Dynamic Inhomogeneities in the La2CuO4-Based Superconductors

Polarization-dependent X-ray-absorption fine-structure (XAFS) measurements on the local structure of the La₂CuO₄-based high-T _c superconductors La_2?x Sr _x CuO₄, La_2?x Ba _x CuO₄, and La_1.6?x Sr _x Nd_0.4CuO₄ find, among others, orientation disorder induced in the Cu–O₂ planes by doping Sr, Ba, and alloying Nd atoms, all such atoms residing in La-sites. The orientation disorder is of two types: mostly static-buckling disorder, and dynamic disordering of the tilt angles of the Cu–O₆ octahedra correlated in nanoscale regions, with respect to neighboring nanoscale regions. Buckling disorder in the Cu–O₂ planes has the greatest detrimental effect on T _c and conductivity for such foreign atoms.     

Impaired pancreatic polypeptide release to insulin hypoglycaemia in chronic autonomic failure with postural hypotension: evidence for parasympathetic dysfunction

1. Release of pancreatic polypeptide (PP) is largely under vagal control and measurement of change in PP after insulin hypoglycaemia offers a non-invasive method of assessing vagal activity. 2. Changes in blood sugar and PP after intravenous insulin (0.2 unit/kg) were examined in six patients with idiopathic chronic autonomic failure (AF) and 12 control subjects. Six of the controls were studied before and after atropine treatment. 3. The PP levels in controls rose from 32 +/- 9 (mean +/- SEM) to 236 +/- 54 pmol/l after 45 min. Patients had similar baseline values (23 +/- 5 pmol/l) but a markedly reduced and delayed PP response to hypoglycaemia (49 +/- 19 pmol/l at 90 min). This impaired PP response was similar to that seen in controls after atropine. 4. The impaired PP response to insulin hypoglycaemia in patients with AF strongly suggests a dysfunction of vagal activity which is often clinically inapparent.     

Propagation Studies of 40 km of Graded-Index Fiber Installed in Cable in an Operational Duct Route

Forty kilometers of graded-index fiber has been installed in cables in duct running from the Post Office Research Center. Its loss and bandwidth have been measured in detail and the extrapolation of both studied as a function of link length. The links are characterized by low loss averaging 4.33 dB/km including joints and by large bandwidth. A number of new effects have been identified and explained during the course of the bandwidth studies.     

An animal behavior model for studying the actions of LSD and related hallucinogens

Cats injected with LSD (d-lysergic acid diethylamide) exhibit a group of behaviors that appear to be specific to hallucinogenic drugs. Two of these behaviors, limb flick and abortive grooming, have an extremely low frequency of occurrence in normal cats, but often dominate the behavior of LSD-treated cats. The frequency of occurrence of this group of behaviors is related to the dose of LSD. The behavioral changes are long-lasting following a single injection of LSD, and exhibit tolerance following the repeated administration of LSD. They are not elicited by a variety of control drugs, but are elicited by other indole nucleus hallucinogens. Because the behavioral effects are specific, reliable, easy to score, and quantifiable, they represent an animal model that can be used in studies of the effects of LSD and related hallucinogens.     

Ferroscan: Toward continuous-aperture scanning

Work done severe years ago, which represents a step toward eliminating the necessity for subdividing a phased array aperture into many discrete elements, each with its own phase shifter, is reported on for the first time. A 5-wavelength,Xband horn aperture, partially loaded with ferrite material, was designed and fabricated. The resulting antenna replaces at least 10 conventional phase shifter-element units and was successfully controlled by an external magnetic circuit to form sum and difference patterns and to scan the beam.     

The dual-mode solution and transport of water in poly(acrylonitrile)

Solubility (sorption) and transport measurements with water in solvent-free poly (acrylonitrile)(PAN) (23) have been interpreted in terms of an extension of the “dual-sorption” model for transport of small molecules in glassy polymers. Satisfactory agreement has been obtained between theory and experimental data. An earlier analysis of similar data for water in PAN containing 0.26 percent (by weight) of a residual solvent (1) has been compared with the present results in order to investigate the effects of residual solvent on the dual-sorption and transport parameters for the water-PAN system.     

Life cycle costing,government policies and the diffusion of energy-conserving technology

Energy conservation has become a major goal of State and Federal policy. Governments are called on to play an active role in identifying promising energy-conserving technologies, and in encouraging their timely and widespread adoption.For their role to be effective, governments must have available—and be willing to use—some economic tools that permit estimation of the costs and benefits of their actions. Costs may consist of funds spent on research, development and public education, of tax revenues foregone, of administrative expenses, or of outright subsidies to producers or consumers. Benefits arise mainly through the earlier adoption of energy-conserving technologies with their attendant economic savings.In evaluating these savings, governments may assign “shadow prices” different from observed market prices to certain energy forms, to reflect more correctly their perceived value to society. They may also want to use discount rates different from those of private businesses or individuals in their benefit-cost calculus, to better take into account the claims of future generations on earth's remaining resources.The main purpose of this paper is to show what special economic tools are required in this evaluation, to develop some of them, and to demonstrate their application. Specifically, the aim is to explain and illustrate the usefulness to public policy makers of the techniques of life cycle costing and of market acceptance estimation.In order to highlight the basic principles without getting embroiled in excessive algebraic details, certain simplifications are introduced (and clearly stated) in the course of the paper. Although the tools are general, the development is made concrete by focussing the discussion on consumer durables that use and/or deliver energy in the performance of their service, and that are ready for application without further research and development effort.     

Cognitive test performance among nondemented elderly African Americans and whites

We examined the neuropsychological test performance of a randomly selected community sample of English-speaking non-Hispanic African American and white elders in northern Manhattan. All participants were diagnosed as nondemented by a neurologist, whose assessment was made independent of neuropsychological test scores. African American elders obtained significantly lower scores on measures of verbal and nonverbal learning and memory, abstract reasoning, language, and visuospatial skill than whites. After using a stratified random sampling technique to match groups on years of education, many of the discrepancies became nonsignificant; however, significant ethnic group differences on measures of figure memory, verbal abstraction, category fluency, and visuospatial skill remained. Discrepancies in test performance of education-matched African Americans and whites could not be accounted for by occupational attainment or history of medical conditions such as hypertension and diabetes. These findings emphasize the importance of using culturally appropriate norms when evaluating ethnically diverse elderly for dementia.