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The general stress response comprises approximately 200 genes and is driven by the alternative sigma factor SigB. Besides the process of sporulation with approximately 500 involved gene products under initial control of Spo0A are the two most significant and extensive cellular responses that can be observed in B. subtilis. The general stress response provides vegetative growing as well as non-growing and non-sporulating cells with a comprehensive cross-protective and preventive multiple stress resistance to various hostile environmental conditions. In contrast, the endospore is the most resistant but also dormant cell type produced by B. subtilis. The scope of this study was the identification of regulatory cascades driven by the general stress response sigma factor SigB to further elucidate the structure and function of the general stress regulon itself and to uncover potential intersections between the SigB response and other major developmental programs in the regulatory network of B. subtilis. It could be shown that the general stress regulon member yqgZ encodes a functional paralogue of Spx, the global regulator of the diamide stress regulon in B. subtilis. Global transcriptome and proteome studies led to the characterization of an YqgZ sub-regulon consisting of 53 positively and 18 negatively regulated genes. Due to its stringent SigB-dependent expression as well as its concerted action with SigB in regulation of its target genes YqgZ was renamed to MgsR which stands for “modulator of the general stress response”. Activity control of MgsR is stringently controlled at multiple levels. In addition to induction by SigB these mechanisms include (i) a positive autoregulatory loop of MgsR on the transcription level of its own structural gene, (ii) a post-translational redox-sensitive activation step by the formation of an intramolecular disulfide-bond within a conserved -CXXC-motif and (iii) rapid proteolytic degradation of MgsR by the ClpCP and ClpXP proteases, resul ting in extremely short in vivo half-lifes below 6 minutes. It was demonstrated that the activation of SigB is a prerequisite but not sufficient for a full expression of all general stress genes and that the SigB-dependent expression of MgsR provides the opportunity for additional redox-sensitive signal-reception, -processing and -integration beyond the primary decision of SigB activation. Our results describe a regulatory cascade integrating secondary oxidative stress signals into a SigB mediated regulatory cascade that is aimed at a precise fine tuning of target gene expression whose products are necessary for proper management of oxidative stress. Although primary oxidative stress stimuli do not typically induce SigB, our observation of redox-sensitive control by MgsR and several other reports that pointed at the implication of the general stress proteins in oxidative stress management led to the proposal that secondary oxidative stress may be a common component of multip le severe physical stress stimuli. This assumption could be supported by the results of a comprehensive phenotype screening of 94 mutants in single general stress genes upon treatment with hydrogen peroxide and the superoxide generating agent paraquat. A substantial amount of 62 mutants (66%) displayed significantly decreased survival rates in response to oxidative stress. The information gained by this phenotypic screening analysis provides a valuable basis for more directed assays to elucidate the biochemical functions of many so far uncharacterized general stress proteins and demonstrates that the SigB response and the regulatory fine tuning by MgsR plays a pivotal role in protection from secondary oxidative stress. Furthermore, it has been intensively discussed throughout the literature of the last years that the general stress response and the process of sporulation may represent mutually exclusive survival strategies of a non-growing B. subtilis cell, but the molecular basis for this assumption was missing until recently. By the identification of a functional SigB-type promoter (PsigB) adjacent to the spo0E, this gene was newly assigned to the general stress regulon. The spo0E gene encodes a phosphatase that specifically inactivates the master regulator of sporulation Spo0A~P by dephosphorylation. The SigB dependent induction of spo0E causes a block of sporulation specific transcription and produces a sporulation deficient phenotype. This effect was overcome by a deletion of the spo0E-SigB promoter, thus clearly addresses SigB activity. This regulatory mechanism is the first example for an integration of SigB inducing stimuli into the decision making process of sporulation initiation that provides a link to interconnect these two dominant and very likely mutually exclusive responses in the regulatory network of B. subtilis. The data presented here provide deeper insights into the structure and function of the general stress regulon in stress management.
