Auction Design with Loss Averse Bidders: The Optimality of All Pay Mechanisms

Auctioneers who have an indivisible object for sale and believe that bidders are risk neutral can find the recipe for an optimal auction in Myerson (1981); auctioneers who believe that bidders are loss averse can find it here: An optimal auction is an all pay auction with minimum bid, and any optimal mechanism is all pay

Enhancing Orthodontic Retraction: A Randomized Controlled Trial on Injectable Platelet-Rich Fibrin\u27s Impact on Tooth Movement

Introduction: Accelerated orthodontics aims to shorten treatment duration while improving patient comfort. Injectable platelet-rich fibrin (i-PRF) has been proposed to enhance orthodontic tooth movement (OTM) by stimulating bone remodeling. This study evaluates the effect of i-PRF on space closure rates, anchor loss, and salivary biomarkers (ALP, AST, and LDH) during orthodontic retraction. Materials and Methods: Twenty-four participants requiring extractions and space closure were divided into two groups (n = 12 each). Group A (experimental) received i-PRF, while Group B (control) did not. Space closure, anchor loss, and salivary enzyme activity were measured at T0 (baseline), T1 (3 weeks), T2 (6 weeks), and T3 (9 weeks). Statistical analysis included the Mann-Whitney and independent t-tests. Results: Eight participants remained in each group after follow-up losses. In the maxillary arch, Group A had a space closure rate of 1.4 ± 1.9 mm at T3 (T0: 10.8 ± 3.01 mm), while Group B reduced from 11.1 ± 2.0 mm at T0 to 4.9 ± 1.5 mm at T3. In the mandibular arch, Group A had a closure rate of 2.6 ± 2.0 mm at T3 (T0: 9.5 ± 2.5 mm), while Group B decreased from 10.0 ± 2.7 mm at T0 to 4.7 ± 2.3 mm at T3. Anchor loss was not significantly different between groups. Conclusion: i-PRF accelerated space closure, with statistical significance in the maxilla at T2 and T3 and the mandible at T2, without affecting anchorage stability. Clinical Significance: i-PRF may be a safe and effective adjunct in orthodontic treatment, reducing treatment duration without compromising anchorage

Hypocoercivity for non-linear infinite-dimensional degenerate stochastic differential equations

The aim of this article is to construct solutions to second order in time stochastic partial differential equations and to show hypocoercivity of the corresponding transition semigroups. More generally, we analyze non-linear infinite-dimensional degenerate stochastic differential equations in terms of their infinitesimal generators. In the first part of this article we use resolvent methods developed by Beznea, Boboc and Röckner to construct diffusion processes with infinite lifetime and explicit invariant measures. The processes provide weak solutions to infinite-dimensional Langevin dynamics. The second part deals with a general abstract Hilbert space hypocoercivity method, developed by Dolbeaut, Mouhot and Schmeiser. In order to treat stochastic (partial) differential equations, Grothaus and Stilgenbauer translated these concepts to the Kolmogorov backwards setting taking domain issues into account. To apply these concepts in the context of infinite-dimensional Langevin dynamics we use an essential m-dissipativity result for infinite-dimensional Ornstein–Uhlenbeck operators, perturbed by the gradient of a potential. We allow unbounded diffusion operators as coefficients and apply corresponding regularity estimates. Furthermore, essential m-dissipativity of a non-sectorial Kolmogorov backward operator associated to the dynamic is needed. Poincaré inequalities for measures with densities w.r.t. infinite-dimensional non-degenerate Gaussian measures are studied. Deriving a stochastic representation of the semigroup generated by the Kolmogorov backward operator as the transition semigroup of a diffusion process enables us to show an $L^2$ -exponential ergodicity result for the weak solution. Finally, we apply our results to explicit infinite-dimensional degenerate diffusion equations

Los vínculos existentes entre los recursos hídricos y la sostenibilidad de los sistemas naturales y humanos en la Marina Baixa

Comunicación presentada en el IV Congreso Ibérico sobre Gestión y Planificación del Agua, Tortosa, 8-12 diciembre 2004.En el marco del proyecto AQUADAPT sobre la gestión del agua se estudian las relaciones entre los sistemas natural y humano en la comarca de la Marina Baixa. Se discute la sostenibilidad de dichos sistemas y la importancia de las dinámicas coevolutivas entre ellos

Quality of Life in Orthodontics

Orthodontic treatment goes beyond mere cosmetic enhancement; it significantly impacts various aspects of an individual\u27s quality of life. Beyond the physical benefits of improved oral function and prevention of dental issues, orthodontics also yields profound psychological benefits. Aligned teeth enhance self-confidence, reduce social anxiety, and contribute to better relationships and professional opportunities. Moreover, addressing dental concerns through orthodontic treatment reduces psychological distress and promotes overall happiness and satisfaction. Real-life case studies vividly illustrate the transformative effects of orthodontic interventions, emphasizing the importance of considering quality of life outcomes in dental care

