuity, collective memory, and mnemonical security, this paper focuses instead on narrative disruption and the retiming of national security and identity via the perception of external shocks. We contend that the Zeitenwende narrative challenged historical concepts of German ontological security, such as Ostpolitik and Wandel durch Handel, that were deeply embedded in a strategic culture of military reticence by calling for the revitalisation of German military power. Yet this retiming remains constrained by incremental policy implementation and historical associations with Germany’s militaristic past, creating ongoing ontological insecurity about Germany’s role in European security.

The impact of two-dimensional (2-D) periodic forcing on transition dynamics in laminar separation bubbles (LSBs) generated on a flat plate is investigated experimentally. Laminar separation is caused by the favourable-to-adverse pressure gradient under an inverted modified NACA $64_3\text{-}618$ and periodic disturbances are generated by an alternating current dielectric barrier discharge plasma actuator located near the onset of the adverse pressure gradient. Surface pressure and time-resolved particle image velocimetry measurements along the centreline and several wall-parallel planes show significant reductions in bubble size with active flow control. Periodic excitation leads to amplification of the Kelvin–Helmholtz (K–H) instability resulting in strong 2-D coherent roller structures. Spanwise modulation of these structures is observed and varies with the forcing amplitude. Intermediate forcing amplitudes result in periodic spanwise deformation of the mean flow at large wavelength ($\lambda _z/L_{b,5kVpp} \approx 0.76$). For high-amplitude forcing, the spanwise modulation of the mean flow agrees with the much smaller wavelength of the difference interaction of two oblique subharmonic modes ($\lambda _z/L_{b,5kVpp} \approx 0.24$). Modal decomposition shows nonlinear interaction of the forced 2-D mode leading to growth of subharmonic and harmonic content, and the observation of several half-harmonics ($[n+1/2]f_{\textit{AFC}}$) at intermediate forcing amplitudes. Strongest amplitudes of the 2-D mode and delay of transition downstream of the time-averaged reattachment are observed for the intermediate forcing amplitudes, previously only observed in numerical simulations. Consistent with numerical results, further increase of the forcing amplitude leads to rapid breakdown to turbulence in the LSB. This suggests that the most effective exploitation of the K–H instability for transition delay is connected to an optimal (moderate) forcing amplitude.

In 1959 the Libraries Committee of the African Studies Association undertook a survey of holdings of Africana in American Theological libraries. The official approval of both the American Theological Library Association and the Catholic Library Association was received and inquiries were sent to a selected group of libraries in each Association. The main purpose was to ascertain the location of significant collections of printed material and to uncover, if possible, unknown or unrecorded manuscripts.

In discussing these three papers as they relate to history, it is an essential starting point to realize that the discipline of history is changing and has changed considerably in the last quarter century. History began as an account of the great deeds of our own ancestors, a record of the past that was essentially a backward extension of our own group personality. It long ago outgrew its concern with our tribal past and came to be concerned with the past of other peoples who share our Western culture. More recently, historians have become increasingly concerned with the past of other cultures as well. Some remnants of the older historical tradition are still around, but broadly speaking history now can be defined as the study of change in human society.

With this shifting focus inside the discipline itself, some of the barriers that used to surround history have also begun to disappear. One of these barriers was a distinction between history and pre-history, made according to the kind of evidence that each used. Historians worked with documentary evidence, leaving the pre-historians to worry with the kind of problem that could be solved only through the combined use of archaeology, oral tradition, linguistic evidence, and the like. In African history no such distinction is possible, and it is now generally abandoned. Documentary evidence about the history of Africa south of the Sahara begins about the ninth century, but it has to be used alongside non-documentary evidence. Documentary evidence, used by itself, only begins to tell the whole story when we come to the twentieth century, and even here it overlaps with the oral evidence of people still alive. African history is thus dominantly a history based on mixed data. The old line between history and pre-history is no longer useful, and theJournal of African History recognized this fact when, for convenience, it set a new division between history and pre-history at the beginning of the Iron Age — a date which will, of course, be somewhat different for different parts of Africa.