Open Space Acquisitions and Management Opportunities in the City of Atlanta and Adjacent Jurisdictions

The great cities of the world are distinguished by their public parks. The urban fabric of New York, Barcelona, Berlin, Moscow, Paris, Rome, Sydney, and Shanghai are all woven around great parks. Yet, with all of Atlanta's outstanding achievements, the City and the region have a notably undistinguished park system. In a study conducted by the Trust for Public Land and the Urban Land Institute, Atlanta ranks near the bottom of the nation's largest 25 cities in acreage of parkland per capita with 7.3 acres for every 1,000 residents. Compare that to Austin, Texas' 39 acres per 1,000 residents or Oklahoma City's 43 acres per 1,000 residents and it becomes clear that something is amiss in metro Atlanta.This study identifies the obstacles to acquiring and maintaining open and green spaces in the metro Atlanta region. Addressing open space shortages in metro Atlanta is a sizable task. This study could be considered the first step in a larger process. Time spent researching the various obstacles and opportunities regarding open space acquisition raised many questions that are beyond the scope of this project. A second phase might test the recommendations made in this phase by working with local officials on a few select projects, and begin to identify critical pieces of property in metro Atlanta that must be protected from development. A detailed inventory of significant open space and natural resources in the metro area that includes the existing inventory of land inside of Interstate 285 should be considered either as a separate study or included in this recommended second phase

Different quantum f-divergences and the reversibility of quantum operations

The concept of classical $f$-divergences gives a unified framework to construct and study measures of dissimilarity of probability distributions; special cases include the relative entropy and the R\'enyi divergences. Various quantum versions of this concept, and more narrowly, the concept of R\'enyi divergences, have been introduced in the literature with applications in quantum information theory; most notably Petz' quasi-entropies (standard $f$-divergences), Matsumoto's maximal $f$-divergences, measured $f$-divergences, and sandwiched and $\alpha$-$z$-R\'enyi divergences. In this paper we give a systematic overview of the various concepts of quantum $f$-divergences with a main focus on their monotonicity under quantum operations, and the implications of the preservation of a quantum $f$-divergence by a quantum operation. In particular, we compare the standard and the maximal $f$-divergences regarding their ability to detect the reversibility of quantum operations. We also show that these two quantum $f$-divergences are strictly different for non-commuting operators unless $f$ is a polynomial, and obtain some analogous partial results for the relation between the measured and the standard $f$-divergences. We also study the monotonicity of the $\alpha$-$z$-R\'enyi divergences under the special class of bistochastic maps that leave one of the arguments of the R\'enyi divergence invariant, and determine domains of the parameters $\alpha,z$ where monotonicity holds, and where the preservation of the $\alpha$-$z$-R\'enyi divergence implies the reversibility of the quantum operation.Comment: 70 pages. v4: New Proposition 3.8 and Appendix D on the continuity properties of the standard f-divergences. The 2-positivity assumption removed from Theorem 3.34. The achievability of the measured f-divergence is shown in Proposition 4.17, and Theorem 4.18 is updated accordingl

Landauer's Principle in Repeated Interaction Systems

We study Landauer's Principle for Repeated Interaction Systems (RIS) consisting of a reference quantum system $\mathcal{S}$ in contact with a structured environment $\mathcal{E}$ made of a chain of independent quantum probes; $\mathcal{S}$ interacts with each probe, for a fixed duration, in sequence. We first adapt Landauer's lower bound, which relates the energy variation of the environment $\mathcal{E}$ to a decrease of entropy of the system $\mathcal{S}$ during the evolution, to the peculiar discrete time dynamics of RIS. Then we consider RIS with a structured environment $\mathcal{E}$ displaying small variations of order $T^{-1}$ between the successive probes encountered by $\mathcal{S}$, after $n\simeq T$ interactions, in keeping with adiabatic scaling. We establish a discrete time non-unitary adiabatic theorem to approximate the reduced dynamics of $\mathcal{S}$ in this regime, in order to tackle the adiabatic limit of Landauer's bound. We find that saturation of Landauer's bound is equivalent to a detailed balance condition on the repeated interaction system, reflecting the non-equilibrium nature of the repeated interaction system dynamics. This is to be contrasted with the generic saturation of Landauer's bound known to hold for continuous time evolution of an open quantum system interacting with a single thermal reservoir in the adiabatic regime.Comment: Linked entropy production to detailed balance relation, improved presentation, and added concluding sectio

Operationalizing the BIG Collective Collection: A Case Study of Consolidation vs Autonomy

