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It is shown that in the case of metals connected by a first order conductor the decomposition of formic acid is less at the element of lower work function while it is more at the element of higher work function. The metals used were Ni, Cd, Zn. The results correspond to the investigations of other authors 1 who showed that the activation energy on alloys depends on how far the concentration of electrons is from full saturation of the lattice type. This effect is explicable in terms of the development of a contact potential, the conditions in the case of metals being similar to those in the case of alloys
Mitochondrien aus Rattenleber (RL) und Rinderherzmuskel (BH) erzeugen bei Behandlung mit O2 eine schwache Chemilumineszenz in dem Spektralbereich zwischen 400 und 650 mµ, deren Intensität bei RL-Mitochondrien durch vorheriges Einfrieren und Auftauen wie durch Ultraschallbehandlung größer wird. Bei beiden Arten verursacht Zusatz von Acridinorange eine wesentliche Verstärkung der Lumineszenz, gleichzeitig wird die O2-Aufnahme gehemmt. RL-Mitochondrien erzeugen unter diesen Bedingungen eine kurzzeitige, BH-Mitochondrien eine langsam ansteigende langandauernde Strahlung; das gleiche Verhalten zeigen aus BH-Mitochondrien gewonnene „electrontransfer-particles“ (ETP). Der zeitliche Ablauf und die Beeinflußbarkeit durch Effektoren der Atmungskette ist andersartig als bei der von VLADIMIROV gefundenen Chemilumineszenz von RL-Mitochondrien. Als Träger der Lumineszenz wird angeregter O2 diskutiert.
Untersuchungen an uv-bestrahlten Schwimmhäuten von Fröschen und Rückenhäuten von Mäusen ergaben, daß mit Hilfe der Nadi - Reaktion (GRÄFF) Oxydationspotentiale an der Bestrahlungsstelle nachgewiesen werden können. Kurzwelliges UV unter λ = 300 mμ hat hierbei die beste Wirkung. Die Stellen stärkster Oxydationskraft liegen bei Schwimmhäuten an den Melanophoren des Corium, bei Mäuserücken-Häuten verteilt im Corium. Bei den Froschhäuten kann zusätzlich bei unphysiologischem pH 4,2 Oxydationswirkung in der Epidermis nachgewiesen werden. Strukturelle Veränderungen an der Schwimmhaut werden polarisationsoptisch deutlich.
Triphenylphosphane 1, its oxide 2 and sulfide 3 undergo one-electron reduction at a mercury cathode in DMF to yield the corresponding radical anions. ESE analysis of the paramagnetic species is facilitated by deuteration and suggests a pyramidal geometry of the radicals. Reduction with potassium metal in DME at low temperature yields also radical anions for 2 and 3. The phosphane 1, however, reacts under phenyl cleavage and potassiumphenyl-assisted ring closure to the dianion of 5H-dibenzophosphole 4. This radical 4· ⊖⊖ is also obtainod by alkali metal reduction of P-phenyldibenzophosphole o, and its spin distribution is compared to iso-.-π-electronic radicals containing CH, N, O, S, or Se links instead of the phosphorus atom.
A thermodynamic interpretation of the liquidus curves of some methyltrichloro-respectively dimethyldichlorosilane/lutidine-systems is given. Based on certain approximations it was possible to fit thermodynamic functions to the experimental results to obtain the excess datas of binary systems. A comparison between the models of Redlich-Kister, Wilson and the NRTL-formalism for the free excess enthalpy of binary mixtures is given.
A phase equilibrium study of the systems dimethyldichlorosilane with 2.4-lutidine and 2.6-lutidine is presented with evidence for the existence of the incongruently melting compounds 2.6-lutidine · Me2SiCl2, (2.6-lutidine)2 · Me2SiCl2 and the congruently melting compound 2.4-lutidine · Me2SiCl2.
The phase diagrams of the systems of trimethylbromosilane and the isomeric lutidines are shown. The existence of the congruently melting addition compounds (CH3)3SiBr ∙ (3,4-lutidine), (CH3)3SiBr (3,5-lutidine) and the incongruently melting addition compounds (CH3)3SiBr • (2,3-lutidine)2, (CH3)3SiBr • (2,3-lutidine), (CH3)3SiBr (2,4-lutidine), ((CH3)3SiBr)2 • (2,4-lutidine), (CH3)3SiBr • (2,5-lutidine)2, (CH3)3SiBr • (2,5-lutidine), (CH3)3SiBr (2,6-lutidine)2 could be proved.
Es wird versucht, Beweise für die indirekte Strahlenwirkung zu erbringen und die einzelnen Reaktionsschritte, die bei Röntgenstrahlen-Wirkung auf wäßrige Lysinlösungen ablaufen, zu erkennen. Zur Untersuchung der durch HO2 oder OH-Radikale ausgelösten Wirkungen wurden 2 Versuchsreihen durchgeführt:
1. Bestrahlung bei Anwesenheit von Sauerstoff,
2. Bestrahlung bei Sauerstoffmangel.
Außerdem wurde der Einfluß der Dosis, Dosisleistung, Temperatur und verschiedener Substrat-Konzentrationen untersucht.
Schließlich wurde versucht, die experimentell gewonnenen Ergebnisse mit Hilfe von Radikalwirkungen, die sich auf
a) Decarboxylierungen,
b) Desaminierungen,
c) und Veränderungen des Kohlenstoff-Gerüstes erstrecken, zu deuten.
Rezension zu: Mathias Rohe (Hrsg.), Mouhanad Khorchide (Hrsg.), Havva Engin (Hrsg.), Hansjörg Schmid (Hrsg.), Ömer Özsoy (Hrsg.), Eugen-Biser-Stiftung (Hrsg.): Handbuch Christentum und Islam in Deutschland. Grundlagen, Erfahrungen und Perspektiven des Zusammenlebens, Freiburg 2015, Verlag Herder, ISBN: 978-3-451-31188-8, zwei Bände, 1297 Seiten, 48 Euro.
