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Trends in der Bioanalytik
(2002)
Towards a better understanding of laser beam melt ablation using methods of statistical analysis
(2002)
Laser beam melt ablation, as a contact free machining process, offers several advantages compared to conventional processing mechanisms. Although the idea behind it is rather simple, the process has a major limitation: with increasing ablation rate surface quality of the workpiece processed declines rapidly. The structures observed show a clear dependence of the line energy. In dependence of this parameter several regimes of the process have been separated. These are clearly distinguishable as well in the surfaces obtained as in the signals gained by the measurement of the process emissions which is the observed quantity chosen.
Tomography of AM Herculis
(2002)
From the root bark of Erythrina burttii three new isoflav-3-enes, 7,4'-dihydroxy-2'-methoxy-6- (1'',1''-dimethylallyl)isoflav-3-ene (trivial name, burttinol-A), 4'-hydroxy-2'- methoxy-(2'',2''-dimethylpyrano[5'',6'':8,7]isoflav-3-ene (trivial name, burttinol-B), 7,4'-dihydroxy-2'-methoxy-8-(3'',3''-dimethylallyl)isoflav-3-ene (trivial name, burttinol-C), and a new 2-arylbenzofuran, 6,4'-dihydroxy-2'-methoxy-5- (1'',1''-dimethylallyl)-2-arylbenzofuran (trivial name, burttinol-D) were isolated. In addition, the known compounds, abyssinone V-4'-methyl ether, bidwillol A, calopocarpin, erybraedin A, erythrabyssin II, isobavachalcone, phaseollidin and phaseollin were identified. The structures were determined on the basis of spectroscopic evidence.
Highly relativistic jets are most probably driven by strong magnetic fields and launched from the accretion disk surrounding a central black hole. Applying the jet flow parameters (velocity, density, temperature) calculated from the magnetohydrodynamic (MHD) equations, we derive the thermal X-ray luminosity along the inner jet flow in the energy range 0.2-10.1 keV. Here, we concentrate on the case of Galactic microquasars emitting highly relativistic jets. For a 5 Msun central object and a jet mass flow rate of dot {M}j = 10-8 Msun yr-1 we obtain a jet X-ray luminosity LX ~ 1033 erg s-1. Emission lines of Fe XXV and Fe XXVI are clearly visible. Relativistic effects such as Doppler shift and boosting were considered for different inclinations of the jet axis. Due to the chosen geometry of the MHD jet the inner X-ray emitting part is not yet collimated. Therefore, depending on the viewing angle, the Doppler boosting does not play a major role in the total spectra.
The continued linguistic contact in the islands of Britain and Ireland over the past two millenia has led to linguistic convergence processes between the Insular Celtic and West Germanic languages involved. While the Latin, Old Norse and Norman French contact scenarios were recognised and have been well studied since the 19c, the Celtic component received much less scholarly attention until the 1990s because of the continued linguistic bias, once fostered by 19c Anglo-Saxonisms and the idea of racial purity of the Egnlish population. It is only in the very recent past that the many different contact areas between English and the Insular Celtic languages have received recognition after New Labour's post-1997 introduction of "devolution" politics. The closest and longest interaction took of course place between English and Welsh. The present article looks at three major types of interaction which led to convergence in a number of important linguistic features: (1) mutual retention of shared archaic features, (2) mutual shared innovations, and (3) transfer from one language to another, either by unilateral or by bilateral transfer. The exemplary contact features discussed in this article relate to the retention of interdental fricatives, the shared innovation of analycity and multi-word verb formation, and clefting as feature transfer. Transfer is likely to have taken place under the following conditions: (a) earlier written documentation in the donor language, (b) higher frequency of occurrence in the donor language, (c) conformity with other structures in the donor language, and (d) grammaticalisation in the donor language. The conclusion endorses Salikoko Mufwene's claim that the making of English in the island of Britain was subject to the same contact processes which created the English based creoles from indigenised Englishes during the colonial period.
