TY - JOUR A1 - Kraft, Peter A1 - Drechsler, Christiane A1 - Gunreben, Ignaz A1 - Heuschmann, Peter Ulrich A1 - Kleinschnitz, Christoph T1 - Regulation of Blood Coagulation Factors XI and XII in Patients with Acute and Chronic Cerebrovascular Disease: A Case-Control Study JF - Cerebrovascular Diseases N2 - Background: Animal models have implicated an integral role for coagulation factors XI (FXI) and XII (FXII) in thrombus formation and propagation of ischemic stroke (IS). However, it is unknown if these molecules contribute to IS pathophysiology in humans, and might be of use as biomarkers for IS risk and severity. This study aimed to identify predictors of altered FXI and FXII levels and to determine whether there are differences in the levels of these coagulation factors between acute cerebrovascular events and chronic cerebrovascular disease (CCD). Methods: In this case-control study, 116 patients with acute ischemic stroke (AIS) or transitory ischemic attack (TIA), 117 patients with CCD, and 104 healthy volunteers (HVs) were enrolled between 2010 and 2013 at our University hospital. Blood sampling was undertaken once in the CCD and HV groups and on days 0, 1, and 3 after stroke onset in patients with AIS or TIA. Correlations between serum FXI and FXII levels and demographic and clinical parameters were tested by linear regression and analysis of variance. Results: The mean age of AIS/TIA patients was 70 ± 12. Baseline clinical severity measured with NIHSS and Barthel Index was 4.8 ± 6.0 and 74 ± 30, respectively. More than half of the patients had an AIS (58%). FXI levels were significantly correlated with different leukocyte subsets (p < 0.05). In contrast, FXII serum levels showed no significant correlation (p > 0.1). Neither FXI nor FXII levels correlated with CRP (p > 0.2). FXII levels were significantly higher in patients with CCD compared with those with AIS/TIA (mean ± SD 106 ± 26% vs. 97 ± 24%; univariate analysis: p < 0.05); these differences did not reach significance in multivariate analysis adjusted for sex and age. FXI levels did not differ significantly between study groups. Sex and age were significantly associated with FXI and/or FXII levels in patients with AIS/TIA (p < 0.05). In contrast, no statistical significant influence was found for treatment modality (thrombolysis or not), pre-treatment with platelet inhibitors, and severity of stroke. Conclusions: In this study, there was no differential regulation of FXI and FXII levels between disease subtypes but biomarker levels were associated with patient and clinical characteristics. FXI and FXII levels might be no valid biomarker for predicting stroke risk. KW - biomarker KW - factor XI KW - factor XII KW - ischemic stroke KW - chronic cerebrovascular disease Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199076 SN - 1015-9770 SN - 1421-9786 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 38 IS - 5 ER - TY - JOUR A1 - Schmid, Michael A1 - Steinlein, Claus A1 - Haaf, Thomas A1 - Mijares-Urrutia, Abraham T1 - Nascent ZW Sex Chromosomes in Thecadactylus rapicauda (Reptilia, Squamata, Phyllodactylidae) JF - Cytogenetic and Genome Research N2 - The chromosomes of the turnip-tailed gecko Thecadactylus rapicauda from the Falcón State in northern Venezuela were examined by means of conventional staining, a variety of banding techniques and in situ hybridization with an 18S + 28S rDNA probe. In female specimens, C-banding analyses detected a cryptic W sex chromosome-associated interstitial heterochromatic segment which is absent in the Z sex chromosome. These ZW sex chromosomes are considered to be in a nascent stage of morphological differentiation and are absent in T. rapicauda collected in Guatemala. The amount, location and fluorochrome affinities of constitutive heterochromatin, the position of the nucleolus organizer region, and the genome sizes of female and male individuals were determined. The previously published cytogenetic data on T. rapicauda are discussed. KW - ZW sex chromosomes KW - Gecko Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199041 SN - 1424-8581 SN - 1424-859X N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 143 IS - 4 ER - TY - JOUR A1 - Papenfort, Kai A1 - Vogel, Jörg T1 - Small RNA functions in carbon metabolism and virulence of enteric pathogens JF - Frontiers in Cellular and Infection Microbiology N2 - Enteric pathogens often cycle between virulent and saprophytic lifestyles. To endure these frequent changes in nutrient availability and composition bacteria possess an arsenal of regulatory and metabolic genes allowing rapid adaptation and high flexibility. While numerous proteins have been characterized with regard to metabolic control in pathogenic bacteria, small non-coding RNAs have emerged as additional regulators of metabolism. Recent advances in sequencing technology have vastly increased the number of candidate regulatory RNAs and several of them have been found to act at the interface of bacterial metabolism and virulence factor expression. Importantly, studying these riboregulators has not only provided insight into their metabolic control functions but also revealed new mechanisms of post-transcriptional gene control. This review will focus on the recent advances in this area of host-microbe interaction and discuss how regulatory small RNAs may help coordinate metabolism and virulence of enteric pathogens. KW - sRNA KW - carbon metabolism KW - Hfq KW - CsrA KW - virulence Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-197520 SN - 2235-2988 VL - 4 IS - 91 ER - TY - JOUR A1 - Schneider, Eberhard A1 - El Hajj, Nady A1 - Haaf, Thomas T1 - Epigenetic Information from Ancient DNA Provides New Insights into Human Evolution BT - Commentary on Gokhman D et al. (2014): Reconstructing the DNA Methylation Maps of the Neanderthal and the Denisovan. Science 344:523–527 JF - Brain, Behavior and Evolution N2 - No abstract available. KW - human evolution KW - Neanderthal Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196800 SN - 0006-8977 SN - 1421-9743 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 84 IS - 3 ER - TY - JOUR A1 - Schraven, Sebastian P. A1 - Dalhoff, Ernst A1 - Wildenstein, Daniela A1 - Hagen, Rudolf A1 - Gummer, Anthony W. A1 - Mlynski, Robert T1 - Alternative Fixation of an Active Middle Ear Implant at the Short Incus Process JF - Audiology and Neurotology N2 - Introduction: Since 1996, the preferred approach for positioning the active middle-ear implant Vibrant Soundbridge© is a mastoidectomy and a posterior tympanotomy. With this device, placement of the floating mass transducer (FMT) on the long incus process is the standard method for treatment of mild-to-severe sensorineural hearing loss in the case of normal middle-ear anatomy. The aim of this study was to determine the vibrational effectiveness of FMT placement at the short incus process. Materials and Methods: An extended antrotomy and a posterior tympanotomy were performed in 5 fresh human temporal bones. As a control for normal middle-ear function, the tympanic membrane was stimulated acoustically and the vibration of the stapes footplate and the round-window (RW) membrane were (sequentially) measured by laser Doppler vibrometry. Vibration responses for coupling of an FMT to the long incus process (standard coupling) were compared to those for coupling to the short incus process. Results: Apart from narrow frequency bands near 3 and 9 kHz for the stapes footplate and RW membrane, respectively, the velocity responses presented no significant differences between standard coupling of the FMT and coupling to the short incus process. Conclusion: Coupling the FMT to the short incus process may be a viable alternative in cases where the surgical approach is limited to an extended antrotomy. A reliable technique for attachment to the short incus process has yet to be developed. KW - middle-ear surgery KW - active middle-ear implant KW - floating mass transducer KW - incus KW - Laser Doppler vibrometer Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196823 