Triply mixed coverings of arbitrary base curves: Quasimodularity, quantum curves and a mysterious topological recursions

Simple Hurwitz numbers enumerate branched morphisms between Riemann surfaces with fixed ramification data. In recent years, several variants of this notion for genus $0$ base curves have appeared in the literature. Among them are so-called monotone Hurwitz numbers, which are related to the HCIZ integral in random matrix theory and strictly monotone Hurwitz numbers which count certain Grothendieck dessins d'enfants. We generalise the notion of Hurwitz numbers to interpolations between simple, monotone and strictly monotone Hurwitz numbers to any genus and any number of arbitrary but fixed ramification profiles. This yields generalisations of several results known for Hurwitz numbers. When the target surface is of genus one, we show that the generating series of these interpolated Hurwitz numbers are quasimodular forms. In the case that all ramification is simple, we refine this result by writing this series as a sum of quasimodular forms corresonding to tropical covers weighted by Gromov-Witten invariants. Moreover, we derive a quantum curve for monotone and Grothendieck dessins d'enfants Hurwitz numbers for arbitrary genera and one arbitrary but fixed ramification profile. Thus, we obtain spectral curves via the semiclassical limit as input data for the CEO topological recursion. Astonishingly, we find that the CEO topological recursion for the genus $1$ spectral curve of the strictly monotone Hurwitz numbers compute the monotone Hurwitz numbers in genus $0$. Thus, we give a new proof that monotone Hurwitz numbers satisfy CEO topological recursion. This points to an unknown relation between those enumerants. Finally, specializing to target surface $\mathbb{P}^1$, we find recursions for monotone and Grothendieck dessins d'enfants double Hurwitz numbers, which enables the computation of the respective Hurwitz numbers for any genera with one arbitrary but fixed ramification profile.Comment: 41 page

Caenorhabditis elegans NPR-1–mediated behaviors are suppressed in the presence of mucoid bacteria

Caenorhabditis elegans exhibits a diverse range of behaviors in response to bacteria. The presence of bacterial food influences C. elegans aerotaxis, aggregation, locomotion, and pathogen avoidance behaviors through the activity of the NPR-1 neuropeptide receptor. Here, we show that mucoid strains of bacteria that produce an exopolysaccharide matrix do not induce NPR-1–dependent behaviors. In the presence of mucoid strains of bacteria, the C. elegans laboratory wild-type (WT) strain N2 exhibits behaviors characteristic of wild isolates and mutants with reduced NPR-1 activity. Specifically, N2 exhibits lawn bordering and roaming behavior on mucoid nonpathogenic bacteria and loss of pathogen avoidance on mucoid Pseudomonas aeruginosa. Alginate biosynthesis by laboratory and clinical isolates of mucoid P. aeruginosa is necessary and sufficient to attenuate NPR-1–mediated behavior and it suppresses C. elegans pathogen avoidance behavior. Our data suggest that the specific interaction with nonmucoid bacteria induces NPR-1–dependent behaviors of C. elegans. These observations provide an example of how exopolysaccharide matrix biosynthesis by a community of bacteria may inhibit specific host responses to microbes.National Institutes of Health (U.S.) (NIH GM084477)Burroughs Wellcome Fund (Career Award in the Biomedical Sciences)National Science Foundation (U.S.) (Graduate Research Fellowship)Massachusetts Institute of Technology (Swanson Career Development award)Jane Coffin Childs Memorial Fund for Medical ResearchMedical Foundation, inc. (Charles A. King Trust Postdoctoral Research Fellowship Program)Canadian Cystic Fibrosis FoundationHoward Hughes Medical Institute (Investigator

Modulation Of Growth Factor/Cytokine Synthesis And Signaling By 1Α,25-Dihydroxyvitamin D<Inf>3</Inf>: Implications In Cell Growth And Differentiation

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