Seit seinen Anfängen ist das Christentum alles andere als einheitlich oder homogen. Mit dem Aufstieg zur Staatsreligion im Römischen Reich und dem Wunsch des Kaisertums, seine Herrschaft zu legitimieren, wuchs der Druck zur Vereinheitlichung. Diese Bemühungen ziehen sich wie ein roter Faden durch die mittelalterliche Geschichte. Doch die Alltags-, Gesellschafts- und Kulturgeschichte verweist in der mittelalterlichen Gesellschaft auf eine große Vielfalt der Ausprägungen des Christentums.
Wirtszellreaktivierung chemisch induzierter Letalschäden im DNS-haltigen Serratia-Phagen Kappa
(1965)
After treating free phage Kappa with nitrous acid, triethylenemelamine, ethylmethanesulfonate, or hydroxylamin and using these phages for infecting Serratia H Y wildtype cells, at least 20% of the lethal damage in the phage-DNA can be reactivated by the host ( = host cell reactivation). It is known that all lethal agents tested so far attack the primary structure of the D N A in different ways. Therefore, we assume that the target for the host cell reactivation consists of some damage in the secondary structure of the DNA, because there is probably some coincidence in the action of all agents. The hypothesis that in the DNA changes of thymine are a prerequisite for host cell reactivation has been disproved by the experiments with nitrous acid and ethylmethanesulfonate because both substances do not act on thymine.
Die Geschichte der frühen Christenverfolgung wird in Hollywoodstreifen wesentlich dramatischer dargestellt, als sie in der jüngeren Forschung beurteilt wird. Auch andere Kulte wurden unterdrückt, denn es bestand kein Recht auf Religionsfreiheit. Die Gründe für solche Maßnahmen lagen nicht in Glaubensvorstellungen, sondern in Handlungen, die als gefährlich für das Gemeinwesen galten. So fürchtete man, dass die Weigerung der Christen, Opfer darzubringen, den Zorn der Götter heraufbeschwören könne oder ein Zeichen mangelnder Loyalität sei. Vor diesem Hintergrund forderten Christen Religionsfreiheit von den Heiden, doch wurde diese auch im später christlichen spätantiken Reich nicht praktiziert.
In ihrem Gespräch beschäftigen sich Prof. Dr. Bekim Agai, geschäftsführender Direktor des Instituts für Studien der Kultur und Religion des Islam, und Ulrike Jaspers, Redakteurin von "Forschung Frankfurt", mit dem Wahrheitsanspruch der Religionen, der Debattenkultur in Deutschland, der jungen islamischen Theologie, den fundamentalistischen Strömungen und anderem mehr.
Als Reaktion auf die von islamischen Extremisten begangenen Terroranschläge sowie auf das Wüten des IS in Syrien und im Irak werden diese Forderungen immer lauter: Muslime müssen selbstkritisch nach dem Zusammenhang von islamischer Religion und Gewalt fragen. Bloße Distanzierungen seien nicht ausreichend, so die Kritik von außen, aber zunehmend auch innerhalb der muslimischen Gemeinschaften. Wie setzt sich die islamische Theologie, wie sie u. a. in Frankfurt betrieben wird, damit auseinander?
In the pyrolysis of 1,2,3-benzoselenodiazole using a short-distance furnace, a short-lived intermediate is detected photoelectron spectroscopically. Mass spectra recorded under similar conditions suggest an isomer C6H4Se rearranging to the more stable final product 6-fulveneselone. The ionization pattern obtained by computerized spectra stripping is assigned to benzselenirene by molecular radical cation state comparison based on MNDO calculations.
Der Islam befindet sich in einer Phase fundamentaler Veränderungen, die neue progressive Spielarten, aber auch beunruhigende Formen religiösen Extremismus hervorbringt. In Deutschland diskutieren Muslime, ob es sinnvoll sei, einen spezifisch deutschen oder europäischen Islam zu entwickeln oder ob die herkunftsorientierte Religion der Moschee-Gemeinschaften beibehalten werden sollte.
Der Streit um das Kopftuch : vom Umgang mit religiösen Geltungsansprüchen in liberalen Ordnungen
(2016)
Im Streit um das Kopftuch geht es um mehr als ein beliebiges Rechtsproblem. Welche Rolle soll die Religion im öffentlichen Leben spielen? Wie geht eine liberale Gesellschaft mit der religiösen Vielfalt um? In Deutschland – im Gegensatz zu Frankreich – orientiert sich das Verfassungsrecht am Modell einer "positiven Neutralität": Der Staat weist die Religion nicht vollständig von sich ab, sondern gibt ihr aktiv Raum zur Entfaltung. Muss dieses Modell hinterfragt werden, wenn Gruppen mit starkem religiösen Geltungsanspruch die Bühne betreten und Religion wieder für gesellschaftlichen Konfliktstoff sorgt?
Gehört Religionsunterricht in den Fächerkanon einer staatlichen Schule? In Deutschland wird dies sogar im Grundgesetz bejaht. Während atheistische Kreise die Abschaffung dieses Grundrechts fordern, sehen Politik und Wissenschaft darin eine Chance, auch Kindern aus muslimischen Familien religiöses Wissen näherzubringen, sie auf diese Weise besser zu integrieren und vielleicht sogar gegen fundamentalistische Hasslehren zu wappnen. In Hessen erhalten Grundschüler seit dem Schuljahr 2013 / 2014 bekenntnisorientierten islamischen Religionsunterricht; die Justus-Liebig-Universität Gießen und künftig auch die Goethe-Universität bilden Lehrer aus.
Kennt die Nächstenliebe Grenzen? : wie christliche Ethik über die aktuelle Migration nachdenkt
(2016)
In der Flüchtlingsdebatte geht es auch um die moralische Frage: Dürfen wir Menschen in Not abweisen? Einfache Antworten sind unseriös. Verschiedenste soziale, kulturelle und religiöse Aspekte müssen berücksichtigt werden. Die christliche Ethik kann zu dieser Diskussion u. a. ihr Handlungsmotiv der "Nächstenliebe" beisteuern, das allerdings auch der Interpretation bedarf.
Sehnsucht nach absoluter Wissenschaft : die moderne Esoterik will nicht glauben, sondern wissen
(2016)
Esoterische Weltanschauungen versprechen "höhere", "ganzheitliche" Einsichten statt kalter, "materialistischer" Erkenntnis. Damit stellen sie sich in ein bewusstes, wenn auch aussichtsloses Konkurrenzverhältnis zu den akademischen Wissenschaften. Dennoch hat sich der esoterische Diskurs immer wieder gerade im Umfeld und im Schatten der gesellschaftlich anerkannten universitären Wissenschaften konstituiert, zumindest in reflexiver Abhängigkeit von ihren normativen Ansprüchen.