SN - 1420-3030 SN - 1421-9700 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 19 IS - 1 ER - TY - JOUR A1 - Schneider, Andreas A1 - Gutjahr-Lengsfeld, Lena A1 - Ritz, Eberhard A1 - Scharnagl, Hubert A1 - Gelbrich, Götz A1 - Pilz, Stefan A1 - Macdougall, Iain C. A1 - Wanner, Christoph A1 - Drechsler, Christiane T1 - Longitudinal Assessments of Erythropoietin-Stimulating Agent Responsiveness and the Association with Specific Clinical Outcomes in Dialysis Patients JF - Nephron Clinical Practice N2 - Background: Dose requirements of erythropoietin-stimulating agents (ESAs) can vary considerably over time and may be associated with cardiovascular outcomes. We aimed to longitudinally assess ESA responsiveness over time and to investigate its association with specific clinical end points in a time-dependent approach. Methods: The German Diabetes and Dialysis study (4D study) included 1,255 diabetic dialysis patients, of whom 1,161 were receiving ESA treatment. In those patients, the erythropoietin resistance index (ERI) was assessed every 6 months during a median follow-up of 4 years. The association between the ERI and cardiovascular end points was analyzed by time-dependent Cox regression analyses with repeated ERI measures. Results: Patients had a mean age of 66 ± 8.2 years; 53% were male. During follow-up, a total of 495 patients died, of whom 136 died of sudden death and 102 of infectious death. The adjusted and time-dependent risk for sudden death was increased by 19% per 5-unit increase in the ERI (hazard ratio, HR = 1.19, 95% confidence interval, CI = 1.07-1.33). Similarly, mortality increased by 25% (HR = 1.25, 95% CI = 1.18-1.32) and infectious death increased by 27% (HR = 1.27, 95% CI = 1.13-1.42). Further analysis revealed that lower 25-hydroxyvitamin D levels were associated with lower ESA responsiveness (p = 0.046). Conclusions: In diabetic dialysis patients, we observed that time-varying erythropoietin resistance is associated with sudden death, infectious complications and all-cause mortality. Low 25-hydroxyvitamin D levels may contribute to a lower ESA responsiveness. KW - dialysis KW - erythropoietin KW - diabetes KW - epidemiology Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196511 SN - 1660-2110 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 128 IS - 1-2 ER - TY - JOUR A1 - Ono, Mitsuaki A1 - Sonoyama, Wataru A1 - Nema, Kazuki A1 - Hara, Emilio Satoshi A1 - Oida, Yasutaka A1 - Pham, Hai Thanh A1 - Yamamoto, Katushi A1 - Hirota, Kazuo A1 - Sugama, Kazushige A1 - Sebald, Walter A1 - Kuboki, Takuo T1 - Regeneration of calvarial defects with Escherichia coli-derived rhBMP-2 adsorbed in PLGA membrane JF - Cells Tissues Organs N2 - Objective: Escherichia coli-derived recombinant human bone morphogenetic protein-2 (E-BMP-2) has been shown to be as effective as mammalian cell-derived BMP-2. However, several in vitro and in vivo experiments are still necessary to validate the effectiveness of E-BMP-2 due to the difference in synthesis process, mainly related to protein nonglycosylation. The objective of this study was to investigate whether biodegradable polylactide-co-glycolide (PLGA) membrane is a suitable carrier for E-BMP-2 delivery for bone regeneration of critical-sized defects in rat calvaria. Materials and Methods: First, the osteoinductive effect of E-BMP-2 was confirmed in vitro in mouse bone marrow stromal cells by analysis of osteocalcin mRNA levels, and calcium deposition was detected by alizarin red staining. Before in vivo experiments, the release profile of E-BMP-2 from PLGA membranes was determined by ELISA. E-BMP-2 (0, 1, 5 and 10 μg/μl) was applied for ectopic and orthotopic bone formation and was analyzed by X-ray, micro-CT and histology. Results: Release-profile testing showed that PLGA membrane could retain 94% of the initially applied E-BMP-2. Ectopic bone formation assay revealed that combination of E-BMP-2/PLGA membrane strongly induced bone formation. Stronger osteoinductivity with complete repair of critical-sized defects was observed only with PLGA membranes adsorbed with 5 and 10 μg/μl of E-BMP-2, whereas no bone formation was observed in the groups that received no membrane or 0-μg/μl dose of E-BMP-2. Conclusion: PLGA membrane was shown to be a suitable carrier for sustained release of E-BMP-2, and the E-BMP-2/PLGA membrane combination was demonstrated to be efficient in bone regeneration in a model of critical-sized defects. KW - Escherichia coli-derived recombinant human bone morphogenetic protein-2 KW - Bone regeneration KW - Polylactide-co-glycolide KW - Ectopic bone formation Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196680 SN - 1422-6405 SN - 1422-6421 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 198 IS - 5 SP - 367 EP - 376 ER - TY - JOUR A1 - Schmid, Michael A1 - Steinlein, Claus A1 - Feichtinger, Wolfgang A1 - Haaf, Thomas A1 - Mijares-Urrutia, Abraham A1 - Schargel, Walter E. A1 - Hedges, S. Blair T1 - Cytogenetic Studies on Gonatodes (Reptilia, Squamata, Sphaerodactylidae) JF - Cytogenetic and Genome Research N2 - Mitotic and meiotic chromosomes of 5 species of the reptile genus Gonatodes are described by means of conventional staining, banding analyses and in situ hybridization using a synthetic telomeric DNA probe. The amount, location and fluorochrome affinities of constitutive heterochromatin, the number and positions of nucleolus organizer regions, and the patterns of telomeric DNA sequences were determined for most of the species. The karyotypes of G. falconensis and G. taniae from northern Venezuela are distinguished by their extraordinarily reduced diploid chromosome number of 2n = 16, which is the lowest value found so far in reptiles. In contrast to most other reptiles, both species have exclusively large biarmed (meta- and submetacentric) chromosomes. Comparison of the karyotypes of G. falconensis and G. taniae with those of other Gonatodes species indicates that the exceptional 2n = 16 karyotype originated by a series of 8 centric fusions. The karyotypes of G. falconensis and G. taniae are further characterized by the presence of considerable amounts of (TTAGGG)n telomeric sequences in the centromeric regions of all chromosomes. These are probably not only relics of the centric fusion events, but a component of the highly repetitive DNA in the constitutive heterochromatin of the chromosomes. The genome sizes of 4 Gonatodes species were determined using flow cytometry. For comparative purposes, all previously published cytogenetic data on Gonatodes and other sphaerodactylids are included and discussed. KW - banding analyses KW - FISH KW - geckos KW - karyotype evolution KW - meiotic chromosomes KW - mitotic chromosomes Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196753 SN - 1424-8581 SN - 1424-859X N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 144 IS - 1 ER - TY - JOUR A1 - Schmid, Michael A1 - Steinlein, Claus A1 - Feichtinger, Wolfgang A1 - Bogart, James P. T1 - Chromosome Banding in Amphibia. XXXI. The Neotropical Anuran Families Centrolenidae and Allophrynidae JF - Cytogenetic and Genome Research N2 - The mitotic chromosomes of 11 species from the anuran families Centrolenidae and Allophrynidae were analyzed by means of conventional staining, banding techniques, and in situ hybridization. The amount, location, and fluorochrome affinities of constitutive heterochromatin, the number and positions of nucleolus organizer regions, and the patterns of telomeric DNA sequences were determined for most of the species. The karyotypes were found to be highly conserved with a low diploid chromosome number of 2n = 20 and morphologically similar chromosomes. The sister group relationship between the Centrolenidae and Allophrynidae (unranked taxon Allocentroleniae) is clearly corroborated by the cytogenetic data. The existence of heteromorphic XY♂/XX♀ sex chromosomes in an initial stage of morphological differentiation was confirmed in Vitreorana antisthenesi. The genome sizes of 4 centrolenid species