18 research outputs found

    Phasen des holozĂ€nen Klimawandels und kulturgeschichtliche Wirkungen in SĂŒdwest-Bulgarien

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    FĂŒr SĂŒdosteuropa wird am Beispiel SĂŒdwest-Bulgariens die Mensch-Umwelt-Beziehung als kausaler Zusammenhang zwischen Klimadynamik und kulturhistorischer Entwicklung aufgezeigt. Unsere heutige Kulturlandschaft hat ihre Wurzeln im Naturpotenzial, welches Gunst- und Ungunstfaktoren der menschlichen Nutzung bestimmt. Das Klima stellt dabei einen entscheidenden Regelfaktor dar. In historischen und prĂ€historischen Zeiten geringerer Bevölkerungsdichte waren wĂ€rmere Klimaperioden stets Gunstzeiten fĂŒr die Bevölkerung, insbesondere in gebirgigen Regionen wie SĂŒdosteuropa. Hochgebirge im Übergangsbereich vom gemĂ€ĂŸigten zum mediterranen Klimagebiet werden als besonders anfĂ€llig fĂŒr die aktuellen globalen VerĂ€nderungen angesehen. GeringfĂŒgige TemperaturverĂ€nderungen verschieben Anbaugrenzen, verĂ€ndern das Abflussregime der FlĂŒsse oder beeintrĂ€chtigen die geomorphologische StabilitĂ€t. Klimaverbesserungen und gesellschaftliche Impulse in Europa konnten vor allem fĂŒr das Atlantikum, das Subatlantikum und fĂŒr die jĂŒngere Neuzeit verzeichnet werden. Dies ist auch fĂŒr SĂŒdosteuropa belegbar. Im Subatlantikum und im frĂŒhen Mittelalter (500-700/1100-1300 AD) haben in SW-Bulgarien optimale Bedingungen fĂŒr Vegetations- und Bodenentwicklung in Höhenlagen geherrscht, die heute deutlich ĂŒber der Waldgrenze liegen. AuffĂ€llig ist die SynchronitĂ€t mit BlĂŒtezeiten gesellschaftlicher Entwicklung (1. und 2. Bulgarenstaat). Klimaverschlechterungen traten im Subboreal und wĂ€hrend der "Kleinen Eiszeit" auf, Zeiten, in denen in Bulgarien die kulturhistorische Entwicklung stagnierte. Letztlich lagen die Temperaturschwankungen im Postglazial aber in einem relativ engen Korridor von ± 2°C. (Autorenreferat)This article uses the example of Southwest Bulgaria to demonstrate the relationship between people and their environment in South-East Europe as a causal connection between the dynamics of the climate and development of cultural history. Our present cultural landscape has its roots in the natural potential that dictates the factors having a favourable or unfavourable impact on its use by humans. Climate is one of the key regulating factors here. Warmer climatic periods were always the best times for people in historical and prehistorical times of low population density, in particular in mountainous regions such as South-East Europe. The high mountains in transition from moderate to the Mediterranean climatic zone are deemed particularly susceptible for the current global changes. Slight temperature changes shift the borders of cultivation, change the drainage regime of rivers or impair geomorphological stability. There have been climate improvements and social impulses in Europe especially for the Atlantic period, the Sub-Atlantic period and the early Modern Times, which can also be demonstrated for South-East Europe. There have been optimum conditions for the development of vegetation and soil in the heights of Southwest Bulgaria in the Sub-Atlantic period and the early Middle Ages (500-700/1100-1300 AD) that are clearly above the border of the forest. What is peculiar is the synchronity of periods when social development has flourished (i.e., the first and second state of the Bulgarians). There was a deterioration in the climate during the Subboreal period and during the "Little Ice Age". These are times when the development of Bulgaria's cultural history stagnated. Recently, the temperature fluctuations in the post glacial period were in a relatively tight corridor of ± 2° C. (author's abstract

    Landschaftsökologische BeitrÀge zum Flusseinzugsgebietsmanagement in der Mesta-Nestos-Region (Bulgarien-Griechenland)