From the peak of a gravitational microlensing high-magnification event in the A component of QSO 2237+0305, which was accurately monitored by the Gravitational Lenses International Time Project collaboration, we derived new information on the nature and size of the optical V-band and R-band sources in the distant quasar. If the microlensing peak is caused by a microcaustic crossing, we first obtain that the standard accretion disk is a scenario more reliable/ feasible than other typical axially symmetric models. Moreover, the standard scenario fits both the V-band and R-band observations with reduced ?2 values very close to 1. Taking into account all these results, a standard accretion disk around a supermassive black hole is a good candidate for the optical continuum main source in QSO 2237+0305. Second, using the standard source model and a robust upper limit on the transverse galactic velocity, we infer that 90% of the V- band and R-band luminosities are emitted from a region with a radial size less than 1.2×10-2 pc (=3.7×1016 cm, at a 2 ? confidence level).
We present models for the complete life and death of a 60 Msolar star evolving in a close binary system, from the main-sequence phase to the formation of a compact remnant and fallback of supernova debris. After core hydrogen exhaustion, the star expands, loses most of its envelope by Roche lobe overflow, and becomes a Wolf-Rayet star. We study its post-mass transfer evolution as a function of the Wolf-Rayet wind mass-loss rate (which is currently not well constrained and will probably vary with the initial metallicity of the star). Varying this mass-loss rate by a factor of 6 leads to stellar masses at collapse that range from 3.1 up to 10.7 Msolar. Because of different carbon abundances left by core helium burning and nonmonotonic effects of the late shell-burning stages as function of the stellar mass, we find that, although the iron core masses at collapse are generally larger for stars with larger final masses, they do not depend monotonically on the final stellar mass or even the C/O core mass. We then compute the evolution of all models through collapse and bounce. The results range from strong supernova explosions (Ekin>1051ergs) for the lower final masses to the direct collapse of the star into a black hole for the largest final mass. Correspondingly, the final remnant masses, which were computed by following the supernova evolution and fallback of material for a timescale of about one year, are between 1.2 and 10 Msolar. We discuss the remaining uncertainties of this result and outline the consequences of our results for the understanding of the progenitor evolution of X-ray binaries and gamma-ray burst models.
The influence of the charge density of polyelectrolytes on the growth of polyelectrolyte multilayers via layer- by-layer self-assembly from pure aqueous solutions was studied. Multilayers were built from strong polyanions, namely poly(styrenesulfonate) and an exfoliated synthetic hectorite, and cationic copolymers of diallyldimethylammonium chloride (DADMAC) with N-methyl-N-vinylformamide (NMVF) for which the composition and thus the charge density was varied systematically. The analysis of the system {cationic copolymer/poly(styrenesulfonate)} reveals that a critical linear charge density Ïc of 0.036 elementary charge/Å of contour length is necessary to obtain stable multilayer growth in pure water. Above Ïc, the increment of thickness/deposition cycle varies with the linear charge density of the cationic copolymers, in good agreement with current theories of polyelectrolyte solutions. As linear charge density increases, the system passes successively through a charge-dependent ?Debye-Hu ckel? regime and then through a chargeindependent ?strong-screening? regime where counterion condensation dominates the behavior. Analogous results were obtained for the variation of the basal spacing of internally structured hybrid multilayers {cationic copolymer/hectorite}. However, by contrast with the first system, no critical linear charge density was found for the hybrid system. This is explained by additional, nonelectrostatic interactions between the clay platelets and the formamide fragment.
Electrostatically self-assembled (ESA) polyelectrolyte films show in general no internal structure. The use of special polycations, however, namely of lyotropic ionenes, may give rise to highly ordered coatings. In this article, the influence of the charge density of the polyanion, as well as the distribution of the charged groups within this polymer, is examined, using a series of anionic cellulose derivatives. Various techniques were used to study the films? growth and internal structure. Both showed to be affected in particular by the charge density but also by the substitution pattern.
We present a new determination of the time delay of the gravitational lens system HE 1104-1805 (``Double Hamburger'') based on a previously unpublished dataset. We argue that the previously published value of Delta tA-B=0.73 years was affected by a bias of the employed method. We determine a new value of Delta tA-B=0.85+/-0.05 years (2sigma confidence level), using six different techniques based on non interpolation methods in the time domain. The result demonstrates that even in the case of poorly sampled lightcurves, useful information can be obtained with regard to the time delay. The error estimates were calculated through Monte Carlo simulations. With two already existing models for the lens and using its recently determined redshift, we infer a range of values of the Hubble parameter: H0=48+/-4 km s-1 Mpc-1 (2sigma ) for a singular isothermal ellipsoid (SIE) and H0=62+/-4 km s-1 Mpc-1 (2sigma ) for a constant mass-to-light ratio plus shear model (M/L+gamma ). The possibly much larger errors due to systematic uncertainties in modeling the lens potential are not included in this error estimate.
