The early role of nitric oxide in evolution

Nitric oxide (NO), which today serves many different purposes in regulating complex cellular functions, must have played a crucial role in the early stages of the evolution of life. The formation of NO may have been a critical defence mechanism for primitive microorganisms at a time when life faced the problem of rising atmospheric levels of ozone (03) formed upon photolysis of oxygen (Oz), which occurred shortly after the development of respiration in cyanobacteria. The production of NO by organisms would have allowed neutralization of toxic 03 by chemical reaction outside the cell, thus acting as a protective mechanism against oxidative destruction, allowing evolutionary advantage. Later, NO production might have allowed the control of reactive OZ species within cells before the development of specific electron-accepting enzymes. The pathway of NO formation was then consequently developed further to serve other useful functions. Although mammalian cells produce NO from L-arginine, the origin of this ability might have arisen from the essential process of either nitrification or denitrification in prokaryotic cells

Environmental Risk and the Traditional Sector Approach: Market Efficiency at the Core of Environmental Law

Professor Gillroy provides an in-depth discussion on the evolution of environmental law and the proposition that market efficiency has been, and still is, at its core

A Proposal for \u27Philosophical Method\u27 in Comparative and International Law

A basic challenge of contemporary thought is to better understand the origin, persistence, and future course of international/ comparative law. I suggest that a foundational step is to begin treating the law as a philosophical matter. I propose that comparative and international legal theory require a distinct methodology that is as integrated and systematic as positivism, but which better recognizes the dialectic interdependence of normative and empirical and the metaphysical interdependence of theory and practice. Philosophical Method, as systematized by R.G. Collingwood, promotes the dialectic over the eristic, looks for overlap rather than definitive scientific classification, argues for comprehensive philosophy rather than isolated theory and recognizes a proper logical metaphysics of absolute and relative presuppositions rather than a positive legal practice isolated from its inherent philosophical determinants

Distribution of catch-per-unit-of-effort and fishing effort for tuna in the Eastern Tropical Pacific Ocean by months of the year 1951-1960

ENGLISH: Comparison of physical and biological environmental factors affecting the aggregation of tunas with the success of fishing by the commercial fleets, requires that catch and effort data be examined in greater detail than has been presented in these publications. Consequently, the United States Bureau of Commercial Fisheries Biological Laboratory, San Diego, to serve the needs of its program of research on causes of variations in tuna abundance, made arrangements with the Tuna Commission to summarize these catch and effort data by month, by one-degree area, by fishing vessel size-class, for the years 1951-1960 for bait boats and 1953-1960 for purse-seiners. The present paper describes the techniques employed in summarizing these data by automatic data processing methods. It also presents the catch and effort information by months, by five-degree areas and certain combinations of five-degree areas for use by fishermen, industry personnel, and research agencies. Because of space limitations and other considerations, the one-degree tabulations are not included but are available at the Tuna Commission and Bureau laboratories. SPANISH: La comparación de los factores ambientales físicos y biológicos que afectan la agrupación del atún, con el éxito obtenido en la pesca por las flotas comerciales, requiere que los datos sobre la captura y el esfuerzo sean examinados con mayor detalle de lo que han sido presentados en estas publicaciones. En consecuencia, el Laboratorio Biológico del Buró de Pesquerías Comerciales de los Estados Unidos, situado en San Diego, a fin de llenar los requisitos de su programa de investigación sobre las causas de las variaciones en la abundancia del atún, hizo arreglos con la Comisión del Atún para sumarizar esos datos sobre la captura y el esfuerzo por meses, por áreas de un grado, por clases de tamaño de las embarcaciones de pesca durante los años 1951-1960 en lo que concierne a los barcos de carnada y durante el período 1953-1960 en lo que respecta a los barcos rederos. El presente trabajo describe la técnica empleada en la sumarización de dichos datos mediante métodos automáticos de manejo de datos. También se da aquí la información sobre la captura y el esfuerzo por meses, por áreas de cinco grados y ciertas combinaciones de áreas de cinco grados para el uso de los pescadores, del personal de la industria y de las oficinas de investigación. Por falta de espacio y otras razones, las tabulaciones de las áreas de un grado no han sido incluídos en este trabajo, pero están a la disposición de quien tenga interés en los laboratorios de la Comisión del Atún y del Buró

Some Things Are Better Left Unseen: Toward More Effective Communication And Team Performance In Video-Mediated Interactions

By default, most video-mediated communication systems show the user his or her own video feed, yet there is no prior research to show if this helps or hinders communication. In general, virtual teams desire richer media to improve team interaction. However, in this case more information may not be helpful. Drawing on Objective Self Awareness theory in social psychology and theories of cognitive overload from communication, hypotheses are proposed concerning how viewing oneself influences virtual team interaction. It is argued that viewing oneself will lead to lower team performance and other negative outcomes. The hypotheses are tested in a laboratory experiment, manipulating whether participants were able to view their own feeds during video-mediated communication. The results suggest that viewing oneself leads to a reduction in team performance and individual satisfaction. The findings, in terms of several theoretical explanations, and implications for managers and systems designers are discussed in the paper

Spontaneous emission from a two--level atom tunneling in a double--well potential

We study a two-level atom in a double--well potential coupled to a continuum of electromagnetic modes (black body radiation in three dimensions at zero absolute temperature). Internal and external degrees of the atom couple due to recoil during emission of a photon. We provide a full analysis of the problem in the long wavelengths limit up to the border of the Lamb-Dicke regime, including a study of the internal dynamics of the atom (spontaneous emission), the tunneling motion, and the electric field of the emitted photon. The tunneling process itself may or may not decohere depending on the wavelength corresponding to the internal transition compared to the distance between the two wells of the external potential, as well as on the spontaneous emission rate compared to the tunneling frequency. Interference fringes appear in the emitted light from a tunneling atom, or an atom in a stationary coherent superposition of its center--of--mass motion, if the wavelength is comparable to the well separation, but only if the external state of the atom is post-selected.Comment: 24 pages, 4 figures; improved discussion on the limitations of the theor

Transmission of ultracold atoms through a micromaser: detuning effects

The transmission probability of ultracold atoms through a micromaser is studied in the general case where a detuning between the cavity mode and the atomic transition frequencies is present. We generalize previous results established in the resonant case (zero detuning) for the mesa mode function. In particular, it is shown that the velocity selection of cold atoms passing through the micromaser can be very easily tuned and enhanced using a non-resonant field inside the cavity. Also, the transmission probability exhibits with respect to the detuning very sharp resonances that could define single cavity devices for high accuracy metrology purposes (atomic clocks).Comment: 5 pages, 7 figure