Marine tephrochronology: a personal perspective

This special volume on marine tephrochronology is remarkable, and timely, because it marks a concerted step towards what might be informally termed ‘phase 3’ of a revolution in Quaternary geosciences that began around 40 years ago. The 10 articles collectively represent a re-focussed examination of tephras and cryptotephras preserved in ocean sediments at various locations and the authors describe their significance for a range of subdisciplines. Eight articles provide a new understanding of the origin, distribution and ages of various tephra and cryptotephra deposits and their stratigraphic inter-relationships; how the terrestrial ages of the tephra/crypotephra deposits relate to those of enclosing sediments and inform the ongoing development of the marine radiocarbon time-scale; mechanisms for the emplacement, remobilization or bioturbation of the tephras or cryptotephras; and volcanic eruption history. Two further articles document the characterization of tephra-derived glass shards using microbeam techniques to analyse 30–40 elements from individual shards as small as 10 µm in diameter. The collection thus provides snapshots of many aspects of the latest developments and directions in tephra studies – volcanology, primary and secondary dispersal, stratigraphy, single-grain characterization, chronology – through the medium of marine sediments. My personal perspective reflects briefly on how this point was reached and identifies a few of the important milestones on the way from ‘phase 1’ to ‘phase 3’. I am privileged to write it. Marine science revolution As an undergraduate in the early-mid 1970s, I recall my first real ‘awakening’ regarding the dynamic nature of science, and of Quaternary geoscience in particular, when told about deep-sea core V28-238 from the equatorial Pacific Ocean (Shackleton & Opdyke 1973; >2650 citations, Google Scholar). Analogous to the opening notes of Beethoven's 5th Symphony, perhaps the most famous quartet of notes in history, the alpha-numerical assemblage ‘V28-

Superstring Phenomenology - A Personal Perspective

In the first part of this paper I review the construction of the realistic free fermionic models, as well as current attempts to study aspects of these models in the nonperturbative framework of M- and F-theories. I discuss the recent demonstration of a Minimal Superstring Standard Model, which contains in the observable sector, below the string scale, solely the MSSM charged spectrum, and provides further support to the assertion that the true string vacuum is connected to the Z_2 X Z_2 orbifold in the vicinity of the free fermionic point in the Narain moduli space. In the second part I review the recent formulation of quantum mechanics from an equivalence postulate, which offers a new perspective on the synthesis of gravity and quantum mechanics, and contemplate possible relations with string theory and beyond.Comment: 25 pages. Standard Latex & iopconf1.sty. To appear in the proceedings of Beyond the Desert 99 - Accelerator and non Accelerator Approaches, Castle Ringberg, Tegernsee, Germany, 6-12 June 199

Racism and Islamophobia: A Personal Perspective

The article employs a subjective personal approach to show that new racisms are alive in the twenty-first century. Tracing my parents’ journey from India and Pakistan to Britain, it explores the political effects of the racism they and their children faced. Locating these reflections in a post-9/11 world, the article describes the turn my academic work has taken in response to media representations of Muslims, and calls for academic research on British Muslim identity to reflect the process of identity-making and its contingencies

Brief History of Quantum Cryptography: A Personal Perspective

Quantum cryptography is the only approach to privacy ever proposed that allows two parties (who do not share a long secret key ahead of time) to communicate with provably perfect secrecy under the nose of an eavesdropper endowed with unlimited computational power and whose technology is limited by nothing but the fundamental laws of nature. This essay provides a personal historical perspective on the field. For the sake of liveliness, the style is purposely that of a spontaneous after-dinner speech.Comment: 14 pages, no figure

A Personal Perspective

Molybdenum-containing enzymes of the xanthine oxidase (XO) family are well known to catalyse oxygen atom transfer reactions, with the great majority of the characterised enzymes catalysing the insertion of an oxygen atom into the substrate. Although some family members are known to catalyse the "reverse" reaction, the capability to abstract an oxygen atom from the substrate molecule is not generally recognised for these enzymes. Hence, it was with surprise and scepticism that the "molybdenum community" noticed the reports on the mammalian XO capability to catalyse the oxygen atom abstraction of nitrite to form nitric oxide (NO). The lack of precedent for a molybdenum- (or tungsten) containing nitrite reductase on the nitrogen biogeochemical cycle contributed also to the scepticism. It took several kinetic, spectroscopic and mechanistic studies on enzymes of the XO family and also of sulfite oxidase and DMSO reductase families to finally have wide recognition of the molybdoenzymes' ability to form NO from nitrite. Herein, integrated in a collection of "personal views" edited by Professor Ralf Mendel, is an overview of my personal journey on the XO and aldehyde oxidase-catalysed nitrite reduction to NO. The main research findings and the path followed to establish XO and AO as competent nitrite reductases are reviewed. The evidence suggesting that these enzymes are probable players of the mammalian NO metabolism is also discussed.publishersversionpublishe

The Beginnings of Optoelectronic Integrated Circuits -— A Personal Perspective

The early work (1960s, 1970s) on Integrated Optics at the Bell Telephone Laboratories and at the California Institute of Technology (Caltech), with which the author was involved, is described from a personal perspective

Education, Human Capital, and Growth: A Personal Perspective

This paper reviews the literature on the relationship of economic growth to the education levels of the labor force. The emphasis is on Ben-Porath's contribution to some of the issues in this field: the endogeneity of schooling, the role of the public sector as an `absorber' of educated labor, and the importance of personal human capital created by investments in reputation and personal relationships, the F-connection.