533 research outputs found

    Systemwechsel in der gesetzlichen Rentenversicherung keine Lösung zur Entschärfung des intergenerationalen Verteilungskonflikts

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    Der Mechanismus eines Umlageverfahren wird modelltheoretisch analysiert und mit dem des Kapitaldeckungsverfahrens verglichen. Es wird gezeigt, dass der wesentliche Unterschied des Umlageverfahrens eine Subventionierung der ersten Generationen auf Kosten später geborener Generationen ist. Der Übergang von einem Umlageverfahren zu einem Kapitaldeckungsverfahren kann daher die nachfolgenden Generationen nicht entlasten

    Systemwechsel in der gesetzlichen Rentenversicherung keine Lösung zur Entschärfung des intergenerationalen Verteilungskonflikts

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    The present German pension system needs to be reformed. The alternative to the present pay-as-you-go pension system is a fully funded system. This retirement system offers a higher rate of return to the now young. Nevertheless, the paper argues, that a transition to a fully funded system will not solve the fundamental problem of the German pension system, because the hidden debt of the present system would requires a tax rate which equalizes the burden of both systems.

    Anreizwirkungen der Arbeitslosenunterstützung auf die Arbeitssuche

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    Mit Hilfe einer modelltheoretischen Analyse wird untersucht, wie sich das zeitliche Profil der Höhe der Lohnersatzleistungen auf die Suchstrategie eines Arbeitslosen auswirkt. Es wird gezeigt, dass eine antizipierte Absenkung nach einer bestimmten Dauer der Arbeitslosigkeit schon zu Beginn der Arbeitslosigkeit das Akzeptanzlohnniveau senkt und somit die Wahrscheinlichkeit einer Arbeitsaufnahme erhöht. Beim faktischen Eintritt der Absenkung erfolgt deshalb nur noch eine vergleichsweise geringe Absenkung des Akzeptanzlohnniveaus

    Mögliche Effekte des demographischen Wandels-Ein Überblick-

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    One of the more important influences shaping the future economic conditions of the highly industrialized countries is the decline and aging of their population. The article is a comprehensive survey of the impact of this development on key economic variables and the institutions of the welfare state. While the overall consequence of the aging process on productivity growth is more likely to be negative, there are also some offsetting forces like the increase in the capital intensity. The institutions of the welfare state, which are based on intergenerational transfers, will have to be reformed, in order to bring them in line with the demographic process. The prediction of a decrease in the rate of unemployment as a consequence of a declining labor force is according to our analysis not justified.

    Enhancing Auxiliary-Mediated Native Chemical Ligation at Challenging Junctions with Pyridine Scaffolds

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    To expand the scope of native chemical ligation (NCL) beyond reactions at cysteine, ligation auxiliaries are appended to the peptide N-terminus. After the introduction of a pyridine-containing auxiliary, which provided access to challenging junctions (proline or β-branched amino acids), we herein probe the role of the pyridine-ring nitrogen. We observed side reactions leading to preliminary auxiliary loss. We describe a new easy to attach β-mercapto-β-(4-methoxy-2-pyridinyl)-ethyl (MMPyE) auxiliary, which 1) has increased stability; 2) enables NCL at sterically encumbered junctions (e. g., Leu-Val); and 3) allows removal under mildly basic (pH 8.5) conditions was introduced. The synthesis of a 120 aa long peptide containing eight MUC5AC tandem repeats via ligation of two 60mers demonstrates the usefulness. Making use of hitherto unexplored NCL to tyrosine, the MMPyE auxiliary provided access to a head-to-tail-cyclized 21-mer peptide and a His6-tagged hexaphosphorylated peptide comprising 6 heptapeptide repeats of the RNA polymerase II C-terminal domain.Peer Reviewe

    Enabling Cysteine-Free Native Chemical Ligation at Challenging Junctions with a Ligation Auxiliary Capable of Base Catalysis

