Aeronautic instruments

The development of aeronautic instruments. Vibrations, rapid changes of the conditions of flight and of atmospheric conditions, influence of the air stream all call for particular design and construction of the individual instruments. This is shown by certain examples of individual instruments and of various classes of instruments for measuring pressure, change of altitude, temperature, velocity, inclination and turning or combinations of these

Kinetic energy driven superconductivity, the origin of the Meissner effect, and the reductionist frontier

Is superconductivity associated with a lowering or an increase of the kinetic energy of the charge carriers? Conventional BCS theory predicts that the kinetic energy of carriers increases in the transition from the normal to the superconducting state. However, substantial experimental evidence obtained in recent years indicates that in at least some superconductors the opposite occurs. Motivated in part by these experiments many novel mechanisms of superconductivity have recently been proposed where the transition to superconductivity is associated with a lowering of the kinetic energy of the carriers. However none of these proposed unconventional mechanisms explores the fundamental reason for kinetic energy lowering nor its wider implications. Here I propose that kinetic energy lowering is at the root of the Meissner effect, the most fundamental property of superconductors. The physics can be understood at the level of a single electron atom: kinetic energy lowering and enhanced diamagnetic susceptibility are intimately connected. According to the theory of hole superconductivity, superconductors expel negative charge from their interior driven by kinetic energy lowering and in the process expel any magnetic field lines present in their interior. Associated with this we predict the existence of a macroscopic electric field in the interior of superconductors and the existence of macroscopic quantum zero-point motion in the form of a spin current in the ground state of superconductors (spin Meissner effect). In turn, the understanding of the role of kinetic energy lowering in superconductivity suggests a new way to understand the fundamental origin of kinetic energy lowering in quantum mechanics quite generally

Impact of change in climate and policy from 1988 to 2007 on environmental and microbial variables at the time series station Boknis Eck, Baltic Sea

Phytoplankton and bacteria are sensitive indicators of environmental change. The temporal development of these key organisms was monitored from 1988 to the end of 2007 at the time series station Boknis Eck in the western Baltic Sea. This period was characterized by the adaption of the Baltic Sea ecosystem to changes in the environmental conditions caused by the conversion of the political system in the southern and eastern border states, accompanied by the general effects of global climate change. Measured variables were chlorophyll, primary production, bacteria number, -biomass and -production, glucose turnover rate, macro-nutrients, pH, temperature and salinity. Negative trends with time were recorded for chlorophyll, bacteria number, bacterial biomass and bacterial production, nitrate, ammonia, phosphate, silicate, oxygen and salinity while temperature, pH, and the ratio between bacteria numbers and chlorophyll increased. Strongest reductions with time occurred for the annual maximum values, e.g. for chlorophyll during the spring bloom or for nitrate during winter, while the annual minimum values remained more stable. In deep water above sediment the negative trends of oxygen, nitrate, phosphate and bacterial variables as well as the positive trend of temperature were similar to those in the surface while the trends of salinity, ammonia and silicate were opposite to those in the surface. Decreasing oxygen, even in the surface layer, was of particular interest because it suggested enhanced recycling of nutrients from the deep hypoxic zones to the surface by vertical mixing. The long-term seasonal patterns of all variables correlated positively with temperature, except chlorophyll and salinity. Salinity correlated negatively with all bacterial variables (as well as precipitation) and positively with chlorophyll. Surprisingly, bacterial variables did not correlate with chlorophyll, which may be inherent with the time lag between the peaks of phytoplankton and bacteria during spring. Compared to the 20-yr averages of the environmental and microbial variables, the strongest negative deviations of corresponding annual averages were measured about ten years after political change for nitrate and bacterial secondary production (~ −60%), followed by chlorophyll (−50%) and bacterial biomass (−40%). Considering the circulation of surface currents in the Baltic Sea we interpret the observed patterns of the microbial variables at the Boknis Eck time series station as a consequence of the improved management of water resources after 1989 and – to a minor extent – the trends of the climate variables salinity and temperature

Effect of triamcinolone acetonide injections on hemiplegic shoulder pain: a randomized clinical trial.

Background and Purpose - Hemiplegic shoulder pain is not uncommon after stroke. Its origin is still unknown, and although many different methods of treatment are applied, none have yet been proved to be effective. We sought to study the efficacy of 3 injections of intra-articular triamcinolone acetonide on pain and arm function in stroke patients with hemiplegic shoulder pain. Methods - In a multicenter, randomized, placebo-controlled clinical trial, patients with hemiplegic shoulder pain received either 3 intra-articular injections of 40 mg triamcinolone acetonide or 1 mL physiological saline solution (placebo). Primary outcomes were pain measured according to 3 visual analogue scales (score range, 0 to 10), and arm function was measured by means of the Action Research Arm test and the Fugl-Meyer assessment scale; secondary outcomes were passive external rotation of the shoulder and general functioning measured according to Barthel Index and the Rehabilitation Activities Profile. Results - In the triamcinolone group (n=18), the median decrease in pain, 3 weeks after the last injection, was 2.3 (interquartile range, 0.3 to 4.3) versus 0.2 (interquartile range, -0.5 to 2.2) in the placebo group. This result was not statistically significant. The change in the other outcome measures did not differ significantly between the 2 treatment groups. Twenty-five patients reported side effects. Conclusions - In the 37 participants included in this study, triamcinolone injections seemed to decrease hemiplegic shoulder pain and to accelerate recovery, but this effect was not statistically significant. Therefore, on the basis of the results of this study, these injections cannot be recommended for the treatment of patients with hemiplegic shoulder pain

