27,629 research outputs found

    Memetic Multilevel Hypergraph Partitioning

    Full text link
    Hypergraph partitioning has a wide range of important applications such as VLSI design or scientific computing. With focus on solution quality, we develop the first multilevel memetic algorithm to tackle the problem. Key components of our contribution are new effective multilevel recombination and mutation operations that provide a large amount of diversity. We perform a wide range of experiments on a benchmark set containing instances from application areas such VLSI, SAT solving, social networks, and scientific computing. Compared to the state-of-the-art hypergraph partitioning tools hMetis, PaToH, and KaHyPar, our new algorithm computes the best result on almost all instances

    Updated global fit to three neutrino mixing: status of the hints of theta13 > 0

    Full text link
    We present an up-to-date global analysis of solar, atmospheric, reactor and accelerator neutrino data in the framework of three-neutrino oscillations. We discuss in detail the statistical significance of the observed "hint" of non-zero theta13 in the solar sector at the light of the latest experimental advances, such as the Borexino spectral data, the lower value of Gallium rate recently measured in SAGE, and the low energy threshold analysis of the combined SNO phase I and phase II. We also study the robustness of the results under changes of the inputs such as the choice of solar model fluxes and a possible modification of the Gallium capture cross-section as proposed by SAGE. In the atmospheric sector we focus on the latest results for nu_e appearance from MINOS and on the recent Super-Kamiokande results from the combined phases I, II and III, and we discuss their impact on the determination of theta13. Finally, we combine all the data into a global analysis and determine the presently allowed ranges of masses and mixing.Comment: 20 pages, 9 figures. Acknowledgments correcte

    Random Chance or Loaded Dice: The Politics of Judicial Designation

    Get PDF
    [Excerpt] “In the 1950s and 1960s, the southern states struggled to respond to the civil rights decisions being issued by the U.S. Supreme Court as well as the new civil rights laws being passed by Congress. The judicial battleground for this perfect storm of evasion and massive resistance was found in the “old” Fifth Circuit Court of Appeals, which encompassed the states of Alabama, Florida, Georgia, Louisiana, Mississippi, and Texas. In the “old” Fifth Circuit, a minority of liberal appeals court judges—sympathetic to the civil rights movement—used all legal and administrative power at their disposal to make sure that the federal district and appeals courts were complying with the U.S. Supreme Court’s mandate in Brown v. Board of Education. In their ground-breaking book A Court Divided: The Fifth Circuit Court of Appeals and the Politics of Judicial Reform, political scientists Deborah J. Barrow and Thomas G. Walker carefully examined the political behavior of these aforementioned liberal appeals court judges and found evidence that Elbert Parr Tuttle, the Fifth Circuit’s chief judge from 1960 to 1967, was manipulating, or “gerrymandering,” the assignment of appeals court judges to both three-judge district court panels, and three-judge appellate court panels to guarantee that the panels had at least two liberal judges who would enforce the Supreme Court’s desegregation rulings.

    Group size effect on cooperation in one-shot social dilemmas II. Curvilinear effect

    Full text link
    In a world in which many pressing global issues require large scale cooperation, understanding the group size effect on cooperative behavior is a topic of central importance. Yet, the nature of this effect remains largely unknown, with lab experiments insisting that it is either positive or negative or null, and field experiments suggesting that it is instead curvilinear. Here we shed light on this apparent contradiction by considering a novel class of public goods games inspired to the realistic scenario in which the natural output limits of the public good imply that the benefit of cooperation increases fast for early contributions and then decelerates. We report on a large lab experiment providing evidence that, in this case, group size has a curvilinear effect on cooperation, according to which intermediate-size groups cooperate more than smaller groups and more than larger groups. In doing so, our findings help fill the gap between lab experiments and field experiments and suggest concrete ways to promote large scale cooperation among people.Comment: Forthcoming in PLoS ON

    Habit Formation, Dynastic Altruism, and Population Dynamics

    Get PDF
    We study the general equilibrium properties of two growth models with overlapping generations, habit formation and endogenous fertility. In the neoclassical model, habits modify the economy's growth rate and generate transitional dynamics in fertility; station- ary income per capita is associated with either increasing or decreasing population and output, depending on the strength of habits. In the AK specification, growing population and increasing consumption per capita require that the habit coefficient lie within definite boundaries; outside the critical interval, positive growth is associated with either declining consumption due to overcrowding, or extinction paths with declining population. In both frameworks, habits reduce fertility: the trade-off between second-period consumption and spending for bequests prompts agents to decrease fertility in order to make parental altru- ism less costly. This mechanism suggests that status-dependent preferences may explain part of the decline in fertility rates observed in most developed economies.Economic Growth, Endogenous Fertility, Habit Formation, Intergenerational Altruism, Overlapping Generations.

    The contribution of Alu exons to the human proteome.

    Get PDF
    BackgroundAlu elements are major contributors to lineage-specific new exons in primate and human genomes. Recent studies indicate that some Alu exons have high transcript inclusion levels or tissue-specific splicing profiles, and may play important regulatory roles in modulating mRNA degradation or translational efficiency. However, the contribution of Alu exons to the human proteome remains unclear and controversial. The prevailing view is that exons derived from young repetitive elements, such as Alu elements, are restricted to regulatory functions and have not had adequate evolutionary time to be incorporated into stable, functional proteins.ResultsWe adopt a proteotranscriptomics approach to systematically assess the contribution of Alu exons to the human proteome. Using RNA sequencing, ribosome profiling, and proteomics data from human tissues and cell lines, we provide evidence for the translational activities of Alu exons and the presence of Alu exon derived peptides in human proteins. These Alu exon peptides represent species-specific protein differences between primates and other mammals, and in certain instances between humans and closely related primates. In the case of the RNA editing enzyme ADARB1, which contains an Alu exon peptide in its catalytic domain, RNA sequencing analyses of A-to-I editing demonstrate that both the Alu exon skipping and inclusion isoforms encode active enzymes. The Alu exon derived peptide may fine tune the overall editing activity and, in limited cases, the site selectivity of ADARB1 protein products.ConclusionsOur data indicate that Alu elements have contributed to the acquisition of novel protein sequences during primate and human evolution
    • 

    corecore