The role of entanglement in dynamical evolution

Entanglement or entanglement generating interactions permit to achieve the maximum allowed speed in the dynamical evolution of a composite system, when the energy resources are distributed among subsystems. The cases of pre-existing entanglement and of entanglement-building interactions are separately addressed. The role of classical correlations is also discussed.Comment: 5 pages, 1 figure. Revised versio

Graduate Education in the Southwest

The preliminary study presented herewith had its inception in conversations with Mr. J. Erik Jonsson early in 1958 when he outlined to me the serious problems facing the intellectual and economic growth of the Southwest in this technological age. Mr. Jonsson pointed out that many of the leaders of the Southwest community realized the imperative need for the generation of an intellectual and scientific climate in the region to ensure its healthy development. To achieve this climate, the graduate education in the region must be augmented

Forecast of World Ocean Objectivities

National Ocean Goals must be supported by a series of discreet objectives which concurrently enhance World Ocean Goals. In general terms these goals are: Improve the Ocean Environment, Promote Economic Development of Ocean Resources, Increase Scientific Knowledge of the Ocean, Assure World Peace and Security, and Enhance International Understanding. The Forecast of World Ocean Objectives has been developed through the year 2000. These objectives have been established in accordance with a time sequence of activities associated with a horizontal consideration of the world ocean

Observations on the composition of the blood in the neonatal period

It has been realised for many years that the infants of diabetic mothers have notably high foetal and neonatal mortality rates, the reasons for which remain obscure. These infants tend to be large, puffy and hyperkinetic. If they are delivered at term, the mortality rate is very high. Even if pregnancy is terminated two or three weeks earlier, the incidence of respiratory distress and of pulmonary hyaline membrane syndrome is high.Typertrophy of the pancreatic islet cells in such infants has been established (Driscoll, Benirschke and Curtis, 1960). Pederson (1952) considers that this is a result of stimulation of the foetus by maternal hyperglycaemia. There is evidence that these infants become hypoglycaemic immediately after birth (Komrower, 1954; Farquhar, 1961). Some evidence of adrenocortical disturbance is present (Farquhar, 1958). There are also some indications of acidosis (Ibid).This study was begun to investigate the possibility that there might be a disturbance in lipid and lipoprotein metabolism in these infants, since it is already known that such a disturbance exists in the mothers (Albrink and Nan, 1958).Information about normal serum lipid concentrations in blood, at birth and in the neonatal period, is limited so that any study of the infants of diabetic mothers necessitates a parallel study of infants of normal mothers. In the course of obtaining blood specimens from so called "normal infants ", a considerable number of samples were obtained from infants whose mothers had various ante- ï_atal complications. These were notably toxaemia and abortive tendencies. The investigation has therefore been extended to cover these groups.Obtainiir_ blood specimens was naturally a rather erratic process, dependin_ entirely on the availability of hospital staff. In order that the intervening periods might be occupied constructively, certain subsidiary investigations were begun.To supplement the earlier work in the Department of Child Life and Health in this University by Dr. J. W. Farquhar on adrenocortical disturbances in the infants of diabetic mothers, a very limited investigation of the urinary excretion of 17- ketosteroids and l7ketogenic steroids has been made in newborn infants. Difficulties in obtaining complete twenty -four hour urine collections are considerable. The amount of blood necessary for studying serum cortico steroid concentrations is prohibitive in infants. Therefore only a small number of urinary steroid estimations were made.Finally some information has been collected on the amino -acid content of urine and serum in the neonatal period in both normal and abnormal infants.The scope of the work to be described in this thesis may be summarised as follows:1. The estimation of serum lipid and lipoprotein lipid concentrations in the cord blood of infants, including those with both normal and abnormal pre- and post natal histories. The term "lipid" includes total lipid, total cholesterol, total esterified fatty acid and phospholipid.2. The estimation of serum lipid and lipoprotein lipid concentrations in the first week of life in the infants of diabetic mothers.3. The estimation of the concentrations of 17- ketosteroids and 17- keto._,enic steroids excreted in the urine of normal infants on the first day of life and of infants of diabetic mothers during the first three days of life.4. A chromatographic investigation of amino acid patterns in cord blood and in venous blood and urine during the neonatal period in normal and some abnormal infants.The methods of chemical analysis used throughout the investigation are given in Appendix I and the methods of statistical analysis in Appendix II. Both appendices will be found at the end of the thesis.General conclusions are drawn at the end of each section and not at the end of the thesis

All-Electrical Quantum Computation with Mobile Spin Qubits

We describe and discuss a solid state proposal for quantum computation with mobile spin qubits in one-dimensional systems, based on recent advances in spintronics. Static electric fields are used to implement a universal set of quantum gates, via the spin-orbit and exchange couplings. Initialization and measurement can be performed either by spin injection from/to ferromagnets, or by using spin filters and mesoscopic spin polarizing beam-splitters. The vulnerability of this proposal to various sources of error is estimated by numerical simulations. We also assess the suitability of various materials currently used in nanotechnology for an actual implementation of our model.Comment: 10 pages, 6 figs, RevTeX

Limits to clock synchronization induced by completely dephasing communication channels

Clock synchronization procedures are analyzed in the presence of imperfect communications. In this context we show that there are physical limitations which prevent one from synchronizing distant clocks when the intervening medium is completely dephasing, as in the case of a rapidly varying dispersive medium.Comment: 6 Pages. Revised version as published in PR