Religion und Gesellschaft
(2016)
Religion und Gesellschaft
(2016)
Kaufen macht Spaß, hat aber einen schlechten Ruf. Schnell ist vom "Tanz um das goldene Kalb" die Rede, womit das religiös motivierte Register noch lang nicht erschöpft ist. Parallelen zwischen Konsum und Gottesglauben sind in der Tat nicht von der Hand zu weisen. Aber lässt sich unser Umgang mit den Waren wirklich auf die Suche nach Erlösung reduzieren?
Religiöse Vielfalt und Differenz gehören zu den zentralen Erfahrungen des Judentums. Im Zentrum stehen dabei einerseits konkurrierende Interpretationen des Jüdischen, aber auch die Auseinandersetzung mit Christentum und Islam. Was lässt sich für den aktuellen Dialog der Religionen daraus lernen? Der Religionsphilosoph Martin Buber plädiert für eine echte Zwiesprache, die die eigene Position ebenso ernst nimmt wie die dialogische Verwiesenheit religiöser Traditionen aufeinander. Aber auch tief greifende Differenzen sollten nicht verschwiegen werden.
Religion sei "das Opium des Volks", das einem herz- und geistlosen "Jammertal" einen Heiligenschein verleihe. Der werde verschwinden, wenn "die Kritik des Jammertals" zur "Wahrheit des Diesseits" geführt habe, so Karl Marx 1844. Und heute: Die Religion existiert weiter, eine "wahre" Gesellschaft ist nicht verwirklicht. Im Gespräch mit vier Frankfurter Professoren erkundet der Philosoph und Publizist Rolf Wiggershaus, wie Religionsexperten das aktuelle Verhältnis von Religion und Gesellschaft sehen.
"Toleranz kommt vor Glückseligkeit" : eine Zeitreise mit der Tugend des gegenseitigen Respekts
(2016)
Toleranz ist gerade da nötig, wo sie besonders schwerfällt. Das war schon vor gut 300 Jahren so, als Denker wie der französische Philosoph Pierre Bayle in Zeiten religiöser Auseinandersetzungen den Grundstein für ein fortschrittliches Toleranz-Verständnis legten. Warum der Begriff gerade heute wieder Konjunktur hat und wie umstritten er noch immer ist, erläutert der politische Philosoph Rainer Forst im Gespräch mit Bernd Frye.
Phenology is the study of periodic life cycle events of living organisms and how these are influenced by environmental factors. Late phenological phases such as the timing of seed release and subsequent seed dispersal considerably affect ecology and evolution in plants. Since plants are mostly sessile organisms, seed dispersal is a crucial life cycle event for the ecology and evolution of plants. In fact, long-distance seed dispersal (LDD) is a very complex process in plant biology and significantly shapes the spatial and temporal dynamics of plant populations. For example, wind dispersal in plants is influenced by a variety of factors such as plant traits, habitat type and environmental conditions (e.g. wind speed). Considering the variability of wind conditions throughout the year, the timing of seed release and dispersal is known to have considerable effects on LDD. Even though late phenologies such as ripening duration and timing of seed release and subsequent dispersal are vital in estimating ecologically highly relevant LDD, these phenologies are not appropriately addressed in ecological research. The aim of this thesis is to gain insights into the factors that shape late plant phenologies. In particular, we address the following questions: which ecologically or evolutionary parameters drive the ripening process of plant species? How does the seasonal variability of wind affect the seed release phenology of plant species? How do these factors interact for plant species in different habitat types?
In order to address these questions, we applied different methodological approaches, ranging from fieldwork and monitoring phenology to computational simulation studies and statistical modeling. To study the ripening process of species, we monitored the flowering, ripening and seed release phenology of more than 100 Central European plant species. We conducted computational simulation studies for estimating LDD by wind to study the phenology of seed release and the parameters determining LDD by wind. In conjunction with phenological data from literature, we used the obtained simulation results to investigate evidence for the existence of phenological adaptations towards LDD in 165 plant species. Further, we used the results from simulation studies of LDD by wind to disentangle the effects of species, habitat types and meteorological conditions and their interactions on the spatial spread of plant species.
The results of the relationship between plant traits, phylogeny, the ripening process and climatic factors provide insights into the basic understanding of the ripening process of plants. We identified ecological factors that shape species’ ripening phenology and seed release timing. In particular, we suggest that the species’ seed weight, life form and phylogeny shapes ripening and seed release phenology. With the statistical models on species’ temperature demands for reproduction, we introduce data that that are well suitable for parametrization and further development of plant dispersal models. The results from the simulation study based on a seasonal perspective showed that heavier seeded tree species with medium wind dispersal potential (including genera Abies, Acer, Fraxinus and Larix) have a clear synchronisation of seed abscission with periods favouring LDD. These species, which are both ecologically and economically important, showed significant synchronisation of the highest rate of seed release with high wind-speed that promoted LDD by wind in wintertime. For the tree species mentioned, we suggest strong seasonal synchronisation as evidence for phenological adaptations in order to match favourable conditions during seed release. With a closer look at the wind conditions that promote LDD by wind, our results showed considerable differences in how specific wind conditions affect LDD in different species and habitat types. We suggest that LDD by wind in species from open habitats with high wind dispersal potential is likely to be driven by thermal updrafts that are mainly driven by the sun providing energy to the ground. By contrast, LDD of heavier-seeded species from open and forested habitats is more likely to be driven by storms that produce shear-driven turbulence. The results from this thesis contribute to an increased understanding of the complete dispersal process of plants and to making more realistic projections of (future) plant distribution.
The results obtained on factors driving ripening and release phenology provide valuable insights into their ecological and phylogenetic factor constraints. The implementation of more realistic assumptions in assessing species’ dispersal potential throughout the year could help considerably in improving landscape management (e.g. timing of mowing) and in the conservation of plant populations. The evidence found for phenological adaptations towards LDD in plants is an important step in understanding the evolutionary basis of LDD in these species.
