An extremely high photometric precision in ground-based observations of two transits in the WASP-50 planetary system

We present photometric observations of two transits in the WASP-50 planetary system, obtained using the ESO New Technology Telescope and the defocussed-photometry technique. The rms scatters for the two datasets are 258 and 211\,ppm with a cadence of 170 to 200\,s, setting a new record for ground-based photometric observations of a point source. The data were modelled and fitted using the \textsc{prism} and \textsc{gemc} codes, and the physical properties of the system calculated. We find the mass and radius of the hot star to be 0.861\pm 0.057\Msun and 0.855\pm0.019\Rsun, respectively. For the planet we find a mass of 1.437\pm 0.068\Mjup, a radius of 1.138\pm0.026\Rjup and a density of 0.911\pm0.033\pjup. These values are consistent with but more precise than those found in the literature. We also obtain a new orbital ephemeris for the system: $T_0 = {\rm BJD/TDB} \,\, 2\,455\,558.61237 (20) \, + \, 1.9550938 (13) \times E$.Comment: 6 Pages, 5 Figures, MNRAS Accepted 5/2/1

Testing the Waters: California's Local Officials Experiment with New Ways to Engage the Public

This report explores the attitudes of California's local officials toward public participation in local governance. These officials believe that the current models for including the public in local decision making fail to meet the needs of both residents and local officials. Most local officials seek broad-based participation from the public and want to hear more about approaches that have worked elsewhere. Many are already experimenting with more inclusive and deliberative forms of engagement. Overall, this study suggests California's local officials may be ready for newer and more effective ways to engage the public and for stronger collaborations with community-based organizations. The report also includes concrete recommendations for local officials and their institutions, civic leaders and their organizations, and foundations and other funders. The recommendations can help improve public engagement in local governance throughout California and, we hope, beyond

High Performance Computing of Gene Regulatory Networks using a Message-Passing Model

Gene regulatory network reconstruction is a fundamental problem in computational biology. We recently developed an algorithm, called PANDA (Passing Attributes Between Networks for Data Assimilation), that integrates multiple sources of 'omics data and estimates regulatory network models. This approach was initially implemented in the C++ programming language and has since been applied to a number of biological systems. In our current research we are beginning to expand the algorithm to incorporate larger and most diverse data-sets, to reconstruct networks that contain increasing numbers of elements, and to build not only single network models, but sets of networks. In order to accomplish these "Big Data" applications, it has become critical that we increase the computational efficiency of the PANDA implementation. In this paper we show how to recast PANDA's similarity equations as matrix operations. This allows us to implement a highly readable version of the algorithm using the MATLAB/Octave programming language. We find that the resulting M-code much shorter (103 compared to 1128 lines) and more easily modifiable for potential future applications. The new implementation also runs significantly faster, with increasing efficiency as the network models increase in size. Tests comparing the C-code and M-code versions of PANDA demonstrate that this speed-up is on the order of 20-80 times faster for networks of similar dimensions to those we find in current biological applications

More on Marriage, Fertility and the Distribution of Income

Publicado también en la serie: UCLA Department of Economics. Penn CARESS. Working paperAccording to Pareto, the distribution of income depends on “the nature of the people comprising a society, on the organization of the latter, and, also, in part, on chance.” An overlapping generations model of marriage, fertility and income distribution is developed here. The “nature of the people” is captured by attitudes toward marriage, divorce, fertility, and children. Singles search for mates in a marriage market. They are free to accept or reject marriage proposals. Married agents make their decisions through bargaining about work, and the quantity and quality of children. They can divorce. Social policies, such as child tax credits or child support requirements, re‡ect the “organization of the (society).” Finally, “chance” is modelled by randomness in income, opportunities for marriage, and marital bliss

Accurate Ab-initio Predictions of III-V Direct-Indirect Band Gap Crossovers

We report the compositional dependence of the electronic band structure for a range of III-V alloys. Density functional theory with the PBE functional is insufficient to mimic the electronic gap energies at different symmetry points of the Brillouin zone. The HSE hybrid functional with screened exchange accurately reproduces the experimental band gaps and, more importantly, the alloy concentration of the direct-indirect gap crossovers for the III-V alloys studied here: AlGaAs, InAlAs, AlInP, InGaP, and GaAsP.Comment: 3 pages, 2 figure

Transits and starspots in the WASP-19 planetary system

We have developed a new model for analysing light curves of planetary transits when there are starspots on the stellar disc. Because the parameter space contains a profusion of local minima we developed a new optimisation algorithm which combines the global minimisation power of a genetic algorithm and the Bayesian statistical analysis of the Markov chain. With these tools we modelled three transit light curves of WASP-19. Two light curves were obtained on consecutive nights and contain anomalies which we confirm as being due to the same spot. Using these data we measure the star's rotation period and velocity to be $11.76 \pm 0.09$ d and $3.88 \pm 0.15$\kms, respectively, at a latitude of 65$^\circ$. We find that the sky-projected angle between the stellar spin axis and the planetary orbital axis is $\lambda = 1.0^{\circ} \pm 1.2^{\circ}$, indicating axial alignment. Our results are consistent with and more precise than published spectroscopic measurements of the Rossiter-McLaughlin effect.Comment: 9 pages, 6 figures, 5 table

Morphogen Gradient from a Noisy Source

We investigate the effect of time-dependent noise on the shape of a morphogen gradient in a developing embryo. Perturbation theory is used to calculate the deviations from deterministic behavior in a simple reaction-diffusion model of robust gradient formation, and the results are confirmed by numerical simulation. It is shown that such deviations can disrupt robustness for sufficiently high noise levels, and the implications of these findings for more complex models of gradient-shaping pathways are discussed.Comment: Four pages, three figure

The renal actions and interactions of nonsteroidal anti-inflammatory drugs in man

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