At its meeting in April 1990 at the University of Cambridge, the Executive Committee of the International Mathematical Union (IMU) decided that the largely unorganized archives of the Union should be properly arranged and catalogued. Simultaneously, the Executive Committee expressed the wish that a history of the Union should be written [1). As Secretary of the Union, I had proposed that these issues be dis cussed at the Cambridge meeting, but without having had in mind any personal role in the practical execution of such projects. At that time, the papers of the IMU were stored in Zurich, at the Eidgenossische Technische Hochschule, and I saw no reason why they could not remain there. At about this time, Professor K. Chandrasekharan produced a handwritten article titled "The Prehistory of the International Mathematical Union" [2), and it seemed to me that this might serve as the beginning of a more compre hensive history. I had first thought that Tuulikki MakeUiinen, who during eight years as the Office Secretary ofthe IMU had become well acquainted with the Union, would do the arranging of the archives in Zurich. She had a preliminary look at the material there, but it soon became clear that the amount of work required to bring order to it was too great to be accomplished in a few short visits from Helsinki. The total volume of material was formidable.

In recent years, mathematical logic has developed in many directions, the initial unity of its subject matter giving way to a myriad of seemingly unrelated areas. The articles collected here, which range from historical scholarship to recent research in geometric model theory, squarely address this development. These articles also connect to the diverse work of Väänänen, whose ecumenical approach to logic reflects the unity of the discipline.

The future of education centers empowered students in a global learning ecosystem. Despite decades of reform, the traditional borders of education—graduation, curriculum, classrooms, schools—have failed to deliver on the goals of excellence and equity. Despite massive societal changes, education remains controlled by an old mindset. It is time to change that limiting mindset and, more importantly, the ineffective practices in education. To truly serve all learners, future classrooms must remove the boundaries of learning and become student-centered, culturally responsive, and personalized—supportive and equitable environments where each student can direct their own learning and seek multiple pathways to skills and knowledge in a global learning ecosystem. This compelling call for transformative change offers all involved in education Evidence-based arguments that reveal the need to break the traditional borders that limit learning Strategies to personalize learning and remove the confinement of traditional pathways Examples from around the world to create equitable and student-centric learning environments Resources for creating a school learning environment that expands opportunities for personalized learning into the global learning ecosystem It is time to now imagine a different kind of learning, without borders, and to begin the shifts in practice that will result in personalized learning for all students.

In Stories without Borders, Julia Sonnevend considers the ways in which we recount and remember news stories of historic significance. Focusing on the Berlin Wall and on subsequent retellings of the event in a variety of ways - from Legoland reenactments to slabs of the Berlin Wall installed in global cities - Sonnevend discusses how certain events become built up into global iconic events.

The contributions in this volume have been written by eminent scientists from the international mathematical community and present significant advances in several theories, methods and problems of Mathematical Analysis, Discrete Mathematics, Geometry and their Applications. The chapters focus on both old and recent developments in Functional Analysis, Harmonic Analysis, Complex Analysis, Operator Theory, Combinatorics, Functional Equations, Differential Equations as well as a variety of Applications. The book also contains some review works, which could prove particularly useful for a broader audience of readers in Mathematical Sciences, and especially to graduate students looking for the latest information.

The theory of semigroups is a relatively young branch of mathematics, with most of the major results having appeared after the Second World War. This book describes the evolution of (algebraic) semigroup theory from its earliest origins to the establishment of a full-fledged theory. Semigroup theory might be termed `Cold War mathematics' because of the time during which it developed. There were thriving schools on both sides of the Iron Curtain, although the two sides were not always able to communicate with each other, or even gain access to the other's publications. A major theme of this book is the comparison of the approaches to the subject of mathematicians in East and West, and the study of the extent to which contact between the two sides was possible.

Amateurs without Borders examines the rise of new actors in the international development world: volunteer-driven grassroots international nongovernmental organizations. These small aid organizations, now ten thousand strong, sidestep the world of professionalized development aid by launching projects built around personal relationships and the skills of volunteers. This book draws on fieldwork in the United States and Africa, web data, and IRS records to offer the first large-scale systematic study of these groups. Amateurs without Borders investigates the aspirations and limits of personal compassion on a global scale.