On the influence of social bots in online protests. Preliminary findings of a Mexican case study

Social bots can affect online communication among humans. We study this phenomenon by focusing on #YaMeCanse, the most active protest hashtag in the history of Twitter in Mexico. Accounts using the hashtag are classified using the BotOrNot bot detection tool. Our preliminary analysis suggests that bots played a critical role in disrupting online communication about the protest movement.Comment: 10 page

Mechanisms of high-frequency song generation in brachypterous crickets and the role of ghost frequencies

Sound production in crickets relies on stridulation, the well-understood rubbing together of a pair of specialised wings. As the file of one wing slides over the scraper of the other, a series of rhythmic impacts cause harmonic oscillations, usually resulting in the radiation of pure tones delivered at low frequencies (2-8 kHz). In the short winged crickets of the Lebinthini tribe, acoustic communication relies on signals with remarkably high frequencies (> 8 kHz) and rich harmonic content. Using several species of the subfamily Eneopterinae, we characterise the morphological and mechanical specialisations supporting the production of high frequencies, and demonstrate that higher harmonics are exploited as dominant frequencies. These specialisations affect the structure of the stridulatory file, the motor control of stridulation and the resonance of the sound radiator. We place these specialisations in a phylogenetic framework and show that they serve to exploit high frequency vibrational modes pre-existing in the phylogenetic ancestor. In Eneopterinae, the lower frequency components are harmonically related to the dominant peak, suggesting they are relicts of ancestral carrier frequencies. Yet, such ghost frequencies still occur in the wings' free resonances, highlighting the fundamental mechanical constraints of sound radiation. These results support the hypothesis that such high frequency songs evolved stepwise, by a form of punctuated evolution which could be related to functional constraints, rather than by the progressive increase of the ancestral fundamental frequency

Transient natural convection flows in closed containers technical report no. 2

Measurements and calculations of natural flow convection and thermal stratification in closed container

Transient, laminar, free-convection heat and mass transfer in closed, partially filled, liquid containers technical report no. 1

Two-dimensional, laminar, transient, natural- convection heat and mass transfer in closed, partially filled liquid container

Exact 2+1 flavour RHMC simulations

We consider the Rational Hybrid Monte Carlo algorithm for performing exact 2+1 flavour fermion simulations. The specific cases of ASQTAD and domain wall fermions are considered. We find that in both cases the naive performance is similar to conventional hybrid algorithms.Comment: 3 pages, no figure

The value premium puzzle, behavior versus risk: new evidence from China

This paper investigates the value premium puzzle in the Chinese stock market. After establishing that the value premium does exist in the Chinese stock market, it uses an innovative technique based on stochastic dominance theory to test the behavior based versus risk based explanations for the puzzle. We find no evidence of a systematic behavioral factor, such as over/under-reaction, that is driving this premium. This finding is robust with respect to negative and positive return regimes. We do, however, find strong evidence that the value premium reflects compensation for bearing more risk associated with financial inflexibility

Amorphous slicing of extended finite state machines

Slicing is useful for many Software Engineering applications and has been widely studied for three decades, but there has been comparatively little work on slicing Extended Finite State Machines (EFSMs). This paper introduces a set of dependency based EFSM slicing algorithms and an accompanying tool. We demonstrate that our algorithms are suitable for dependence based slicing. We use our tool to conduct experiments on ten EFSMs, including benchmarks and industrial EFSMs. Ours is the first empirical study of dependence based program slicing for EFSMs. Compared to the only previously published dependence based algorithm, our average slice is smaller 40% of the time and larger only 10% of the time, with an average slice size of 35% for termination insensitive slicing