In memoriam Prof. Dr. habil. Hugo Weinitschke

Hugo Weinitschke, langjähriger Direktor des Instituts für Landschaftsforschung und Naturschutz Halle (ILN), verschied kurz vor Vollendung seines 80. Lebensjahres in Halle (Saale). Mit Ihm verlieren wir einen Repräsentanten des Naturschutzes in der DDR, der sein gesamtes berufliches Leben der wissenschaftlichen und ehrenamtlichen Aufgabe des Schutzes von Natur und Landschaft gewidmet hat. Anlässlich seines 70. Geburtstages wurde sein Lebenswerk bereits im Jahr 2000 in dieser Zeitschriftenreihe (37. Jg. H.1, S.35) gewürdigt

Zustand, Entwicklungstendenzen und Pflege der Bergwiesen

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Sustainable Transport Planning for Israel and Palestine

The paper presents the results of a trilateral research project carried out jointly by German, Israeli, and Palestinian institutions. The overall objective of the project was to develop and adapt models and tools for resource-preserving transport planning in the West Bank and the adjacent areas. Because of its high dynamics and the particular political circumstances, broader socio-economic and political considerations needed to be included in the analysis of present conditions and the exploration of future developments in this area. Compared to other countries, transport planning in Palestine is much more linked to sensitive issues such as security, Israeli settlements, bypass road s and checkpoints, which cannot always be separated in a clean way. To evaluate different policy options for transport planning, a modelling system has been developed consisting of a GIS database, integrated transport and environmental models and network extensions tools. The paper pres ents the integrated database and the modelling system developed, describes the scenarios implemented and compares the outcomes of the model runs with respect to their environmental and social impacts.The research project “GIS-Based Models and GIS-Tools for Sustainable Transport Planning in Israel and Palestine” was funded by the German Research Council (DFG) within the framework of their trilateral research programme bringing German, Israeli and Palestinian researchers together. The project was conducted in two phases. Phase 1 started in March 1997 and ended in February 1999. Phase 2 started in March 2000 and officially ended in February 2000. The project consortium wishes to thank the German Research Council for making this study possible through a generous research grant

Cloud engineering is search based software engineering too

Many of the problems posed by the migration of computation to cloud platforms can be formulated and solved using techniques associated with Search Based Software Engineering (SBSE). Much of cloud software engineering involves problems of optimisation: performance, allocation, assignment and the dynamic balancing of resources to achieve pragmatic trade-offs between many competing technical and business objectives. SBSE is concerned with the application of computational search and optimisation to solve precisely these kinds of software engineering challenges. Interest in both cloud computing and SBSE has grown rapidly in the past five years, yet there has been little work on SBSE as a means of addressing cloud computing challenges. Like many computationally demanding activities, SBSE has the potential to benefit from the cloud; ‘SBSE in the cloud’. However, this paper focuses, instead, of the ways in which SBSE can benefit cloud computing. It thus develops the theme of ‘SBSE for the cloud’, formulating cloud computing challenges in ways that can be addressed using SBSE

Are SMBHs shrouded by "super-Oort" clouds of comets and asteroids?

The last decade has seen a dramatic confirmation that an in situ star formation is possible inside the inner parsec of the Milky Way. Here we suggest that giant planets, solid terrestrial-like planets, comets and asteroids may also form in these environments, and that this may have observational implications for Active Galactic Nuclei (AGN). Like in debris discs around main sequence stars, collisions of large solid objects should initiate strong fragmentation cascades. The smallest particles in such a cascade - the microscopic dust - may provide a significant opacity. We put a number of observational and physical constraints on AGN obscuring torii resulting from such fragmentation cascades. We find that torii fed by fragmenting asteroids disappear at both low and high AGN luminosities. At high luminosities, $L \sim L_{\rm Edd}$, where $L_{\rm Edd}$ is the Eddington limit, the AGN radiation pressure blows out the microscopic dust too rapidly. At low luminosities, on the other hand, the AGN discs may avoid gravitational fragmentation into stars and solids. We also note that these fragmentation cascades may be responsible for astrophysically "large" dust particles of approximately micrometer sizes that were postulated by some authors to explain unusual absorption properties of the AGN torii.Comment: a typo in the title correcte