Telecommunications companies traditionally offer several tariffs from which their customers can choose the tariff that best suits their preferences. Yet, customers sometimes make choices that are not optimal for them because they do not minimize their bill for a certain usage amount. We show in this paper that companies should be very concerned about choices in which customers pick tariffs that are too small for them because they lead to a significant increase in customers churn. In contrast, this is not the case if customers choose tariffs that are too big for them. The reason is that in particular flat-rates provide customers with the additional benefit that they guarantee a constant bill amount that consumption can be enjoyed more freely because all costs are already accounted for.
Correlated activity of cortical neurons survives extensive removal of feedforward sensory input
(2016)
A fundamental property of brain function is that the spiking activity of cortical neurons is variable and that some of this variability is correlated between neurons. Correlated activity not due to the stimulus arises from shared input but the neuronal circuit mechanisms that result in these noise correlations are not fully understood. Here we tested in the visual system if correlated variability in mid-level area V4 of visual cortex is altered following extensive lesions of primary visual cortex (V1). To this end we recorded longitudinally the neuronal correlations in area V4 of two behaving macaque monkeys before and after a V1 lesion while the monkeys fixated a grey screen. We found that the correlations of neuronal activity survived the lesions in both monkeys. In one monkey, the correlation of multi-unit spiking signals was strongly increased in the first week post-lesion, while in the second monkey, correlated activity was slightly increased, but not greater than some week-by-week fluctuations observed. The typical drop-off of inter-neuronal correlations with cortical distance was preserved after the lesion. Therefore, as V4 noise correlations remain without feedforward input from V1, these results suggest instead that local and/or feedback input seem to be necessary for correlated activity.
Infections are an important cause for morbidity and mortality in pediatric acute myeloid leukemia (AML). We therefore characterized infectious complications in children treated according to the trial AML-BFM 2004. Patients with Down syndrome were excluded from the analysis. Data were gathered from the medical records in the hospital where the patients were treated. A total of 405 patients (203 girls; median age 8.4 years) experienced 1326 infections. Fever without identifiable source occurred in 56.1% of the patients and clinically and microbiologically documented infections in 17.5% and 32.4% of the patients, respectively. In all, 240 Gram-positive (112 viridans group streptococci) and 90 Gram-negative isolates were recovered from the bloodstream. Invasive fungal infection was diagnosed in 3% of the patients. Three children each died of Gram-negative bacteremia and invasive aspergillosis, respectively. As compared with the results of AML-BFM 93 with lower dose intensity, infection-related morbidity was slightly higher in AML-BFM 2004 (3.3. versus 2.8 infections per patient), whereas infection-related mortality significantly decreased (1.5% versus 5.4%; P=0.003). Specific anti-infective recommendations included in the treatment protocol, regular training courses for pediatric hematologists and increasing experience may be the reason for reduced infection-related mortality in children with AML. Further studies are needed to decrease infection-related morbidity.
A complex aberrant karyotype consisting of multiple unrelated cytogenetic abnormalities is associated with poor prognosis in patients with acute myeloid leukemia (AML). The European Leukemia Net classification and the UK Medical Research Council recommendation provide prognostic categories that differ in the definition of unbalanced aberrations as well as the number of single aberrations. The aim of this study on 3526 AML patients was to redefine and validate a cutoff for karyotype complexity in AML with regard to adverse prognosis. Our study demonstrated that (1) patients with a pure hyperdiploid karyotype have an adverse risk irrespective of the number of chromosomal gains, (2) patients with translocation t(9;11)(p21~22;q23) have an intermediate risk independent of the number of additional aberrations, (3) patients with greater than or equal to4 abnormalities have an adverse risk per se and (4) patients with three aberrations in the absence of abnormalities of strong influence (hyperdiploid karyotype, t(9;11)(p21~22;q23), CBF-AML, unique adverse-risk aberrations) have borderline intermediate/adverse risk with a reduced overall survival compared with patients with a normal karyotype.
DNA methylation is a major regulatory process of gene transcription, and aberrant DNA methylation is associated with various diseases including cancer. Many compounds have been reported to modify DNA methylation states. Despite increasing interest in the clinical application of drugs with epigenetic effects, and the use of diagnostic markers for genome-wide hypomethylation in cancer, large-scale screening systems to measure the effects of drugs on DNA methylation are limited. In this study, we improved the previously established fluorescence polarization-based global DNA methylation assay so that it is more suitable for application to human genomic DNA. Our methyl-sensitive fluorescence polarization (MSFP) assay was highly repeatable (inter-assay coefficient of variation = 1.5%) and accurate (r2 = 0.99). According to signal linearity, only 50–80 ng human genomic DNA per reaction was necessary for the 384-well format. MSFP is a simple, rapid approach as all biochemical reactions and final detection can be performed in one well in a 384-well plate without purification steps in less than 3.5 hours. Furthermore, we demonstrated a significant correlation between MSFP and the LINE-1 pyrosequencing assay, a widely used global DNA methylation assay. MSFP can be applied for the pre-screening of compounds that influence global DNA methylation states and also for the diagnosis of certain types of cancer.
The mitochondrial cascade hypothesis of dementia assumes mitochondrial dysfunction leading to reduced energy supply, impaired neuroplasticity, and finally cell death as one major pathomechanism underlying the continuum from brain aging over mild cognitive impairment to initial and advanced late onset Alzheimer's disease. Accordingly, improving mitochondrial function has become an important strategy to treat the early stages of this continuum. The metabolic enhancer piracetam has been proposed as possible prototype for those compounds by increasing impaired mitochondrial function and related aspects like mechanisms of neuroplasticity. We here report that piracetam at therapeutically relevant concentrations improves neuritogenesis in the human cell line SH-SY5Y over conditions mirroring the whole spectrum of age-associated cognitive decline. These effects go parallel with improvement of impaired mitochondrial dynamics shifting back fission and fusion balance to the energetically more favorable fusion site. Impaired fission and fusion balance can also be induced by a reduction of the mitochondrial permeability transition pore (mPTP) function as atractyloside which indicates the mPTP has similar effects on mitochondrial dynamics. These changes are also reduced by piracetam. These findings suggest the mPTP as an important target for the beneficial effects of piracetam on mitochondrial function.