were determined using flow cytometry. For completeness and for comparative purposes, all previously published cytogenetic data on centrolenids are included. KW - Allophrynidae KW - Anura KW - chromosome evolution KW - sex chromosomes KW - Centrolenidae Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196763 SN - 1424-8581 SN - 1424-859X N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 142 IS - 4 ER - TY - JOUR A1 - Hohmann, Cynthia A1 - Pinart, Mariona A1 - Tischer, Christina A1 - Gehring, Ulrike A1 - Heinrich, Joachim A1 - Kull, Inger A1 - Melén, Eric A1 - Smit, Henriette A. A1 - Torrent, Maties A1 - Wijga, Alet H. A1 - Wickman, Magnus A1 - Bachert, Claus A1 - Lødrup Carlsen, Karin C. A1 - Carlsen, Kai-Håkon A1 - Bindslev-Jensen, Carsten A1 - Eller, Esben A1 - Esplugues, Ana A1 - Fantini, Maria Pia A1 - Annesi-Maesano, Isabella A1 - Momas, Isabelle A1 - Porta, Daniela A1 - Vassilaki, Maria A1 - Waiblinger, Dagmar A1 - Sunyer, Jordi A1 - Antó, Josep M. A1 - Bousquet, Jean A1 - Keil, Thomas T1 - The Development of the MeDALL Core Questionnaires for a Harmonized Follow-Up Assessment of Eleven European Birth Cohorts on Asthma and Allergies JF - International Archives of Allergy and Immunology N2 - Background: Numerous birth cohorts have been initiated in the world over the past 30 years using heterogeneous methods to assess the incidence, course and risk factors of asthma and allergies. The aim of the present work is to provide the stepwise proceedings of the development and current version of the harmonized MeDALL-Core Questionnaire (MeDALL-CQ) used prospectively in 11 European birth cohorts. Methods: The harmonization of questions was accomplished in 4 steps: (i) collection of variables from 14 birth cohorts, (ii) consensus on questionnaire items, (iii) translation and back-translation of the harmonized English MeDALL-CQ into 8 other languages and (iv) implementation of the harmonized follow-up. Results: Three harmonized MeDALL-CQs (2 for parents of children aged 4-9 and 14-18, 1 for adolescents aged 14-18) were developed and used for a harmonized follow-up assessment of 11 European birth cohorts on asthma and allergies with over 13,000 children. Conclusions: The harmonized MeDALL follow-up produced more comparable data across different cohorts and countries in Europe and will offer the possibility to verify results of former cohort analyses. Thus, MeDALL can become the starting point to stringently plan, conduct and support future common asthma and allergy research initiatives in Europe. KW - harmonization KW - MeDALL KW - european birth cohorts KW - asthma KW - allergy KW - questionnaire assessment Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196594 SN - 1018-2438 SN - 1423-0097 VL - 163 IS - 3 ER - TY - JOUR A1 - Kiesler, Reinhard T1 - Anja Overbeck / Wolfgang Schweickard / Harald Völker (edd.), Lexikon, Varietät, Philologie: Romanistische Studien. Günter Holtus zum 65. Geburtstag, Berlin, De Gruyter, 2011, XLIV + 824 p. JF - Zeitschrift für romanische Philologie N2 - Kein Abstract verfügbar. KW - Rezension Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195505 SN - 1865-9063 SN - 0049-8661 N1 - Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich. VL - 130 IS - 4 SP - 1165 EP - 1170 ER - TY - JOUR A1 - Reber, Elisabeth T1 - Constructing evidence at Prime Minister's Question Time: An analysis of the grammar, semantics and pragmatics of the verb see JF - Intercultural Pragmatics N2 - Abstract Constructing evidence constitutes a practice to establish the speaker's authority at Prime Minister's Question Time (PMQT), a weekly half-hour session in the British House of Commons. Here the verb see constitutes a resource for both the questioning Leader of the Opposition (LO) and Members of Parliament (MP) as well as for the responding Prime Minister (PM) to claim first-hand perceptual experience. This paper takes an integrated approach, offering a combined analysis of the grammatical formatting, semantics and pragmatics of the verb see in the context of evidential moves at PMQT. It shows how the verb see is functional in referring to the perceptual basis of a claim made and how its grammatical formatting is reflective of the contingencies of the local interactional context. The analysis is grounded in 32 sessions of PMQT (ca. 16 hrs of video-recordings). The results can be summarised as follows: 1) The evidential function of the verb is achieved through its context-specific grammatical formatting and semantics. 2) The reference to the perceptual basis of a claim evoked by see may co-occur with epistemic qualification and evaluative expressions. 3) The formatting of the verb may be indexical of the political relationship between the questioner and the responding PM. KW - parliamentary interaction KW - perception KW - evidentiality KW - epistemic modality KW - see Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195549 SN - 1613-365X SN - 1612-295X N1 - Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich. VL - 11 IS - 3 SP - 357 EP - 387 ER - TY - JOUR A1 - Karremann, Isabel T1 - April London.The Cambridge Introduction to the Eighteenth-Century Novel. Cambridge Introductions to Literature. Cambridge: Cambridge University Press, 2012, 260 pp., $ 26.99 pb. JF - Anglia N2 - No abstract available. KW - novel Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195307 SN - 1865-8938 SN - 0340-5222 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 132 IS - 3 ER - TY - JOUR A1 - Gwosdek, Hedwig T1 - Nicholas Orme. English School Exercises, 1420–1530. Studies and Texts 181. Toronto: Pontifical Institute of Mediaeval Studies, 2013, xi + 441 pp., $ 95.00. JF - Anglia N2 - No abstract available. KW - exercise Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195318 SN - 1865-8938 SN - 0340-5222 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 132 IS - 3 ER - TY - JOUR A1 - Cull, Benjamin A1 - Lima Prado Godinho, Joseane A1 - Fernandes Rodrigues, Juliany Cola A1 - Frank, Benjamin A1 - Schurigt, Uta A1 - Williams, Roderick AM A1 - Coombs, Graham H A1 - Mottram, Jeremy C T1 - Glycosome turnover in Leishmania major is mediated by autophagy JF - Autophagy N2 - Autophagy is a central process behind the cellular remodeling that occurs during differentiation of Leishmania, yet the cargo of the protozoan parasite's autophagosome is unknown. We have identified glycosomes, peroxisome-like organelles that uniquely compartmentalize glycolytic and other metabolic enzymes in Leishmania and other kinetoplastid parasitic protozoa, as autophagosome cargo. It has been proposed that the number of glycosomes and their content change during the Leishmania life cycle as a key adaptation to the different environments encountered. Quantification of RFP-SQL-labeled glycosomes showed that promastigotes of L. major possess ~20 glycosomes per cell, whereas amastigotes contain ~10. Glycosome numbers were significantly greater in promastigotes and amastigotes of autophagy-defective L. major Δatg5 mutants, implicating autophagy in glycosome homeostasis and providing a partial explanation for the previously observed growth and virulence defects of these mutants. Use of GFP-ATG8 to label autophagosomes showed glycosomes to be cargo in ~15% of them; glycosome-containing autophagosomes were trafficked to the lysosome for degradation. The number of autophagosomes increased 10-fold during differentiation, yet the percentage of glycosome-containing autophagosomes remained constant. This indicates that increased turnover of glycosomes was due to an overall increase in autophagy, rather than an upregulation of autophagosomes containing this cargo. Mitophagy of the single mitochondrion was not observed in L. major during normal growth or differentiation; however, mitochondrial remnants resulting from stress-induced fragmentation colocalized with autophagosomes and lysosomes, indicating that autophagy is used to recycle these damaged organelles. These data show that autophagy in Leishmania has a central role not only in maintaining cellular homeostasis