Wind in the Sails: Grantmaking for General Operating Support at The Atlantic Philanthropies (1982-2016)

This case study delves into why and how Atlantic made nearly half of its grants with considerable general operating support contributions. It examines the foundation's decisions at key junctures and responses to challenges. The report also offers mini case studies and lessons that may be useful to funders carrying out this type of grantmaking

End-Game Evaluation: Building a Legacy of Learning In a Limited-Life Foundation

This article shares the emerging hypotheses of two foundations, The Atlantic Philanthropies and the S. D. Bechtel, Jr. Foundation — each four years from sunset — about the opportunities and challenges for evaluation in the limited-life context. Few, if any, of the problems philanthropy seeks to address can be solved within a brief, defined time frame. Limited-life foundations can only strive to move the ball down the field before they sunset, and then enlist others to carry the work forward. Given this reality, these foundations are obligated to make a deliberate effort to share what they have learned with the players who remain. The article argues that systematically capturing and sharing knowledge — about programs, as well as social-change methods and grantmaking practices — can increase a foundation’s influence and impact during its final years and beyond

A Promising Place-Based Collaborative Impact Investing Fund Strengthens Community and Informs Philanthropic Practice

A recent evaluation of the Western New York Impact Investment Fund adds to the proof-of-concept literature regarding “doing good and doing well” while pointing to experience-based best practices in philanthropic impact investing. Born of a collaboration between regional and national philanthropies, the fund brings together corporate, individual, and philanthropic investors to deliver an inclusive impact investment mechanism. Founded in 2017, the fund evolved from concept to operating entity, focusing on mitigating capital gaps, longterm economic decline, and wealth divides. Evaluation at Year 5 describes how the professionally managed, collaboratively governed fund has attracted and deployed capital, contributing to ecosystem improvements and concrete results. Portfolio companies have created jobs with livable wages, reduced carbon footprints, reclaimed abandoned space, and committed to maintain operations in the region long term. Alongside these impacts, investors’ stakes have increased in value and realized returns. Performance bred opportunity and its second round of fundraising, 42% larger than the first, brought the total under management to over $20 million. With this evaluation, the Western New York Impact Investment Fund articulates lessons for the fund, foundation investors, and intermediaries seeking to nurture place-based impact investing

A symplectic proof of a theorem of Franks

A celebrated theorem in two-dimensional dynamics due to John Franks asserts that every area preserving homeomorphism of the sphere has either two or infinitely many periodic points. In this work we reprove Franks' theorem under the additional assumption that the map is smooth. Our proof uses only tools from symplectic topology and thus differs significantly from all previous proofs. A crucial role is played by the results of Ginzburg and Kerman concerning resonance relations for Hamiltonian diffeomorpisms.Comment: 15 pages. Minor changes. Final version to appear in Compositio Mathematic

Flux tube dynamics in the dual superconductor

We study plasma oscillations in a flux tube of the dual superconductor model of 't Hooft and Mandelstam. A magnetic condensate is coupled to an electromagnetic field by its dual vector potential, and fixed electric charges set up a flux tube. An electrically charged fluid (a quark plasma) flows in the tube and screens the fixed charges via plasma oscillations. We investigate both Type I and Type II superconductors, with plasma frequencies both above and below the threshold for radiation into the Higgs vacuum. We find strong radiation of electric flux into the superconductor in all regimes, and argue that this invalidates the use of the simplest dual superconductor model for dynamical problems.Comment: 25 pages Revtex with 11 EPS figure

Can One Trust Quantum Simulators?

Various fundamental phenomena of strongly-correlated quantum systems such as high-$T_c$ superconductivity, the fractional quantum-Hall effect, and quark confinement are still awaiting a universally accepted explanation. The main obstacle is the computational complexity of solving even the most simplified theoretical models that are designed to capture the relevant quantum correlations of the many-body system of interest. In his seminal 1982 paper [Int. J. Theor. Phys. 21, 467], Richard Feynman suggested that such models might be solved by "simulation" with a new type of computer whose constituent parts are effectively governed by a desired quantum many-body dynamics. Measurements on this engineered machine, now known as a "quantum simulator," would reveal some unknown or difficult to compute properties of a model of interest. We argue that a useful quantum simulator must satisfy four conditions: relevance, controllability, reliability, and efficiency. We review the current state of the art of digital and analog quantum simulators. Whereas so far the majority of the focus, both theoretically and experimentally, has been on controllability of relevant models, we emphasize here the need for a careful analysis of reliability and efficiency in the presence of imperfections. We discuss how disorder and noise can impact these conditions, and illustrate our concerns with novel numerical simulations of a paradigmatic example: a disordered quantum spin chain governed by the Ising model in a transverse magnetic field. We find that disorder can decrease the reliability of an analog quantum simulator of this model, although large errors in local observables are introduced only for strong levels of disorder. We conclude that the answer to the question "Can we trust quantum simulators?" is... to some extent.Comment: 20 pages. Minor changes with respect to version 2 (some additional explanations, added references...

Passage of charmed particles through the mixed phase in high-energy heavy-ion collisions

We employ a modified cascade hydrodynamics code to simulate the phase transition of an expanding quark-gluon plasma and the passage of a charmed particle through it. When inside the plasma droplets, the charmed quark experiences drag and diffusion forces. When outside the plasma, the quark travels as a $D$ meson and experiences collisions with pions. Additional energy transfer takes place when the quark enters or leaves a droplet. We find that the transverse momentum of $D$ mesons provides a rough thermometer of the phase transition.Comment: 20 pages, 9 Postscript figures included with epsfig.st

Wild-type and mutant SOD1 share an aberrant conformation and a common pathogenic pathway in ALS.

Many mutations confer one or more toxic function(s) on copper/zinc superoxide dismutase 1 (SOD1) that impair motor neuron viability and cause familial amyotrophic lateral sclerosis (FALS). Using a conformation-specific antibody that detects misfolded SOD1 (C4F6), we found that oxidized wild-type SOD1 and mutant SOD1 share a conformational epitope that is not present in normal wild-type SOD1. In a subset of human sporadic ALS (SALS) cases, motor neurons in the lumbosacral spinal cord were markedly C4F6 immunoreactive, indicating that an aberrant wild-type SOD1 species was present. Recombinant, oxidized wild-type SOD1 and wild-type SOD1 immunopurified from SALS tissues inhibited kinesin-based fast axonal transport in a manner similar to that of FALS-linked mutant SOD1. Our findings suggest that wild-type SOD1 can be pathogenic in SALS and identify an SOD1-dependent pathogenic mechanism common to FALS and SALS