Investigation of the β-pinene photooxidation by OH in the atmosphere simulation chamber SAPHIR

Beside isoprene, monoterpenes are the non-methane volatile organic compounds (VOC) with the highest global emission rates. Due to their high reactivity towards OH, monoterpenes can dominate the radical chemistry of the atmosphere in forested areas. In the present study the photochemical degradation mechanism of β-pinene was investigated in the Jülich atmosphere simulation chamber SAPHIR. The focus of this study is on the OH budget in the degradation process. Therefore the SAPHIR chamber was equipped with instrumentation to measure radicals (OH, HO2, RO2), the total OH reactivity, important OH precursors (O3, HONO, HCHO), the parent VOC beta-pinene, its main oxidation products, acetone and nopinone, and photolysis frequencies. All experiments were carried out under low NOx conditions (≤ 2 ppb) and at atmospheric beta-pinene concentrations (≤ 5 ppb) with and without addition of ozone. For the investigation of the OH budget, the OH production and destruction rates were calculated from measured quantities. Within the limits of accuracy of the instruments, the OH budget was balanced in all β-pinene oxidation experiments. However, even though the OH budget was closed, simulation results from the Master Chemical Mechanism 3.2 showed that the OH production and destruction rates were underestimated by the model. The measured OH and HO2 concentrations were underestimated by up to a factor of two whereas the total OH reactivity was slightly overestimated because of the poor reproduction of the measured nopinone by the model by up to a factor of three. A new, theory-derived first-generation product distribution by Vereecken and Peeters was able to reproduce the measured nopinone time series and the total OH reactivity. Nevertheless the measured OH and HO2 concentrations remained underestimated by the numerical simulations. These observations together with the fact that the measured OH budget was closed suggest the existence of unaccounted sources of HO2

Similarities and differences in the autonomic control of airway and urinary bladder smooth muscle

The airways and the urinary bladder are both hollow organs serving very different functions, i.e. air flow and urine storage, respectively. While the autonomic nervous system seems to play only a minor if any role in the physiological regulation of airway tone during normal breathing, it is important in the physiological regulation of bladder smooth muscle contraction and relaxation. While both tissues share a greater expression of M2 than of M3 muscarinic receptors, smooth muscle contraction in both is largely mediated by the smaller M3 population apparently involving phospholipase C activation to only a minor if any extent. While smooth muscle in both tissues can be relaxed by β-adrenoceptor stimulation, this primarily involves β2-adrenoceptors in human airways and β3-adrenoceptors in human bladder. Despite activation of adenylyl cyclase by either subtype, cyclic adenosine monophosphate plays only a minor role in bladder relaxation by β-agonists; an important but not exclusive function is known in airway relaxation. While airway β2-adrenoceptors are sensitive to agonist-induced desensitization, β3-adrenoceptors are generally considered to exhibit much less if any sensitivity to desensitization. Gene polymorphisms exist in the genes of both β2- and β3-adrenoceptors. Despite being not fully conclusive, the available data suggest some role of β2-adrenoceptor polymorphisms in airway function and its treatment by receptor agonists, whereas the available data on β3-adrenoceptor polymorphisms and bladder function are too limited to allow robust interpretation. We conclude that the distinct functions of airways and urinary bladder are reflected in a differential regulation by the autonomic nervous system. Studying these differences may be informative for a better understanding of each tissue

Zustand, Entwicklungstendenzen und Pflege der Bergwiesen

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Landschaftspflege und Naturschutz zwischen gestern und morgen

Fünf Jahre sind seit der politischen Wende vergangen, die Fläche der Naturschutzgebiete im Land Sachsen-Anhalt konnte fast verdreifacht werden, neue Schutzkategorien, wie der Nationalpark oder die § 30 Biotope laut Naturschutzgesetz des Landes Sachsen-Anhalt (NatSchG LSA), sind entstanden, die Anzahl der hauptamtlichen Mitarbeiter im Naturschutz aller Ebenen ist um das fünf- bis sechsfache angewachsen. So ist es an der Zeit, rückschauend eine Bilanz zu ziehen, aber auch zu fragen, ob wir schon auf der Höhe der erforderlichen Leistungen sind