This thesis describes investigations of metal clusters stored in an ion-cyclotron resonance (ICR) trap, as well as corresponding trap research and development. Charged clusters are produced and investigated in the experimental setup Cluster-Trap, comprising a cluster-ion source, an ICR trap and a time-of-flight (ToF) mass spectrometer. In the framework of its move to the new building of the Institute of Physics, new components have been added to the ClusterTrap setup. A radio-frequency ion trap is now used for cluster ion preparation prior to the performance of cluster experiments in the ICR trap. A quadrupole ion deflector allows an optimized usage of the ICR trap, as well as simultaneous use of several ion sources and detectors. The implementation of a potential lift at the ToF mass spectrometer enables a more flexible operation of the setup with ion energies up to several hundreds of electron volts. The new components have been tested and characterized, and the experimental procedures have been adapted. An important aspect of cluster investigations is the manipulation of trapped ions by application of appropriate excitation fields. For the ICR trap, a vector representation model has been developed for quick analysis of radial excitation fields, applied to the quarter-segmented ring electrode of an ICR trap. Its application has been demonstrated for asymmetric radial quadrupolar excitation of stored cluster ions, confirming the observation of unintended ion ejection from the trap. Investigation of multiply negatively charged metal clusters at ClusterTrap has been continued. By the "electron-bath" technique, i.e. simultaneous storage of cluster mono-anions and electrons in the ICR trap, high charge states are produced up to a limit which arises from restrictions for ion trapping. A modification of the electron bath, which bypasses this limit, has been introduced and demonstrated by the first-time production and detection of aluminum cluster anions carrying five excess electrons (penta-anions). Results of the penta-anion production as a function of the trapping voltage relate to the Coulomb potentials of the cluster anions involved, in agreement with previous findings. The observed poly-anionic clusters are meta-stable and their abundance as a function of the cluster size is determined by their lifetimes. Observed poly-anion abundances are described by a thermionic-emission approach, by means of the Richardson-Dushman formula. The height of the Coulomb potential in the formula is decreased to match experimental data, thus accounting for electron tunneling. Poly-anions are observed only above a minimum cluster size, the appearance size. To determine this limit from experimental results, a new data evaluation method has been introduced, which considers the poly-anion lifetimes and respective abundances of a range of cluster sizes. As a result, the experimental appearance size is larger than the smallest poly-anionic cluster observed, in contrast to previous approaches.
Written language in the public sphere (shop signs, advertisements, placards, graffiti, etc.) constitutes the “Linguistic Landscape” of an urban agglomeration. An examination of such displays gives us an insight into function, status and spread of certain languages. Here, the study of linguistic landscapes does not only bear a purely linguistic dimension, but necessarily links to other fields such as politics, semiotics, urban development, communication and literacy. In this case study the cityscapes of the Moldovan capital Chisinau and the Lithuanian capital Vilnius will be analyzed. Peripheral and central districts of the cities have been chosen. From each of these districts, data on the number of mother tongue speakers have been obtained. Two corpora, each containing 1000 items of specimen of written language have been made and contextualized with the help of GPS tracking to ensure the possibility of future diachronic research. The data for these corpora was collected in December 2010 and March 2011. The aim of this study is two-fold: On the one hand this approach gives an insight into the general use of different languages in Moldova and Lithuanian as well as on the functional domains they fulfill. On the other hand the distribution of different languages on signs in each district shows how minority languages such as Russian are represented in public. The results suggest that the linguistic landscape of Chisinau is actually very diverse and alongside Romanian, English and especially Russian are used frequently. The functional domains differ though. Whereas the national language is part of almost all shop signs and advertising in general, it is usually used in conjunction with Russian. Informal displays of written language such as graffiti or small placards are mostly written in Russian alone. Other minority languages in Moldova such as Gagauz and Ukrainian were almost never visible on written displays of language in the city. In contrast to that the linguistic landscape of Vilnius is far less diverse and although the Lithuanian capital is home to sizeable Russian- and Polish-speaking minorities, these demographic patterns do not show. Yet, apart from Lithuanian English is an integral part of the linguistic landscape, especially in advertising.