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    Ligation auxiliaries are used in chemical protein synthesis to extend the scope of native chemical ligation (NCL) beyond cysteine. However, auxiliary-mediated ligations at sterically demanding junctions have been difficult. Often the thioester intermediate formed in the thiol exchange step of NCL accumulates because the subsequent S→N acyl transfer is extremely slow. Here we introduce the 2-mercapto-2-(pyridin-2-yl)ethyl (MPyE) group as the first auxiliary designed to aid the ligation reaction by catalysis. Notably, the MPyE auxiliary provides useful rates even for junctions containing proline or a β-branched amino acid. Quantum chemical calculations suggest that the pyridine nitrogen acts as an intramolecular base in a rate-determining proton transfer step. The auxiliary is prepared in two steps and conveniently introduced by reductive alkylation. Auxiliary cleavage is induced upon treatment with TCEP/morpholine in presence of a MnII complex as radical starter. The synthesis of a de novo designed 99mer peptide and an 80 aa long MUC1 peptide demonstrates the usefulness of the MPyE auxiliary.Peer Reviewe

    Geometry and dynamics of higher-spin frame fields

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    We give a systematic account of unconstrained free bosonic higher-spin fields on D-dimensional Minkowski and (Anti-)de Sitter spaces in the frame formalism. The generalized spin connections are determined by solving a chain of torsion-like constraints. Via a generalization of the vielbein postulate these allow to determine higher-spin Christoffel symbols, whose relation to the de Wit--Freedman connections is discussed. We prove that the generalized Einstein equations, despite being of higher-derivative order, give rise to the AdS Fronsdal equations in the compensator formulation. To this end we derive Damour-Deser identities for arbitrary spin on AdS. Finally we discuss the possibility of a geometrical and local action principle, which is manifestly invariant under unconstrained higher-spin symmetries.Comment: 30 pages, uses youngtab.sty, v2: minor changes, references adde

    A Novel Class of Defensive Compounds in Harvestmen: Hydroxy-γ-Lactones from the Phalangiid Egaenus convexus

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    When threatened, the harvestman Egaenus convexus (Opiliones: Phalangiidae) ejects a secretion against offenders. The secretion originates from large prosomal scent glands and is mainly composed of two isomers of 4-hydroxy-5-octyl-4,5-dihydro-3H-furan-2-one (1), a β-hydroxy-γ-lactone. The compounds were characterized by GC-MS of their microreaction derivatives, HRMS, and NMR. After the synthesis of all four possible stereoisomers of 1, followed by their separation by chiral-phase GC, the absolute configurations of the lactones in the Egaenus secretion was found to be (4S,5R)-1 (90%) and (4S,5S)-1 (10%). Hydroxy-γ-lactones represent a new class of exocrine defense compounds in harvestmen

    Anodic and Cathodic Platinum Dissolution Processes Involve Different Oxide Species

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    The degradation of Pt-containing oxygen reduction catalysts for fuel cell applications is strongly linked to the electrochemical surface oxidation and reduction of Pt. Here, we study the surface restructuring and Pt dissolution mechanisms during oxidation/reduction for the case of Pt(100) in 0.1 M HClO4 by combining operando high-energy surface X-ray diffraction, online mass spectrometry, and density functional theory. Our atomic-scale structural studies reveal that anodic dissolution, detected during oxidation, and cathodic dissolution, observed during the subsequent reduction, are linked to two different oxide phases. Anodic dissolution occurs predominantly during nucleation and growth of the first, stripe-like oxide. Cathodic dissolution is linked to a second, amorphous Pt oxide phase that resembles bulk PtO2 and starts to grow when the coverage of the stripe-like oxide saturates. In addition, we find the amount of surface restructuring after an oxidation/reduction cycle to be potential-independent after the stripe-like oxide has reached its saturation coverage.Funding is acknowledged from Deutsche Forschungsgemeinschaft for OMM and SC (project number 418603497), for OMM by the German Federal Ministry of Education and Research (BMBF) via project 05K19FK3, and for DAH by the NSERC (grant RGPIN-2017-04045). FCV acknowledges that the grants PID2021-127957NB-I00 and TED2021-132550B-C21 were funded by MCIN/AEI/ 10.13039/501100011033 and by the European Union. The use of supercomputing facilities at SURFsara was sponsored by NWO Physical Sciences, with financial support by NWO. Open Access funding enabled and organized by Projekt DEAL
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