The general assumption that brain size differences are an adequate proxy for subtler differences in brain organization turned neurobiologists toward the question why some groups of mammals such as primates, elephants, and whales have such remarkably large brains. In this meta-analysis, an extensive sample of eutherian mammals (115 species distributed in 14 orders) provided data about several different biological traits and measures of brain size such as absolute brain mass (AB), relative brain mass (RB; quotient from AB and body mass), and encephalization quotient (EQ). These data were analyzed by established multivariate statistics without taking specific phylogenetic information into account. Species with high AB tend to (1) feed on protein-rich nutrition, (2) have a long lifespan, (3) delayed sexual maturity, and (4) long and rare pregnancies with small litter sizes. Animals with high RB usually have (1) a short life span, (2) reach sexual maturity early, and (3) have short and frequent gestations. Moreover, males of species with high RB also have few potential sexual partners. In contrast, animals with high EQs have (1) a high number of potential sexual partners, (2) delayed sexual maturity, and (3) rare gestations with small litter sizes. Based on these correlations, we conclude that Eutheria with either high AB or high EQ occupy positions at the top of the network of food chains (high trophic levels). Eutheria of low trophic levels can develop a high RB only if they have small body masses.
G protein coupled receptors (GPCRs) constitute the largest family of cell-surface receptors in mammals and are key players in signal transduction. By responding to a plethora of extracellular stimuli ranging from photons to amines to fatty acids to peptides and proteins, these receptors trigger intracellular signalling cascades and regulate a variety of cellular responses. Approximately 800 genes in humans encode GPCRs which are classified according to sequence conservation into rhodopsin-like, glutamate, adhesion, frizzled/taste2 and secretin receptors. GPCRs share a seven transmembrane domain fold undergoing a conformational change upon ligand binding which is translated to the intracellular surface of the receptor thereby allowing a heterotrimeric G protein to couple. Heterotrimeric G proteins consist of a Ga, Gb and Gg subunit and dissociate into their Ga and Gbg entities upon activation by a GPCR. Subsequently, distinct signalling cascades are triggered by each G protein protomer.
Membrane proteins and GPCRs in particular, are highly important targets in drug design and development as currently approximately 60% of all marketed drugs target membrane proteins. Although these classes of proteins are of high therapeutic interest, our understanding of their mechanism of action and structure remains limited. The first structure of a human GPCR was determined in 2007 and required the development of protein engineering and innovative crystallisation techniques. Since then, approximately 130 GPCR structures of less than 40 individual receptors have been determined providing insights into the structural arrangement of the transmembrane helices, ligand binding pockets and G protein interactions. Combined with spectroscopic methods, these studies allowed a more detailed understanding of the molecular aspects of GPCR activation and signalling. Despite the tremendous advances in GPCR structural biology, certain aspects of GPCR function still remain poorly understood. Due to their size and inherent flexibility, the interaction of protein and peptide ligands with their receptors remains a challenging aspect in the structural characterisation of GPCRs. Moreover, structural information on subtype selectivity of peptide ligands continues to be scarce. To contribute functional and structural information on the molecular mechanisms of peptide interactions with GPCRs, this thesis focused on characterising receptors from the chemoattractant cluster using radioligand binding assays as well as NMR spectroscopy.
The chemoattractant cluster mainly groups the kinin, angiotensin, anaphylatoxin chemotactic complement and apelin receptors according to conserved residues in their ligand binding cavities. All receptors in this cluster bind to peptide ligands deriving from high molecular weight protein precursors upon proteolytic processing. Comparable to the conserved binding pocket of the chemoattractant receptors, the peptide ligands display a certain sequence conservation although they differ strongly in size. The largest ligands used in this thesis are the anaphylatoxins complement 3a and 5a, comprising 77 or 74 residues, respectively. Due to their size and complex fold involving three intramolecular disulphide bonds, solid phase synthesis is impossible, which prompted us to develop a modified cell-free expression system to produce these ligands in tritiated form for subsequent functional characterisation of the complement receptors. To demonstrate the versatility of the developed system, it was applied to another disulphidebond containing peptide ligand, the 21 amino acid endothelin-1. We describe a reliable and multifaceted tool to generate custom labelled peptide ligands for the structural and functional characterisation of GPCRs. The system allows the production of custom radioligands, peptides labelled for NMR studies or with fluorescent amino acids.
Apart from the modulation of GPCR activity by orthosteric ligands, GPCR signalling has long been described to be regulated by allosteric ligands including peptides, small molecules and ions. In this thesis, the influence of sodium ions on the activity state of the chemoattractant cluster receptors and in particular on the apelin, bradykinin 2 and angiotensin II type 1 receptors was examined. In recent high resolution crystal structures an allosteric sodium ion pocket beneath the orthosteric ligand binding cavity was identified and residues contributing to the coordination of sodium ions are conserved throughout the chemoattractant cluster receptors. This allosteric sodium ion coordinated within the transmembrane domain bundle has been described to negatively influence the affinity of agonists but not of antagonists. It was found that sodium ions have distinct influences on the affinity state as well as the available number of binding sites of the chemoattractant receptors. In case of the apelin and bradykinin 2 receptors, sodium ions drastically reduced the number of available binding sites whereas the affinity of peptide ligands to the bradykinin 2 receptors remained constant and the ligand binding affinities to the apelin receptor were completely abolished. In contrast, the angiotensin II type 1 receptor affinity state towards the endogenous peptide ligand angiotensin II is highly dependent on the presence of sodium ions, whereas binding of the synthetic peptide antagonist Sar1-Ile8-angiotensin II remained unaffected by the sodium ion concentration. As differential effects irrespective of the efficacy class but dependent on the amino acid composition of the applied ligands are observed, it can be concluded that electrostatic interactions between charged residues of the peptide ligands and amino acids on the extracellular surface of the receptors are influenced by sodium ions thereby adding another layer of complexity on GPCR signalling.
