High-resolution spectroscopy of single Pr3+^{3+} ions on the 3^3H4_4-1^1D2_2 transition

Rare earth ions in crystals exhibit narrow spectral features and hyperfine-split ground states with exceptionally long coherence times. These features make them ideal platforms for quantum information processing in the solid state. Recently, we reported on the first high-resolution spectroscopy of single Pr$^{3+}$ ions in yttrium orthosilicate (YSO) nanocrystals. While in that work we examined the less explored $^3$H$_4$-$^3$P$_0$ transition at a wavelength of 488 nm, here we extend our investigations to the $^3$H$_4$-$^1$D$_2$ transition at 606 nm. In addition, we present measurements of the second-order autocorrelation function, fluorescence lifetime, and emission spectra of single ions as well as their polarization dependencies on both transitions; these data were not within the reach of the first experiments reported earlier. Furthermore, we show that by a proper choice of the crystallite, one can obtain narrower spectral lines and, thus, resolve the hyperfine levels of the excited state. We expect our results to make single-ion spectroscopy accessible to a larger scientific community.Comment: 5 pages, 5 figure

Detection, spectroscopy and state preparation of a single praseodymium ion in a crystal

Solid-state emitters with atom-like optical and magnetic transitions are highly desirable for efficient and scalable quantum state engineering and information processing. Quantum dots, color centers and impurities embedded in inorganic hosts have attracted a great deal of attention in this context, but influences from the matrix continue to pose challenges on the degree of attainable coherence in each system. We report on a new solid-state platform based on the optical detection of single praseodymium ions via 4f intrashell transitions, which are well shielded from their surroundings. By combining cryogenic high-resolution laser spectroscopy with fluorescence microscopy, we were able to spectrally select and spatially resolve individual ions. In addition to elaborating on the essential experimental steps for achieving this long-sought goal, we demonstrate state preparation and read out of the three ground-state hyperfine levels, which are known to have lifetimes of the order of hundred seconds

Sticky rebates: rollback rebates induce non-rational loyalty in consumers ; experimental evidence

We investigate whether and how targeted rebates impede rational switching of consumers from an incumbent to an outside option (e.g., market entrant). In a real trading problem, participants repeatedly buy tokens and can enter a target rebate scheme. Buying in a rebate scheme considerably reduces the likelihood that they switch to a higher-payoff outside option later. We conclude that targeted rebates might have an underestimated potential to foreclose consumer markets. The stickiness effect increases with the increasing number of previous buying in the rebate scheme, but not with the size of the rebate. Prospect Theory can partially account for these effects

Komplexität und Normenklarheit – oder: Gesetze sind für Juristen gemacht

Der Beitrag befasst sich mit der Komplexität von Rechtsnormen und dem zu ihrer Bändigung ersonnenen Instrument des deutschen Verfassungsrechts, der Normenklarheit. In einem ersten Schritt wird eine Definition des Begriffs “Komplexität” für positive Normen eingeführt, die durch die Dichte (Anzahl der zu berücksichtigenden Elemente) und Interdependenzen (innerhalb einer und zwischen verschiedenen Normen) konzeptionalisiert wird. Dadurch wird der Schwerpunkt der Überlegungen dieses Beitrages auf die Komplexität der inhaltlichen Regelung gelegt, eine durch die sprachliche Fassung hervorgerufene Komplexität bleibt außer Betracht. Komplexität ist demnach ein kognitives Problem; es handelt sich mithin um eine subjektive Perspektive auf Komplexität, die beim Individuum ansetzt, das den Rechtstext zu verstehen versucht. Die Technizität einer Norm kann die Komplexität für juristisch gebildete Rechtsanwender reduzieren, sie aber zugleich auch für Laien erhöhen. So kann die Rechtsdogmatik auch als Instrumentarium verstanden werden, Kohärenz im Recht zu erhöhen und Komplexität zu vermindern. Das Erfordernis der Normenklarheit ist jedoch kein Mittel zur Reduktion von Komplexität, sondern allein zu deren Kontrolle. Im Beitrag wird dargelegt, dass der Grundsatz der Normenklarheit im Prinzip der Gewaltengliederung gründet, sein Maßstab ist die Vollstreckbarkeit. Entgegen vorherrschender Auffassungen wird daher geschlossen, dass nicht der Normadressat das Gesetz verstehen muss, sondern ein Jurist. Nur dann kann dem Problem rechtlicher Komplexität in gesetzeszentrierten Rechtssystemen angemessen begegnet werden. Die These wird mit theoretischen, verhaltenswissenschaftlichen und rechtsdogmatischen Argumenten gestützt

