It is natural to relate partially ordered sets (posets in short) and classes of equivalent words over partially commutative alphabets. Their common graphical representation are Hasse diagrams. We investigate this relation in detail and propose an efficient online algorithm that decompresses a concurrent word to its Hasse diagram. The lexicographically minimal representative of a trace (an equiv...

This paper presents a formal framework for the automatic transformation of ineecient generate and test programs into equivalent programs by learning from the proofs of example queries. In the resulting program the search is guided by strategies based on abstracted proof traces obtained from the interpretation of example computations. Strategies are incre-mentally improved in an iterative proces...

The behaviour of 25 major and trace elements, together with mineral changes, has been examined in a deep weathering profile on the Cammenellis granite, Cornwall. The bulk chemical and mineralogical composition of the regolith shows only minor changes from the parent rock indicating a low degree of chemical weathering. However, within the regolith marked differences occur between the fine fracti...

Ge distributions in ten iron meteorites with bulk Ge contents of 8.7 to 2000 ppm have been measured by electron probe microanalysis. Ge is concentrated almost entirely in the metallic phases. It was redistributed in the temperature range at which the Widmanstatten pattern developed. Ge content shows a positive correlation with Ni content, reaching a maximum in taenite and a minimum in kamacite ...

In this paper, refusal testing ideas are applied to deene a testing semantics for a probabilistic process algebra. A testing equivalence is deened by combining the greater discriminatory power of refusal testing and a simple treatment of the prob-abilistic component of processes. This testing equivalence is characterized by two fully abstract denotational semantics. The rst of them is based on ...

Synchrotron micro X-ray fluorescence has been used to study differences in the trace element concentration between the dentine and cementum rings of human teeth. The results show that metals such as zinc are concentrated in the cementum rings. This suggests that if the rings are deposited annually a temporal record of metal exposure may be extracted from this material.

Parameters of iron uptake have been determined for blade tissue of Macrocystis pyrifera (L.) C. Ag. These include the effects of iron concentration, light, various inhibitors, and blade type. All experiments were conducted in the defined artificial seawater Aquil. Iron uptake is light independent, energy dependent, and dependent on the reduction from Fe(3+) to Fe(2+). Iron is concentrated in th...

Phytic acid is a bioactive compound widely distributed in plant foods. Due to its molecular structure, phytic acid has affinity to polyvalent cations, such as minerals and trace elements, and could in this way interfere with their intestinal absorption in man and animals. Most studies in humans have therefore concentrated on the effect of phytate on mineral absorption and deficiencies. Currentl...

The traces over infinite dimensional representations of the central extended Yangian double for the product of operators which intertwine these representations are calculated. For the special combinations of the intertwining operators the traces are identified with form factors of local operators in SU(2)-invariant Thirring model. This identification is based on the identities which are deforme...