1 INTRODUCTION This paper addresses the problem of coordinating a team of software developers concurrently working on a common software system. The standard approach to coordinate concurrent activities on a common set of data is locking. Any part of data used by one person is locked against concurrent use by another person. The second person has to wait until the first person has finished his o...

The structure of the ribonucleoprotein (RNP) complex of three coronaviruses was investigated. A single-stranded helix of diam. 14 to 16 nm and up to 320 nm in length was released from disrupted particles of human coronavirus strain 229E and mouse hepatitis virus strain 3 after incubation in mild conditions. The helical complexes appeared to be composed of globular subunits with long axes of 5 t...

A mechanical spring-block model is used for realizing an objective space partition of settlements from a geographic territory in region-like structures. The method is based on the relaxation-dynamics of the spring-block system and reveals in a hierarchical manner region-like entities at different spatial scales. It takes into account in an elegant manner both the spatiality of the elements and ...

In 1938, Owen described a malignant renal neoplasm with a peculiar histological pattern. The peculiarity consisted in the tumour cells forming glomerular structures made up of cuboidal cells with clear cytoplasm, indistinct borders and round hyperchromatic nuclei. The glomerular structures had no vascular tufts but showed, at the periphery, a limiting membrane lined by cuboidal cells in one or ...

In this letter we explore an alternative structural representation for Steinbuch-type binary associative memories. These networks offer very generous storage capacities (both asymptotic and finite) at the expense of sparse coding. However, the original retrieval prescription performs a complete search on a fully-connected network, whereas only a small fraction of units will eventually contain d...

In freeze-fracture replicas, biological membranes appear as smooth surfaces interrupted by random globular protrusion, the intramembrane particles. Smooth areas correspond to the membrane phospholipidic domain, while intramembrane particles are the morphological counterpart of membrane proteins. In the present work, examination of membranes in a variety of cell types reveals that a number of in...

Theorem 1. Let K = 〈K,+, ·, . . .〉 be an expansion of K all of whose atomic relations are definable in R. If K is a proper expansion of 〈K,+, ·〉 then the field R is definable in K. By “proper expansion of 〈K,+, ·〉”, we mean that there is a definable set in K which is not definable in 〈K,+, ·〉 (even with parameters). In particular, the theorem implies that there are no proper expansions of an al...

Stalk formation is a novel pattern of multicellular organization. Yeast cells which survive UV irradiation form colonies that grow vertically to form very long (0.5 to 3.0 cm) and thin (0.5 to 4 mm in diameter) multicellular structures. We describe the conditions required to obtain these stalk-like structures reproducibly in large numbers. Yeast mutants, mutated for control of cell polarity, de...