Diversität in Rechtswissenschaft und Rechtspraxis

German law schools and legal practice are significantly less diverse than society; in particular, people of colour are missing. The empirical findings so far allow a first analysis of the factors that contribute to the current homogeneity. The legal system not only lacks diverse perspectives, the diversity deficit can also lead to problems for social acceptance and legitimacy. The essay proposes measures for equal participation in the legal professions and invites to an exchange about diversity as a current and pressing challenge for scholarship and practice. The text is an invitation for joint action, but also for reflection and further research.illustratorDie deutsche Rechtswissenschaft und Rechtspraxis sind deutlich weniger divers als die Gesellschaft; insbesondere People of Color fehlen. Die bisherigen empirischen Befunde erlauben eine erste Analyse der Faktoren, die zur gegenwärtigen Homogenität beitragen. Dem Rechtssystem fehlen nicht nur diverse Perspektiven, das Diversitätsdefizit kann auch gesellschaftliche Akzeptanz- und Legitimationsprobleme nach sich ziehen. Der Essay macht Vorschläge für gleichberechtigte Teilhabe an den juristischen Berufsfeldern und lädt ein zum Austausch über Diversität als aktueller und drängender Herausforderung für Wissenschaft und Praxis. Der Text ist eine Einladung zum gemeinsamen Handeln, aber auch zum gemeinsamen Nachdenken und Weiter-forschen

ASXL1 but not TET2 mutations adversely impact overall survival of patients suffering systemic mastocytosis with associated clonal hematologic non-mast-cell diseases.

Systemic mastocytosis with associated hematologic clonal non-mast cell disease (SM-AHNMD) is a rare and heterogeneous subtype of SM and few studies on this specific entity have been reported. Sixty two patients with Systemic mastocytosis with associated hematologic clonal non-mast cell disease (SM-AHNMD) were presented. Myeloid AHNMD was the most frequent (82%) cases. This subset of patients were older, had more cutaneous lesions, splenomegaly, liver enlargement, ascites; lower bone mineral density and hemoglobin levels and higher tryptase level than lymphoid AHNMD. Defects in KIT, TET2, ASXL1 and CBL were positive in 87%, 27%, 14%, and 11% of cases respectively. The overall survival of patients with SM-AHNMD was 85.2 months. Within the myeloid group, SM-MPN fared better than SM-MDS or SM-AML (p = 0.044,). In univariate analysis, the presence of C-findings, the AHNMD subtypes (SM-MDS/CMML/AML versus SM-MPN/hypereosinophilia) (p = 0.044), Neutropenia (p = 0.015), high monocyte level (p = 0.015) and the presence of ASXL1 mutation had detrimental effects on OS (p = 0.007). In multivariate analysis and penalized Cox model, only the presence of ASXL1 mutation remained an independent prognostic factor that negatively affected OS (p = 0.035). SM-AHNMD is heterogeneous with variable prognosis according to the type of the AHNMD. ASXL1 is mutated in a subset of myeloid AHNMD and adversely impact on OS

Demographic, clinical and biological characteristics of patients with myeloid and lymphoid SM-AHNMD patients at inclusion.

1<p>C-findings according to WHO classification.</p>2<p>including fatigue, headache, flushes, fever, hypotension, choc, syncope, WHO; world health organization, CM; cutaneous mastocytosis, AHNMD; associated clonal hematologic non-mast cell lineage disease, UP; urticaria pigmentosa, TEMP; telengietasia eruptive macularis persistans, DCM; diffuse cutaneous mastocytosis, BMD; bone mineral density.</p

A Unified Approach to the Revelation of Public Goods Preferences and to Optimal Income Taxation

We study a large economy model in which individuals have private information about their productive abilities and their preferences for public goods. A mechanism design approach is used to characterize implementable tax and expenditure policies. A robustness requirement in the sense of Bergemann and Morris (2005) yields individual incentive compatibility constraints that are equivalent to those in the theory of optimal income taxation in the tradition of Mirrlees (1971). Adding a requirement of coalition-proofness yields a set of collective incentive conditions which are akin those in the literature on public goods provision under private information on preferences, in the tradition of Clarke (1971) and Groves (1973)