It is demonstrated on the basis of the Dirac equation that quarks cannot be confined by a vector gluon potential of the form(r/r 0)a or[ln(r/r 0]a, a>0, if the quark-gluon interaction conserves parity. In order to confine quarks with the parity-conserving interaction, the effective gluon potential must be a pseudovector or a scalar. These are shown in a simple Yang-Mills field with theSU(2) group.

It is proposed in this paper to develop a method by which the most general problem of the algebra of propositions is solved. This problem is to construct all propositions whose truth is independent of the form of the variables. As might be expected this method will enable us to determine without the use of matrices the consistency and independence of propositions, except in the case of those fundamental properties, which taken together define consistency itself. In the discussion which follows (...) no limitations are placed on the meaning of the terms and the word proposition is used simply in the sense of a variable. If we were to say, for example, that our variables must be restricted to zero or one values, we would be introducing a limitation which would reduce the generality of our science. A logic may be false in the sense that its postulates lead to contradictory theorems, or it may be false in the sense that it lacks generality, and the situation is not saved by calling it a two-valued, or a three-valued logic, or a logic of “propositions,” or by designating it by some other euphuism. (shrink)

The so-called fourth book of Aristotle's Meteorologica is not about meteorological phenomena at all. It describes the formation out of the four elements of ‘homoeomerous’ substances, by which are meant minerals such as stones and metals, and organic substances like flesh, skin, and hair, and the changes they can undergo under the influence of heat, cold, and moisture. Most commentators, ancient and modern, have seen that it has very little to do with the first three books of the Meteorologica to (...) which it is attached, and Alexander suggested that it should be placed after the second book de Generation et Corruptione. (shrink)

Abstract. There is an ongoing debate in the philosophical and jurisprudential literature regarding the nature and possibility of Contract theory. On one hand, are those who argue (or assume) that there is, or should be, a single, general, universal theory of Contract Law, one applicable to all jurisdictions and all times. On the other hand, are those who assert that Contract theory should be localized to particular times and places, perhaps even with different theories for different types of agreements. This (...) article considers one facet of this debate: evaluating the relevance of the fact that the remedies available for breach of contract can vary significantly from one jurisdiction to another. This wide variation in remedies for breach of a (contractual) promise is one central difference between promises in morality and enforceable agreements in law. The article asserts that variation of remedies strongly supports the conclusion that there is (and can be) no general, universal theory of Contract Law. (shrink)

Objective To determine the attitudes of Egyptian patients regarding their participation in research and with the collection, storage and future use of blood samples for research purposes. Design Cross-sectional survey. Study population Adult Egyptian patients (n=600) at rural and urban hospitals and clinics. Results Less than half of the study population (44.3%) felt that informed consent forms should provide research participants the option to have their blood samples stored for future research. Of these participants, 39.9% thought that consent forms should (...) include the option that future research be restricted to the illness being studied. A slight majority (66.2%) would donate their samples for future genetic research. Respondents were more favourable towards having their blood samples exported to other Arab countries (62.0%) compared with countries in Europe (41.8%, p<0.001) and to the USA (37.2%, p<0.001). Conclusions This study shows that many individuals do not favour the donation of a blood sample for future research. Of those who do approve of such future research, many favour a consent model that includes an option restricting the future research to the illness being studied. Also, many Egyptians were hesitant to have their blood samples donated for genetic research or exported out of the Arab region to the USA and European countries. Further qualitative research should be performed to determine the underlying reasons for many of our results. (shrink)