To elucidate the structure-function relationship of ligand selectivity between the kinin receptors, the structure of desArg10-kallidin (DAK) bound to the bradykinin 1 receptor was determined using solid state NMR (SSNMR) in the course of this thesis. The kinin peptides DAK and bradykinin bind with high affinity and high selectivity to either the bradykinin 1 or bradykinin 2 receptor, respectively. The binding pockets of the receptors are highly conserved and the two peptide ligands only differ in one amino acid at their N- and C-termini whereas the remaining eight amino acids are fully conserved. DAK adopts a U-shaped structure when bound to the bradykinin 1 receptor which resembles a horse shoe-like conformation. Using 2D TEDOR spectroscopy it could furthermore be demonstrated that positively charged residues at the N-terminal part of the peptide engage in ionic interactions with negatively charged amino acids on the extracellular surface of the bradykinin 1 receptor. In contrast, bradykinin displays a distinct b-turn at the C-terminus and an S-shaped conformation of the N-terminal segment when bound to the bradykinin 2 receptor. By using SSNMR to study the binding mode of DAK on the bradykinin 1 receptor we could determine that subtype selectivity between the kinin receptors is conferred by distinct conformational restraints within the peptide ligands and by the formation of specific ionic interaction between charged residues on the peptide and receptor, respectively.
In brief, this thesis contributes structural and functional data on the binding mechanisms and binding mode of different peptide-ligand GPCRs helping to understand subtype selectivity and allosteric modulation of the chemoattractant cluster receptors. In addition, a versatile cell-free expression system was developed that allows the custom synthesis of isotopically labelled peptides containing disulphide bonds for the functional characterisation of GPCRs.
Melt segregation inside the earth consists of two different processes: 1) Generation of partially molten rock and 2) separation of melt, produced from partially molten rock, from the solid residual matrix. This thesis focuses on the later process. The 2 phase flow dynamics combines the study of flow dynamics of melt and matrix. Several studies have given the background theoretical frameworks for the flow dynamics of melt inside the earth. [McKenzie, 1984] summarizes the studies of [Ahern and Turcotte, 1979; Frank, 1968; Sleep, 1975] and gives a complete set of governing equations for the 2-phase flow problem.
[Bercovici et al., 2001] gives a general formulation considering the univariate system of equations related to matrix and melt flow which includes the interfacial surface force. The assumption of melt having negligible viscosity compare to the matrix has been abandoned. Therefore, based on these formulations, we have constructed our numerical model and thereafter a fortran code PERCOL2D to get an insight of melt percolation process through porous media. Additionally, we have used the Helmhotz decomposition, which splits a smooth and rapidly decaying vector field into an irrotational vector field and an incompressible vector field [Srámek, 2007], for matrix and fluid viscosity in order to lower the number of linearly independent variables to minimize the computational complications. The melt residing at inter-granular areas of lithosphere, forms an interconnected network even at low porosity. Therefore, being less dense than the matrix, melt moves up through porous media due to its buoyancy. Compaction of matrix, which occurs to compensate the melt separation, is considered in this thesis, where the effective bulk and shear viscosity of matrix are function of melt fraction. We have effective bulk viscosity of matrix as inversely proportional to melt fraction. Porosity dependence of effective bulk and shear viscosity leads to stronger melt focusing in highly porous region like mid ocean ridges [Katz, 2008] since the ratio of bulk and shear viscosity is smaller (< 10) than the constant viscosity case for the porous waves having non dimensional amplitude 5% or higher. Moreover, it is observed in [Richard et al., 2012] that the solitary wave formed in porosity dependent viscous matrix settings are steeper than the one formed in the constant matrix viscosity setting.
Firstly some 1D numerical experiments with PERCOL2D have been carried out using fixed and periodic boundary conditions for zero source term (i.e. no melting or no freezing) and negligible surface tension.
3 series of model setups with different initial conditions have been carried out varying the width, non-dimensional amplitude and the background porosity value of the initial input of porous wave.
A mathematical derivation for 1D solitary wave solution for the two phase flow through porosity dependent compacting media, is obtained in this thesis which is different than the study of [Barcilon and Lovera, 1989; Barcilon and Richter, 1986; Scott and Stevenson, 1984; Spiegelman, 1993a,b] as the effective viscosity of matrix is constant there.
Although [Simpson and Spiegelman, 2011] gives the solitary wave solutions in 1D, 2D and 3D considering the porosity dependent effective viscosity of the matrix, but using the small background porosity approximation, they neglect the background porosity (i.e φ0) and therefore the effect of variation of compaction lengths, which causes variation in the shape and dynamics of the solitary wave. Therefore, the study [This thesis, Richard et al., 2012] can be used for more general purpose. Solitary waves in varying viscous medium, are steeper (cf fig.5.1) compared to the one in constant viscous medium and their speed decreases as an inverse function of the background porosity. Additionally, this analytical solution is used in our code PERCOL2D and also in FDCON for numerical benchmarking (1D) of PERCOL2D.
The role of melt grain contiguity is considered in the revised viscosity formulation [Schmeling et al., 2012] based on elastic moduli theory of a fluid filled poro-elastic medium. This formulation is used in this thesis to produce a comparative dispersion relationship between speed of the wave and the non dimensional amplitude of porous wave, based on both the viscosity formulations (fig. 6.20) where one can see that the model based on [Bercovici et al., 2001] formulation, converges to the same dispersion relationship obtained from [Simpson and Spiegelman, 2011]. Whereas, the dispersion relationship using [Schmeling et al., 2012] formulations, shows time-dependent decrease of phase velocity with increasing amplitude and it is not yet clear that whether these solutions converge to steady state porosity waves before the porosity becomes 1.
Amid increasing regulation, structural changes of the market and Quantitative Easing as well as extremely low yields, concerns about the market liquidity of the Eurozone sovereign debt markets have been raised. We aim to quantify illiquidity risks, especially such related to liquidity dry-ups, and illiquidity spillover across maturities by examining the reaction to illiquidity shocks at high frequencies in two ways:
a) the regular response to shocks using a variance decomposition and,
b) the response to shocks in the extremes by detecting illiquidity shocks and modeling those as ultivariate Hawkes processes.
We find that:
a) market liquidity is more fragile and less predictable when an asset is very illiquid and,
b) the response to shocks in the extremes is structurally different from the regular response.
In 2015 long-term bonds are less liquid and the medium-term bonds are liquid, although we observe that in the extremes the medium-term bonds are increasingly driven by illiquidity spillover from the long-term titles.