Bound States in Mildly Curved Layers

It has been shown recently that a nonrelativistic quantum particle constrained to a hard-wall layer of constant width built over a geodesically complete simply connected noncompact curved surface can have bound states provided the surface is not a plane. In this paper we study the weak-coupling asymptotics of these bound states, i.e. the situation when the surface is a mildly curved plane. Under suitable assumptions about regularity and decay of surface curvatures we derive the leading order in the ground-state eigenvalue expansion. The argument is based on Birman-Schwinger analysis of Schroedinger operators in a planar hard-wall layer.Comment: LaTeX 2e, 23 page

Comparing Discounting of Potentially Real Rewards and Losses by Means of Functional Magnetic Resonance Imaging

AimDelay discounting (DD) has often been investigated in the context of decision making whereby individuals attribute decreasing value to rewards in the distant future. Less is known about DD in the context of negative consequences. The aim of this pilot study was to identify commonalities and differences between reward and loss discounting on the behavioral as well as the neural level by means of computational modeling and functional Magnetic Resonance Imaging (fMRI). We furthermore compared the neural activation between anticipation of rewards and losses.MethodWe conducted a study combining an intertemporal choice task for potentially real rewards and losses (decision-making) with a monetary incentive/loss delay task (reward/loss anticipation). Thirty healthy participants (age 18-35, 14 female) completed the study. In each trial, participants had to choose between a smaller immediate loss/win and a larger loss/win at a fixed delay of two weeks. Task-related brain activation was measured with fMRI.ResultsHyperbolic discounting parameters of loss and reward conditions were correlated (r = 0.56). During decision-making, BOLD activation was observed in the parietal and prefrontal cortex, with no differences between reward and loss conditions. During reward and loss anticipation, dissociable activation was observed in the striatum, the anterior insula and the anterior cingulate cortex.ConclusionWe observed behavior concurrent with DD in both the reward and loss condition, with evidence for similar behavioral and neural patterns in the two conditions. Intertemporal decision-making recruited the fronto-parietal network, whilst reward and loss anticipation were related to activation in the salience network. The interpretation of these findings may be limited to short delays and small monetary outcomes

Generalized Statistics and High Tc Superconductivity

Introducing the generalized, non-extensive statistics proposed by Tsallis[1988], into the standard s-wave pairing BCS theory of superconductivity in 2D yields a reasonable description of many of the main properties of high temperature superconductors, provided some allowance is made for non-phonon mediated interactions.Comment: 14 pages, 5 figure

Effects of pre- and postnatal exposure to chlorinated dioxins and furans on human neonatal thyroid hormone concentrations.

Animal studies have shown that dioxins influence plasma thyroid hormone concentrations. To investigate the effect of chlorinated dioxins and furans on thyroid hormone concentrations in humans, we studied 38 healthy breast-fed infants. The study population was divided into two groups according to the dioxin concentrations in milk fat of their mothers. Blood samples were taken at birth and at the ages of 1 and 11 weeks. At birth a tendency to higher total thyroxine (tT4) concentrations was found in the high exposure group. At the ages of 1 and 11 weeks the increase of mean tT4 concentrations and tT4/thyroxine-binding globulin ratios in the high exposure group reached significance as compared to the low exposure group. At birth and 1 week after birth, mean thyrotropin (TSH) concentrations were similar in both groups, but at the age of 11 weeks the mean TSH concentrations were significantly higher in the high exposure group. We postulate that the observed plasma tT4 elevation in infants exposed to dioxins before and after birth is the result of an effect on the thyroid hormone regulatory system

Geometric Phase, Curvature, and Extrapotentials in Constrained Quantum Systems

We derive an effective Hamiltonian for a quantum system constrained to a submanifold (the constraint manifold) of configuration space (the ambient space) by an infinite restoring force. We pay special attention to how this Hamiltonian depends on quantities which are external to the constraint manifold, such as the external curvature of the constraint manifold, the (Riemannian) curvature of the ambient space, and the constraining potential. In particular, we find the remarkable fact that the twisting of the constraining potential appears as a gauge potential in the constrained Hamiltonian. This gauge potential is an example of geometric phase, closely related to that originally discussed by Berry. The constrained Hamiltonian also contains an effective potential depending on the external curvature of the constraint manifold, the curvature of the ambient space, and the twisting of the constraining potential. The general nature of our analysis allows applications to a wide variety of problems, such as rigid molecules, the evolution of molecular systems along reaction paths, and quantum strip waveguides.Comment: 27 pages with 1 figure, submitted to Phys. Rev.

Influence of short-term dietary measures on dioxin concentrations in human milk.

Breast-feeding may expose infants to high levels of toxic chlorinated dioxins. To diminish intake of these lipophilic compounds by the baby, two diets were tested for their ability to reduce concentrations of dioxins in human milk. The diets were a low-fat/high- carbohydrate/low-dioxin diet. (about 20% of energy intake derived from fat) and a high fat /low-carbohydrate/low-dioxin diet. These diets were tested in 16 and 18 breast-feeding women, respectively. The test diets were followed for 5 consecutive days in the fourth week after delivery. Milk was sampled before and at the end of the dietary regimen, and dioxin concentrations and fatty acid concentrations were determined. Despite significant influences of these diets on the fatty acid profiles, no significant influence on the dioxin concentrations in breast milk could be found. We conclude that short-term dietary measures will not reduce dioxin concentration in human milk