913 research outputs found

    Pareto optimality in house allocation problems

    Get PDF
    We study Pareto optimal matchings in the context of house allocation problems. We present an O(\sqrt{n}m) algorithm, based on Gales Top Trading Cycles Method, for finding a maximum cardinality Pareto optimal matching, where n is the number of agents and m is the total length of the preference lists. By contrast, we show that the problem of finding a minimum cardinality Pareto optimal matching is NP-hard, though approximable within a factor of 2. We then show that there exist Pareto optimal matchings of all sizes between a minimum and maximum cardinality Pareto optimal matching. Finally, we introduce the concept of a signature, which allows us to give a characterization, checkable in linear time, of instances that admit a unique Pareto optimal matching

    "Almost stable" matchings in the Roommates problem

    Get PDF
    An instance of the classical Stable Roommates problem (SR) need not admit a stable matching. This motivates the problem of finding a matching that is “as stable as possible”, i.e. admits the fewest number of blocking pairs. In this paper we prove that, given an SR instance with n agents, in which all preference lists are complete, the problem of finding a matching with the fewest number of blocking pairs is NP-hard and not approximable within n^{\frac{1}{2}-\varepsilon}, for any \varepsilon>0, unless P=NP. If the preference lists contain ties, we improve this result to n^{1-\varepsilon}. Also, we show that, given an integer K and an SR instance I in which all preference lists are complete, the problem of deciding whether I admits a matching with exactly K blocking pairs is NP-complete. By contrast, if K is constant, we give a polynomial-time algorithm that finds a matching with at most (or exactly) K blocking pairs, or reports that no such matching exists. Finally, we give upper and lower bounds for the minimum number of blocking pairs over all matchings in terms of some properties of a stable partition, given an SR instance I

    Psilocybin for depression and anxiety associated with life-threatening illnesses

    Get PDF
    [No abstract available

    Embryonic expression and cloning of the murine GATA-3 gene.

    Get PDF
    We describe the embryonic expression pattern as well as the cloning and initial transcriptional regulatory analysis of the murine (m) GATA-3 gene. In situ hybridization shows that mGATA-3 mRNA accumulation is temporally and spatially regulated during early development: although found most abundantly in the placenta prior to 10 days of embryogenesis, mGATA-3 expression becomes restricted to specific cells within the embryonic central nervous system (in the mesencephalon, diencephalon, pons and inner ear) later in gestation. GATA-3 also shows a restricted expression pattern in the peripheral nervous system, including terminally differentiating cells in the cranial and sympathetic ganglia. In addition to this distinct pattern in the nervous system, mGATA-3 is also expressed in the embryonic kidney and the thymic rudiment, and further analysis showed that it is expressed throughout T lymphocyte differentiation. To begin to investigate how this complex gene expression pattern is elicited, cloning and transcriptional regulatory analyses of the mGATA-3 gene were initiated. At least two regulatory elements (one positive and one negative) appear to be required for appropriate tissue-restricted regulation after transfection of mGATA-3-directed reporter genes into cells that naturally express GATA-3 (T lymphocytes and neuroblastoma cells). Furthermore, this same region of the locus confers developmentally appropriate expression in transgenic mice, but only in a subset of the tissues that naturally express the gene

    Bosons in Disordered Optical Potentials

    Full text link
    In this work we systematically investigate the condensate properties, superfluid properties and quantum phase transitions in interacting Bose gases trapped in disordered optical potentials. We numerically solve the Bose-Hubbard Hamiltonian exactly for different: (a) types of disorder, (b) disorder strengths, and (c) interatomic interactions. The three types of disorder studied are: quasiperiodic disorder, uniform random disorder and random speckle-type disorder. We find that the Bose glass, as identified by Fisher et al [Phys. Rev. B {\bf 40}, 546 (1989)], contains a normal condensate component and we show how the three different factors listed above affect it.Comment: 4 pages, 4 figures (low res) v2 Title,Abstract,Introduction: changes; Figure 3: Add label to axi

    GATA-2 and GATA-3 regulate trophoblast-specific gene expression in vivo.

    Get PDF
    We previously demonstrated that the zinc finger transcription factors GATA-2 and GATA-3 are expressed in trophoblast giant cells and that they regulate transcription from the mouse placental lactogen I gene promoter in a transfected trophoblast cell line. We present evidence here that both of these factors regulate transcription of the placental lactogen I gene, as well as the related proliferin gene, in trophoblast giant cells in vivo. Placentas lacking GATA-3 accumulate placental lactogen I and proliferi

    Design of fluorinated cyclopropane derivatives of 2-phenylcyclopropylmethylamine leading to identification of a selective serotonin 2C (5-HT2C) receptor agonist without 5-HT2B agonism

    Get PDF
    A new series of fluorinated 5-HT2C agonists were designed and synthesized on the basis of our previous work on 2-phenylcyclopropylmethylamines as a potential approach for the treatment of central nervous system disorders. Key fluorinated cyclopropane moieties were constructed through transition metal catalyzed [2 + 1]-cycloaddition of aromatic vinyl fluorides, and the absolute stereochemistry of the representative compound (–)-21a was established. Functional activity measuring calcium flux at 5-HT2 receptors reveals high potency for compounds (+)-21a-d. In particular, (+)-21b had no detectable 5-HT2B agonism and displayed reasonable selectivity against 5-HT2A. Molecular docking studies were further performed to explain the compounds’ possible binding poses to the 5-HT2C receptor. © 201

    Hydrodynamic excitations of trapped dipolar fermions

    Full text link
    A single-component Fermi gas of polarized dipolar particles in a harmonic trap can undergo a mechanical collapse due to the attractive part of the dipole-dipole interaction. This phenomenon can be conveniently manipulated by the shape of the external trapping potential. We investigate the signatures of the instability by studying the spectrum of low-lying collective excitations of the system in the hydrodynamic regime. To this end, we employ a time-dependent variational method as well as exact numerical solutions of the hydrodynamic equations of the system.Comment: 4 pages, 2 eps figures, final versio

    Design and Discovery of Functionally Selective Serotonin 2C (5-HT2C) Receptor Agonists

    Get PDF
    On the basis of the structural similarity of our previous 5-HT2C agonists with the melatonin receptor agonist tasimelteon and the putative biological cross-talk between serotonergic and melatonergic systems, a series of new (2,3-dihydro)benzofuran-based compounds were designed and synthesized. The compounds were evaluated for their selectivity toward 5-HT2A, 5-HT2B, and 5-HT2C receptors in the calcium flux assay with the ultimate goal to generate selective 5-HT2C agonists. Selected compounds were studied for their functional selectivity by comparing their transduction efficiency at the G protein signaling pathway versus β-arrestin recruitment. The most functionally selective compound (+)-7e produced weak β-arrestin recruitment and also demonstrated less receptor desensitization compared to serotonin in both calcium flux and phosphoinositide (PI) hydrolysis assays. We report for the first time that selective 5-HT2C agonists possessing weak β-arrestin recruitment can produce distinct receptor desensitization properties. Š 2016 American Chemical Society

    Ab-initio calculation of the 6Li{}^6Li binding energy with the Hybrid Multideterminant scheme

    Full text link
    We perform an ab-initio calculation for the binding energy of 6Li{}^6Li using the CD-Bonn 2000 NN potential renormalized with the Lee-Suzuki method. The many-body approach to the problem is the Hybrid Multideterminant method. The results indicate a binding energy of about 31MeV31 MeV, within a few hundreds KeV uncertainty. The center of mass diagnostics are also discussed.Comment: 18 pages with 3 figures. More calculations added, to be published in EPJ
    • …
    corecore