On sharing NATO defence burdens in the 1990s and beyond

This article investigates NATO burden sharing in the 1990s in light of strategic, technological, political and membership changes. Both an ability-to-pay and a benefits-received analysis of burden sharing are conducted. During 1990-99, there is no evidence of disproportionate burden sharing, where the large allies shoulder the burdens of the small. Nevertheless, the theoretical model predicts that this disproportionality will plague NATO in the near future. Thus far, there is still a significant concordance between benefits received and defence burdens carried. When alternative expansion scenarios are studied, the extent of disproportionality of burden sharing increases as NATO grows in size. A broader security burden-sharing measure is devised and tested; based on this broader measure, there is still no disproportionality evident in the recent past.

Evaluation of the cardiovascular system during various circulatory stresses Progress report, 1 Sep. 1968 - 1 May 1969

Cardiac response to chemotherapy after myocardial infraction and diagnostic methods of heart disease in man and animal

Enhancement of the Kondo effect through Rashba spin-orbit interactions

We analyze the physics of a one-orbital Anderson impurity model in a two-dimensional electron gas in the presence of Rashba spin-orbit (RSO) interactions in the Kondo regime. The spin SU(2) symmetry breaking results in an effective two-band electron gas coupled to the impurity. The Kondo regime is obtained by a Schrieffer-Wolff transformation revealing the existence of a parity breaking term with the form of the Dzyaloshinsky-Moriya (DM) interaction. The DM term vanishes at the particle-hole symmetric point of the system, but it has important effects otherwise. Performing a renormalization group (RG) analysis we find that the model describes a two-channel Kondo system with ferro- and anti-ferromagnetic couplings. Furthermore, the DM term renormalizes the antiferromagnetic Kondo coupling producing an exponential enhancement of the Kondo temperature. We suggest that these effects can be observed in semiconducting systems, as well as in graphene and topological insulators.Comment: 4 pages, 1 figure. Final published versio

Endocrine and fluid metabolism in males and females of different ages after bedrest, acceleration and lower body negative pressure

Space shuttle flight simulations were conducted to determine the effects of weightlessness, lower body negative pressure (LBNP), and acceleration of fluid and electrolyte excretion and the hormones that control it. Measurements were made on male and female subjects of different ages before and after bedrest. After admission to a controlled environment, groups of 6 to 14 subjects in the age ranges 25 to 35, 35 to 45, 45 to 55 to 65 years were exposed to +3 G sub z for 15 minutes (G1) and to LBNP (LBNP1) on different days. On 3 days during this prebedrest period, no tests were conducted. Six days of bedrest followed, and the G sub z (G2) and LBNP (LBNP2) tests were run again. Hormones, electrolytes, and other parameters were measured in 24-hour urine pools throughout the experiment. During bedrest, cortisol and aldosterone excretion increased. Urine volume decreased, and specific gravity and osmolality increased. Urinary electrolytes were statistically unchanged from levels during the non-stress control period. During G2, cortisol increased significantly over its control and bedrest levels. Urine volume, sodium, and chloride were significantly lower; specific gravity and osmolality were higher during the control period or bedrest. The retention of fluids and electrolytes after +G sub z may at least partially explain decreased urine volume and increased osmolality observed during bedrest in this study. There were some who indicated that space flight would not affect the fluid and electrolyte metabolism of females or older males any more severely than it has affected that of male astronauts

Zero-field Kondo splitting and quantum-critical transition in double quantum dots

Double quantum dots offer unique possibilities for the study of many-body correlations. A system containing one Kondo dot and one effectively noninteracting dot maps onto a single-impurity Anderson model with a structured (nonconstant) density of states. Numerical renormalization-group calculations show that while band filtering through the resonant dot splits the Kondo resonance, the singlet ground state is robust. The system can also be continuously tuned to create a pseudogapped density of states and access a quantum critical point separating Kondo and non-Kondo phases.Comment: 4 pages, 4 figures; Accepted for publication in Physical Review Letter

Intrapericardial Denervation: Responses to Water Immersion in Rhesus Monkeys

Eleven anesthetized rhesus monkeys were used to study cardiovascular, renal, and endocrine alterations associated with 120 min of head-out water immersion. Five animals underwent complete intrapericardial denervation using the Randall technique, while the remaining six monkeys served as intact controls. Each animal was chronically instrumented with an electromagnetic flow probe on the ascending aorta, a strain gauge pressure transducer implanted in the apex of the left ventricle (LV), and electrocardiogram leads anchored to the chest wall and LV. During immersion, LV end-diastolic pressure, urine flow, glomerular filtration rate, sodium excretion, and circulating atrial natriuretic peptide (ANP) each increased (P less than 0.05) for intact and denervated monkeys. There were no alterations in free water clearance in either group during immersion, yet fractional excretion of free water increased (P less than 0.05) in the intact monkeys. Plasma renin activity (PRA) decreased (P less than 0.05) during immersion in intact monkeys but not the denervated animals. Plasma vasopressin (PVP) concentration decreased (P less than 0.05) during the first 30 min of immersion in both groups but was not distinguishable from control by 60 min of immersion in denervated monkeys. These data demonstrate that complete cardiac denervation does not block the rise in plasma ANP or prevent the natriuresis associated with head-out water immersion. The suppression of PVP during the first minutes of immersion after complete cardiac denervation suggests that extracardiac sensing mechanisms associated with the induced fluid shifts may be responsible for the findings

Kondo regime in triangular arrangements of quantum dots: Molecular orbitals, interference and contact effects

Transport properties of an interacting triple quantum dot system coupled to three leads in a triangular geometry has been studied in the Kondo regime. Applying mean-field finite-U slave boson and embedded cluster approximations to the calculation of transport properties unveils a set of rich features associated to the high symmetry of this system. Results using both calculation techniques yield excellent overall agreement and provide additional insights into the physical behavior of this interesting geometry. In the case when just two current leads are connected to the three-dot system, interference effects between degenerate molecular orbitals are found to strongly affect the overall conductance. An S=1 Kondo effect is also shown to appear for the perfect equilateral triangle symmetry. The introduction of a third current lead results in an `amplitude leakage' phenomenon, akin to that appearing in beam splitters, which alters the interference effects and the overall conductance through the system.Comment: 14 pages, 9 figures, submitted to PR