Cell competition compares cells within a growing population and eliminates the weaker ones by apoptosis. In a recent issue of Cell, Li and Baker (2007) show in the Drosophila wing disc that cells fated to die induce in neighboring cells the activity of engulfment genes, whose function is essential to complete the apoptotic program.

Dissecting the mechanisms underlying synapse formation and elimination is fundamental to understand how the nervous system is constructed and subsequently modified. Two studies by Tashiro et al. and by Hashimoto and Kano in this issue of Neuron provide new insights into the roles of neurotransmitter glutamate release in regulating the motility of hippocampal mossy fiber filopodia and synaptic c...

I review two papers, addressing the issue of competition and quality determination in the market for Internet access services (Crémer, Rey, and Tirole (2000), Foros and Hansen (2001)). These two works come to seemingly opposite conclusions. After having summarized the two papers, I try to highlight what lies behind the differences in the results.

Humorous images can be seen in many social media websites. However, newcomers to these websites often have trouble fitting in because the community subculture is usually implicit. Among all the types of humorous images, Internet memes are relatively hard for newcomers to understand. In this work, we develop a system that leverages crowdsourcing techniques to generate explanations for memes. We ...

Abstract Through their day-to-day usage collaboration tools collect data on the work process. These data can be used to aid participants’ retrospective reflection on the process. The paper shows how this can be done in software development project work. Through a case study we demonstrate how retrospective reflection was conducted by use of an industry approach to project retrospectives combine...

Today, communication is main part of everybody’s life. Security is the most important issue in any communication. So we need a secured system to exchange data securely between users. For this purpose of security there are various techniques like cryptography, watermarking and steganography. Steganography is used to transmit information in covered form. In steganography we hide the presence of d...

In this paper, we present the 2006 survey study origin destination and price that we carried out during 2006 fall in the area in the Moroccan region of Rabat-Salé-Zemmour-Zaer. The survey concerns the people’s characteristics, their displacements behavior and the price that they will be able to pay for a tramway ticket. The main objective is to study a set of relative features to the households...

Equipping medical devices with long range telemetry opens completely new possibilities for emergency response, home care and remote diagnosis. Mobile communications nowadays seem to be a generaly accepted part of our modern world, but bridging the gap between new (consumer-) technologies and medical devices still is a challenge today. Providing a telemetry link (GSM) is just the trivial part – ...

How cells generate a single axis of polarity for mating, division, and movement is unknown. In this issue, Howell et al. (2009) use a synthetic biology approach to demonstrate that rapid competition for a soluble signaling component (Bem1) is essential to ensure a unique axis of polarity in budding yeast.

Welcome to the special issue of Autonomous Robots devoted to the topic of The Science Behind Embodied AI : The Robots of the AAAI Competition and Exhibition. The robotics competition held at the annual conference of the American Association for Artificial Intelligence (AAAI) was first held in 1993 as a way to help promote the science of embodied AI as illustrated by the use of robotics. The com...