Background: There is evidence that the borderline symptomatology of the mother longitudinally predicts the number of borderline criteria met by the children. However, possible underlying mechanisms have rarely been examined. In line with transactional models of borderline personality disorder (BPD), we analyzed a broad concept of maladaptive mother-child interactions of mothers with BPD symptoms towards their children, including insensitive parenting and mother-child discrepancies, in reporting the child's psychopathological behavior. Sampling/Methods: The sample was drawn from the population-based Greifswald Family Study and consisted of 295 children and their biological mothers. Both were examined at two points in time, first when the children were about 15 years old (T₀) and again 5 years later (T<sub>1</sub>), using path analyses. Results: Maladaptive mother-child interactions (especially an overprotective and rejecting parenting style and high discrepancies regarding internalizing problems) mediate the longitudinal transmission of borderline symptoms from mother to child. Furthermore, our data revealed that this result is consistent for various youth symptoms which are associated with BPD such as impulsivity or dissociation. Conclusion: The data of the current study imply that the transmission of borderline symptoms from mother to child is mediated by maladaptive mother-child interactions. For this reason early and professional support may be useful to prevent these children from developing severe psychopathology.
Background: To determine the suitability of different superimposed high-frequency jet ventilation (SHFJV) application methods during tracheal bleeding. Objective: To determine the effect of SHFJV on the aspiration of blood during tracheal bleeding. Methods: A test lung was ventilated using SHFJV via a rigid endoscope, a jet laryngoscope and a 4-lumen jet catheter. Packed red blood cells (PRBCs) were injected into the artificial trachea caudally to the rigid endoscope and jet laryngoscope ventilation, and both caudally and cranially during ventilation via the 4-lumen jet catheter, and the migration of PRBCs during ventilation was studied using continuous video recording. Results: Migration of blood into the lower respiratory tract did not occur during SHFJV via the rigid endoscope and jet laryngoscope and via the 4-lumen jet catheter with the bleeding caudal to ventilation source. If the bleeding was cranial to the 4-lumen jet catheter ventilation, migration of blood into the lower respiratory tract was seen when reflux of blood reached the entrainment area. From this area, blood is transported within the jet stream into the lower respiratory tract. Conclusions: SHFJV protects the lower respiratory tract from blood aspiration in case of tracheal bleeding. During SHFJV via the 4-lumen jet catheter, aspiration of blood only occurs if bleeding is localized cranial to the 4-lumen jet catheter ventilation. In case of heavy tracheal bleeding, the jet sources should be positioned cranial to the site of bleeding.
The autism susceptibility locus on human chromosome 7q32 contains the maternally imprinted MEST and the non-imprinted COPG2 and TSGA14 genes. Autism is a disorder of the ‘social brain’ that has been proposed to be due to an overbalance of paternally expressed genes. To study regulation of the 7q32 locus during anthropoid primate evolution, we analyzed the methylation and expression patterns of MEST, COPG2, and TSGA14 in human, chimpanzee, Old World monkey (baboon and rhesus macaque), and New World monkey (marmoset) cortices. In all human and anthropoid primate cortices, the MEST promoter was hemimethylated, as expected for a differentially methylated imprinting control region, whereas the COPG2 and TSGA14 promoters were completely demethylated, typical for transcriptionally active non-imprinted genes. The MEST gene also showed comparable mRNA expression levels in all analyzed species. In contrast, COPG2 expression was downregulated in the human cortex compared to chimpanzee, Old and New World monkeys. TSGA14 either showed no differential regulation in the human brain compared to chimpanzee and marmoset or a slight upregulation compared to baboon. The human-specific downregulation supports a role for COPG2 in the development of a ‘social brain’. Promoter methylation patterns appear to be more stable during evolution than gene expression patterns, suggesting that other mechanisms may be more important for inter-primate differences in gene expression.