Es werden Gemeinsamkeiten und Unterschiede von in der Mutter- bzw. Fremdsprache erzeugten Texten behandelt. Es wird zunächst zwischen unterschiedlichen Konstellationen fremdsprachiger Kommunikation differenziert. Die Gemeinsamkeiten werden v.a. auf der soziolinguistischen Ebene gesehen, da es immer um die Bewältigung kommunikativer Anforderungen in bestimmten Kommunikationssituationen geht. Unterschiede betreffen vor allem die psycholinguistische Ebene, da bei der Kommunikation in der Fremdsprache eine Disproportionalität zwischen Bewusstseinsinhalten und dem Verfügen über Ausdrucksmittel besteht. Die sich daraus ergebenden Abweichungen werden systematisch an zwei Beispieltexten exemplifiziert.
Temperature and polymer induced structural changes in SDS/decanol based multilamellar vesicles
(2002)
Teilleistungsstörungen
(2002)
Taraxacum Sectio Naevosa M. P. Christiansen (Taraxacum spectabile auct. germ. p. p.) in Deutschland
(2002)
Tagungsbericht
(2002)
Söldner aus Böhmen
(2002)
We consider an ensemble of coupled nonlinear noisy oscillators demonstrating in the thermodynamic limit an Ising-type transition. In the ordered phase and for finite ensembles stochastic flips of the mean field are observed with the rate depending on the ensemble size. When a small periodic force acts on the ensemble, the linear response of the system has a maximum at a certain system size, similar to the stochastic resonance phenomenon. We demonstrate this effect of system size resonance for different types of noisy oscillators and for different ensemblesùlattices with nearest neighbors coupling and globally coupled populations. The Ising model is also shown to demonstrate the system size resonance.
Citrate-capped gold nanoparticles as well as planar gold surfaces can be efficiently grafted with a covalently attached polymer monolayer a few nanometers thick, by simple contact of the metal surface with dilute aqueous solutions of hydrophilic polymers that are end-capped with disulfide moieties, as shown by UV/vis absorption, dynamic light scattering, and surface plasmon resonance studies. The hydrophilic polymer-coated gold colloids can be freeze-dried and stored as powders that can be subsequently dissolved to yield stable aqueous dispersions, even at very large concentrations. They allow for applying filtrations, gel permeation chromatography, or centrifugation. They do not suffer from undesirable nonspecific adsorption of proteins while allowing the diffusion of small species within the hydrogel surface coating. In addition, specific properties of the original hydrophilic polymers are retained such as a lower critical solution temperature. The latter feature could be useful to enhance optical responses of functionalized gold surfaces toward interaction with various substrates.
In this article, the synthesis of analogs of N,N',N''-triacetylchitotriose in which the central sugar residue was replaced by a succinic acid is presented. Mol. modeling calcns. revealed that the pseudotrisaccharides exist in low energy extended conformations which show similar space filling as N,N',N''-triacetylchitotriose. Of the N,N',N''-triacetylchitotriose pseudosugar analogs tested as chitinase inhibitors, none showed any appreciable competition (numerical data not presented). The conformational anal. along with further synthetic efforts will hopefully lead to more efficient pseudosaccharides as chitinase inhibitors.
We analyse time series from a study on bimanual rhythmic movements in which the speed of performance (the external control parameter) was experimentally manipulated. Using symbolic transformations as a visualization technique we observe qualitative changes in the dynamics of the timing patterns. Such phase transitions are quantitatively described by measures of complexity. Using these results we develop an advanced symbolic coding which enables us to detect important dynamical structures. Furthermore, our analysis raises new questions concerning the modelling of the underlying human cognitive-motor system.
