The successive determination of chloride, fluoride and sodium in single samples of orthophosphate minerals by means of ion-sensitive electrodes

A buffer system composed of perchloric acid, citric acid and triethanolamine has been used for the successive determination of chloride, fluoride and sodium in a single sample of an orthophosphate mineral. The conventional sodium-sensitive glass electrode compares favourably with the more expensive Orion sodium-sensitive electrode.     

Inverse monoids and rational Schreier subsets of the free group

An inverse monoidM is an idempotent-pure image of the free inverse monoid on a setX if and only ifM has a presentation of the formM=Inv<X:e_o=f_i, i∈I>, wheree _i ,f _i are idempotents of the free inverse monoid: every inverse monoid is an idempotent-separating image of one of this type. IfR is anR-class of such an inverse monoid, thenR may be regarded as a Schreier subset of the free group onX. This paper is concerned with an examination of which Schreier subsets arise in this way. In particular, ifI is finite, thenR is a rational Schreier subset of the free group. Not every rational Schreier set arises in this way, but every positively labeled rational Schreier set does. Research supported by National Science Foundation grant #DMS8702019.     

Measurable multiattribute value functions defined on binary attributes

A set of preference independence conditions is defined with respect to a binary attribute set. It is argued that these conditions can be used to show that a value function describing the preference for alternatives over binary attributes has an additive form. This argument emphasizes that strengthened independence concepts are necessary in the binary attribute case since solvability axioms cannot be defined to allow an algebraic proof of additivity based on the independence conditions of an additive conjoint structure.     

Libraries of random-sequence polypeptides produced with high yield as carboxy-terminal fusions with ubiquitin

Summary Libraries of random-sequence polypeptides have been shown to be valuable sources of novel molecules possessing a variety of useful biologic-like activities, some of which may hold promise as potential vaccines and therapeutics. Previous random peptide expression systems were limited to low levels of peptide production and often to short sequences. Here we describe a series of libraries designed for increased polypeptide length. Cloned as carboxy-terminal extensions of ubiquitin, the fusions were produced inE. coli at high levels, and were purified to homogeneity. The majority of the extension proteins examined could be cleaved from ubiquitin by treatment with a ubiquitin-fusion hydrolase. The libraries described here are appropriate sources of novel polypeptides with desired binding or catalytic function, as well as tools with which to examine inherent properties of proteins as a whole. Toward the latter goal, we have examined structural properties of random-sequence proteins purified from these libraries. Quite surprisingly, fluorescence emission spectra of intrinsic tryptophan residues in several purified fusion proteins, under native-like and denaturing conditions, often resemble those expected for folded and unfolded states, respectively. The results presented here detail an important expansion in the range of potential uses for random-sequence polypeptide libraries.     

A problem of excess subsidization…

Experimental Techniques -     

Inconsistency of the Copenhagen interpretation

The Bohr-Heisenberg scheme, which forms the basis of any current version of the standard or Copenhagen interpretation of quantum mechanics, is shown to be internally inconsistent. Although the inconsistencies demonstrated here are directly relatable to Einstein's opinion that it is unsatisfactory to interpret physical theory solely in terms of the knowledge gained from experimental outcomes, it is nevertheless shown that Einstein's view requires important modification. The implications of the Bohr-Heisenberg schem's self-inconsistency are discussed in relation to Bell's theorem and Aspect's experiments.