and recycling damaged organelles but crucially in the adaptation to environmental change through the turnover of glycosomes. KW - ATG8 KW - Leishmania KW - TEM KW - glycosome KW - protozoan parasite KW - ATG KW - autophagy-related KW - GFP KW - green fluorescent protein KW - MVT KW - multivesicular tubule KW - RFP KW - red fluorescent protein KW - transmission electron microscopy KW - adaptation KW - autophagy KW - mC KW - mCherry KW - fluorescent protein Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150277 VL - 10 IS - 12 ER - TY - JOUR A1 - Kuhtz, Juliane A1 - Schneider, Eberhard A1 - El Hajj, Nady A1 - Zimmermann, Lena A1 - Fust, Olga A1 - Linek, Bartosz A1 - Seufert, Rudolf A1 - Hahn, Thomas A1 - Schorsch, Martin A1 - Haaf, Thomas T1 - Epigenetic heterogeneity of developmentally important genes in human sperm: Implications for assisted reproduction outcome JF - Epigenetics N2 - The molecular basis of male infertility is poorly understood, the majority of cases remaining unsolved. The association of aberrant sperm DNA methylation patterns and compromised semen parameters suggests that disturbances in male germline epigenetic reprogramming contribute to this problem. So far there are only few data on the epigenetic heterogeneity of sperm within a given sample and how to select the best sperm for successful infertility treatment. Limiting dilution bisulfite sequencing of small pools of sperm from fertile donors did not reveal significant differences in the occurrence of abnormal methylation imprints between sperm with and without morphological abnormalities. Intracytoplasmic morphologically selected sperm injection was not associated with an improved epigenetic quality, compared to standard intracytoplasmatic sperm injection. Deep bisulfite sequencing (DBS) of 2 imprinted and 2 pluripotency genes in sperm from men attending a fertility center showed that in both samples with normozoospermia and oligoasthenoteratozoospermia (OAT) the vast majority of sperm alleles was normally (de)methylated and the percentage of epimutations (allele methylation errors) was generally low (<1%). However, DBS allowed one to identify and quantify these rare epimutations with high accuracy. Sperm samples not leading to a pregnancy, in particular in the OAT group, had significantly more epimutations in the paternally methylated GTL2 gene than samples leading to a live birth. All 13 normozoospermic and 13 OAT samples leading to a child had <1% GTL2 epimutations, whereas one (7%) of 14 normozoospermic and 7 (50%) of 14 OAT samples without pregnancy displayed 1–14% GTL2 epimutations. KW - ART outcome KW - deep bisulfite sequencing KW - epigenetic heterogeneity KW - GTL2 KW - sperm DNA methylation KW - IMSI KW - ICSI Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150261 VL - 9 IS - 12 ER - TY - THES A1 - Makgotlho, Phuti Edward T1 - Molecular characterization of the staphylococcal two component system sae and its role in the regulation of the adhesin Eap under SDS stress stimulation T1 - Die molekulare charakterisierung des zwei komponenten-systems sae in staphylokokken und seiner rolle in der Regulation des Eap adhäsins unter SDS vermittelten stress bedingungen N2 - The Staphylococcus aureus two component system (TCS) sae governs expression of numerous virulence factors, including Eap (extracellular adherence protein), which in turn among other functions also mediates invasion of host cells. The sae TCS is encoded by the saePQRS operon, with saeS coding for the sensor histidine kinase (SaeS) and saeR encoding the response regulator (SaeR). The saeRS system is preceded by two additional open reading frames (ORFs), saeP and saeQ, which are predicted to encode a lipoprotein (SaeP) and a membrane protein (SaeQ), respectively. Earlier, we have shown that SDS-containing subinhibitory concentrations of biocides (Perform®) and SDS alone activate sae transcription and increase cellular invasiveness in S. aureus strain Newman. The effect is associated with an amino acid exchange in the N-terminus of SaeS (L18P), specific to strain Newman. In this work, the role of whether the two additional genes, saePQ coding for the accessory proteins SaeP and SaeQ, respectively, are involved in SDS-mediated saeRS was investigated. It could demonstrated that the lack of the SaeP protein resulted in an increased saeRS transcription without SDS stress in both SaeSL/P variants, while the SDS effect was less pronounced on sae and eap expression compared to the Newman wildtype, suggesting that the SaeP protein represses the sae system. Also, SDS-mediated inductions of sae and eap transcription along with enhanced invasion were found to be dependent on presence of the SaeSP variant in Newman wildtype. On the other hand, the study also shows that the saePQ region of the sae operon is required for fully functional two-component system saeRS under normal growth conditions, but it is not involved in SDS-mediated activation of the saeS signaling and sae-target class I gene, eap. In the second approach, the study investigates whether SDS-induced sae expression and host cell invasion is common among S. aureus strains not carrying the (L18P) point mutation. To demonstrate this strain Newman, its isogenic saeS mutants, and various S. aureus isolates were analysed for sae, eap expression and cellular invasiveness. Among the strains tested, SDS exposure resulted only in an increase of sae transcription, Eap production and cellular invasiveness in strain Newman wild type and MRSA strain ST239-635/93R, the latter without an increase in Eap. Interestingly, the epidemic community-associated MRSA strain, USA300 LAC showed a biphasic response in sae transcription at different growth stages, which, however, was not accompanied by increased invasiveness. All other clinical isolates investigated displayed a decrease of the parameters tested. While in strain Newman the SDS effect was due to the saeSP allele, this was not the case in strain ST239-635/93R and the biphasic USA300 strains. Also, increased invasiveness of ST239-635/93R was found to be independent of Eap production. Furthermore, to investigate the global effect of SDS on sae target gene expression, strain Newman wild-type and Newman ∆sae were treated with SDS and analyzed for their transcription profiles of sae target genes using microarray assays. We could show that subinhibitory concentrations of SDS upregulate and downregulate gene expression of several signaling pathways involved in biosynthetic, metabolic pathways as well as virulence, host cell adherence, stress reponse and many hypothetical proteins. In summary, the study sheds light on the role of the upstream region saePQ in SDS-mediated saeRS and eap expression during S. aureus SDS stress. Most importantly, the study also shows that subinhibitory SDS concentrations have pronounced strain-dependent effects on sae transcription and subsequent host cell invasion in S. aureus, with the latter likely to be mediated in some strains by other factors than the known invasin Eap and FnBP proteins. Moreover, there seems to exist more than the saeSP-mediated mechanism for SDS-induced sae transcription in clinical S. aureus isolates. These results help to further understand and clarify virulence and pathogenesis mechanisms and their regulation in S. aureus. N2 - Das Zwei Komponenten-Systems (TCS) Sae in S. aureus reguliert die Expression einer Vielzahl von Virulenzfaktoren, dazu gehört unter anderem das extrazelluläre Adhärenzprotein Eap, welches neben weiteren Funktionen, die Invasion in eukaryotische Wirtszellen vermittelt. Die Gene des sae TCS sind in einem Operon organisiert (saePQRS), wobei saeS für die sensorische Histidinkinase (SaeS) und saeR für den „Response Regulator“ (SaeR) kodieren. Diesen Genen sind zwei weitere Genabschnitte, saeP und saeQ, vorangestellt, wobei saeP vermutlich für ein Lipoprotein (SaeP) und saeQ für ein Membranprotein (RelQ) kodieren. In einer früheren Arbeit konnten wir zeigen, dass SDS-haltige Biozide (Perform©) unter sub- inhibitorischen