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    Das Mesta-Nestos-Einzugsgebiet in Bulgarien und Griechenland stellt ein Beispiel fĂŒr die Erarbeitung grenzĂŒberschreitender Entscheidungssysteme sowie die Entwicklung von Methoden und Informationen fĂŒr eine integrierte Regionalplanung in SĂŒdosteuropa dar. Landschaftsökologische BeitrĂ€ge sind fĂŒr eine nachhaltige Nutzung der Naturressourcen und insbesondere dem Wasserressourcenmanagement vor dem Hintergrund der neu zu implementierenden EU-Wasserrahmenrichtlinie notwendig. In dem Beitrag wird eine geographische Einzugsgebietscharakteristik prĂ€sentiert und es werden die wichtigsten grenzĂŒberschreitenden AktivitĂ€ten zusammengefasst. Die Mesta wird hauptsĂ€chlich aus den bulgarischen Gebirgen Rila, Pirin und Rhodopen, den sog. "WassertĂŒrmen", gespeist, so dass hier ein pluvio-nivales Abflussregime herrscht. Hochgebirgsvegetation ĂŒber 2.000 m NN sowie ausgedehnte NadelwĂ€lder in der montanen Stufe dominieren in den Gebirgen, wĂ€hrend die intramontanen Becken und TĂ€ler anthropogen ĂŒberprĂ€gten Steppencharakter aufweisen. Ab der griechischen Grenze heißt der Fluss Nestos und mediterrane Klimate beeinflussen zunehmend den Abflussgang. Bei Xanthi mĂŒndet der Nestos in einem breiten Delta in die ÄgĂ€is. Am Unterlauf nehmen die Nutzungskonflikte um die Ressource Wasser zu: Trinkwasserproduktion, Energiegewinnung, BewĂ€sserungsfeldbau, industrielles Brauchwasser sind Beispiele dafĂŒr. OberflĂ€chen-Grundwasser gekoppelte Einzugsgebietsmodelle, die wesentliche Gebietsparameter wie Klima, Böden, Landnutzung oder Bewirtschafterdaten berĂŒcksichtigen, sind fĂŒr die Erstellung von Abflussszenarien notwendig. FĂŒr die Mesta-Nestos-Region wurde das fĂŒr derartige Aufgabenstellungen geeignete hydrologische Modell MODCOU angewendet. Messungen hinsichtlich der GewĂ€sserqualitĂ€t wurden als Fallstudien im oberen Einzugsgebiet der Mesta realisiert. Im Beitrag werden Ergebnisse fĂŒr den Nationalpark Pirin, das Becken von Razlog sowie zur Umweltsituation im Gebiet des ehemaligen Uranbergbaus bei EleĆĄnica diskutiert. Die Analysen im Hochgebirge zeigten eine relativ geringe Beeinflussung der GewĂ€ssersysteme auf. Erhöhte Stoffgehalte wurden in den urban-wirtschaftlich genutzten Beckenbereichen nachgewiesen. Die Selbstreinigungskraft der FließgewĂ€sser ist aber auch in diesen Abschnitten recht hoch, was gute saprobiologische GewĂ€sserzustĂ€nde belegten. Untersuchungen der Urankonzentrationen an der Mesta zeigten im Mittel keine GrenzwertĂŒberschreitungen an. Die ehemaligen Gruben und Tailings besitzen jedoch ein hohes GefĂ€hrdungspotenzial. Mit der Sanierung der Altlasten ist mit UnterstĂŒtzung der EU begonnen worden. Die Forcierung der sozioökonomischen Entwicklung der peripheren, grenzĂŒberschreitenden Region stellt eine gegenwĂ€rtige und zukĂŒnftige Aufgabe dar. Damit ist zu erwarten, dass sich die NutzungsansprĂŒche an die Wasserressourcen erhöhen. Mit den regionalen Auswirkungen des globalen Klimawandels dĂŒrfte sich die Situation noch verschĂ€rfen, so dass ein problembezogenes Einzugsgebietsmanagement unbedingt notwendig ist.The Mesta-Nestos river basin in Bulgaria and Greece is a case study for transboundary decision making support in Southeastern Europe and a show case for the development of methodologies and information gathering for integrated regional planning of water resources. Landscape ecology offers a necessary contribution to the sharing of these natural resources for integrated water resource management in compliance with the new European Water Framework Directive. Originated in the Bulgarian Mountains of Rila, Pirin and Rhodopes, the Mesta River is characterized by an abundant precipitation induced flow out of these "water towers". High mountains vegetation in the upper ranges contrast with intra-mountain basins and valleys with steppes and cultivated fields. Down river, passing the boundary with Greece, more typical Mediterranean climatic conditions regulate the runoff regime of the Nestos river. Toward its end the stream is flowing through a delta nearby Xanthi into the Aegean Sea. Land use conflicts in this water scarce region cover a wide spectrum of activities like agricultural irrigation, drinking water production, diversions for industrial water and pollution from mining as a few examples. A geographic characterisation of the catchment area is presented here as well as important actions and agreements. Surface-groundwater coupled models of watersheds need to be integrated with a wide variety of tools simulating the meteorological, soils and farming inputs, among others. Due to its progressive grid system, the MODCOU hydrological model is well suited to such schemes, especially in the Mesta-Nestos region. It is used to evaluate the annual discharge of fresh water entering Greek territory. Measures of the water quality have been done in the upper basin. Results will be illustrated by the example of the environmental situation in the alpine region of the Pirin National Park as well as in the Basin of Razlog with a stronger anthropogenic impact and pollution around a former uranium mine near the village of EleĆĄnica. The analysis performed in the upper mountain areas indicates relatively low background pollution. Settlements, industrial areas and extens ive agricultural land use at the bottom of the mountain slopes (e.g. Valley of Razlog) induce higher matter contents in the runoff. But the self-purification process in the river network buffers this inputs as shown by bio-ecological water investigations. Although the EleĆĄnica uranium mining plant and tailings induce radioactive traces in the runoff water with decade median concentrations which are below Bulgarian standard limits, the mine dumps and tailings are still a potential environmental hazard and the impact on neighbouring ecosystems must be monitored. The social and economic development of this transboundary region is a recently set priority for the future. It will mean an increase in water usage and more stress for the water resources if predicted global climate change regional impacts are verified. A problem focused management of the catchment area as a whole is needed for the future

