Tommaso Salini revisited: two new attributions

Tommaso Salini (c.1575–1625) is a frequently forgotten Baroque artist that fell under Caravaggio’s spell, despite having a tempestuous relationship with the great painter. Salini, also known as Mao, was a friend of Giovanni Baglione, the Italian art biographer, who included Salini in his Le vite de’ pittori (1642). Salini is better remembered for his role in the Baglione libel trial of 1603 than he is for his oil paintings, which sit between Caravaggio’s innovative way of painting and Baglione’s mediocre Mannerism. Art historians have often shied away from exploring Salini’s career because the canvases that have carried his name seem stylistically dissimilar. The recent tendency has been to attribute these works to the anonymous ‘Pseudo-Salini’ painters, but this should form the topic of a separate article. The twentieth century saw art historians generously attribute an excessive amount of work to Salini, and many of these pictures were probably done decades after his death. In order for Salini’s oeuvre to be presented with accuracy, connoisseurs have had to inspect the original works that Baglione mentions being by Salini’s hand, as well as the pictures that have been successfully attributed to him. Bearing in mind what Baglione wrote, Salini can be revealed as an innovate artist and still life specialist. This article includes a newly attributed still life (Museum of Fine Arts, Boston) as a forgotten Salini, as well as a refreshed attribution of the masterful Piping Shepherd Boy (Foundling Museum, London). These works add weight to Salini being a more famous and better-known painter in his own time than scholarship has shown.Publisher PD

Low-noise nozzle valve

A low noise, variable discharage area, valve is constructed having opposed recesses within which a pair of gates are slidably disposed. Each of the gates is provided with upstream edges having a radius thereon, the radius enabling smooth, accelerated, low noise flow therebetween. The gates are further provided with tracks along each side, which in turn slide along splines set in the side walls of the valve. A threaded rod which rotates in a threaded insert in a rear wall of each of the gates, serves to move the gates within their respective recesses

Curvature Spectra and Nongaussianities in the Roulette Inflation Model

Using the gradient expansion method of Rigopoulos, Shellard and van Tent which treats cosmological perturbations as gradients on top of a homogeneous and isotropic FRW background, we study the production of nongaussianities in the roulette model of inflation. Investigating a number of trajectories within this two-field model of inflation, we find that while the superhorizon influence of the isocurvature modes on the curvature bispectrum produces nonzero contribution to f_NL, the effect is negligible next to the standard inflationary prediction |f_NL| ~ n_s - 1. This is the case in both the squeezed and equilateral configurations of the bispectrum, although the former is slightly larger in the trajectories under consideration.Comment: 23 pages, 6 figures, 3 tables, 1 appendix; Added references, slightly extended section

Crowdsourcing Swarm Manipulation Experiments: A Massive Online User Study with Large Swarms of Simple Robots

Micro- and nanorobotics have the potential to revolutionize many applications including targeted material delivery, assembly, and surgery. The same properties that promise breakthrough solutions---small size and large populations---present unique challenges to generating controlled motion. We want to use large swarms of robots to perform manipulation tasks; unfortunately, human-swarm interaction studies as conducted today are limited in sample size, are difficult to reproduce, and are prone to hardware failures. We present an alternative. This paper examines the perils, pitfalls, and possibilities we discovered by launching SwarmControl.net, an online game where players steer swarms of up to 500 robots to complete manipulation challenges. We record statistics from thousands of players, and use the game to explore aspects of large-population robot control. We present the game framework as a new, open-source tool for large-scale user experiments. Our results have potential applications in human control of micro- and nanorobots, supply insight for automatic controllers, and provide a template for large online robotic research experiments.Comment: 8 pages, 13 figures, to appear at 2014 IEEE International Conference on Robotics and Automation (ICRA 2014

Order one differential equations on nonisotrivial algebraic curves

In this paper we provide new examples of geometrically trivial strongly minimal differential algebraic varieties living on nonisotrivial curves over differentially closed fields of characteristic zero. These are systems whose solutions only have binary algebraic relations between them. Our technique involves developing a theory of $\tau$-forms, and building connections to deformation theory. This builds on previous work of Buium and Rosen. In our development, we answer several open questions posed by Rosen and Hrushovski-Itai