Observational data of natural systems, as measured in medical measurements are typically quite different from those obtained in laboratories. Due to the peculiarities of these data, wellknown characteristics, such as power spectra or fractal dimension, often do not provide a suitable description. To study such data, we present here some measures of complexity, which are basing on symbolic dynamics. Firstly, a motivation for using symbolic dynamics and measures of complexity in data analysis based on the logistic map is given and next, two applications to medical data are shown. We demonstrate that symbolic dynamics is a useful tool for the risk assessment of patients after myocardial infarction as well as for the evaluation of th e architecture of human cancellous bone.
Water-soluble block copolymers were prepared from the non-ionic monomer N-isopropylacrylamide (NIPA) and the zwitterionic monomer 3-[N-(3-methacrylamidopropyl)-N,N-dimethyl]-ammonio propane sulfonate (SPP) by sequential free radical polymerization via the RAFT process. Such block copolymers with two hydrophilic blocks exhibit double thermo- responsive behavior in water: the poly-NIPA block shows a lower critical solution temperature, whereas the poly-SPP block exhibits an upper critical solution temperature. Appropriate design of the block lengths leads to block copolymers which stay in solution in the full temperature range between 0°C and 100°C. Both blocks of these polymers dissolve in water at intermediate temperatures, whereas at high temperatures, the poly-NIPA block forms colloidal hydrophobic associates that are kept in solution by the poly-SPP block, and at low temperatures, the poly-SPP block forms colloidal polar aggregates that are kept in solution by the poly-NIPA block. In this way, colloidal aggregates can be prepared in water which switch reversibly, and without any additive, their "inside" to the "outside", and vice versa. The aggregates provide microdomains and surfaces of different character, which can be controlled by a simple thermal stimulus.
Superoxide sensor based on cytochrome c immobilized on mixed-thiol SAM with a new calibration method
(2002)
Chitinase B (ChiB) from Serratia marcescens is a family 18 exochitinase whose catalytic domain has a TIM-barrel fold with a tunnel-shaped active site. We have solved structures of three ChiB complexes that reveal details of substrate binding, substrateassisted catalysis, and product displacement. The structure of an inactive ChiB mutant (E144Q) complexed with a pentameric substrate (binding in subsites 22 to 13) shows closure of the ''roof'' of the active site tunnel. It also shows that the sugar in the 21 position is distorted to a boat conformation, thus providing structural evidence in support of a previously proposed catalytic mechanism. The structures of the active enzyme complexed to Allosamidin (an analogue of a proposed reaction intermediate) and of the active enzyme soaked with pentameric substrate show events after cleavage of the glycosidic bond. The latter structure shows reopening of the roof of the active site tunnel and enzyme-assisted product displacement in the 11 and 12 sites, allowing a water molecule to approach the reaction center. Catalysis is accompanied by correlated structural changes in the core of the TIM barrel that involve conserved polar residues whose functions were hitherto unknown. These changes simultaneously contribute to stabilization of the reaction intermediate and alternation of the pKa of the catalytic acid during the catalytic cycle.
Structural changes induced in bovine serum albumin by covalent attachment of chlorogenic acid
(2002)
Bovine serum albumin (BSA) was modifed by covalent attachment of chlorogenic acid using different concentrations at pH 9. The derivatization was accompanied by a reduction of lysine, cysteine and tryptophan residues. The isoelectric points were shifted to lower pH values and formation of high molecular weight fractions was noted. The structural changes were studied using circular dichroism, differential scanning calorimetry (DSC), intrinsic fluorescence, and binding of anilinonaphthalenesulfonic acid. The results showed that the content of alpha-helix decreased with a parallel increase in unordered structures with higher degrees of derivatization. DSC revealed a decrease in both denaturation temperature and enthalpy. Surface hydrophobicity declined, indicating that hydrophilic regions were exposed on the molecular surface. Proteolytic digestion showed that, at a lower degree of derivatization,the tryptic degradation was most adversely effected, whereas the peptic digestion declined with increasing modification. A trypsin inhibitory effect of the breakdown products released from derivatized BSA was also observed.