    Essential histidine pairs indicate conserved haem binding in epsilonproteobacterial cytochrome c haem lyases

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    Bacterial cytochrome c maturation occurs at the outside of the cytoplasmic membrane, requires transport of haem b across the membrane, and depends on membrane-bound cytochrome c haem lyase (CCHL), an enzyme that catalyses covalent attachment of haem b to apocytochrome c. Epsilonproteobacteria such as Wolinella succinogenes use the cytochrome c biogenesis system II and contain unusually large CCHL proteins of about 900 amino acid residues that appear to be fusions of the CcsB and CcsA proteins found in other bacteria. CcsBA-type CCHLs have been proposed to act as haem transporters that contain two haem b coordination sites located at different sides of the membrane and formed by histidine pairs. W. succinogenes cells contain three CcsBA-type CCHL isoenzymes (NrfI, CcsA1 and CcsA2) that are known to differ in their specificity for apocytochromes and apparently recognize different haem c binding motifs such as CX2CH (by CcsA2), CX2CK (by NrfI) and CX15CH (by CcsA1). In this study, conserved histidine residues were individually replaced by alanine in each of the W. succinogenes CCHLs. Characterization of NrfI and CcsA1 variants in W. succinogenes demonstrated that a set of four histidines is essential for maturing the dedicated multihaem cytochromes c NrfA and MccA, respectively. The function of W. succinogenes CcsA2 variants produced in Escherichia coli was also found to depend on each of these four conserved histidine residues. The presence of imidazole in the growth medium of both W. succinogenes and E. coli rescued the cytochrome c biogenesis activity of most histidine variants, albeit to different extents, thereby implying the presence of two functionally distinct histidine pairs in each CCHL. The data support a model in which two conserved haem b binding sites are involved in haem transport catalysed by CcsBA-type CCHLs

    Strong Association of a Common Dihydropyrimidine Dehydrogenase Gene Polymorphism with Fluoropyrimidine-Related Toxicity in Cancer Patients

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    variations associated with enhanced drug toxicity. = 0.001; the attributable risk was 56.9%. Comparing tumor-type matched sets of samples, correlation of c.496A>G with toxicity was particularly present in patients with gastroesophageal and breast cancer, but did not reach significance in patients with colorectal malignancies. polymorphism strongly contributes to the occurrence of fluoropyrimidine-related drug adverse effects. Carriers of this variant could benefit from individual dose adjustment of the fluoropyrimidine drug or alternate therapies

    A randomized multi-center phase II trial of the angiogenesis inhibitor Cilengitide (EMD 121974) and gemcitabine compared with gemcitabine alone in advanced unresectable pancreatic cancer