The main objective of this research was to enhance the understanding of the inte¬ractions of bentonite with iron in the near field of a HLW-repository. One target was to investigate natural Fe-rich bentonites as a possible analogue. Another topic was to recognize the mineralogical interaction of bentonite with iron powder simulating the contact of bentonite with steel containers (thermodynamic approach). An additional objective was to explore the idea that bentonites have a specific dissolution potential (kinetic approach). In order to take the thermodynamic approach, compacted MX80 bentonite and Friedland clay were used as starting materials for clay/iron interaction experiments in per¬colation systems (Clay/Iron-ratio = 0.1). The natural processes were studied by examining a tropical wea¬thering profile of serpentiniz¬ed diabase from the Thanh Hoa province of Vietnam. The kinetic approach was taken by investigating a series of well characterized bentonites, 9 from API-standard series, 12 from the BGR-collection and 4 others, all of them saturated with deionized water (liquid/solid-ratio = 10/1) and NaCl 1N solution (liquid/solid-ratio = 4/1) for 30 days, followed by exposing the soft gels to mechanical agitation by overhead shaking corresponding to two energy levels (20 rpm and 60 rpm). XRD and TEM – EDX measurement were the major analytical techniques applied in this research, with FT-IR and XRF analyses as additional tools to characterizing the structure and composition of the smectites. Thermodynamic Approach MX80 bentonite and Friedland Clay clearly show that chemical and mineralogical changes have occured in the reaction products. They are exemplified by the neoformation of serpentine and chlorite in certain mixed layer phases. The smectite in the reaction products had also undergone changes especially in the constitution of the octahedral and tetrahedral sheets as well as in the interlayer space. These alterations were evident by the difference in key peak positions and ratios of XRD-patterns, and by TEM-investigations, as well as by different positions and intensities of FT-IR-bands of octahedral and tetrahedral features. The alteration was also seen in the bulk chemical composition data (XRF). MX80 bentonite and Friedland clay show various types and stages of alteration under different experimental conditions. The alteration can be described as “illitization” in open reaction systems and “smectitization” in closed reaction systems. The degree of alteration was controlled by the degree of chemical activities (ion strength, Fe- & Si-activity, con-centration). Higher reactivities give higher degrees of dissolution and release of Si from clay minerals. The oxidation of native iron (Fe0 → Fe2+) was recognized as the main driving force for dissolution, but also the oxidation of Fe2+ (Fe2+ → Fe3+) appeared to reverse an open to a closed reaction system by increased Si-pre¬cipitation. The thermodynamic modelling of C/I-experiments by Mingliang Xie (GRS mbH) verified identified mineralogical alterations in the reaction products. Generally, the contact with metallic iron caused a strong increase in dissolution potential. The reason for this is the reducing potential of oxidation of iron which raised pH to become alkaline and increase dissolution of Si from clay particles. The mineralogical transformations recognized in the experiments, such as the neoformation of serpentine and chlorite phases, were also observed in the tropical weathering profile of serpentinized diabase. The wellknown fast development of Fe-rich montmorillonite in alteration of ultramafic rocks (e.g., Schnellmann, 1964) was also identified by mineralogical investigation of the weather¬ing profile. This confirms that smectitization is linked with higher Fe-activities also in nature. Fe2+ was present in this system and during oxidation acted as driving force for alteration. The reduction potential of Fe-oxidation caused an increase of pH into alkaline conditions. Kinetic Approach The hypothesis that smectite clays have a specific dissolution potential emanated from the study. This would mean that high amounts of Fe and Mg in the octahedral sheet can accelerate alteration in agreement to what was early proposed by Cicel & Novak (1976). The larger ion diameter of Fe and Mg in comparison with Al may well be responsible for a higher sheet stress, which would facilitate dissolution of smectites. The idea proposed Kaufhold & Dohrmann (2008) concerning a mechanism that makes Ca- and Mg-cations in the interlayer space stabilize quasicrystals is also supported by the present study. The performed investigation indicate which mechanisms that serve to protect smectites from undergoing alteration and which promote alteration. Stable smectites, i.e. those with a low specific dissolution potential, were called here “Sleepers”, while fast reacting bentonites, which have a high specific dissolution potential, were termed “Sprinters”. Smectites react with different rates of reaction in laboratory experiments. As said, each smectite sample has its specific potential for dissolution and this potential is controlled by the composition of both the octahedral sheets and the interlayer space. Increasing amounts of octahedral Fe and Mg compared to octahedral Al