Search

Background Conventional vagus nerve stimulation (cVNS) is approved to treat major depression. Within this context, auricular VNS (aVNS) is of increasing interest due to its non-invasiveness. Still, the question of optimum stimulation parameters has to be solved. Method 50 subjects with major depressive disorder were stimulated over 20 min. in the area of the auricular branch of the vagus nerve. Control stimulation (CS) was done at the ear lobe. Before and after each stimulation the participants were asked to rate their actual affective state. 30 participants were stimulated continuously, while in 20 subjects, stimulation was interrupted every 5 min. for 30 s. (pulsatile stimulation). Results Only using pulsatile stimulation, participants significantly more often rated to feel better ( F 1 , 18 = 12.35 ; p = 0.002) and to be more optimistic ( F 1 , 18 = 12.24 ; p = 0.003) after aVNS than after CS. Using pulsatile as well as using continuous stimulation, subjects indicated to be more happy ( F 1 , 18 = 24.61 ; p F 1 , 28 = 8.03 ; p = 0.008, resp.). Rating of pictures of the Internatonal Affective Picture System (IAPS) showed no statistical significant difference between the stimulation methods. Conclusion Stimulating in a pulsatile way showed more difference between aVNS and CS than stimulating in a continuous way. Self rating of the emotional state by means of a visual analogue scale seems to be a reliable tool for the examination of non-invasive stimulation techniques.

3D city models offered by digital map providers typically consist of several thousands or even millions of individual buildings. Those buildings are usually generated in an automated fashion from high resolution cadastral and remote sensing data and can be very detailed. However, not in every application such a high degree of detail is desirable. One way to remove complexity is to aggregate individual buildings, simplify the ground plan and assign an appropriate average building height. This task is computationally complex because it includes the combinatorial optimization problem of determining which subset of the original set of buildings should best be aggregated to meet the demands of an application. In this article, we introduce approaches to express different aspects of the aggregation of LoD 1 building models in the form of Mixed Integer Programming (MIP) problems. The advantage of this approach is that for linear (and some quadratic) MIP problems, sophisticated software exists to find exact solutions (global optima) with reasonable effort. We also propose two different heuristic approaches based on the region growing strategy and evaluate their potential for optimization by comparing their performance to a MIP-based approach.

The electrical and optical properties of indium tin oxide (ITO) thin films deposited by plasma ion-assisted evaporation are reported. With deposition at room temperature using certain ion-source parameters ITO films with an electrical resistivity of 5×10−6 Ω m and an absorptance at 550 nm of less than 5% for 300 nm film thickness were obtained. Variation of oxygen pressure during deposition results in different band gap energies and different resistivities. The complex index of refraction was determined using a dispersion model suitable for explaining the particular properties of ITO in the visible and near infrared spectral range.

The two-point correlation function of inhomogeneous hard sphere fluids is analyzed within a certain version of weighted density functional theory. We have determined the direct correlation function and, based on the Ornstein–Zernicke equation, its inverse, yielding the structure factor for such fluids confined by hard, structureless, and parallel walls. We have also calculated the excess coverage and the finite size contribution to the free energy as a function of the slit width L for various bulk densities. In quantitative agreement with rigorous results, the present version of density functional theory yields a constant and large but finite number density profile in the slit for the limiting case that L is reduced to the diameter of the hard spheres.

The 15N nuclear reaction technique for hydrogen analysis is applied for the first time to study hydrogen depth profiles in polymer thin films. Relevant details of this technique are given and in particular the important question of depth resolution is discussed. By using an optimized geometry a depth resolution of the order of 10 nm is achieved. Energy straggling data for 15N ions in polystyrene have been deduced from measured H-profiles. The ion dose necessary for the analysis is found to be low enough that radiation damage in the sample is of minor influence. Since the 15N technique discriminates between the isotopes H and D a suitable contrast between different components of a film system is obtained by deuterating one of them. This is illustrated by several examples, including interdiffusion of polystyrene layer systems and surface enrichment of one component of a diblock copolymer.

During the natural development in snails of the intestinal fluke Isthmiophora melis there are two generations of macropharyngeate rediae followed only by generations of micropharyngeate rediae and cercariae. Macropharyngeate rediae do not appear in snails infected by implantation of micropharyngeate rediae. Snails harboring micropharyngeate rediae only were reinfected by implantation of miracidia of the same trematode strain. Development of macropharyngeate rediae after reinfection in part of the snails is proof of reinfection success, but the mean infection success of miracidia is three to five times lower when the miracidia are introduced in a snail already harboring that parasite. There is evidence that this reduction of the infection success is not due to a lack of attractiveness nor to a surface barrier of the snail but is caused by an alteration of internal conditions, possibly by a stimulated defence mechanism.

When donor snails, Lymnaea stagnalis , infected with Echinoparyphium aconiatum were held at 13 C for at least 24 days, transplantation of newborn rediae from them to uninfected snails was 2.5 times as successful as when donor snails were held at 23 C. The difference does not seem to be do to the fact that rediae transferred from 13 C-snails were slightly larger than those from 23 C. This effect of temperature was not observed in analogous experiments with another echinostome, Isthmiophora melis . The mechanism of this phenomenon found in the experiments with E. aconiatum is still unknown.

Positive ion composition, total ion and electron density and ion production by energetic electrons were measured by rocket-borne experiments above Andoya (69.3°N, 16.0°E) in northern Norway. Observed altitudes of transition from molecular ions to proton hydrates and from electrons to negative ions are compared to results from an ion-chemical model. Nitric oxide and water vapour densities are inferred from the ion composition.

A strain of Isthmiophora melis rediae has been kept for 8 years by transplantation from infected to uninfected snails. This strain has passed with undiminished redial reproductive ability in 45 transplantation steps through 46 Lymnaea stagnalis specimens which corresponds to a minimum of 93 successive redial generations. It was possible to start a normal sexual cycle of the trematode with cercariae deriving from rediae of the 41st snail passage, corresponding at least to the 83rd redial generation. Generative adults and infective miracidia were obtained. Hence the sexual reproduction potentiality of Isthmiophora melis has not been impaired by this artificial extension of the intramolluscan development for more than 7 years.