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    BACKGROUND: Anti-angiogenic treatment is believed to have at least cystostatic effects in highly vascularized tumours like pancreatic cancer. In this study, the treatment effects of the angiogenesis inhibitor Cilengitide and gemcitabine were compared with gemcitabine alone in patients with advanced unresectable pancreatic cancer. METHODS: A multi-national, open-label, controlled, randomized, parallel-group, phase II pilot study was conducted in 20 centers in 7 countries. Cilengitide was administered at 600 mg/m(2 )twice weekly for 4 weeks per cycle and gemcitabine at 1000 mg/m(2 )for 3 weeks followed by a week of rest per cycle. The planned treatment period was 6 four-week cycles. The primary endpoint of the study was overall survival and the secondary endpoints were progression-free survival (PFS), response rate, quality of life (QoL), effects on biological markers of disease (CA 19.9) and angiogenesis (vascular endothelial growth factor and basic fibroblast growth factor), and safety. An ancillary study investigated the pharmacokinetics of both drugs in a subset of patients. RESULTS: Eighty-nine patients were randomized. The median overall survival was 6.7 months for Cilengitide and gemcitabine and 7.7 months for gemcitabine alone. The median PFS times were 3.6 months and 3.8 months, respectively. The overall response rates were 17% and 14%, and the tumor growth control rates were 54% and 56%, respectively. Changes in the levels of CA 19.9 went in line with the clinical course of the disease, but no apparent relationships were seen with the biological markers of angiogenesis. QoL and safety evaluations were comparable between treatment groups. Pharmacokinetic studies showed no influence of gemcitabine on the pharmacokinetic parameters of Cilengitide and vice versa. CONCLUSION: There were no clinically important differences observed regarding efficacy, safety and QoL between the groups. The observations lay in the range of other clinical studies in this setting. The combination regimen was well tolerated with no adverse effects on the safety, tolerability and pharmacokinetics of either agent

    Biogeochemistry of Peat and Environmental Change in the ”Erzgebirge“ Mountains (Central Europe)

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    Abstract: Peat bogs are spread over the upper altitudes in the low mountain range „Erzgebirge“. Beside the drainage especially climate change and change of depositions affect the peat quality. The microbial activity and the soluble organic matter are strongly influenced by the relationship of the content of carbon, nitrogen, phosphorus and sulfur in the upper peat layers. During the last years the environmental conditions caused lower sulfur content, closer relationship of the C/N and a higher degree of decomposition of the peat, and increased the activity of microbes and the solubility of natural organic matters. These interactions are exemplified by two sites of the western and eastern part of the range.Zusammenfassung: In den oberen Lagen des Erzgebirges kommen verbreitet Hochmoore vor. Neben der EntwĂ€sserung haben sich insbesondere Klimawandel und verĂ€nderte Stoffdeposition auf die Torfe der Gebirgsmoore ausgewirkt. In den stark zersetzten oberen Schichten hĂ€ngt die mikrobielle AktivitĂ€t sehr stark von den VerhĂ€ltnissen zwischen den Stoffgehalten von Stickstoff, Schwefel, Phosphor und Kohlenstoff ab. Ferner variiert das stoffliche Mobilisierungspotenzial. Die UmwelteinflĂŒsse der letzten Jahre haben zu geringeren Schwefelgehalten, engeren C/N-VerhĂ€ltnissen und höheren Zersetzungsgraden im Torf gefĂŒhrt, was die MikrobenaktivitĂ€t und die Löslichkeit von natĂŒrlichen organischen Stoffen forcierte. Diese ZusammenhĂ€nge werden an zwei Beispielen aus dem West- und Osterzgebirge aufgezeigt.DFG, SUB Göttingen, DGMTresearc

    Investigation of water and matter balance in catchments with degraded peat bogs in the Oberes Erzgebirge, barrage Carlsfeld

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    Abstract: Environmental change and management activities were observed by means of a combined plot sub-catchment approach in forested areas with high share of degraded peat bogs in the upper Ore Mountains using the example of Carlsfeld watershed. The investigation focused on pathways and control factors of water and matter balance. Especially we discuss the parameter ‘Dissolved Organic Carbon (DOC)’ and ‘Spectral Absorption Coefficient at 254 nm (SAK254)’ in its time dynamic and spatial characteristic. The results represent basics for stakeholder interests of user and nature protection.Zusammenfassung: Mittels eines kombinierten Standort-Kleinsteinzugsgebietsansatzes werden Umweltwandel und Maßnahmewirkungen in unterschiedlich degradierten und sich in Revitalisierung befindlichen Fichtenforsten mit hohem Anteil von Hochmooren in oberen Lagen des Erzgebirges am Beispiel Carlsfeld untersucht. Im Fokus stehen Pfade und Steuerungsfaktoren des Wasser- und Stoffhaushaltes. Insbesondere die Parameter „löslicher organischer Kohlenstoff (DOC)“ und „spektraler Absorptionskoeffizient bei 254 nm (SAK254)“ werden in zeitlicher Dynamik und rĂ€umlich vergleichend diskutiert. Die Ergebnisse stellen Grundlagen sowohl fĂŒr wasser- und forstwirtschaftliche als auch klima- und naturschutzfachliche InteressensabwĂ€gungen dar.DFG, SUB Göttingen, DGMTresearc
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