increase the specific dissolution potential. This potential is also affected by the ion radius, implying that the larger ion radius of Fe and Mg compared to Al increases the mechanical sheet stresses in the octahedral sheet. In summary, this means that, the investigations have confirmed the initial hypothesis concerning the impact of the composition of the octahedral sheet. It results primarily from the pH during the formation of the smectite clay and therefore serves as a geological fingerprint. The Al-Fe ratio in the octahedral sheet influences the stability of the interlayer: A) Aloct > 1.4 and Feoct > 0.2 (per (OH)2 O10) favour delamination of quasicrystals. The swelling pressure increases by a co-volume process between the delaminated layers wiht higher numbers of quasicrystals for Na-dominant population of the interlayer space (Laird, 2006). The microstructural components including both small and large particles and parts of them have a very small ability to move and undergo free rotation. Such Na-montmorillonites are consider as stable phases and have only a low specific dissolution potential. They are „Sleepers“. B) Aloct > 1.4 and Feoct < 0.2 or Aloct < 1.4 and Feoct > 0.2 (per (OH)2 O10) promote demixing of monovalent and divalent interlayer cations (Laird, 2006). In the case of Ca and Mg-dominant interlayers, quasicrystal can break Na-bearing interlayers and help to maintain the quasicrystal structure. Such Ca and Mg-mont¬morillonites can be also be taken as „Sleepers“ because of their low specific dissolution potential. Depending on the octahedral composition, certain cations in the inter¬layer can stabilize bentonites against mineralogical changes. Montmorillonites stabilized by high concentration of Na-cations were classified as belonging to category A, while montmorillonites stabilized by high Ca, Mg-cations in the interlayer sheet were grouped in category B. The classification of a smec¬tite into the categories A or B defined above can be best achieved by IR analyses that yield useful chemical information concerning the composition of the octahedral sheets. Smectites with Na as stabilizing interlayer cation (group A) have shown δAlAlOH-bands with increasing wavenumbers for increasing octahedral Al in FT-IR spectra. The other reaction type of smectite, with Ca, Mg-cations in the interlayers (group B), is characterized by a decreasing octahedral Al-amount for increasing wavenumbers of δAlAlOH-bands in such spectra. Also the FT-IR δAlFeOH-bands are different in the two reaction types of smectite. Increasing octahedral Fe-amounts were mirrored by decreasing wavenumbers of δAlFeOH-bands. However, smectites of group B do contain higher Fe-amounts for the same wavenumber than smectites of group A. Expected alteration of bentonite close and far from a steel canister In the early interaction of smectite-rich clay – the “buffer” - and steel, the system behaves as being chemically closed. Within the clay barrier, Si will be dissolved from clay mineral particles in accordance with its specific dis¬solution potential. The dissolved Si can stay by contributing neoformation of mont¬morillonite layers in mixed layer phases. The interlayer charge decreases by substitution of Mg by Al, which leads to an increase in the swelling pressure. Also minor Si-precipitation may occur if not all the dissolved Si is used up by the neoformed montmorillonite layers. Such precipitation of Si will cause cementation of some quasicrystals and lead to a reduction in porosity. Enhanced temperature and additional Fe-activity, representing an increased reduction potential, increases notably the amount of dissolved Si at the interface between bentonite and steel canister, and as a consequence there will be significant precipitation of Si. The resulting cementation of quasicrystals is ac¬com¬panied also by their collapse which induces broadening of pores. This caused the channel-like migration of infiltrating solutions and switches the system into an open one. Thermodynamic predictions indicate that “illite” will be generated close to the steel canister (via “illitization”) and kaolinite or pyrophyllite to be formed farther away (via smectitization). The “illitization” process results in higher interlayer charges and lower swelling pressures. In contrast, the formation of smectite reduces interlayer charges and promotes higher swelling pressures. At the end of the thermodynamic evolution, the swelling pressure will drop also far from the canister because kaolinite and pyrophyllite are non-swelling minerals. In both cases, the applications of so-called “Sleeper”-bentonites are required to slow the reaction progress. For designers of the engineered barriers in a repository, i.e. the canister and the “buffer” clay, some basic rules are recommend on the basis of the present study. Thus, the presence of native Fe or Fe2+-cations in the clay or in accessory minerals in it, or emanating from the canisters, will speed up the reaction process and make it extensive. Likewise, use of Fe-poor “buffer” clay, representing “Sleepers”-type are suitable for slowing down the reaction. Copper as canister material, and very dense Na-rich montmorillonite of group A as “buffer” seem to be ideal rather than steel/iron and less dense Ca-saturated clay.