A significant seasonal variation in size at settlement has been observed in newly settled larvae of Dreissena polymorpha in Lake Constance. Diet quality, which varies temporally and spatially in freshwater habitats, has been suggested as a significant factor influencing the life history and development of freshwater invertebrates. Accordingly, experiments were conducted with field-collected larvae to test the proposal that diet quality can determine planktonic larval growth rates, size at settlement and subsequent post-metamorphic growth rates. Larvae were fed one of two diets or starved. One diet was composed of cyanobacterial cells, which are de; cient in polyunsaturated fatty acids (PUFAs) and the other was a mixed diet rich in PUFAs. Freshly metamorphosed animals from the starvation treatment had a carbon content per individual 70% lower than that of larvae fed the mixed diet. This apparent exhaustion of larval internal reserves resulted in a 50% reduction of the post-metamorphic growth rates. Growth was also reduced in animals previously fed the cyanobacterial diet. Hence, low food quantity or low food quality during the larval stage of D. polymorpha, lead to irreversible effects for post-metamorphic animals and are related to inferior competitive abilities.
We employ classical statistical methods of multivariate classification for the exploitation of the stellar content of the Hamburg/ESO objective prism survey (HES). In a simulation study we investigate the precision of a three- dimensional classification (Teff, log g, [Fe/H]) achievable in the HES for stars in the effective temperature range 5200 K<Teff<6800 K, using Bayes classification. The accuracy in temperature determination is better than 400 K for HES spectra with S/N>10 (typically corresponding to BJ<16.5). The accuracies in log g and [Fe/H] are better than 0.68 dex in the same S/N range. These precisions allow for a very efficient selection of metal-poor stars in the HES. We present a minimum cost rule for compilation of complete samples of objects of a given class, and a rejection rule for identification of corrupted or peculiar spectra. The algorithms we present are being used for the identification of other interesting objects in the HES data base as well, and they are applicable to other existing and future large data sets, such as those to be compiled by the DIVA and GAIA missions.
Spätabtreibungen
(2002)
The analysis of Wolf-Rayet spectra requires adequate model atmospheres which treat the non-LTE radiation transfer in a spherically expanding medium. Present state-of-the-art calculations account for complex model atoms with, typically, a few hundred energy levels and a few thousand spectral lines of He and CNO elements. In the most recent version of our model code, blanketing by millions of lines from iron-group elements is also included. These models have been widely applied for the spectral analysis of WN stars in the Galaxy and LMC. WN spectra can be well reproduced in most cases. WC stars have not yet been analyzed comprehensively, because the agreement with observations becomes satisfactory only when line-blanketed models are applied. The introduction of inhomogeneities (clumping), although treated in a rough approximation, has significantly improved the fit between synthetic and observed spectra with respect to the electron-scattering wings of strong lines. The mass-loss rates obtained from spectral analyses become smaller by a factor 2-3 if clumping is accounted for. A pre-specified velocity law is adopted for our models, but the radiation pressure can be evaluated from our detailed calculation and can be compared a posteriori with the required wind acceleration. Surprisingly we find that the line-blanketed models are not far from being hydrodynamically consistent, thus indicating that radiation pressure is probably the main driving force for the mass-loss from WR stars.
Soziale Vergleichsprozesse
(2002)
In this paper, we discuss some formal properties of the model of bidirectional Optimality Theory that was developed in Blutner 2000. We investigate the conditions under which bidirectional optimization is a well-defined notion, and we give a conceptually simpler reformulation of Blutner's definition. In the second part of the paper, we show that bidirectional optimization can be modeled by means of finite state techniques. There we rely heavily on the related work of Frank and Satta 1998 about unidirectional optimization.
The soln.-state conformations of the hevamine inhibitor allosamidin and six potential inhibitor analogs were studied by various NMR spectroscopic techniques and mol. modeling using force field calcns. Detn. solely of the global energy min. conformation was found to be insufficient for consensus with the NMR results, and agreement between the NMR exptl. data and the theor. calcns. was only reached by assessing the structures as population-weighted av. conformers on the basis of Boltzmann distributions derived from the calcd. relative energies. The conformations of the glycosidic linkages in the compds. were found to be similar when the sugar residues were the same, but differences were markedly evident otherwise and also for the various heterocyclic group linkages. The binding of the compds. to hevamine, which may also complex to chitinases in general, was assessed using HMQC, transfer-NOESY, and both 1-D and 2-D satn. transfer difference NMR expts. Under the conditions employed, only allosamidin was implicated to be bound to hevamine, and then only by HMQC with the dipolar coupling-based expts. failing to substantiate the formation of the complex. However, the results are consistent with the biochem. activities of the compds. whereby only allosamidin has been shown to act as a competitive inhibitor.
