The vertebrate organizer has been of intense interest since its discovery in amphibia by Spemann and Mangold in the early 1920s (Ref. 1). The organizer was operationally defined as a piece of tissue that can induce a duplicated dorsal body axis and head when transplanted into the ventral side of a host embryo. The original Spemann and Mangold organizer experiment provided the first convincing d...

The authors, as the local organizers of the RoboCup European Championship, present a brief, informal overview of this event, with the aim to archive the main results, but also as a report to support organizers of future RoboCup events in the organization and coordination of such a rather complex tournament. © 2001 Published by Elsevier Science B.V.

This paper presents some of the results of the simulation in the radiation section of an industrial boiler using an advanced mathematical model. Calculations are described for the flow, heat transfer, and chemical reaction processes occurring within a gas-fired cylindrical furnace. The calculation procedure is a two dimensional one in which the main hydrodynamic variables are the velocity and s...

A critical step in synaptic development is the differentiation of presynaptic and postsynaptic compartments. This complex process is regulated by a variety of secreted factors that serve as synaptic organizers. Specifically, fibroblast growth factors, Wnts, neurotrophic factors and various other intercellular signaling molecules are proposed to regulate presynaptic and/or postsynaptic different...

Many in cognitive science have noted the importance of external visualizations for reasoning and learning, and have suggested that such visualizations play a role in complex reasoning contexts such as scientific investigation. However, what cognitive role diagrams play in scientific reasoning is unclear. I suggest that mechanistic diagrams function as search organizers in active research projec...

Combinatorics, sometimes also called Discrete Mathematics, is a branch of mathematics focusing on the study of discrete objects and their properties. Although Combinatorics is probably as old as the human ability to count, the field experienced tremendous growth during the last fifty years and has matured into a thriving area with its own set of problems, approaches and methodology. Extremal an...

BACKGROUND The most frequently pursued intervention in the $100 million, 18-state Children's Health Insurance Program Reauthorization Act of 2009 (CHIPRA) quality demonstration (2010-2015) was quality improvement collaboratives, which 12 states offered to more than 300 primary care practices. A study was conducted to identify which aspects of these collaboratives were viewed by organizers and p...