Studies on transposable elements of the Ac family have led to different models for excision gap repair in either plants or Drosophila. Excision products generated by the plant transposable elements Ac and Tam3 imply a more or less straightforward ligation of broken ends; excision products of the Drosophila P element indicate the involvement of ‘double‐strand break’ (DSB) repair. Recent findings that excision products of Ac and Tam3 can also contain traces of the element ends indicate, however, that DSB repair might (...) be an alternative repair mechanism in plants. A functional DSB repair mechanism in plants can also be deduced from the observed rapid increases of Ac copy number during plant development and from the involvement of Ac in the generation of internal Ac deletions. On the other hand, alternative repair mechanisms may also be functional in Drosophila, because some of the ‘footprints’ generated upon P excision can be explained by a mechanism that has been postulated for excision gap repair in plants. It is concluded that plants and Drosophila can use similar repair mechanisms, but that the predominance of a certain repair mechanism is determined by the host. (shrink)

On Sikh ethics; includes brief biographies of Sikh religious leaders.

Arab countries; intellectual life; congresses.

Non-pharmaceutical interventions, including social distancing, quarantine, and isolation, are a potentially attractive means to limit the transmission of a pandemic virus. Many of these interventions are directed at children given children’s disproportionate role in amplifying epidemics. The ethics of non-pharmaceutical interventions can be analyzed using Nancy Kass’ ethics framework for public health. Such an analysis highlights the limited data supporting these interventions’ effectiveness. It also suggests the framework itself needs to be expanded to consider harms other than constraints on liberty (...) and to consider affirmative programs to mitigate these broader harms. (shrink)

Mysticism ; Islamic philosophy ; Sufism.

Speeches of the author on theory of knowledge in the context of Islamic philosophy.

Study of rationalism in Urdu literature.

In elementary derivations of the quantization of azimuthal angular momentum the eigenfunction is determined to be exp(im φ), which is “oversensitive” to the rotation φ → φ+2π, unlessm is an integer. In a recent paper Kerner examined the classical system of charge and magnetic pole, and expressed Π, a vector constant of motion for the system, in terms of a physical angle ψ, to deduce a remarkable paradox. Kerner pointed out that Π(ψ) is “oversensitive” to ψ → ψ+2π unless a (...) certain charge quantization condition is met. Our explicandum of this paradox highlights the distinction between coordinates in classical and quantum physics. It is shown why the single-valuedness requirement on Π(ψ) is devoid of physical significance. We are finally led to examine the classical analog of the quantum mechanical argument that demonstrates the quantization of magnetic charge, to show that there is “no hope” of a classical quantization condition. (shrink)

This is a reproduction of the original artefact. Generally these books are created from careful scans of the original. This allows us to preserve the book accurately and present it in the way the author intended. Since the original versions are generally quite old, there may occasionally be certain imperfections within these reproductions. We're happy to make these classics available again for future generations to enjoy!

A review of a work in which a systematic and general theory of the nature of the conventions governing the semantics of a natural language is developed, with the object of offering a conceptual framework within which semantic phenomena can be understood in relation to syntax and to the communicative and social aspects of language. The empiricist theory of language is criticized for not supplying an adequate framework for the explanation of language learning. Taxonomy is a solution to the problems (...) caused by the limited application of general names. General concepts are not mastered individually, but rather as systems of the arbitrary division of ranges. Linguistic devices are systems of rules showing how human beings communicate with each other in order to forward specific human purposes. One such device can incorporate another and a natural language is merely a system of such systems. An attempt is made to put Wittgenstein's idea of "meaning as use" to work in the context of a general theory of language. A discussion follows on the relationship of Harrison's views to Chomsky's work in grammar and to recent studies in child language learning. R. Gaskill. (shrink)