Tugging and pulling in asymmetric cell divisions n asymmetric divisions, the cell alters the normal process that centers the spindle in the mother cell, but how it regulates the timing of spindle movement is unclear. Now, on page 245, Labbé et al. describe a tethering system that resists premature movement of the mitotic spindle during asymmetric cell divisions in C. elegans embryogenesis. It w...

T HE portion of the alimentary canal in which the final processes of normal digestion occur, and in which almost all the digested food is absorbed, is the small intestine. At the lower end of this long tube is the large intestine, serving, it is usually taught, as a reservoir to receive, store, and periodically discharge the accumulation of waste. Throughout the small intestine the contents are...

We consider a class of integer-valued discrete convex functions, called BS-convex functions, defined on integer lattices whose affinity domains are sets of integral points of integral bisubmodular polyhedra. We examine discrete structures of BSconvex functions and give a characterization of BS-convex functions in terms of their convex conjugate functions by means of (discordant) Freudenthal sim...

Knowledge sharing between employees has long been viewed as a major driver of firm productivity growth, and the strength spill-overs within firms is common measure knowledge sharing. Using data from three Bangladeshi garment factories, I first find that are stronger organizational sub-divisions factories than across. then show management intervention routinely brought together workers producing...

A body of literature suggests that ethnic heterogeneity limits economic growth. This paper provides microeconometric evidence on the direct effect of ethnic divisions on productivity. In team production at a plant in Kenya, an upstream worker supplies and distributes flowers to two downstream workers who assemble them into bunches. The plant uses an essentially random rotation process to assign...

We consider the problem of selecting fair divisions of a heterogeneous divisible good among a set of agents. Recent work (Cohler et al., AAAI 2011) focused on designing algorithms for computing optimal—social welfare maximizing (maxsum)—allocations under the fairness notion of envyfreeness. Maxsum allocations can also be found under alternative notions such as equitability. In this paper, we as...

Imagine you have spent many years trying to develop new techniques that could one day cure cardiac disease, cancer or Parkinson's disease, you finally arrive at the point where it appears logical to move up from mice to human cell cultures, only to find yourself accused of 'cannibalism' by an archbishop preaching one of the year's most important masses at Cologne cathedral. Unbelievable? It hap...

Introduction Meiosis is a special type of cell division through which haploid gametes are generated from diploid parent cells. This is accomplished by a first division that induces homologous chromosome segregation followed by a second mitosis-like division that promotes sister chromatid separation. During the prophase of meiosis I, three basic events take place: pairing of homologous chromosom...