Streptococcus pneumoniae, more commonly known as the pneumococcus, is a Gram-positive bacterium colonizing the human upper respiratory tract as a commensal. However, these apparently harmless bacteria have also a high virulence potential and are known as the etiologic agent of respiratory and life-threatening invasive diseases. Dissemination of pneumococci from the nasopharynx into the lungs or bloodstream leads to community-acquired pneumonia, septicaemia and meningitis. Pneumococcal diseases are treated with antibiotics and prevented with polysaccharide-based vaccines. However, due to the increase of antibiotic resistance and limitations of the current vaccines, the burden of diseases remains high. Interactions of pneumococci with soluble host proteins or cellular receptors are crucial for adherence, colonization, transmigration of host barriers and immune evasion. The pneumococcal surface-exposed proteins are the main players involved in this host-pathogen interaction. Therefore, combating pneumococcal transmission and infections has emphasized the need for a new generation of immunogenic and highly protective pneumococcal vaccines, based on surface-exposed adhesins virtually expressed by all pneumococcal strains and serotypes. The genomic analysis of S. pneumoniae strains helped to identify pneumococcal virulence factors such as pili, PsrP and PavB, which have been demonstrated to interact with human proteins playing an important role during the pathogenic process of pneumococci, and are currently considered as new potential vaccine candidates against S. pneumoniae. A subclass of pneumococcal strains produces pili that are encoded by the pathogenicity islet pilus islet-1 (rlrA islet) and/or the pilus islet-2. Both types of pili are implicated in bacterial adherence to host cells. A further pathogenicity islet encoded protein is PsrP. The presence of the psrP-secY2A2 islet correlated positively with the ability of pneumococci to cause invasive pneumococcal diseases. Recent studies indicated that PsrP is a protective adhesin interacting with keratin 10 on lung epithelial cells. In this study, the genomic loci of the pneumococcal virulence factors pili, PsrP and PavB were molecularly analyzed and used as molecular markers for molecular epidemiology studies of S. pneumoniae. The genotyping results obtained here showed the impact of the PCV7 immunization of children, started in July 2006, on the distribution of these pneumococcal virulence factors among clinical isolates in Germany. These findings gave more insights into the role of pili, PsrP and PavB in pneumococcal pathogenesis and may strongly support the idea of including these pneumococcal constituents in a broad coverage protein-based vaccine against pneumococcal infections produced by invasive serotypes in the future. The mature PavB protein contains a variable number of repetitive sequences referred to as the Streptococcal Surface Repeats (SSURE). PavB has been demonstrated to interact with fibronectin and plasminogen in a dose-dependent manner and it was identified as a surface-exposed adhesin with immunogenic properties, which contributes to pneumococcal colonization and respiratory airways infections. The complete molecular analysis performed here for PavB, allowed to know more accurately its structure and to estimate the real number of SSURE units in different pneumococcal strains. With these findings, a new primary sequence-based structural model was constructed for the PavB protein and its SSURE domain, and, at least for TIGR4, the complete pavB gene and PavB protein sequences with five SSURE units was reported in the GenBank database of the NCBI website. Due to its immediate neighborhood on the pneumococcal genome with the tcs08 genes, PavB is likely linked with this pneumococcal TCS. Here, a significant reduction of the PavB protein expression was observed in delta-tcs08-mutant strains, which may strongly suggest that the TCS08 does play a role in pneumococcal virulence and metabolisme, as further observed in growth behaviour experiments carried out with the TCS08-deficient mutants, cultured in chemically defined medium. Despite several studies suggest that the molecular mechanism underlying the bacterial signal transduction is very sophisticated, the majority of reports in prokaryotic TCS, including those for S. pneumoniae, are still focused in single cognate pairs. The pneumococcal genome encodes 14 TCSs and an orphan response regulator. It is obvious that TCS pathways are often arranged into complex circuits with extensive cross-regulation at a variety of levels, thereby endowing cells with the ability to perform sophisticated information processing tasks. This study established also the experimental and molecular bases for the construction of a comprehensive genome-wide interaction map of the complex TCS pathways for its application in the gene regulation of pneumococcal virulence factors.
