48 research outputs found
Redefining government's role in agriculture in the nineties
The authors argue that government policies in agriculture have been costly and misdirected worldwide. For them, this inefficiency need not continue. The Urugauy Round is an ideal opportunity for developed and developing nations to strike a bargain. They suggest 1) making agricultural trade subject to the full discipline of the GATT by eliminating waivers and exemptions that have set agricultural commodities apart from other products in their treatment under the GATT, 2) bringing developing countries fully into the GATT, by eliminating their special status, 3) getting all countries to reform their agricultural policies, to reduce the many policy-induced distortions that plague the sector. The authors claim that such a bargain would result in a redefinition of governments'role in agriculture, increased sectoral efficiency nationally, and a more smoothly functioning and tightly knit world agricultural trading system.Crops&Crop Management Systems,Environmental Economics&Policies,Agricultural Knowledge&Information Systems,Economic Theory&Research,Agricultural Research
Gradient Optics of subwavelength nanofilms
Propagation and tunneling of light through subwavelength photonic barriers,
formed by dielectric layers with continuous spatial variations of dielectric
susceptibility across the film are considered. Effects of giant
heterogeneity-induced non-local dispersion, both normal and anomalous, are
examined by means of a series of exact analytical solutions of Maxwell
equations for gradient media. Generalized Fresnel formulae, visualizing a
profound influence of gradient and curvature of dielectric susceptibility
profiles on reflectance/transmittance of periodical photonic heterostructures
are presented. Depending on the cutoff frequency of the barrier, governed by
technologically managed spatial profile of its refractive index, propagation or
tunneling of light through these barriers are examined. Nonattenuative transfer
of EM energy by evanescent waves, tunneling through dielectric gradient
barriers, characterized by real values of refractive index, decreasing in the
depth of medium, is shown. Scaling of the obtained results for different
spectral ranges of visible, IR and THz waves is illustrated. Potential of
gradient optical structures for design of miniaturized filters, polarizers and
frequency-selective interfaces of subwavelength thickness is considered
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery