Address reprint requests to Dr. David G. Nathan, Children's Hospital Medical Center, Boston, MA 02115. Received for publication 6 April 1982 and in revised form 12 July 1982. in environmental erythropoietin and burst-promoting activities.

The emergent spatial patterns generated by growing bacterial colonies have been the focus of intense study in physics during the last twenty years. Both experimental and theoretical investigations have made possible a clear qualitative picture of the different structures that such colonies can exhibit, depending on the medium on which they are growing. However, there are relatively few quantita...

A possible role for natural killer (NK) ~ cells in regulating hematopoiesis was originally suggested by Cudkowicz and Hochman (1) and Kiessling et al. (2), in the mouse system. These authors showed that parental hematopoietic or lymphoid grafts do not survive in lethally irradiated F1 hybrids, even though these animals are universal recipients of grafts of other types of parental tissues. Exper...

Carrying out polymerase chain reaction in a gel layer generates a 2-D pattern of DNA colonies comprising pure genetic clones. Here we demonstrate that transcription, translation and protein folding can be performed in the same gel. The resulting nucleoprotein colonies mimic living cells by serving as compartments in which the synthesized RNAs and proteins co-localize with their templates. Yet, ...

at room temperature (70? to 80?F.) it grows in the form of spreading colonies similar to the ' swarming' Proteus colonies. When incubated at 37?C., the growth is limited to the area of the inoculum. At room temperature the growth continues to spread for three days. If a plate that has been incubated at room temperature and shows a spreading form of growth is subsequently incubated at 37?C., the...

Simulated ant colonies form a helpful example for multi-agent simulations, as their communication works based on indirect interaction. In this paper I describe a framework that was developed for the simulation of ant colonies, but can also be applied to other domains. Starting from the overall structure in the multi-agent model, followed by a description of primitive framework components, activ...

MALLIGO, JOHN E. (Fort Detrick, Frederick, Md.). Evaluation of an automatic electronic device for counting bacterial colonies. Appl. Microbiol. 13:931-934. 1965.-An automatic colony counter was tested extensively with colonies of two bacterial species, Serratia marcescens and Bacillus subtilis var. niger, grown on agar media. A stable relationship was established between machine counts and coun...

We study P colonies introduced in [8] as a class of abstract computing devices composed of independent membrane agents, acting and evolving in a shared environment. In the present paper especially P colonies are considered, which are homogeneous with respect to the type of rules in each program of agents. The number of agents, as well as the number of programs in each agent are bounded, which a...

Eco-P colonies are constructed as natural extension of P colonies with dynamical evolution of environment. P colonies are one of the kind of computational models based on independent autonomous agents represented by membrane systems working and evolving in a shared environment. These acts are based on the set of program associated with every agent. There are two types of agents in eco-P colonie...

An increased number of granulocytic and mononuclear cell colonies was grown in vitro from blood of patients with myelofibrosis and ranged between 162-4370 colonies/mi of blood. The number of colonies grown from normal individuals and ranged between 40120/mI blood. There was no correlation between the number of colonies and number of potentially proliferating granulocytic cells (myeloblasts, pro...