Most defined contribution pension plans pay benefits as lump sums, yet the US Treasury has recently encouraged firms to protect retirees from outliving their assets by converting a portion of their plan balances into longevity income annuities (LIA). These are deferred annuities which initiate payouts not later than age 85 and continue for life, and they provide an effective way to hedge systematic (individual) longevity risk for a relatively low price. Using a life cycle portfolio framework, we measure the welfare improvements from including LIAs in the menu of plan payout choices, accounting for mortality heterogeneity by education and sex. We find that introducing a longevity income annuity to the plan menu is attractive for most DC plan participants who optimally commit 8-15% of their plan balances at age 65 to a LIA that starts paying out at age 85. Optimal annuitization boosts welfare by 5-20% of average retirement plan accruals at age 66 (assuming average mortality rates), compared to not having access to the LIA. We also compare the optimal LIA allocation versus two default options that plan sponsors could implement. We conclude that an approach where a fixed fraction over a dollar threshold is invested in LIAs will be preferred by most to the status quo, while enhancing welfare for the majority of workers.
Am 27. Dezember 2015 verabschiedete der Ständige Ausschuss des Nationalen Volkskongresses das erste Antiterrorgesetz in der Geschichte der Volksrepublik China (VRC). Damit wurde eine über 25 Jahre erarbeitete umfangreiche Antiterrorstrategie zu Papier gebracht und mit ihr endlich eine verbindliche rechtliche Definition von „Terrorismus.“ Bereits gängige Praktiken wie öffentliche Medienzensur oder die Verpflichtung von Telekommunikationsunternehmen und Internetprovidern zur Bereitstellung von Inhaltsdaten wurden formalisiert und verschärft, sowie auch die Mobilisierung zivilgesellschaftlicher Organisationen auf eine rechtliche Grundlage gestellt. Allerdings stellt das Gesetz nur den finalen, formalen Schritt einer fünfundzwanzigjährigen Entwicklung dar. Tatsächlich kämpft Beijing seit Anfang der 1990er Jahre in der Provinz Xinjiang mit einer Mischung aus separatistisch und islamistisch motivierter politischer Gewalt, an deren Spitze seit spätestens 2008 das East Turkestan Independence Movement (ETIM) steht. ETIM weist ideell und organisatorisch eine Nähe zu Al Qaeda auf, und arbeitet transnational mit der Islamischen Bewegung Usbekistans, Tehrik-i-Taliban (Pakistan) und der al-Nusra Front (Syrien) zusammen...
Systemic co-jumps
(2016)
The simultaneous occurrence of jumps in several stocks can be associated with major financial news, triggers short-term predictability in stock returns, is correlated with sudden spikes of the variance risk premium, and determines a persistent increase (decrease) of stock variances and correlations when they come along with bad (good) news. These systemic events and their implications can be easily overlooked by traditional univariate jump statistics applied to stock indices. They are instead revealed in a clearly cut way by using a novel test procedure applied to individual assets, which is particularly effective on high-volume stocks.
This paper addresses whether and to what extent econometric methods used in experimental studies can be adapted and applied to financial data to detect the best-fitting preference model. To address the research question, we implement a frequently used nonlinear probit model in the style of Hey and Orme (1994) and base our analysis on a simulation stud. In detail, we simulate trading sequences for a set of utility models and try to identify the underlying utility model and its parameterization used to generate these sequences by maximum likelihood. We find that for a very broad classification of utility models, this method provides acceptable outcomes. Yet, a closer look at the preference parameters reveals several caveats that come along with typical issues attached to financial data, and that some of these issues seems to drive our results. In particular, deviations are attributable to effects stemming from multicollinearity and coherent under-identification problems, where some of these detrimental effects can be captured up to a certain degree by adjusting the error term specification. Furthermore, additional uncertainty stemming from changing market parameter estimates affects the precision of our estimates for risk preferences and cannot be simply remedied by using a higher standard deviation of the error term or a different assumption regarding its stochastic process. Particularly, if the variance of the error term becomes large, we detect a tendency to identify SPT as utility model providing the best fit to simulated trading sequences. We also find that a frequent issue, namely serial correlation of the residuals, does not seem to be significant. However, we detected a tendency to prefer nesting models over nested utility models, which is particularly prevalent if RDU and EXPO utility models are estimated along with EUT and CRRA utility models.
Microeconomic modeling of investors behavior in financial markets and its results crucially depends on assumptions about the mathematical shape of the underlying preference functions as well as their parameterizations. With the purpose to shed some light on the question, which preferences towards risky financial outcomes prevail in stock markets, we adopted and applied a maximum likelihood approach from the field of experimental economics on a randomly selected dataset of 656 private investors of a large German discount brokerage firm. According to our analysis we find evidence that the majority of these clients follow trading pattern in accordance with Prospect Theory (Kahneman and Tversky (1979)). We also find that observable sociodemographic and personal characteristics such as gender or age don't seem to correlate with specific preference types. With respect to the overall impact of preferences on trading behavior, we find a moderate impact of preferences on trading decisions of individual investors. A classification of investors according to various utility types reveals that the strength of the impact of preferences on an investors' rading behavior is not connected to most personal characteristics, but seems to be related to round-trip length.
Shortcomings revealed by experimental and theoretical researchers such as Allais (1953), Rabin (2000) and Rabin and Thaler (2001) that put the classical expected utility paradigm von Neumann and Morgenstern (1947) into question, led to the proposition of alternative and generalized utility functions, that intend to improve descriptive accuracy. The perhaps best known among those alternative preference theories, that has attracted much popularity among economists, is the so called Prospect Theory by Kahneman and Tversky (1979) and Tversky and Kahneman (1992). Its distinctive features, governed by its set of risk parameters such as risk sensitivity, loss aversion and decision weights, stimulated a series of economic and financial models that build on the previously estimated parameter values by Tversky and Kahneman (1992) to analyze and explain various empirical phenomena for which expected utility doesn't seem to offer a satisfying rationale. In this paper, after providing a brief overview of the relevant literature, we take a closer look at one of those papers, the trading model of Vlcek and Hens (2011) and analyze its implications on Prospect Theory parameters using an adopted maximum likelihood approach for a dataset of 656 individual investors from a large German discount brokerage firm. We find evidence that investors in our dataset are moderately averse to large losses and display high risk sensitivity, supporting the main assumptions of Prospect Theory.