Konzentrationen, sowie reines SDS, die sae Transkription aktiviert und dadurch zu einer erhöhten Invasion des S. aureus Stamms Newman in Wirtszellen führt. Dieser Effekt ist assoziiert mit einem spezifischen Aminosäureaustausch im N-terminus von SaeS (L18P) des Stamm Newman. In dieser Arbeit soll nun die Beteiligung der zwei zusätzlichen Gene, saeP und saeQ, an der SDS vermittelten transkriptionellen Induktion von saeR/S untersucht werden. Es konnte gezeigt werden, dass ohne SaeP, die saeR/S Transkription in beiden SaeL/P Varianten erhöht war, wobei eine zusätzliche SDS Behandlung hierfür nicht notwendig war. Im Gegenteil, es zeigte sich, dass der SDS Effekt auf die sae und eap Expression in der saeP Mutante deutlich weniger ausgeprägt ist als im Wildtyp Stamm. Das läßt vermuten, dass das Lipoprotein SaeP repremierend auf das sae System einwirkt. Des Weiteren wurde festgestellt, dass die SDS vermittelte transkriptionelle Induktion von sae und eap, zusammen mit der erhöhten Invasion, abhängig vom vorhanden sein der SaeSP Variante im Newman Wildtyp Stamm ist. Die Arbeit zeigt, dass die saePQ Region wichtig ist für die vollständige Funktion des Zwei Komponenten Systems SaeRS unter normalen Wachstumsbedingungen. Jedoch ist diese Region nicht involviert in der Aktivierung von SaeS, mit SDS als Signalgeber, sowie der darauffolgenden Aktivierung des sae Zielgens eap. In einem zweiten Ansatz wurde untersucht, ob die SDS induzierte sae Expression und Wirtszellinvasion auch häufig in S. aureus Stämmen auftritt, welche keine (L18P) Punktmutation besitzen. Dafür wurde Stamm Newman, die isogene saeS Mutante und verschiedene S. aureus Klinikisolate auf ihre sae, eap Expression, sowie zelluläre Invasionsfähigkeit hin analysiert. Von den getesteten Stämmen reagiert nur Wildtyp Stamm Newman und ein MRSA Stamm ST239-635/93R mit gesteigerter sae Transkription, Eap Produktion und zellulärer Invasion. Der MRSA Stamm jedoch ohne erhöhte Eap Produktion. Interessanterweise zeigt der „community- associated“ MRSA Stamm USA300 LAC eine biphasische sae Transkription in verschiedenen Wachstumsphasen, welche jedoch nicht einhergeht mit erhöhter Invasion. Alle anderen Klinikisolate zeigten abnehmende Tendenzen in den getesteten Parametern. Während im Stamm Newman der SDS Effekt auf das saeSP Allel zurückzuführen ist, gilt dies nicht für den Stamm ST239-635/93R, sowie den biphasischen Stamm USA300. Außerdem konnte gezeigt werden, dass die erhöhte Invasion des Stamms ST239-635/93R unabhängig von seiner Eap Produktion ist. Des Weiteren zeigten wir den globalen Effekt von SDS auf die sae Zielgenexpression. Dafür behandelten wir Wildtyp Stamm Newman mit SDS und analysierten die Transkription der sae Zielgene mittels Microarray Analyse. Wir konnten zeigen, dass subinhibitorische SDS Konzentrationen, induzierende als auch repremierende Auswirkungen auf die Genexpression haben. Dabei sind Gene betroffen, die involviert sind in verschiedene Signalwege, Biosynthese/Metabolismus als auch in Virulenz, Wirtzelladhärenz und Stressantwort. Zusammenfassend gibt die Arbeit Aufschluss über die Rolle der „upstream“ Region saePQ hinsichtlich der SDS-abhängigen saeRS und eap Expression in S. aureus. Am wichtigsten ist hierbei die Erkenntnis, das subinhibitorische SDS Konzentrationen einen deutlichen stammabhängigen Effekt auf die sae Transkription und daraus folgernd auf die Wirtszellinvasion von S. aureus haben. Letzteres wird vermutlich in manchen Stämmen durch andere Faktoren als die bekannten Invasinproteine Eap und FnBP vermittelt. Außerdem scheint es in den klinischen S. aureus Isolaten mehr als nur den saeSP abhängigen Mechanismus der sae Induktion durch SDS zu geben. Diese Ergebnisse helfen uns die Virulenz und pathogenen Mechanismen als auch deren Regulation in S. aureus zu verstehen. Die Beobachtungen tragen zu unserem Verständnis bei, wie das sae System Signale der Umgebung detektieren kann. Dies ist bis jetzt eine Fragestellung mit vielen Unbekannten. KW - Staphylococcus aureus KW - Eap KW - Newman strain sae KW - virulence KW - Cellular invasion Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149403 ER - TY - JOUR A1 - Schulze, Daniel T1 - Josephine Machon. Immersive Theatres: Intimacy and Immediacy in Contemporary Performance. Basingstoke: Palgrave, 2013, xix + 324 pp., € 22,30. JF - Journal of Contemporary Drama in English N2 - No abstract available. KW - Rezension Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-194050 SN - 2195-0164 SN - 2195-0156 VL - 2 IS - 2 ER - TY - THES A1 - Pasquet, Vivian T1 - Characterization of thioredoxin and glutathione reductase activities of Mesocestoides vogae, a flatworm parasite useful as a laboratory model for the screening of drugs. T1 - Charakterisierung von Thioredoxin- und Glutathionreduktase Aktivitäten von Mesocestoides vogae, einem parasitären Plattwurm der als Labormodell für die Testung von Arzneistoffen verwendet werden kann N2 - Flatworm parasites (platyhelminths) cause serious infection diseases in humans, such as schistosomiasis and hydatid disease, mainly prevalent in developing countries. However, the current repertoire of drug armamentarium used to combat flatworm infections is limited. For instance, praziquantel is the only drug available for mass treatment of Schistosoma infections. In contrast to their hosts, flatworm parasites possess a distinct redox arrangement of redox pathways in which the selenoenzyme thioredoxin glutathione reductase (TGR) controls the overall redox homeostasis. Interference with this enzyme leads to parasite death. Hence, this key redox enzyme seems to be a new promising drug target against flatworm infections. Because most flatworms are difficult to cultivate in the laboratory (e.g. Echinococcus granulosus experimental infection in mice takes about 10 month to develop into cysts), this work was focused on Mesocestoides vogae (syn. corti), a non-human flatworm parasite which is an interesting laboratory model to study other flatworm infections: it is very rare in humans, can be easily manipulated both in vivo and in vitro and grows extremely fast in mice. With the aim to assess TGR inhibitors as possible drugs to treat flatworm infections, the thioredoxin and glutathione pathways of M.vogae were studied. Here, the objectives were to study whether the biochemical pathways that maintain the redox homeostasis in M. vogae conform to the general biochemical scenario proposed for other platyhelminth parasites. Here, it was proven that M. vogae extracts possess both thioredoxin and glutathione reductase activities. The thioredoxin and glutathione reductase activities were partially purified from total extracts by a combination of ammonium sulfate precipitation, anion exchange and hydroxyapatite chromatography. Both activities co-purified in all steps which strongly indicates the existence of TGR rather than a single TR and GR. Furthermore partially purified activities could be inhibited by the organogold compound auranofin, a known TGR inhibitor. Moreover, the glutathione reductase activity displays hysteresis (a peculiar kinetic behavior) at high concentrations of oxidised glutathione, a feature typical of flatworm TGRs, but not of conventional GR. Although M. vogae activities could not be purified to homogeneity, the overall results strongly indicate that this flatworm possesses TGR and lacks conventional GR and TR. Furthermore the thiadiazole WPQ75 and the N-oxide VL16E (a furoxan derivate) were identified as inhibitors of TGR activity of M.vogae at a 10 µM concentration. These inhibitors were able to kill M.vogae larval worms in vitro as well as in experimental infection in mice. Due to the existence of TGR activity in M.vogae, the possibility to inhibit this activity with recently discovered inhibitors of flatworm TGR and the successes achieved by testing these inhibitors both in vitro and in vivo, it is strongly evident that M. vogae would be an excellent model to assess TGR inhibitors in flatworm infections. N2 - Charakterisierung von Thioredoxin- und Glutathionreduktase Aktivitäten von