Informations- und Datenmanagement am Beispiel einer Langzeitstudie zum Ökologischen Landbau (“Hof Ritzerau”, Norddeutschland)

Scientists from various disciplines and different research institutes form the interdisciplinary project “Hof Ritzerau” (Ritzerau, Northern Germany) focussing on the effects of organic farming on animals, plants, crop production, crop diseases, soils and economics. Due to the longterm runtime and to the multidisciplinarity a consequent and consistent management of data and information is developed on the basis of Open Source software. Two core elements of this web-based scientific information system are presented here - a metadata server (GeoNetwork) and a map server (UMN Map-server). Conclusions: The importance of professional management of data, information and knowledge can hardly be underestimated. For developing the infrastructure and specific profiles, knowledge from other disciplines (e.g. business sciences, library sciences, environmental informatics) was used

Characterization of fluids involved in the Gneiss-Charnockite transformation in Southern Kerala (India)

The characterization of fluids involved in the gneiss-charnockite transformation in southern Kerala are discussed. Using a variety of techniques, including microthermometry, Raman laser probe analysis, and mass spectrometry, it was concluded that the CO2-rich, N2-bearing metamorphic fluids in these rocks were internally-derived rather than having been introduced by CO2-streaming

Kabbaldurga-type charnockitization: A local phenomenon in the granulite to amphibolite grade transition zone

In the deeply eroded Precambrian crust of South India and Sri Lanka, a series of spectacular exposures shows progressive development of coarse-grained charnockite through dehydration of amphibolite grade gneisses in different arrested stages. At Kabbaldurga, charnockitization of Archaean grey biotite-hornblende gneisses occurred about 2.5 Ga ago and evidently was induced by the influx of external carbonic fluids along a system of ductile shears and the foliation planes. The results of oxygen isotope thermometry and of geothermobarometry in adjacent areas indicate a P-T regime of 700 to 750 C and 5 to 7 kb. The decrease of water activity in the fluid infiltrated zones caused an almost complete breakdown of hornblende and biotite and the new growth of hypersthene. Detailed petrographic and geochemical studies revealed marked changes in mineralogy and chemistry from granodioritic to granitic which document the metasomatic nature of the process

Atomic mutagenesis of stop codon nucleotides reveals the chemical prerequisites for release factor-mediated peptide release.

Termination of protein synthesis is triggered by the recognition of a stop codon at the ribosomal A site and is mediated by class I release factors (RFs). Whereas in bacteria, RF1 and RF2 promote termination at UAA/UAG and UAA/UGA stop codons, respectively, eukaryotes only depend on one RF (eRF1) to initiate peptide release at all three stop codons. Based on several structural as well as biochemical studies, interactions between mRNA, tRNA, and rRNA have been proposed to be required for stop codon recognition. In this study, the influence of these interactions was investigated by using chemically modified stop codons. Single functional groups within stop codon nucleotides were substituted to weaken or completely eliminate specific interactions between the respective mRNA and RFs. Our findings provide detailed insight into the recognition mode of bacterial and eukaryotic RFs, thereby revealing the chemical groups of nucleotides that define the identity of stop codons and provide the means to discriminate against noncognate stop codons or UGG sense codons

Petrogenesis of Tertiary Alkaline Magmas in the Siebengebirge, Germany

Basanites from the Tertiary Siebengebirge area of Germany (part of the Central European Volcanic Province; CEVP) have high Mg# (>0·60), moderate to high Cr (>300 ppm) and Ni (>200 ppm) contents and strong light rare earth element enrichment, but systematic depletion in Rb and K relative to trace elements of similar compatibility in anhydrous mantle. Rare earth element melting models can explain the petrogenesis of these basanites in terms of partial melting of a spinel peridotite source containing residual amphibole. It is inferred that amphibole, indicated by the relative K and Rb depletion and the melting model, was precipitated in the spinel peridotite lithospheric mantle beneath the Siebengebirge, by metasomatic fluids or melts from a rising mantle diapir or plume. Alkali basalts and more differentiated rocks have lower Mg# and lower abundances of Ni and Cr, and have undergone fractionation of mainly olivine, clinopyroxene, Fe-Ti oxides, amphibole and plagioclase. Most of the basanites and alkali basalts approach the Sr-Nd-Pb isotope compositions inferred for the European Asthenospheric Reservoir component. Trace element constraints (i.e. low Nb/U and Ce/Pb ratios) and the Sr-Nd-Pb isotope composition of the differentiated rocks indicate that assimilation of lower crustal material has modified the composition of the primary mantle-derived magmas. High 207Pb/204Pb ratios in the differentiated lavas point to assimilation of ancient lower crustal components having high U/Pb and Th/Pb ratios. Relatively shallow melting of inferred amphibole-bearing spinel peridotite sources may suggest an origin from the metasomatized part of the thermal boundary layer. Application of new thermobarometric equations for the basaltic magmas indicates relatively normal mantle potential temperatures (1300-1400°C); thus the inferred mantle ‘baby plume' or ‘hot finger' is not thermally anomalou

