Fiscal Policy in a Monetary Union: Can Fiscal Cooperation be Counterproductive?

We analyze the interaction of monetary and fiscal policies in a monetary union where the common central bank is more conservative than the fiscal authorities. When monetary and fiscal policies are discretionary, we find that the Nash equilibrium is sub-optimal with higher output and lower inflation than the cooperative Ramsey op- timum. In a further example of counterproductive cooperative, we find that fiscal cooperation makes matters worse. We also examine cooperative and non-cooperative fiscal policy in the case where the central bank can commit and has the same prefer- ences as the fiscal authorities.fiscal-monetary policy interactions, fiscal cooperation and non-cooperation.

From the XXZ chain to the integrable Rydberg-blockade ladder via non-invertible duality defects

Strongly interacting models often possess ``dualities'' subtler than a one-to-one mapping of energy levels. The maps can be non-invertible, as apparent in the canonical example of Kramers and Wannier. We find an algebraic structure in the XXZ spin chain and three other Hamiltonians that yields non-invertible maps between them and also guarantees all are integrable. The other models describe Rydberg-blockade bosons with one particle per square of a ladder, a three-state antiferromagnet, and two Ising chains coupled in a zigzag fashion. We construct the non-invertible maps explicitly by using topological defects coming from fusion categories and the lattice version of the orbifold construction. The Rydberg and Ising ladders also possess interesting non-invertible symmetries, with the spontaneously breaking of one in the former resulting in an unusual ground-state degeneracy. We give explicit conformal-field-theory partition functions describing their critical regions, and provide a detailed correspondence between lattice and continuum operators in the integrable Rydberg-blockade ladder.Comment: 43 pages. v2: expanded section on connection of lattice and CF

Overcoming temperature limits in the optical cooling of solids using light-dressed states

Laser cooling of solids currently has a temperature floor of 50 - 100 K. We propose a method that could overcome this using defects, such as diamond color centers, with narrow electronic manifolds and bright optical transitions. It exploits the dressed states formed in strong fields which extend the set of phonon transitions and have tunable energies. This allows an enhancement of the cooling power and diminishes the effect of inhomogeneous broadening. We demonstrate these effects theoretically for the silicon-vacancy and the germanium-vacancy, and discuss the role of background absorption, phonon-assisted emission, and non-radiative decay.Comment: 10 pages, 7 figures. v2: Improved discussion of competing heating processes and phonon-assisted decay. New supplemental material with summary of methods, analysis of validity of Born-Markov approach, results for the germanium-vacanc

A Viable Business Model for Innovations with Digital Healthcare Applications in Germany

Germany established laws to quickly introduce digital innovations in healthcare by forcing statutory insurances to reimburse companies producing digital applications. This could enhance the well-being of patients. For example, an application in psychotherapy can cut the waiting time for a psychotherapist in Germany. However, such enhancements will reach the patients only if companies offering digital applications have a viable business model to survive. Our analysis of the business model of a company offering a recognized digital application shows that such business models are not easy to develop. The analysis is transferrable to other countries, if they establish similar laws. First, we describe the legal framework for digital healthcare applications set up in Germany. We also describe the conditions that must be met for such an application to be recognized by the relevant body so that statutory insurances must pay for it. This is followed by a discussion of the reimbursement amount. Then, we develop the business model of a producer of a specific digital healthcare application. Although the possibility of reimbursement for accepted applications constitutes a competitive advantage, underestimating costs from the approval process and marketing may be dangerous. The same is true for relying on revenues from reimbursement

Decision support for efficient XAI services - A morphological analysis, business model archetypes, and a decision tree

The black-box nature of Artificial Intelligence (AI) models and their associated explainability limitations create a major adoption barrier. Explainable Artificial Intelligence (XAI) aims to make AI models more transparent to address this challenge. Researchers and practitioners apply XAI services to explore relationships in data, improve AI methods, justify AI decisions, and control AI technologies with the goals to improve knowledge about AI and address user needs. The market volume of XAI services has grown significantly. As a result, trustworthiness, reliability, transferability, fairness, and accessibility are required capabilities of XAI for a range of relevant stakeholders, including managers, regulators, users of XAI models, developers, and consumers. We contribute to theory and practice by deducing XAI archetypes and developing a user-centric decision support framework to identify the XAI services most suitable for the requirements of relevant stakeholders. Our decision tree is founded on a literature-based morphological box and a classification of real-world XAI services. Finally, we discussed archetypical business models of XAI services and exemplary use cases