Mesocestoides vogae, einem parasitären Plattwurm der als Labormodell für die Testung von Arzneistoffen verwendet werden kann KW - Thioredoxin KW - Mesocestoides vogae KW - Glutathione Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-106759 ER - TY - THES A1 - Kaiser, Dorkas T1 - Termites and ants in BURKINA FASO (WEST AFRICA): taxonomic and functional diversity along land-use gradients; ecosystem services of termites in the traditional ZAÏ SYSTEM T1 - Termiten und Ameisen in Burkina Faso (West Africa): Taxonomische und funktionelle Diversität entlang Landnutzungs-Gradienten, Ökosystemdienste von Termiten im traditionellen Zai system N2 - The consequences of habitat change for human well-being are assumed to be especially extreme in Burkina Faso. The country is located in a highly drought-sensitive zone of West Africa, and small‐scale subsistence farmers may be especially affected if losses of biodiversity lead to changes in ecosystem functioning; many depend on more or less degraded lands for agricultural production. The overall aim of the present thesis consequently was to characterize the functional traits of soil-organisms which are crucial for a productive and balanced soil environment in the study region – termites and ants. They are true ecosystem engineers whose activity alters the habitat. Through soil-turnover in the course of constructing biogenic structures of varying size and nature (mounds, nests, galleries, soil-sheetings, foraging-holes), they bioturbate huge amounts of soil masses and exert massive effects on soil structure, positively influencing the fertility, stability, aeration and water infiltration rate into soils; and they provide habitats for other species. In sub-Saharan Africa, ants and termites are the only active soil macrofauna during the long dry season; in the sub-Sahel zone of Burkina Faso, termites even represent the only active, quantitatively remarkable decomposers all year round. Since no information was available about the actual diversity of the focal arthropods, I divided the thesis in two main parts: In the first part, a baseline study, I assessed the local termite and ant fauna, and investigated their quantitative and qualitative response to changing habitat parameters resulting from increasing human impact (‘functional response traits’). In the second and applied part, I addressed the impact of the biogenic structures which are important for the restoration of degraded soils (‘functional effect traits’). Two traditional agricultural systems characteristic for the study region were selected. Each system represented a land-use intensification gradient comprising four distinct habitats now differing in the magnitude of human intervention but formerly having the same initial state. The first disturbance gradient, the temporal cross-section of a traditional soil water conservation technique to restore degraded heavily encrusted, barren soil named Zaï in Ouahigouya (Yatenga province, sub-Sahel zone); the second disturbance gradient, an agriculture type using crop rotation and fallow as nutrient management techniques near Fada N’Gourma (Gourma province, North-Sudanese zone). No standard protocol existed for the assessment of termite and ant diversity in semi-arid (agro-) ecosystems; two widely accepted standard protocols provided the basis for the newly revised and combined rapid assessment protocol ‘RAP’: the ALL protocol for leaf litter ants of Agosti and Alonso (2000), and the transect protocol for termites in tropical forests of Jones and Eggleton (2000). In each study site, three to four replicate transects were conducted during the rainy seasons (2004—2008). The RAP-protocol turned out to be very effective to characterize, compare and monitor the taxonomic and functional diversity of termites and ants; between 70% and 90% of the estimated total species richness were collected on all levels (transects, habitats, regions). Together in both regions, 65 ant species (25 genera) and 39 termite species (13 genera) were collected. These findings represent the first records for Burkina Faso. The data indicate a high sensitivity of termites and ants to land-use intensification. The diversity strongly decreased with increasing anthropogenic impact in the North-Sudan region. In total, 53 ant species (23 genera) and 31 termite species (12 genera) were found. Very promising results concerning the recovery potential of the soil-arthropods’ diversity were gathered in the Zaï system. The diversity of both taxa strongly increased with increasing habitat rehabilitation – in total, 41 ant species (16 genera) and 33 termite species (11 genera) were collected. For both taxa significant differences could be noted in the shape of the density variations along the gradient. For instance termites: Fungus-growers showed the greatest adaptability to different management practices. The greatest variations between the habitats were observed in soil and grass-feeding termites. Whole functional groups were missing in heavily impacted habitats, e.g. soil-, grass-, and wood-feeders were absent in the degraded site in the sub-Sahel zone. Several environmental parameters could be identified which significantly explained a great part of the variations in the composition of the arthropods’ communities; they indicate the importance of the habitats’ structural complexity (vegetation structure) and concomitant effects on diurnal temperature and moisture fluctuations, the availability of food sources, and the soil-structure. The diversity of termites in the sub-Sahel region was strongly correlated with the crown-cover percentages, the topsoils’ sand-content, and the availability of litter; in the North-Sudan region with the cumulated woody plant basal area, the topsoils’ clay- and organic matter-content. The parameters identified for ant communities in the Zaï system, were the height of trees, the topsoils’ clay-content and air humidity; in the North-Sudan region the habitats’ crown-cover percentages, the quantity of litter and again the height of trees. In the second part of the thesis, I first rapidly assessed the (natural) variations in the amount of epigeal soil-structures along the two disturbance gradients in order to judge the relative importance of termites and ants for soil-turnover. The results illustrated impressively that a) in all study sites, termites were the main bioturbators while ant structures were of minor importance for soil turn-over; b) earthworms and grass-feeding termites contributed significantly to soil turn-over in the more humid North-Sudan region; and c) the bioturbated soil mass varied between seasons and years, however, the relative importance of the different taxa seemed to be fairly constant. In the sub-Sahel zone, fungus-growing Odontotermes and Macrotermes species fully take over the important function of bioturbation, leading to the transport of huge amounts of fine-textured soil material to the surface; with increasing habitat restoration, coarse fragments decreased in the upper horizons and became concentrated deeper along the soil profile. Consequently, in the applied part, I concentrated on the bioturbation activity of fungus-growing termites in the four main stages of the Zaï system: crusted bare soil (initial stage), millet field, young and old forest. In each of the four Zaï sites nine experimental blocks (each comprising four plots of 1m2) were used to stimulate the foraging activity of fungus-growing termites with different, locally available organic materials (Aristida kerstingii hay, Bombax costatum wooden blocks, compost and a control without any organic amendment). The experiment was conducted twice for the duration of four weeks (rainy season 2005, dry season 2006). The plots were regularly checked and the increase of the area covered by sheetings chronologically followed. After four weeks a) all sheeting-soil was collected, air dried and separately weighed according to the different genera, and b) the foraging-holes were counted and their diameter measured. Additionally, c) ponded