Total systems intervention: A research program

The development of TSI represents a real advance in management science in our view. Further developments are necessary however. This Research Note has outlined what we currently consider to be key issues in this development. We welcome other criticisms and suggestions. We invite you to join with us in this project.     

Assumptional analysis: An elucidation and appraisal for systems practitioners

The purpose of this paper is to review the ‘assumptional analysis’ methodology developed by R. O. Mason and I. I. Mitroff. The importance of this approach is that it was primarily constructed to deal with ill-structured problems at the strategic level in social systems. The 1980s has seen systems practitioners demonstrating an increased interest in exactly this type of problem. The principles and procedures of the approach are set out, its use in three organisations described, and an assessment of its potential contribution to systems practice provided.     

Population of households in England to 2021

This article outlines the methodology and results of the Department of the Environment, Transport and the Regions (DETR) 1996-based household projections for England, and its regions. It examines differences between this round of projections and the previous 1992-based round. The 1996-based projections indicate that between 1996 and 2021 a growth of 3.8 million households can be expected in England, if recent trends continue. Both the national and subnational methodology and results are covered.     

Insect communication: 'no entry' signal in ant foraging

Forager ants lay attractive trail pheromones to guide nestmates to food, but the effectiveness of foraging networks might be improved if pheromones could also be used to repel foragers from unrewarding routes. Here we present empirical evidence for such a negative trail pheromone, deployed by Pharaoh's ants (Monomorium pharaonis) as a 'no entry' signal to mark an unrewarding foraging path. This finding constitutes another example of the sophisticated control mechanisms used in self-organized ant colonies.     

Targeting the DNA repair defect in BRCA mutant cells as a therapeutic strategy

BRCA1 and BRCA2 are important for DNA double-strand break repair by homologous recombination, and mutations in these genes predispose to breast and other cancers. Poly(ADP-ribose) polymerase (PARP) is an enzyme involved in base excision repair, a key pathway in the repair of DNA single-strand breaks. We show here that BRCA1 or BRCA2 dysfunction unexpectedly and profoundly sensitizes cells to the inhibition of PARP enzymatic activity, resulting in chromosomal instability, cell cycle arrest and subsequent apoptosis. This seems to be because the inhibition of PARP leads to the persistence of DNA lesions normally repaired by homologous recombination. These results illustrate how different pathways cooperate to repair damage, and suggest that the targeted inhibition of particular DNA repair pathways may allow the design of specific and less toxic therapies for cancer.     

Ethylene, the natural regulator of leaf abscission

Natural leaf fall is triggered by increased ethylene production in senescing cells close to abscission zones.     

Epithelial cell swelling during incubation of rat small intestine in vitro

Résumé L'augmentation du fluide du tissu de l'intestin grèle incubé in vitro s'accompagne d'un accroissement du volume des cellules épithéliales.     

Influence of the pineal gland on the reproductive system of the male house mouse

Summary Procedures designed to express pineal-mediated antigonadotropic activity were performed upon male house mice. Neither blinding nor blinding plus olfactory bulbectomy of house mice resulted in testicular involution within 12 weeks. The pineal gland appears to be of little significance to reproduction in the house mouse.Supported by NICHHD grant No. HDO 7119-092.Supported by NICHHD grant No. 5P5 OHDO 8338.Supported by NSF grant No. SPI 7922 372.