Low frequency radio-FIR correlation in normal galaxies at ~1 kpc scales

We study the radio--FIR correlation between the nonthermal (synchrotron) radio continuum emission at \lambda 90 cm (333 MHz) and the far infrared emission due to cool (~20 K) dust at \lambda 70\mu m in spatially resolved normal galaxies at scales of ~1 kpc. The slope of the radio--FIR correlation significantly differs between the arm and interarm regions. However, this change is not evident at a lower wavelength of \lambda 20 cm (1.4 GHz). We find the slope of the correlation in the arm to be 0.8 \pm 0.12 and we use this to determine the coupling between equipartition magnetic field (B_{eq}) and gas density (\rho_{gas}) as B_{eq} \propto \rho_{gas}^{0.51 \pm 0.12}. This is close to what is predicted by MHD simulations of turbulent ISM, provided the same region produces both the radio and far infrared emission. We argue that at 1 kpc scales this condition is satisfied for radio emission at 1.4 GHz and may not be satisfied at 333 MHz. Change of slope observed in the interarm region could be caused by propagation of low energy (~1.5 GeV) and long lived (~ 10^8 yr) cosmic ray electrons at 333 MHz.Comment: 8 Pages, 5 Figures, Accepted to be published in Ap

Environmental Effects in Clusters: Modified Far-Infrared--Radio Relations within Virgo Cluster Galaxies

(abridged) We present a study on the effects of the intracluster medium (ICM) on the interstellar medium (ISM) of 10 Virgo cluster spiral galaxies using {\it Spitzer} far-infrared (FIR) and VLA radio continuum imaging. Relying on the FIR-radio correlation within normal galaxies, we use our infrared data to create model radio maps which we compare to the observed radio images. For 6 of our sample galaxies we find regions along their outer edges that are highly deficient in the radio compared with our models. We believe these observations are the signatures of ICM ram pressure. For NGC 4522 we find the radio deficit region to lie just exterior to a region of high radio polarization and flat radio spectral index, although the total 20 cm radio continuum in this region does not appear strongly enhanced. These characteristics seem consistent for other galaxies with radio polarization data in the literature. The strength of the radio deficit is inversely correlated with the time since peak pressure as inferred from stellar population studies and gas stripping simulations, suggesting the strength of the radio deficit is good indicator of the strength of the current ram pressure. We also find that galaxies having {\it local} radio {\it deficits} appear to have {\it enhanced global} radio fluxes. Our preferred physical picture is that the observed radio deficit regions arise from the ICM wind sweeping away cosmic-ray (CR) electrons and the associated magnetic field, thereby creating synchrotron tails as observed for some of our galaxies. We propose that CR particles are also re-accelerated by ICM-driven shocklets behind the observed radio deficit regions which in turn enhances the remaining radio disk brightness.Comment: 19 pages, 10 figures; Astrophysical Journa

The Radio-FIR correlation: Is MHD Turbulence the Cause?

The radio - far infrared correlation is one of the tightest correlations found in astronomy. Many of the models explaining this correlation rely on the association of of global magnetic field strength with gas density. In this letter we put forward that the physical reason for this association lies within the processes of magnetohydrodynamic turbulence.Comment: Accepted by Publications of the Astronomical Society of Australi

The Far-Infrared--Radio Correlation at High Redshifts: Physical Considerations and Prospects for the Square Kilometer Array

(Abridged) I present a predictive analysis for the behavior of the FIR--radio correlation as a function of redshift in light of the deep radio continuum surveys which may become possible using the SKA. To keep a fixed ratio between the FIR and predominantly non-thermal radio continuum emission of a normal star-forming galaxy requires a nearly constant ratio between galaxy magnetic field and radiation field energy densities. While the additional term of IC losses off of the cosmic microwave background (CMB) is negligible in the local Universe, the rapid increase in the strength of the CMB energy density (i.e. $\sim(1+z)^{4})$ suggests that evolution in the FIR-radio correlation should occur with infrared (IR; 8-1000 \micron)/radio ratios increasing with redshift. At present, observations do not show such a trend with redshift; $z\sim6$ radio-quiet QSOs appear to lie on the local FIR-radio correlation while a sample of $z\sim4.4$ and $z\sim2.2$ SMGs exhibit ratios that are a factor of $\sim$2.5 {\it below} the canonical value. I also derive a 5$\sigma$ point-source sensitivity goal of $\approx$20 nJy (i.e. $\sigma_{\rm RMS} \sim 4$ nJy) requiring that the SKA specified be $A_{\rm eff}/T_{\rm sys}\approx 15000$ m$^{2}$ K$^{-1}$; achieving this sensitivity should enable the detection of galaxies forming stars at a rate of \ga25 M_{\sun} {\rm yr}^{-1}, at all redshifts if present. By taking advantage of the fact that the non-thermal component of a galaxy's radio continuum emission will be quickly suppressed by IC losses off of the CMB, leaving only the thermal (free-free) component, I argue that deep radio continuum surveys at frequencies \ga10 GHz may prove to be the best probe for characterizing the high-$z$ star formation history of the Universe unbiased by dust.Comment: 16 pages, 8 figures, accepted for publication in Ap