Effect of β-Li3N phase, Li2O addition and thermal treatment on the hydrogen sorption behavior of Li3N

The hydriding of Li3N to LiNH2 is investigated to clarify the influence of the beta-Li3N phase, the addition of Li2O and the thermal treatment of Li3N on the hydrogen storage properties of the Li-N-H system. As-milled Li3N displays fast initial absorption that is attributed to the formation of beta-Li3N nanograins, the increase of the surface area, and the presence of surface defects induced by mechanical milling. However, further hydrogen absorption is retarded in comparison with the as-received sample due to the presence of the beta-Li3N phase formed during milling. Thus, commercial Li3N exhibits the highest hydrogen storage capacity in the first cycle in comparison with as-heated Li3N and as-milled samples. In the case of Li2O addition, no interaction with Li3N was detected. The addition of LiH to the commercial Li3N, as-milled Li3N and Li3N-Li2O influences only the stability of the samples under hydrogen cycling. The hydrogen absorption/desorption behavior is mainly controlled by the amount of beta-Li3N formed during milling, while at long times the microstructure has a minor effect.Fil: Fernández Albanesi, Luisa Francisca. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Arneodo Larochette, Pierre Paul. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Gennari, Fabiana Cristina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

The Intersections of Biological Diversity and Cultural Diversity: Towards Integration

There is an emerging recognition that the diversity of life comprises both biological and cultural diversity. In the past, however, it has been common to make divisions between nature and culture, arising partly out of a desire to control nature. The range of interconnections between biological and cultural diversity are reflected in the growing variety of environmental sub-disciplines that have emerged. In this article, we present ideas from a number of these sub-disciplines. We investigate four bridges linking both types of diversity (beliefs and worldviews, livelihoods and practices, knowledge bases and languages, and norms and institutions), seek to determine the common drivers of loss that exist, and suggest a novel and integrative path forwards. We recommend that future policy responses should target both biological and cultural diversity in a combined approach to conservation. The degree to which biological diversity is linked to cultural diversity is only beginning to be understood. But it is precisely as our knowledge is advancing that these complex systems are under threat. While conserving nature alongside human cultures presents unique challenges, we suggest that any hope for saving biological diversity is predicated on a concomitant effort to appreciate and protect cultural diversity

IgD shapes the pre-immune naïve B cell compartment in humans

B cell maturation and immunoglobulin (Ig) repertoire selection are governed by expression of a functional B cell receptor (BCR). Naïve B cells co-express their BCR as IgM and IgD isotype. However, the role of the additionally expressed IgD on naïve B cells is not known. Here we assessed the impact of IgD on naïve B cell maturation and Ig repertoire selection in 8 individuals from 3 different families with heterozygous loss-of-function or loss-of expression mutations in IGHD. Although naïve B cells from these individuals expressed IgM on their surface, the IGHD variant in heterozygous state entailed a chimeric situation by allelic exclusion with almost half of the naïve B cell population lacking surface IgD expression. Flow cytometric analyses revealed a distinct phenotype of IgD-negative naïve B cells with decreased expression of CD19, CD20 and CD21 as well as lower BAFF-R and integrin-β7 expression. IgD-negative B cells were less responsive in vitro after engaging the IgM-BCR, TLR7/9 or CD40 pathway. Additionally, a selective disadvantage of IgD-negative B cells within the T2 transitional and mature naïve B cell compartment as well as reduced frequencies of IgMlo/- B cells within the mature naïve B cell compartment lacking IgD were evident. RNA-Ig-seq of bulk sorted B cell populations showed an altered selection of distinct VH segments in the IgD-negative mature naïve B cell population. We conclude that IgD expression on human naïve B cells is redundant for generation of naïve B cells in general, but further shapes the naive B cell compartment starting from T2 transitional B cells. Our observations suggest an unexpected role of IgD expression to be critical for selection of distinct Ig VH segments into the pre-immune Ig repertoire and for the survival of IgMlo/- naïve B cells known to be enriched in poly-/autoreactive B cell clones