Quantum-enhanced reinforcement learning for finite-episode games with discrete state spaces

Quantum annealing algorithms belong to the class of metaheuristic tools, applicable for solving binary optimization problems. Hardware implementations of quantum annealing, such as the quantum annealing machines produced by D-Wave Systems, have been subject to multiple analyses in research, with the aim of characterizing the technology's usefulness for optimization and sampling tasks. Here, we present a way to partially embed both Monte Carlo policy iteration for finding an optimal policy on random observations, as well as how to embed (n) sub-optimal state-value functions for approximating an improved state-value function given a policy for finite horizon games with discrete state spaces on a D-Wave 2000Q quantum processing unit (QPU). We explain how both problems can be expressed as a quadratic unconstrained binary optimization (QUBO) problem, and show that quantum-enhanced Monte Carlo policy evaluation allows for finding equivalent or better state-value functions for a given policy with the same number episodes compared to a purely classical Monte Carlo algorithm. Additionally, we describe a quantum-classical policy learning algorithm. Our first and foremost aim is to explain how to represent and solve parts of these problems with the help of the QPU, and not to prove supremacy over every existing classical policy evaluation algorithm.Comment: 17 pages, 7 figure

The persistent effects of place-based policy: Evidence from the West-German Zonenrandgebiet

We show that temporary place-based subsidies generate persistent effects on economic density. As our design allows us to control for agglomeration economies, we attribute an important role to policy-induced locational advantage (e.g. capital structures) in explaining persistent spatial patterns of economic activity. With regard to distributional implications, we show that subsidies have capitalized in land rents, so pre-treatment land owners have benefitted predominantly from the program

Eutactic quantum codes

We consider sets of quantum observables corresponding to eutactic stars. Eutactic stars are systems of vectors which are the lower dimensional ``shadow'' image, the orthogonal view, of higher dimensional orthonormal bases. Although these vector systems are not comeasurable, they represent redundant coordinate bases with remarkable properties. One application is quantum secret sharing.Comment: 6 page

Prevalence of Opioid Dependence and Opioid Agonist Treatment in the Berlin Custodial Setting: A Cross-Sectional Study

Background: Among people living in detention, substance use is highly prevalent, including opioid dependence. Opioid agonist treatment (OAT) has been established as an evidence-based, first-line treatment for opioid dependence. Despite high prevalence of opioid dependence, conclusive data regarding its prevalence and the OAT practice in German prisons is scarce; rather, the existing data widely diverges concerning the rates of people in detention receiving OAT. Materials and Methods: We conducted a cross-sectional survey of all detention facilities in Berlin. On the date of data collection, a full census of the routine records was completed based on the medical documentation system. For each opioid dependent individual, we extracted sociodemographic data (i.e., age, sex, and non-/German nationality, whether people experienced language-related communication barriers), information about OAT, comorbidities (HIV, hepatitis C, schizophrenia), and the detention center, as well as the anticipated imprisonment duration and sentence type. The data was first analyzed descriptively and secondly in an evaluative-analytical manner by analyzing factors that influence the access to OAT of people living in detention. Results: Among the 4,038 people in detention in the Berlin custodial setting under investigation, we identified a 16% prevalence of opioid dependence. Of the opioid-dependent individuals, 42% received OAT; 31% were treated with methadone, 55% were treated with levomethadone, and 14% were treated with buprenorphine. Access to OAT seemed mainly dependent upon initial receipt of OAT at the time of imprisonment, detention duration, the prisons in which individuals were detained, German nationality, and sex. The overall prevalence of HIV was 4-8%, hepatitis C was 31-42%, and schizophrenia was 5%. Conclusions: The prevalence of opioid dependence and access to OAT remains a major health issue in the custodial setting. OAT implementation must be especially intensified among male, non-German, opioid-dependent individuals with a short detention period. Treatment itself must be diversified regarding the substances used for OAT, and institutional treatment differences suggest the need for a consistent treatment approach and the standardized implementation of treatment guidelines within local prison's standard operating procedures. Testing for infectious diseases should be intensified among opioid-dependent people living in detention to address scarcely known infection statuses and high infection rates

Lignin repolymerisation in spruce autohydrolysis pretreatment increases cellulase deactivation

This study presents a modified autohydrolysis pretreatment which helps to overcome the recalcitrance of softwood for enzymatic hydrolysis of its cellulose. Autohydrolysis pretreatments of spruce wood were performed with 2-naphthol, which prevents lignin repolymerisation reactions, thereby increasing the enzymatic digestibility of cellulose by up to 64%. The negative influence of repolymerised lignin structures on enzymatic hydrolysis was confirmed by the addition of resorcinol in autohydrolysis, which is known to promote repolymerisation reactions and decreased the biomass digestibility. Several analyses were performed to study the underlying mechanism of this effect on hydrolysis, indicating that cellulolytic enzymes are adsorbed and deactivated especially by repolymerised lignin structures, which accounts for the high differences in biomass digestibility. It was shown that lignin repolymerisation significantly increases its specific surface area through modification of the lignin nanostructure, which is supposed to increase the unproductive binding of enzymes

Paratexte der Bibel

Apart from the Greek and Latin text of the New Testament, Erasmus’ epochal edition contains a few well-known “editorial” paratexts, i. e. the paraclesis, the methodus, and the apologia. Much less known is that the edition, in its various versions, also contained a few Greek (and Latin) “traditional” paratexts, i. e. material taken from the manuscript sources, such as chapter lists, biographies of the evangelists and subscriptiones. The analysis of these small texts is promising for several reasons. Firstly, the Byzantine “dowry” of the New Testament on its way into early modern Europe becomes visible: some of those small texts were translated by Martin Luther or others along with the Biblical text. Some texts in the edition are important because they have not been critically edited since the initial publication (e. g. Eusebius’ canon tables). Secondly, these paratexts and their manuscript sources allow for a deeper understanding of the making of Erasmus’ edition. A good case in point is the only figurative image in the New Testament, i. e. the representation of the trinity in the edition of 1519. It can be traced back to the Corsendonck Codex, which in this instance served also as an iconographic Vorlage. The canon tables are another example for which it can be shown that the same Greek codex was used, but – maybe even more importantly – a Latin Bible printed by Froben in 1514 as well. Thirdly, the way in which Erasmus and his collaborators made use of Greek manuscripts can in many cases be better analysed on the basis of small paratextual material than on the basis of the (highly standardized) Biblical text itself