Soldaten nach Amerika
(2002)
Die Verfasserin kommentiert in ihrer Anmerkung das Urteil des BGH vom 05.10.2001, V 237/00, in dem zur Sittenwidrigkeit bei einem auffälligen Missverhältnis zwischen Leistung und Gegenleistung im Falle eines entgeltlichen Geschäftes, durch das sich eine Partei zur Aufgabe einer Rechtsposition verpflichtet, die bei wirtschaftlicher Betrachtung einem Erbbaurecht an einem unbebauten Grundstück gleichsteht, Stellung genommen.
Oligosaccharides composed of 2-acetamido-2-deoxy-D-glucopyranose (GlcNAc) and/or 2-amino-2-deoxy-D- glucopyranose (GlcN) were prepd. by chem. degrdn. of chitin or chitosan and sepd. by gel permeation chromatog. Oligosaccharides obtained after enzymic hydrolysis of chitosan [FA 0.19] with a fungal chitinase were derivatized by reductive amination with 2-aminoacridone and sequenced by matrix-assisted laser desorption ionization time-of-flight postsource decay (PSD) mass spectrometry (MS). The sequence of a trimer, D1A2, was established as D-A-A. The compn. of a hexamer D3A3 was .apprx.65% D-A-D-D-A-A and 35% D-D-A-D-A-A. The PSD MS of a nonamer D5A4-amac revealed four isobaric species D-X-Y-D-X-Y-D-A-A, where A is GlcNAc, D is GlcN, and X and Y (X ¹ Y) are mutually either D or A. This structure motif was also obsd. in a dodecamer D7A5 which was composed of eight isobaric sequences of the general formula (D-X-Y)3- D-A-A.
Especially sulphur containing compounds are suitable for the separation of noble metals. 1,2-Dithioethenes are weak chelate-forming ligands and in the case of bis(methylthio)maleo-nitrile the donor power of both of the sulphur atoms is further decreased by the electron withdrawing effect of the cyanogroups. Crowned dithiomaleonitrile are macrocyclic chelate ligands which extract Pd(II) at sufficient rate in a very good yields. The synthesis of the immobilised ligands proceeds from the 2-allyloxy-1,2-propanediol forming the dicar-bon acid which is reduced to the diole. With the help of thionylchloride the dichloro compound is synthe-sized forming the macrocycle together with a dithiolate (1,2-disodium-1,2-dicyanethene-1,2-dithiolate, 1,2-disodium-4-methylbenzene-1,2-dithiolate) at high dilution conditions. The allylsubstituted crown ether is sillylated and the resulting alkoxysilane is immobilised onto activated silica gel. The extraction results with crown ethers are compared with that achieved with the help of substituted ß- diketones and 4-acyl-5-pyrazolones. By modification of the cavity of the macrocyclus the extraction rate increases from the acyclic compound through maleonitrile-dithio-21-crown-7, maleonitrile-dithio-15-crown-5 and maleonitrile-18-crown-6. The best results can be observed at the maleonitrile-dithio-12-crown-4. The rise of the function log D= f(log L) gives the composition of the extracted compounds as 1:1. The separa-tion is unsatisfactory in the case of Ag(I), Hg(II), Pt(II), Tl (I) and the most 3d-elements. Summarizing, a very good separation of palladium from the examined elements can be specified. Additional to the extraction experiments, as well as the crystal structures and by UV spectroscopy the for- mation constants of selected chelates were determined.
