This article studies the principal component analysis (PCA) estimation of weak factor models with sparse loadings. We uncover an intrinsic near-sparsity preservation property for the PCA estimators of loadings, which comes from the approximately (block) upper triangular structure of the rotation matrix. It suggests an asymmetric relationship among factors: the sparsity of the rotated loadings for a stronger factor can be contaminated by the loadings from weaker ones, but the sparsity of the rotated loadings of a weaker factor is almost unaffected by the loadings of stronger ones. Then, we propose a simple alternative to the existing penalized approaches to sparsify the loading estimators by screening out the small PCA loading estimators directly, and construct consistent estimators for factor strengths. The proposed estimators perform well in finite samples, as shown by a set of Monte Carlo simulations.

Stanley N. Katz served as the Class of 1921 Bicentennial Professor of the History of American Law and Liberty at Princeton University from 1978 to 1986. He left to become President of the American Council of Learned Societies, the national humanities organization in the United States. When he stepped down from that position in 1997, he returned to teaching and high-level institutional service at Princeton, including as the Acting Director of the Program in Law and Public Affairs from 2004 to 05 and 2016 to 17. Katz’s contributions to legal history include, in addition to a vast array of articles and the books cited in the footnotes below, his work as Editor in Chief of the Oxford International Encyclopedia of Legal History and of the Oliver Wendell Holmes Devise History of the United States Supreme Court. He has served as President of the Organization of American Historians and American Society for Legal History, as Vice President of the Research Division of the American Historical Association, and as a member of the Board of Trustees of the Newberry Library, the Center for Jewish History, and many other institutions. He is a Fellow of the American Society for Legal History, the American Academy of Arts and Sciences, and the Society of American Historians. President Barack Obama awarded him the National Humanities Medal in 2011.

The Qabus-nama (AD eleventh century) has been translated into Turkish many times by different translators. While one of the Chagatai Turkish translations of the work was completed by Âgehî (1809–1874) and is located in Uzbekistan, the other, by an unknown translator, is in the British Library (BL) (Or. 9661), but its beginning and end are missing. This article evaluates the Lund University Library (LUL) copy of the translation (Jarring Prov. 342), for which, unlike the other copies, the translator and translation date can be identified, as its beginning and end are intact. In this article, introductory information will be provided about Muhammad Siddiq al-Muqallib (Rushdie), the translator of the work, as well as Khoja Kefek Bey, who was instrumental in its translation. Additionally, the BL and LUL copies of the Qabus-nama will be compared using different criteria.

Online music streaming has emerged as a central mode of consumption in Europe and many other parts of the world, representing a distinct break from older forms of music media such as compact discs or broadcast radio. Instead of the one-to-many models that have historically dominated music dissemination – where an individual’s listening habits could only be guessed at through aggregate sales figures or broadcast audience estimates – streaming has introduced a one-to-one model. This shift, which gradually gained momentum during the last two decades (Drott 2024, p. 1), hinges on platforms and devices that also allow unprecedented observation of how individual listeners engage with recorded music. Consequently, hundreds of millions of people are now individually tracked in near-real time, generating vast amounts of granular data.

The U.S. National Library of Medicine holds two collections by Adolf Nichtenhauser (1903–53) that have become important sources for historians of medical and health films: an unpublished book-manuscript in which he surveys the history of medical and health films to around 1950, primarily in Europe and North America; and the valuable collection of documents he amassed partly during his research for this book-manuscript. Such is the richness of these collections that it is difficult to imagine a history of medical and health film that is not in some way indebted to Nichtenhauser. Indeed, his book-manuscript has become a standard citation in the historiography of medicine, health and film. Yet very little is known about Nichtenhauser himself, other than that he was a European immigrant to the United States who wrote this key history and died before its completion. This article seeks to do three things: to provide the first English-language biography of Nichtenhauser from his early life in Austria to his career in the United States; to use this biography to explain how he came to write this book-manuscript; and to explore the relationship between his historiography and efforts in the 1940s and 1950s to identify and solve problems with application of film to medicine and health.

This ethnographic study examines the transformation of Italian indie culture under platform capitalism, tracing how digital infrastructures have reconfigured the relationship between independence and mainstream commercial logic. Drawing on fieldwork with musicians, industry professionals, and audiences across Italy, it argues that the semantic and aesthetic coordinates of indie have shifted from oppositional autonomy to a stylised modality compatible with platform logics, where visibility and metric optimisation increasingly dictate artistic legitimacy through commercial imperatives and through the internalisation of platform-mediated evaluative frameworks. The Italian case, rooted in a tradition of politicised independence, reveals how local infrastructures and cultural histories mediate these global transformations. Synthesising grounded, abductive analysis with historical reconstruction, the study identifies three intertwined processes – mainstreamisation, semantic drift, and platform gravity – through which visibility metrics and sponsorship logics recalibrate artistic practice, legitimacy, and audience address, recognising that these dynamics interact with diverse cultural trajectories and do not operate as a uniform homogenising force. The emerging configurations still depend on established intermediaries, informal circuits, and human decision-making embedded in longstanding power structures, even as platform mediation intensifies the circulation and repetition of certain stylistic and organisational practices. To theorise these shifts, the article advances ‘poptimism’ as a structural condition. The analysis shows how this gravitational field is absorbed into existing professional sensibilities, where platform mentalities recur within industry judgements shaped by longstanding organisational logics.

We consider the family of infinite positive Borel measures $\mu $ in the unit disc, with finite degree of contact at the unit circle, and the set $E_{\mu }$ of points in the unit circle for which every neighborhood contains infinite mass of $\mu $. Assuming that $E_{\mu }$ is a Carleson set, we show that all Blaschke sequences are zero sets for the corresponding Dirichlet space $D_{\mu }$.