This is a discussion paper prepared in collaboration with the Big Ten Academic Alliance (BTAA) Library Initiatives. It presents a framework for operationalizing the BTAA collective collection. A collective collection is a collection managed collaboratively across a network of libraries. We have a very specific focus in this paper on the ”purchased” or print collection, acknowledging that other areas of library collections are sometimes managed collectively, digitized collections for example. The BTAA justifiably claims to be the premier academic collaboration in the US. Once described as “the world\u27s greatest common market in education3,” it leverages the combined research and teaching capacity of major research universities to scale innovation, impact, and economies across its 14 members. Together, the BTAA members have a profound social and economic impact throughout a large part of the US. Libraries are a central part of the BTAA research, learning, and teaching endeavor. They collectively mobilize major expertise and resources. In fact, the BTAA collection represents more than a fifth of all titles in the North American print book collection. The BTAA libraries align with BTAA goals by collaborating at scale to increase both impact and efficiency. The character of library spaces, services, and collections is evolving with changing learning and research behaviors. It is widely recognized that continued autonomous development of large standalone collections does not meet needs and is not efficient. A library cannot collect all that its members would like to see, and much of what it does collect does not get used. At the same time, library space is being configured around engagement rather than around collections, the long-term stewardship costs of print materials are being recognized, and the role of books in research and learning is changing. Libraries are re-evaluating traditional approaches to building, managing, and sharing collections, and are increasingly looking to do this cooperatively. In this paper, we define and explore key attributes of collective collections and present a series of recommendations designed to advance the BTAA libraries toward a more purposeful coordination of their collections. Doing all that we propose would involve an extensive multi-year program. The approach we recommend here is broadly applicable in other consortium settings as well, which is why we characterize the paper as a case study

Effective DNA Inhibitors of Cathepsin G by In Vitro Selection

Cathepsin G (CatG) is a chymotrypsin-like protease released upon degranulation of neutrophils. In several inflammatory and ischaemic diseases the impaired balance between CatG and its physiological inhibitors leads to tissue destruction and platelet aggregation. Inhibitors of CatG are suitable for the treatment of inflammatory diseases and procoagulant conditions. DNA released upon the death of neutrophils at injury sites binds CatG. Moreover, short DNA fragments are more inhibitory than genomic DNA. Defibrotide, a single stranded polydeoxyribonucleotide with antithrombotic effect is also a potent CatG inhibitor. Given the above experimental evidences we employed a selection protocol to assess whether DNA inhibition of CatG may be ascribed to specific sequences present in defibrotide DNA. A Selex protocol was applied to identify the single-stranded DNA sequences exhibiting the highest affinity for CatG, the diversity of a combinatorial pool of oligodeoxyribonucleotides being a good representation of the complexity found in defibrotide. Biophysical and biochemical studies confirmed that the selected sequences bind tightly to the target enzyme and also efficiently inhibit its catalytic activity. Sequence analysis carried out to unveil a motif responsible for CatG recognition showed a recurrence of alternating TG repeats in the selected CatG binders, adopting an extended conformation that grants maximal interaction with the highly charged protein surface. This unprecedented finding is validated by our results showing high affinity and inhibition of CatG by specific DNA sequences of variable length designed to maximally reduce pairing/folding interactions

Magnetic flux tube models in superstring theory

Superstring models describing curved 4-dimensional magnetic flux tube backgrounds are exactly solvable in terms of free fields. We first consider the simplest model of this type (corresponding to `Kaluza-Klein' Melvin background). Its 2d action has a flat but topologically non-trivial 10-dimensional target space (there is a mixing of angular coordinate of the 2-plane with an internal compact coordinate). We demonstrate that this theory has broken supersymmetry but is perturbatively stable if the radius R of the internal coordinate is larger than R_0=\sqrt{2\a'}. In the Green-Schwarz formulation the supersymmetry breaking is a consequence of the presence of a flat but non-trivial connection in the fermionic terms in the action. For R < R_0 and the magnetic field strength parameter q > R/2\a' there appear instabilities corresponding to tachyonic winding states. The torus partition function Z(q,R) is finite for R > R_0 (and vanishes for qR=2n, n=integer). At the special points qR=2n (2n+1) the model is equivalent to the free superstring theory compactified on a circle with periodic (antiperiodic) boundary condition for space-time fermions. Analogous results are obtained for a more general class of static magnetic flux tube geometries including the a=1 Melvin model.Comment: 28 pages, harvmac. Minor changes, final version to appear in NP

Higher order terms for the quantum evolution of a Wick observable within the Hepp method

The Hepp method is the coherent state approach to the mean field dynamics for bosons or to the semiclassical propagation. A key point is the asymptotic evolution of Wick observables under the evolution given by a time-dependent quadratic Hamiltonian. This article provides a complete expansion with respect to the small parameter \epsilon > 0 which makes sense within the infinite-dimensional setting and fits with finite-dimensional formulae

Symbol correspondences for spin systems

The present monograph explores the correspondence between quantum and classical mechanics in the particular context of spin systems, that is, SU(2)-symmetric mechanical systems. Here, a detailed presentation of quantum spin-j systems, with emphasis on the SO(3)-invariant decomposition of their operator algebras, is followed by an introduction to the Poisson algebra of the classical spin system and a similarly detailed presentation of its SO(3)-invariant decomposition. Subsequently, this monograph proceeds with a detailed and systematic study of general quantum-classical symbol correspondences for spin-j systems and their induced twisted products of functions on the 2-sphere. This original systematic presentation culminates with the study of twisted products in the asymptotic limit of high spin numbers. In the context of spin systems, it shows how classical mechanics may or may not emerge as an asymptotic limit of quantum mechanics.Comment: Research Monograph, 171 pages (book format, preliminary version