Social insect societies and more specifically ant colonies, are distributed systems that, in spite of the simplicity of their individuals, present a highly structured social organization. As a result of this organization, ant colonies can accomplish complex tasks that in some cases exceed the individual capabilities of a single ant. The study of ant colonies behavior and of their self-organizin...

BALB/c mice immunized with bacterial levan (BL), a /3(2---*6) fructosan with fl(2--*l) branched points, produce antibodies of two general types (1). One group of molecules is specific for inulin, which is a fl(2---* 1) fructosan, as well as for levan; such antibodies, which can first be detected in BALB/c mice at 28 d of age (2), express idiotypes (Id) that cross-react with those found on inuli...

The characterization in vitro of a newly discovered promoter {P,~} in the bacteriophage P22 i m m I region is described. P.,, is located within the ant gene and is directed toward the major i m m l promoter, P.~t. The entire intercistronic region between the P22 arc and ant genes (69 bp) is transcribed. The initiation and termination of sar (small antisense regulatory) RNA transcription are unu...

An adequate vascular supply is important to provide endocrine and paracrine signals during follicular development. We evaluated the direct in vivo effects of both the GnRH-agonist Leuprolide acetate (LA) and the GnRH-antagonist Antide (Ant) on the expression of VEGF-A and ANPT-1 and their receptors in ovarian follicles from prepubertal eCG-treated rats. We also examined whether the changes obse...

T h e antibodies that are p roduced in man as a result of specific vaccination or infectious disease comprise only a small propor t ion o f the bulk o f the IgG molecules circulating in the blood. T h e immunity towards these antigens is a t t r ibuted mostly to a relatively high n u m b er o f memory cells and a low titer o f synthesized antibodies. In view of kinetic studies o f ant ibody pro...

Studies that rigorously measure the effectiveness of anti-predator traits in complex ecological communities are rare. Rarer still are studies that compile the results of these trait analyses in a framework that explains the variation in predation pressure by a predator assemblage. Here the risk of predation by ants is quantified for a community of caterpillar species that employ several putativ...

1. Many plants engage ants in defensive mutualisms by offering extrafloral nectar (EFN). Identifying sources of variation in EFN quantity (amount) and quality (composition) is important because they can affect ant visitation and identity and hence effectiveness of plant defence. 2. I investigated plant size and reproductive state (vegetative or flowering) as sources of variation in EFN quantity...

The concept of idiotypy of ant igen-binding receptors suggests that in addi t ion to possessing a par t icular b inding site for antigen, each receptor has a set of serologic de terminants (idiotypes) which distinguish it from other receptors. T h e finding of idiotypy of an t ibody molecules (1) eventual ly led to a proposal for a network theory of the i m m u n e response (2). The network the...

An ant colony operates without central control. Each ant uses only local information, mostly odor, and no ant can make global assessments about what needs to be done. No ant gives instructions to another. Through the local decisions of individuals, colonies adjust their behavior to current conditions. An ant decides where to go and what to do based on its recent experience of brief interactions...

See Figure 3 for an example. We define an n-path to be a collection of n paths from a set of n origins to a set of n destinations. To compute the number of 4-paths in our example, we first find the number of ways that each ant can reach each morsel. In the example these numbers can be computed easily using calculations similar to those that arise in Pascal’s triangle (see Figure 2). We record t...