On the proper reconstruction of complex dynamical systems spoilt by strong measurement noise

This article reports on a new approach to properly analyze time series of dynamical systems which are spoilt by the simultaneous presence of dynamical noise and measurement noise. It is shown that even strong external measurement noise as well as dynamical noise which is an intrinsic part of the dynamical process can be quantified correctly, solely on the basis of measured times series and proper data analysis. Finally real world data sets are presented pointing out the relevance of the new approach

Internal gamma gamma-opacity in Active Galactic Nuclei and the consequences for the TeV observations of M87 and Cen A

Low Luminosity Active Galactic Nuclei (LLAGNs) possess the characteristic features of more luminous Active Galactic Nuclei (AGNs) but exhibit a much lower nuclear Halpha luminosity than their more luminous counterparts. M87 (NGC 4486) and Centaurus A (NGC 5128, CenA) are well-studied nearby LLAGNs. As an additional feature they show gamma-radiation up to TeV (10^{12}eV) energies, but the origin of this radiation is not resolved. The coincident observation of a radio and TeV flare in M87 suggests that the TeV radiation is produced within around 50-100 gravitational radii of the central supermassive black hole, depending on the assumed value of the mass of the black hole. Strong radiation fields can be produced in the central region of an (LL)AGN, e.g., by the accretion flow around the black hole, the jet plasma, or stars closely orbiting the black hole. These radiation fields can lead to the absorption of emitted TeV photons, and in fact high optical depths of such fields can make TeV detection from inner regions impossible. In this paper we consider the accretion flow around the black hole as the most prominent source for such a radiation field and we accordingly calculate the probability for absorption of TeV photons produced near the black holes in M87 and CenA assuming a low luminosity Shakura-Sunyaev Disk (SSD). We find that the results are very different for between the two LLAGNs. While the inner region of M87 is transparent for TeV radiation up to 15TeV, the optical depth in CenA is >> 1, leading to an absorption of TeV photons that might be produced near the central black hole. These results imply either that the TeV gamma production sites and processes are different for both sources, or that LLAGN black holes do not accrete (at least only) in form of a low luminosity SSD.Comment: accepted for publication in Ap

Dynamics of the land use, land use change, and forestry sink in the European Union: the impacts of energy and climate targets for 2030

A 2030 climate and energy policy framework was endorsed by the European Council in 2014. The main elements are a binding 40 % greenhouse gas (GHG) reduction target compared to 1990, a renewable energy share of 27 %, and an energy savings target of at least 27 % by 2030. In this paper, we assess the impact of these targets on the European land use, land use change, and forestry (LULUCF) sector using a Europe focused global land use model linked with a detailed forest management model. We show that implementing a 40 % GHG emission reduction target by 2030 may only have a small negative impact on the domestic LULUCF sink if the additional biomass demand for energy is mostly met through ligno-cellulosic energy crops rather than forest removals. However, if the increased biomass demand were met through higher rates of forest harvest removals, a more negative impact on the LULUCF sink could be expected

Enlarged cross-sectional area of the left vagus nerve in patients with major depressive disorder

PurposeAutonomic dysfunction and a chronic low-grade inflammation are supposed to play a role in the etiology of major depressive disorder (MDD). The vagus nerves (VN) form a major part of the parasympathetic nervous system and of the gut-brain axis. They are supposed to exert anti-inflammatory and epithelial barrier protective effects in the gut. A reduced vagal activity was described in patients with MDD. We aimed to examine the VN in patients with MDD with high-resolution ultrasound (HRUS) and hypothesized that the cross-sectional area (CSA) and the echogenicity of the VNs were altered in comparison to healthy controls.Materials and methodsThe echogenicity (gray scale mean) and the CSA of the cervical VNs at the level of the thyroid gland and both median nerves were examined with HRUS in 50 patients with MDD and 50 matched healthy controls.ResultsThe left VN-CSA was significantly larger in the MDD group compared to the control group (1.7 ± 0.4 mm2 versus 1.5 ± 0.4 mm2; p = 0.045). The CSA of the right VN and both median nerves (MN) were similar between groups. In MDD subgroup analyses, recurrent depressive disorders were the main contributing factor for the left VN-CSA enlargement. Echogenicity was not altered in the VN and MN between groups.ConclusionThe enlargement of the left VN-CSA in patients with MDD, and especially in these patients with recurrent depressive disorders, might turn out as a promising imaging biomarker. Longitudinal studies are warranted to examine whether the VNs-CSA change in the course of MDD

