Galaxy clustering constraints on deviations from Newtonian gravity at cosmological scales II: Perturbative and numerical analyses of power spectrum and bispectrum

We explore observational constraints on possible deviations from Newtonian gravity by means of large-scale clustering of galaxies. We measure the power spectrum and the bispectrum of Sloan Digital Sky Survey galaxies and compare the result with predictions in an empirical model of modified gravity. Our model assumes an additional Yukawa-like term with two parameters that characterize the amplitude and the length scale of the modified gravity. The model predictions are calculated using two methods; the second-order perturbation theory and direct N-body simulations. These methods allow us to study non-linear evolution of large-scale structure. Using the simulation results, we find that perturbation theory provides reliable estimates for the power spectrum and the bispectrum in the modified Newtonian model. We also construct mock galaxy catalogues from the simulations, and derive constraints on the amplitude and the length scale of deviations from Newtonian gravity. The resulting constraints from power spectrum are consistent with those obtained in our earlier work, indicating the validity of the previous empirical modeling of gravitational nonlinearity in the modified Newtonian model. If linear biasing is adopted, the bispectrum of the SDSS galaxies yields constraints very similar to those from the power spectrum. If we allow for the nonlinear biasing instead, we find that the ratio of the quadratic to linear biasing coefficients, b_2/b_1, should satisfy -0.4 < b_2/b_1<0.3 in the modified Newtonian model.Comment: 12 pages, 7 figure

Structurally Diverse Chaetophenol Productions Induced by Chemically Mediated Epigenetic Manipulation of Fungal Gene Expression

Epigenetic manipulation of gene expression in <i>Chaetomium indicum</i> using a HDAC inhibitor led to the isolation of structurally diverse chaetophenols, and <b>3</b>, <b>4</b> and <b>5</b> bear unprecedented polycyclic skeletons. The expression of two silent genes (<i>pksCH-1</i> and <i>pksCH-2</i>) for nonreducing PKSs involved in chaetophenol biosynthesis was associated with an increase of histone acetylation level. The heterologous gene expression study in <i>Aspergillus oryzae</i> revealed <i>pksCH-2</i> to be the NR-PKS gene for <b>8</b>

Modeling Nonlinear Evolution of Baryon Acoustic Oscillations: Convergence Regime of N-body Simulations and Analytic Models

We used a series of cosmological N-body simulations and various analytic models to study the evolution of the matter power spectrum in real space in a A cold dark matter universe. We compared the results of N-body simulations against three analytical model predictions; standard perturbation theory, renormalized perturbation theory, and a closure approximation. We included the effects from a finite simulation box size under comparison. We determined the values of the maximum wavenumbers, k(1%)(lim) and k(3%)(lim) below which the analytic models and the simulation results agree with accuracy to within 1 and 3 percent. We then provided a simple empirical function that describes the convergence regime determined by comparisons between our simulations and the analytical models. We found that if we use the Fourier modes within the convergence regime alone. the characteristic scale of baryon acoustic oscillations can be determined with an accuracy of 1% from future surveys with a volume of a few h(-3) Gpc(3) at z similar to 1 or z similar to 3 in the absence of any systematic distortion of the power spectrum

Structural Diversity of New C₁₃-Polyketides Produced by <i>Chaetomium mollipilium</i> Cultivated in the Presence of a NAD⁺‑Dependent Histone Deacetylase Inhibitor

Cultivation of <i>Chaetomium mollipilium</i> with nicotinamide, a NAD⁺-dependent HDAC inhibitor, stimulated its secondary metabolism, leading to the isolation of structurally diverse new C₁₃-polyketides, mollipilin A–E (<b>1</b>–<b>5</b>) as well as two known compounds (<b>6</b> and <b>7</b>). Spectroscopic methods, X-ray single crystal diffraction analysis, and VCD elucidated the absolute configurations of structures <b>1</b>–<b>6</b>, and plausible biosynthetic pathways for <b>1</b>–<b>7</b> were proposed based on structural relationships. Mollipilins A (<b>1</b>) and B (<b>2</b>) exhibited moderate growth inhibitory effects on HCT-116 cells

Structural Diversity of New C₁₃-Polyketides Produced by <i>Chaetomium mollipilium</i> Cultivated in the Presence of a NAD⁺‑Dependent Histone Deacetylase Inhibitor

Cultivation of <i>Chaetomium mollipilium</i> with nicotinamide, a NAD⁺-dependent HDAC inhibitor, stimulated its secondary metabolism, leading to the isolation of structurally diverse new C₁₃-polyketides, mollipilin A–E (<b>1</b>–<b>5</b>) as well as two known compounds (<b>6</b> and <b>7</b>). Spectroscopic methods, X-ray single crystal diffraction analysis, and VCD elucidated the absolute configurations of structures <b>1</b>–<b>6</b>, and plausible biosynthetic pathways for <b>1</b>–<b>7</b> were proposed based on structural relationships. Mollipilins A (<b>1</b>) and B (<b>2</b>) exhibited moderate growth inhibitory effects on HCT-116 cells