Die Landschaftsplanung und ihre Integration in die übergeordnete räumliche Planung kann zur konzeptionellen Vorbereitung und Absicherung von Schutzgebietssystemen vor allem die Vorgabe und Verankerung eines breiten, innerfachlich abgeglichenen Zielespektrums leisten. Die moderne wissenschaftliche Erkenntnisse berücksichtigende Herleitung dieser Ziele sowie die Auswahl von geeigneten, möglichst repräsentativen Räumen bedürfen jedoch noch weiterer Fundierung, die nach derzeitigem Stand wohl nicht allein innerhalb der Landschaftsplanung geleistet werden kann. Unter den Planungsebenen ist die Aufgabe der überörtlichen Landschaftsrahmenplanung vorrangig in der Formulierung von Zielgrößen für regionale Umweltqualitätsziele und Mindeststandards (etwa Flächenumfänge, das Spektrum in Schutzgebietssysteme einzubeziehender Lebensräume und Standortausprägungen) zu sehen. Neben einem rein naturschutzfachlichen Konzept ist dabei die gezielte Aufbereitung für die Regionalplanung wichtig. Die Chance der örtlichen Ebene hingegen liegt in einer örtlichen Leitbildentwicklung und Entscheidungsvorbereitung, die unter Integration partizipativer Elemente die Akzeptanz vor Ort erhöhen kann; auch diese kann jedoch nach derzeitigem Stand nicht von der kommunalen Landschaftsplanung allein geleistet werden, sondern bedarf der Ergänzung durch informelle Konzepte und Herangehensweisen. Dabei sind noch nähere Überlegungen notwendig, wie das Zusammenspiel und Ineinandergreifen beider Ebenen der Landschaftsplanung verbessert werden kann: Ein Ansatz, der lediglich seitens der Landschaftsrahmenplanung "top-down" Ziele vorgibt, birgt Gefahr, ins Leere zu laufen, da er an den konkreten Erfordernissen vor Ort vorbeigeht. Vielmehr bedarf es zugleich "bottom-up" einer Hinterfütterung oft abstrakter Zielgrößen mit konkreten, möglichst vor Ort bereits abgestimmten Flächen. Damit alle naturräumlichen Großeinheiten und Großökosysteme in Deutschland über Schutzgebiete repräsentiert sind, wäre des weiteren - wie vom Rat von Sachverständigen für Umweltfragen (SRU 1996, Rn. 262) gefordert - über die Ländergrenzen hinweg die Erarbeitung einer Bundes-Naturschutzkonzeption erforderlich und damit eine Ergänzung der Planungshierarchie. Zwar existieren derartige Vorstellungen bereits als Fachkonzepte (vgl. den Beitrag von FINCK in diesem Band), jedoch bietet das derzeitige rahmenrechtlich organisierte Planungssystem für deren Verankerung noch keinen Ansatz. Vor dem Hintergrund der vielfältigen Anforderungen an Schutzgebietssysteme darf zugleich der breit gefächerte konzeptionelle Auftrag der Landschaftsplanung gerade auch mit Blick auf ihren flächendeckenden Anspruch und die Berücksichtigung der Auswirkungen der verschiedenen Landnutzungen nicht aus den Augen verloren werden. So wurde bereits von anderer Seite (SRU 1996a, Rn. 139) darauf hingewiesen, dass die Entscheidungen der Ministerkonferenz für Raumordnung (MKRO) von 1992 und 1995, 15 % der nicht für Siedlungszwecke genutzten Flächen für den Aufbau eines Biotopverbunds mit Vorrang für Natur und Landschaft zu verwenden, die Gefahr bergen, dass dadurch eine Vorgabe für die Landschaftsrahmenplanung gemacht worden ist, die sie quasi auf die inhaltliche Ausgestaltung von Biotopverbundsystemen reduziert. Es ist wichtig, dass die Landschaftsplanung Schutzgebietssysteme in angemessenem Umfang berücksichtigt und ein breites Spektrum an Schutzzielen verankert, sich dabei aber das Aufgabenfeld ihrerseits zugleich nicht zu sehr auf die zwar originären, aber letztlich doch nur einen Teilbereich des Naturschutzes erfassenden Belange des Flächen- und Gebietsschutzes einengen lässt.
Der Verfasser kommentiert das Urteil des BGH vom 13.9.2001, VII ZR 415/99. Danach ist derjenige, der die Beseitigung der Folgen aus einer nach widerrechtlicher Drohung eingegangenen Verpflichtung verlangen kann, grundsätzlich nicht dem Einwand des Mitverschuldens nach $ 254 Abs.1 BGB ausgesetzt. Weiterhin beschäftigt sich der Autor mit der Möglichkeit, neben der Anfechtung nach $ 123 BGB einen Schadensersatzanspruch auf Befreiung von der eingegangenen Verbindlichkeit nach den Grundsätzen der c.i.c. durchzusetzen. Schließlich geht er auf weitere Ansprüche des Klägers ein. Hier geht es in erster Linie um bereicherungsrechtliche Ansprüche.