Die Schutzmacht. Die Amerikaner in Berlin 1945-1994

Von Feinden zu Freunden? Eine Geschichte der US-Militärpräsenz in West-Berlin und der transatlantischen Beziehungen. In den Nachkriegsjahren entstand eine Meistererzählung, die noch heute die Geschichte der Beziehungen zwischen West-Berlin und den USA prägt: Die sowjetische Blockade 1948/49 habe die USA zur wichtigsten »Schutzmacht« des bedrohten »Vorpostens der Freiheit« inmitten der DDR werden lassen. Aus den einstigen Feinden seien damals Freunde geworden, die erst abzogen, als ihre Mission 1989 /90 erfüllt war. Dieser linearen Erfolgsgeschichte stehen Bilder von Protesten gegen den Vietnamkrieg oder im Umfeld der Besuche des US-Präsidenten Ronald Reagan diametral entgegen. Stefanie Eisenhuth fügt diese widersprüchlichen Elemente zu einer neuen Erzählung zusammen, die sowohl die Höhe- als auch die Tiefpunkte des transatlantischen Verhältnisses erörtert. Sie fragt nach der Wahrnehmung und Deutung der US-Militärpräsenz sowie nach den Bedingungen des deutsch-amerikanischen Zusammenlebens in einer Stadt, die eine räumliche Abgrenzung nur bedingt erlaubte und zudem von enormer symbolischer Bedeutung war. Sie analysiert Begegnungen auf offizieller und informeller Ebene, individuelle und inszenierte Freundschaftsbekundungen, organisierte Proteste und Konflikte in West- sowie in Ost-Berlin zwischen 1945 und 1994

Hypocoercivity for infinite-dimensional non-linear degenerate stochastic differential equations with multiplicative noise

We analyze infinite-dimensional non-linear degenerate stochastic differential equations with multiplicative noise. First, essential m-dissipativity of their associated Kolmogorov backward generators on $L^2(\mu^{\Phi})$ defined on smooth finitely based functions is established. Here $\Phi$ is an appropriate potential and $\mu^{\Phi}$ is the invariant measure with density $e^{-\Phi}$ w.r.t. an infinite-dimensional non-degenerate Gaussian measure. Second, we use resolvent methods to construct corresponding right processes with infinite lifetime, solving the martingale problem for the Kolmogorov backward generators. They provide weak solutions, with weakly continuous paths, to the non-linear degenerate stochastic partial differential equations. Moreover, we identify the transition semigroup of such a process with the strongly continuous contraction semigroup $(T_t)_{t\geq 0}$ generated by the corresponding Kolmogorov backwards generator. Afterwards, we apply a refinement of the abstract Hilbert space hypocoercivity method, developed by Dolbeaut, Mouhot and Schmeiser, to derive hypocoercivity of $(T_t)_{t\geq 0}$. I.e. we take domain issues into account and use the formulation in the Kolmogorov backwards setting worked out by Grothaus and Stilgenbauer. The method enables us to explicitly compute the constants determining the exponential convergence rate to equilibrium of $(T_t)_{t\geq 0}$. The identification between $(T_t)_{t\geq 0}$ and the transition semigroup of the process yields exponential ergodicity of the latter. Finally, we apply our results to second order in time stochastic reaction-diffusion and Cahn-Hilliard type equations with multiplicative noise. More generally, we analyze corresponding couplings of infinite-dimensional deterministic with stochastic differential equations

REvoLd: Ultra-Large Library Screening with an Evolutionary Algorithm in Rosetta

Ultra-large make-on-demand compound libraries now contain billions of readily available compounds. This represents a golden opportunity for in-silico drug discovery. One challenge, however, is the time and computational cost of an exhaustive screen of such large libraries when receptor flexibility is taken into account. We propose an evolutionary algorithm to search combinatorial make-on-demand chemical space efficiently without enumerating all molecules. We exploit the feature of make-on-demand compound libraries, namely that they are constructed from lists of substrates and chemical reactions. Our novel algorithm RosettaEvolutionaryLigand (REvoLd) explores the vast search space of combinatorial libraries for protein-ligand docking with full ligand and receptor flexibility through RosettaLigand. A benchmark of REvoLd on five drug targets showed improvements in hit rates by factors between 869 and 1,622 compared to random selections. REvoLd is available as an application within the Rosetta software suite.Comment: 29 pages, 9 figure