water infiltration was measured in selected plots, and d) the physicochemical properties of sheeting-soil were analyzed. In case of complete consumption of the offered hay during the experimental 4-weeks-duration, the same procedure (a, b) was followed before adding new hay to the respective plot. The comparison between the different plots, sites and seasons revealed clearly that hay was the most attractive bait; for each gram of hay removed, Odontotermes brought about 12 g soil to the surface, Macrotermes 4 g. Odontotermes was the only genus attracted by organic material to the degraded area, and was therefore the decisive primary physical ecosystem engineer in the Zaï system, initiating the restoration process. The mass of soil bioturbated in the course of foraging increased strongly from the degraded, barren towards the most rehabilitated reforested site. Combining all 36 experimental plots per Zaï stage, Odontotermes bioturbated 31.8 tons of soil per hectare and month dry season in the degraded area, and 32.4 tons ha-1 mon-1 in the millet fields; both genera moved 138.9 tons ha-1 mon-1 in the young and 215.5 tons ha-1 mon-1 in the old Zaï forest. Few comparable figures were found in the literature. In northern Burkina Faso, both genera constructed 20 tons of sheetings ha-1 mon-1 after mulching with a straw-wood mixture (Mando & Miedema 1997), and in Senegal, around 10 tons ha-1 mon-1 were moved in heavily foraged plots (Rouland et al. 2003). Within a site, soil turn-over and the number of foraging holes created was always highest in hay, followed by compost, then by wood and in the end control. The fungus-growers’ foraging-activity was leading to an enormous increase in surface pore space – after one month of induced foraging activity in hay-plots, the median number of foraging-holes increased from 142 m-2 in the degraded site up to 921 m-2 in the old Zaï forest. The creation of subterranean galleries and macropores significantly increased the water infiltration rate by a mean factor 2–4. Laboratory analyses revealed that sheeting-soil differed strongly from the respective control soil as well as between the seasons, the food-type covered, and the two genera. Odontotermes-sheetings differed in more parameters than Macrotermes-sheetings, and dry season sheetings differed in more parameters (and more strongly) than rainy season sheetings. In the present study, soil organic matter, carbon and nitrogen contents were significantly increased in all dry season sheetings; in the rainy season mainly in those built on compost. Texture analysis pointed out that both genera used topsoil and soil from deeper horizons in varying mixture ratios, thereby supporting findings of Jouquet et al. (2006). To summarize, the present thesis contributes to a better understanding of the functional response traits of termites and ants to changing environmental parameters resulting from increasing human impact. The RAP-protocol represents an easy-to-learn and very effective method to representatively characterize, compare and monitor the taxonomic and functional diversity of termites and ants. The experiment has provided conclusive evidence of the importance of the consideration of fungus-growing termites (particularly Odontotermes and Macrotermes species) when aiming to restore infertile, degraded and crusted soils and to maintain a sustainable agricultural production in the Sahel‐Sudanese zone of West Africa. N2 - Die Folgen von Lebensraumveränderungen für die Lebensqualität der Bevölkerung sind vermutlich besonders extrem in Burkina Faso. Das Land liegt in einem für Dürren sehr anfälligen Gebiet von Westafrika. Die Kleinbauern, welche die Hauptproduzenten für Lebensmittel der Region sind, können besonders betroffen sein, wenn Verluste der biologischen Vielfalt zu Veränderungen in den Ökosystemfunktionen führen, da viele von degradierten Flächen für die landwirtschaftliche Produktion abhängen. Das Hauptziel der vorliegenden Arbeit war daher, die funktionellen Merkmale derjenigen Bodenorganismen zu charakterisieren, die im Untersuchungsgebiet von entscheidender Bedeutung für ertragreiche und ausgewogene Böden sind: Termiten und Ameisen. Sie sind wahre Ökosystem‐Ingenieure, deren Aktivität den Lebensraum verändert. Durch Bodenumwälzung während des Baus von biogenen Strukturen unterschiedlicher Größe und Natur (Hügel, Nester, unterirdischer Gänge, Schutzschichten aus Erde, sogenannte „soil-sheetings“, Furagierlöcher, etc.) bewegen sie riesige Bodenmassen und haben enorme Auswirkungen auf die Bodenstruktur. Dies wirkt sich wiederrum positiv auf die Bodenfruchtbarkeit, die Stabilität, die Bodenbelüftung und die Wasserinfiltration aus, und bietet so auch Lebensraum für andere Arten. In den afrikanischen Ländern südlich der Sahara sind Ameisen und Termiten die einzige nennenswerte aktive Bodenmakrofauna während des gesamten Jahres. In der Sub-Sahelregion von Burkina Faso sind während der Trockenzeit Termiten die einzigen aktiven Primärzersetzer. Da keine Informationen über den Artenreichtum der Termiten- und Ameisen-Fauna in Burkina Faso vorlagen, setzte ich in der Dissertation zwei Schwerpunkte: Im ersten Teil, einer Grundlagenstudie, erfasste ich die lokale Termiten und Ameisenfauna in verschiedenen Landnutzungssystemen und untersuchte deren quantitative und qualitative Reaktion auf sich ändernde Umweltbedingungen, die aus dem zunehmenden Einfluss des Menschen resultieren ("funktionelle Reaktionsmerkmale"). Im zweiten und anwendungsbezogenen Teil befasste ich mich mit dem Einfluss der für die Regeneration degradierter Böden wichtigen biogenen Strukturen ("funktionelle Wirkungsmerkmale"). Es wurden zwei für die Untersuchungsregion typische traditionelle Landwirtschafts-formen ausgewählt. Jede stellte einen Landnutzungsgradienten dar, der vier verschiedene Habitate umfasste, welche sich in der Stärke des anthropogenen Einflusses unterschieden, ursprünglich aber den gleichen Anfangszustand hatten. Der erste Nutzungsgradient in Ouahigouya (Provinz Yatenga, Sub-Sahel-Zone) – namens Zaï – war ein zeitlicher Querschnitt durch eine traditionelle Boden- und Wasserschutztechnik zur Regeneration stark verkrusteter, degradierter Böden. Der zweite Nutzungsgradient nahe der Stadt Fada N’Gourma (Provinz Gourma, Nord-Sudan Region) war ein Landwirtschaftstyp, der Fruchtfolge und Brachzeiten für das Nährstoffmanagement nutzte. Zur Erhebung der Termiten- und Ameisen-Diversität in semi-ariden (Agrar-) Ökosystemen existierte kein Standardprotokoll; zwei international akzeptierte Protokolle bildeten die Grundlage für das neu überarbeitete und kombinierte Protokoll „RAP“ zur schnellen Erhebung der Termiten- und Ameisenfauna: Das ALL-Protokoll für Ameisen der Laubstreuschicht von Agosti and Alonso (2000) und das Transektprotokoll für Termiten in tropischen Wäldern von Jones and Eggleton (2000). In meiner Untersuchung wurden zwischen 2004 und 2008 während der Regenzeit in jedem der Untersuchungsgebiete drei bis vier Transekte abgesammelt. Das RAP-Protokoll erwies sich als sehr effektive Methode, um die taxonomische und funktionelle Vielfalt von Termiten und Ameisen zu beschreiben, zu vergleichen und zu überwachen. Zwischen 70% und 90% der geschätzten Gesamtartenzahl wurden auf allen Ebenen (Transekte, Lebensräume, Regionen) gesammelt. Insgesamt wurden in beiden Regionen 65 Ameisenarten (25 Gattungen) und 39 Termitenarten (13 Gattungen) gesammelt. Dies sind bislang die ersten Nachweise für Burkina Faso. Die Daten weisen auf eine hohe Sensitivität von Termiten und Ameisen gegenüber einer Landnutzungsintensivierung hin. Mit zunehmendem anthropogenem Einfluss nahm die Artenvielfalt in der Nord-Sudanregion stark zu. Insgesamt wurden 53 Ameisenarten (23 Gattungen) und 31 Termitenarten (12 Gattungen) gefunden. Sehr vielversprechende Ergebnisse wurden bezüglich des Erholungspotenzials der Bodenarthropoden-Diversität im Zaï-System gesammelt; die Vielfalt beider Taxa nahm in mit zunehmender Lebensraumsanierung stark zu: Insgesamt wurden 41 Ameisenarten (16 Gattungen) und 33 Termitenarten (11 Gattungen) dieser Region gefunden. Entlang der Landnutzungsgradienten zeigten sich signifikante Unterschiede im Vorkommen von Termiten und Ameisen. So bewiesen bei Termiten beispielsweise die Pilzzüchter die größte Anpassungsfähigkeit an die unterschiedlichen Bewirtschaftungspraktiken. Die größten Unterschiede zwischen den Lebensräumen wurden bei den boden- und den grasfressenden Termiten beobachtet. In stark vom Menschen beeinflussten Lebensräumen fehlten ganze funktionelle Gruppen, beispielsweise kamen in der degradierten Fläche der Sub-Sahelregion weder Bodenfresser noch Grasfresser oder Holzfresser vor. Mehrere Umweltparameter wurden identifiziert, welche einen großen Teil der Veränderungen in der Zusammensetzung der Arthropoden-Gemeinschaften entlang der Gradienten signifikant erklärten; sie lassen auf eine große Bedeutung der strukturellen Habitat-Komplexität (Vegetationsstruktur) und den damit verbundenen mikroklimatischen Schwankungen (Temperatur- und Feuchtigkeit), der Nahrungsverfügbarkeit und der Bodenstruktur schließen. Die Termitenvielfalt in der Sub-Sahelzone korrelierte stark mit dem Überschirmungsgrad, dem Sandgehalt im Oberboden und der Verfügbarkeit von Streu. Ihre Vielfalt in der Nord-Sudanregion korrelierte stark mit der kumulierten Gehölzpflanzen-Grundfläche, dem Tongehalt und dem organischen Material im Oberboden. Die identifizierten Parameter für die Ameisen-Gemeinschaften im Zaï-System waren die Höhe der Bäume, der Sandgehalt im Oberboden und die Luftfeuchte. Ihre Vielfalt in der Nord-Sudanregion korrelierte stark mit dem Überschirmungsgrad, dem Trockengewicht der verfügbaren Streu und der Baumhöhe. Um die relative Bedeutung von Termiten und Ameisen für die Bodenumwälzung beurteilen zu können, erfasste ich im zweiten Teil der Arbeit zunächst die natürlichen Schwankungen im Trockengewicht der in jedem Untersuchungsgebiet oberirdisch vorhandenen biogenen Strukturen. Die Ergebnisse veranschaulichen eindrucksvoll, dass: 1. Termiten in allen Untersuchungsgebieten die Hauptumwälzer, Ameisenstrukturen dagegen von untergeordneter Bedeutung für die Bioturbation waren; 2. Regenwürmer und grasfressende Termiten in der regenreicheren Nord-Sudanregion wesentlich zur Bodenumwälzung beitrugen; 3. die Gesamtmasse der umgewälzten Erde von Jahr zu Jahr schwankte, die relative Bedeutung beider Taxa für die Bioturbation jedoch ziemlich konstant war; 4. in der Sub-Sahelzone die wichtige Funktion der Bodenumwälzung vollständig von pilzzüchtenden Macrotermes- und Odontotermes-Arten übernommen wird, die zusammen große Mengen von feinkörnigem Bodenmaterial an die Oberfläche transportieren. Dadurch sank mit zunehmender Habitat-Rehabilitation der Gehalt an grobkörnigem Bodenmaterial in den oberen Bodenschichten und reicherte sich zunehmend in den tieferen Horizonten an. Im anwendungsbezogen Teil der Arbeit konzentrierte ich mich daher auf die Bioturbationsleistung pilzzüchtender Termiten in den vier Hauptstadien des Zaï-Systems: der degradierten Fläche (Ausgangsstadium der vier Sukzessionsstadien), dem Hirsefeld, dem jungen und dem alten Zaï-Wald. In jedem dieser vier Sukzessionsstadien wurde die Furagiertätigkeit von pilzzüchtenden Termiten folgendermaßen angeregt: Es wurden neun Versuchsblöcke installiert, mit je vier Unterquadraten mit einer Fläche von 1 m2. Drei der Unterquadrate wurde mit unterschiedlichen, lokal verfügbaren organischen Materialien bedeckt (mit Aristida kerstingii Stroh, Bombax costatum Holz, Kompost), eines blieb als Kontrolle ohne organisches Material. Das vierwöchige Experiment wurde zweimal durchgeführt (Regenzeit 2005, Trockenzeit 2006). Dabei wurden die Untersuchungsflächen regelmäßig auf Termitenaktivität überprüft und die Zunahme der “soil-sheetings“ kartiert. Nach vier Wochen wurde: i. Die gesamte Termitenerde gesammelt, luftgetrocknet und für jede Gattung getrennt gewogen; ii. die Furagierlöcher gezählt und ihr Durchmesser vermessen; iii. in ausgewählten Flächen die Wasserinfiltrationsrate gemessen; iv. die physikalisch-chemischen Eigenschaften der Sheeting-Erde analysiert. Sobald das Stroh in einem Unterquadrat abgetragen war, wurde nach den betreffenden Messungen (s. oben i. und ii.) neues aufgebracht. Der Vergleich der Ergebnisse beider Durchläufe zeigte deutlich, dass Stroh der attraktivste Köder war. Für jedes Gramm abgetragenes Stroh wurden von Odontotermes etwa 12 g, von Macrotermes etwa 4 g Erde an die Oberfläche gebracht. Odontotermes war die einzige Gattung, die in der degradierten Fläche von organischem Material angelockt wurde. Sie ist damit der entscheidende primäre physikalische Ökosystem-Ingenieur im Zaï-System, der den Restaurierungsprozess anstößt. Mit zunehmender Habitatsanierung nahm die Menge der umgewälzten Erde stark zu: In den 36 Unterquadraten der degradierten Fläche bewegte Odontotermes insgesamt 31,8 Tonnen Erde pro Hektar und Monat Trockenzeit, in denen der Hirsefelder insgesamt 32,4 Tonnen. Beide Gattungen zusammen bewegten im jungen Zaï-Wald insgesamt 138,9 Tonnen, im alten Wald 215,5 Tonnen Erde pro Hektar und Monat Trockenzeit. In jedem Sukzessionsstadium waren sowohl die Bodenumwälzung als auch die Anzahl der Furagierlöcher in den Versuchsflächen mit Stroh am größten, gefolgt von denen mit Kompost, dann denen mit Holz und zuletzt den Kontrollflächen. Die Furagiertätigkeit der pilzzüchtenden Termiten führte zu einer starken Zunahme der Makroporosität des Oberbodens. Nach einem Monat induzierter Fraßaktivität stieg im Mittel die Anzahl der Furagierlöcher pro Quadratmeter von 142 in der degradierten Fläche auf 921 Löcher im alten Zaï Wald. Die bei der Nahrungssuche gegrabenen Gänge und Löcher führten zu einem signifikanten Anstieg der Wasserinfiltrationsrate, im Mittel um den Faktor 2–4. Nur wenige vergleichbare Zahlen konnten in der Literatur gefunden werden. Bei den Untersuchungen von Mando and Miedema (1997) im Norden von Burkina Faso wälzten die beiden Gattungen nach Mulchen mit einem Holz-Stroh-Gemisch Sheetings mit einem Trockengewicht von insgesamt 20 Tonnen je Hektar und Monat Trockenzeit um. Im Senegal wurden in Versuchsflächen mit starker Furagieraktivität rund 10 Tonnen Erde bewegt (Rouland et al. 2003). Laboranalysen ergaben, dass sich Sheeting-Erde stark sowohl von der entsprechenden Kontroll-Erde unterschied als auch dem überdeckten Futtertyp und ebenso zwischen den beiden Gattungen. Dabei unterschied sich Sheeting-Erde von Odontotermes in mehr Parametern als Sheeting-Erde von Macrotermes, und Sheetings aus der Trockenzeit unterschieden sich in mehreren Parametern und in stärkerem Maße als Sheetings aus der Regenzeit. Der Gehalt an organischem Material, an Kohlenstoff und Stickstoff war in allen Trockenzeit-Sheetings deutlich erhöht, in der Regenzeit vor allem in Sheetings, die über Kompost gebaut wurden. Die Analyse der Korngrößenverteilung ließ darauf schließen, dass beide Gattungen Erde aus dem Oberboden und aus tieferen Horizonten in unterschiedlichen Mischungsverhältnissen nutzten. Dies bestätigt Beobachtungen von Jouquet et al. (2006). Zusammenfassend lässt sich sagen, dass die vorliegende Untersuchung zu einem besseren Verständnis der funktionellen Reaktionsmerkmale von Termiten und Ameisen auf sich ändernde Umweltparameter beiträgt, die aus dem zunehmenden Einfluss des Menschen resultieren. Das RAP-Protokoll erwies sich als eine einfach zu erlernende und sehr effektive Methode, um die taxonomische und funktionelle Vielfalt von Termiten und Ameisen in semi-ariden Savannen und Agrarökosystemen repräsentativ zu charakterisieren, zu vergleichen und zu überwachen. Das Experiment erbrachte schlüssige Beweise für die Bedeutung pilzzüchtender Termiten (insbesondere Odontotermes und Macrotermes-Arten) für die Sanierung vollständig degradierter und verkrusteter Böden, und für eine nachhaltige landwirtschaftliche Produktion in der Sub-Sahelzone in Westafrika. KW - Termiten KW - termites KW - Ameisen KW - Biodiversität KW - menschlicher Einfluss KW - ants KW - diversity KW - human impact Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-107001 ER -