The goal of this thesis was to study the systematic relationships within the superfamily Sylvioidea (Aves: Passeriformes) in general and within the closely related families Acrocephalidae and Locustellidae in particular, by means of DNA sequences. Sylvioidea itself and families therein were the focus of many studies based as well on morphological characters as on DNA. Due to their morphological similarity and their presumably rapid radiation most studies failed to solve relationships between sylvioidean families and also demarcations of single families and relations within are still in progress. In this study, an enlargement of previous datasets, both taxa and number of DNA sequences, and more sophisticated analysis methods were used to improve the resolution in Sylvioidea, Acrocephalidae and Locustellidae. In addition, the applicability of barcoding in Acrocephalidae was tested. The monophyly of Sylvioidea could be supported and the families Paridae and Remizidae, which were sometimes still included, clustered among the outgroup taxa. Four families, Nicatoridae, Panuridae, Alaudidae, and Macrosphenidae constitute basal splits within Sylvioidea. The division of the former sylviid/timaliid clade in five families, Sylviidae, Leiothrichidae, Pellorneidae, Timaliidae, and Zosteropidae was supported. Scotocerca, Erythrocercus, and Hylia, previously supposed to be members of Cettiidae, were shown not to belong to this family. As the three genera are also morphologically and ecologically different, they were here proposed to be elevated to family rank, Scotocercidae, Erythrocercidae and Hyliidae, respectively. The family Acrocephalidae consisted of the four genera, Nesillas, Acrocephalus, Hippolais, and Chloropeta. In the analysis for this thesis, the latter three appeared to be non-monophyletic. One Acrocephalus species, A. aedon was sister to a clade containing four species of Hippolais as well as two out of three Chloropeta species. They were all merged in the genus Iduna, based on the DNA evidence and shared morphological and ecological characters. Iduna had priority over Hippolais or Chloropeta according to the International Code of Zoological Nomenclature. The one remaining Chloropeta species (C. gracilirostris) had to be renamed to Calamonastides as Chloropeta was no longer available for this taxon. Seven genera were included in the re-analysis of the family Locustellidae: Locustella, Bradypterus, Megalurus, Dromaeocercus, Schoenicola, Cincloramphus, and Eremiornis. Apart from the monotypic genera Dromaeocercus and Eremiornis and Schoenicola, of which only one species was included, the remaining genera were found to be non-monophyletic. One clade contained all Locustella species, Megalurus pryeri and all Asian/Oriental Bradypterus species. All species in this clade were synonymized with Locustella, as the type species of Locustella was included, whereas the type species of Bradypterus fell in a different clade. Therefore, the remaining African Bradypterus species retained their genus name, and Dromaeocercus was renamed to Bradypterus as it clustered within Bradypterus. Cincloramphus, intermingling with the remaining Megalurus species, was synonymized with the latter. Barcoding, growing in popularity for delimiting species, was tested in its applicability for Acrocephalidae. Fourteen taxa currently recognized as full species would fall under the 2% threshold of sequence divergence proposed for delimiting species using the mitochondrial cytochrome b gene. It was also shown that it is important to clarify which part of a DNA sequence is used, as different parts can give different results regarding the 2% threshold. In addition, the choice of “complete deletion” or “pairwise deletion” in calculating genetic distances is important, if incomplete are sequences used.
In aged humans, stroke is a major cause of disability for which no neuroprotective measures are available. In animal studies of focal ischemia, short-term hypothermia often reduces infarct size. Nevertheless, efficient neuroprotection requires long-term, regulated lowering of whole-body temperature. Previously, it is reported that post-stroke exposure to hydrogen sulfide (H2S) effectively lowers whole-body temperature and confers neuroprotection in aged animals. Here we report for the first time that the animals exposed to H2S the normal sleep–wake oscillations are replaced by a low-amplitude EEG dominated by a 4-Hz rhythmicactivity, reminiscent of EEG recordings in hibernating animals. In the present study using magnetic resonance imaging, reverse transcriptase polymerase chain reaction, western blotting and immunofluorescence, we characterized the central nervous system response to H2S -induced hypothermia and report, that annexin A1, a major constituent of peripheral leukocytes that is upregulated after stroke, was consistently downregulated in polymorphonuclear cells in the peri-lesional cortex of post-ischemic, aged rat brain after 48 hours of hypothermia induced by exposure to H2S. This might be due to the reduced kinetics of recruitment, adherence and infiltration of PMN cells by H2S -induced hypothermia. Our findings further suggest that, in contrast to monotherapies that have thus far uniformly failed in clinical practice, prolonged hypothermia has pleiotropic effects on brain physiology that may be necessary for effective protection of the brain after stroke.