X-ray continuum variability of MCG-6-30-15

This paper presents a comprehensive examination of the X-ray continuum variability of the bright Seyfert 1 galaxy MCG-6-30-15. The source clearly shows the strong, linear correlation between rms variability amplitude and flux first seen in Galactic X-ray binaries. The high frequency power spectral density (PSD) of MCG-6-30-15 is examined in detail using a Monte Carlo fitting procedure and is found to be well represented by a steep power-law at high frequencies (with a power-law index alpha ~ 2.5), breaking to a flatter slope (alpha ~ 1) below f_br ~ 0.6 - 2.0 x 10^-4 Hz, consistent with the previous results of Uttley, McHardy & Papadakis. The slope of the power spectrum above the break is energy dependent, with the higher energies showing a flatter PSD. At low frequencies the variations between different energy bands are highly coherent while at high frequencies the coherence is significantly reduced. Time lags are detected between energy bands, with the soft variations leading the hard. The magnitude of the lag is small (<200 s for the frequencies observed) and is most likely frequency dependent. These properties are remarkably similar to the temporal properties of the Galactic black hole candidate Cygnus X-1. The characteristic timescales in these two types of source differ by ~10^5; assuming that these timescales scale linearly with black hole mass then suggests a black hole mass ~10^6 M_sun for MCG-6-30-15. We speculate that the timing properties of MCG-6-30-15 may be analogous to those of Cyg X-1 in its high/soft state and discuss a simple phenomenological model, originally developed to explain the timing properties of Cyg X-1, that can explain many of the observed properties of MCG-6-30-15.Comment: 19 pages, 24 figures, accepted for publication in MNRA

Spontaneous emission and level shifts in absorbing disordered dielectrics and dense atomic gases: A Green's function approach

Spontaneous emission and Lamb shift of atoms in absorbing dielectrics are discussed. A Green's-function approach is used based on the multipolar interaction Hamiltonian of a collection of atomic dipoles with the quantised radiation field. The rate of decay and level shifts are determined by the retarded Green's-function of the interacting electric displacement field, which is calculated from a Dyson equation describing multiple scattering. The positions of the atomic dipoles forming the dielectrics are assumed to be uncorrelated and a continuum approximation is used. The associated unphysical interactions between different atoms at the same location is eliminated by removing the point-interaction term from the free-space Green's-function (local field correction). For the case of an atom in a purely dispersive medium the spontaneous emission rate is altered by the well-known Lorentz local-field factor. In the presence of absorption a result different from previously suggested expressions is found and nearest-neighbour interactions are shown to be important.Comment: 6 pages no figure

Strategien für die Melissezüchtung (Melissa officinalis)

Es wurden 120 Melisseherkünfte in Feldversuchen evaluiert. In diesem Material wurde die Variabilität für Winterhärte, Gehalt und Zsammensetzung des ätherischen Öls, Rosmarinsäuregehalt und eingeschränkt Blattertrag beschrieben. Die beschriebene Variabilität ermöglichte die Entwicklung homozygoter Linien mit hoher Eigenleistung für die genannten Zuchtziele bis zur I4-Inzuchtgeneration. Die Kreuzung definierter Linien ermöglichte die Schaffung eines neuen Genpools als Ausgansmaterial für die Entwicklung weiterer aussichtsreicher Linien. Stichwörter: Melisse, Melissa officinalis L., Winterhärte, ätherisches Öl, Rosmarinsäure, ZüchtungBreeding strategies for lemon balm (Melissa officinalis)Evaluation was carried out in field experiments with 120 accessions of lemon balm. This material was characterized for winter hardiness, amount and composition of essential oil, amount of rosmarinic acid and, to a certain degree, for yield of leaves. The characterized variability opened the possibility to develop homozygous lines for the mentioned breeding goals up to inbreed generation I4. Crossing of defined lines created a new gene pool of basic material for development of new promising lines. Keywords: lemon balm, Melissa officinalis L., winter hardiness, essential oil, rosmarinic acid, breedin