Ongoing demographic change will lead to a relative scarcity of raw labor to the effect that output growth will be decreasing in the next decades, a secular stagnation. As physical capital will be relatively abundant, this decrease of output will be accompanied by reductions of asset returns. We quantify these effects for the US economy by developing an overlapping generations model with risky and risk-free assets. Without adjustments of human capital, risky returns decrease until 2035 by about 0.7 percentage point, and the risk-free rate by about one percentage point, leading to substantial welfare losses for asset rich households. Per capita output is reduced by 6%. Endogenous human capital adjustments strongly mitigate these effects. We conclude that human capital policies will be crucial in the context of labor shortages.
We study whether the presence of low-latency traders (including high-frequency traders (HFTs)) in the pre-opening period contributes to market quality, defined by price discovery and liquidity provision, in the opening auction. We use a unique dataset from the Tokyo Stock Exchange (TSE) based on server-IDs and find that HFTs dynamically alter their presence in different stocks and on different days. In spite of the lack of immediate execution, about one quarter of HFTs participate in the pre-opening period, and contribute significantly to market quality in the pre-opening period, the opening auction that ensues and the continuous trading period. Their contribution is largely different from that of the other HFTs during the continuous period.
The equity trading landscape all over the world has changed dramatically in recent years. We have witnessed the advent of new trading venues and significant changes in the market shares of existing ones. We use an extensive panel dataset from the European equity markets to analyze the market shares of five categories of lit and dark trading mechanisms. Market design features, such as minimum tick size, immediacy and anonymity; market conditions, such as liquidity and volatility; and the informational environment have distinct implications for order routing decisions and trading venues' resulting market shares. Furthermore, these implications differ distinctly for small and large trades, probably because traders jointly optimize their trade size and venue choice. Our results both confirm and go beyond current theoretical predictions on trading in fragmented markets.
Using two datasets containing demographically representative samples of the Dutch population, I study how lifetime experiences of aggregate labor market conditions affect personality. Three sets of findings are reported. First, experienced aggregate unemployment is negatively correlated with the levels of all Big Five personality traits, except for conscientiousness (no significant correlation). Second, in panel data models with individual fixed effects I find that changes in experienced aggregate unemployment cause changes in emotional stability and agreeableness for men, and conscientiousness for women. The correlation is positive, and effects are economically large. Thirdly, I report suggestive evidence that the main driver is experienced aggregate unemployment, instead of other macroeconomic variables as experienced GDP, stock market returns or inflation. Taken together, these findings suggest that changes in Big Five personality traits are systematically related to experienced aggregate labor market conditions.
This paper is the outcome of a related broader project, exploring the explanatory power of the Legal Theory of Finance, which proposes a new institution-based analytical framework for the analysis of phenomena of financial markets. One of its most important theoretical assumptions, the legal construction of financial markets, is highlighted by the example of the private creation of money by structured finance products in this paper. Further implications can then be shown referring to pari passu clauses and collective action clauses, which are both exhibit a differential application of these legal rules according to the hierarchical status of the respective market participant, and can therefore endanger sovereign debt restructurings. Legal instruments to avoid this are briefly explored. An example of another key role of the law in crisis that is the task to resolve the tension between market discipline and financial stability is exemplified by the regulation of the OTC derivatives market and proposals of effective loss-sharing among CCPs. Related questions about the significance of legal rules to ensure financial stability are raised in the analysis of minimum capital requirements under Basel III.
Na temelju terenskoga istraživanja u radu se donosi sinkronijski prikaz naglasnih paradigma imenica e-vrste i i-vrste u slivanjskim govorima Slivna Ravnoga, Mihalja, Blaca i Podgradine. Riječ je o govorima koji pripadaju istočnohercegovačkomu dijalektu, slivanjsko-zažapskomu govornom tipu. Utvrdit će se postoje li kolebanja u pojedinoj paradigmi i među paradigmama te čuvanje kračine u d./l./i.
Rad opisuje jedan od dvaju interpunkcijskih znakova (središnje crte i navodnici) koji bitno odstupaju od odnosa jednoga znaka za jedno (unikodno) značenje. Dok navodnici imaju višestruke grafeme (točnije, osam) za jedno značenje, središnje crte najčešće imaju dva grafema (kraća i dulja crta) koja pokrivaju čak 11 (unikodnih i latiničnih) crtnih znakova. Dok je kriterij crtne duljine tradicionalno visoko istaknut u pravopisnim priručnicima, u predstavljenoj se kategorizaciji on nalazi tek na šestoj hijerarhijskoj razini. Osim što su u međuvremenu standardizirana dva nova unikodna crtna znaka (two-em dash i three-em dash, Unicode 6.1, siječanj 2012.), drugačija metodologija i uspoređivanje jezičnopovijesnoga i računalnojezikoslovnoga aspekta proširila je spoznaje o crtnim znakovima u hrvatskome jeziku o kojima je pisano u Portada i Stojanov (2009). Predstavlja se kategorizacija osjetljiva na dihotomiju grafičkoga prikaza i značenja koja sve crtne znakove dijeli u pet hijerarhijskih razina. Između 44 unikodna vodoravna i neprekinuta crtna znaka, podjelom prema tipu, vremenu, funkciji, smjeru i visini, došlo se do 11 latiničnih suvremenih pismovnih vodoravnih središnjih znakova među kojima svaki latinični jezik odabire svoje crtne znakove. Svim se crtnim unikodnim grafemima opisalo značenje i uporaba. S druge strane, crtni se znakovi promatraju u kroatističkoj jezičnopovijesnoj pravopisnoj perspektivi. U odnosu na bogati repozitorij unikodno standardiziranih crtnih znakova utvrdilo se da je pravopisna norma bitno redukcijska. Pravopisno normiranje crtnih znakova podijelilo se u dva razdoblja i tri skupine, ovisno o grafemskome obliku (prva i druga generacija pravopisnih pri ručnika) i nazivlju (prijestandardna faza i dva standardna smjera normiranja ovisno o prihvaćanju terminoloških parova spojnica – crtica i crtica – crta). Na temelju jezičnopovijesnoga i računalnojezikoslovnoga poredbenog istraživanja te na temelju supostavljanja unikodne standardizacije crtnih znakova pravopisnoj tradiciji opisa središnjih crta željelo se ukazati na (i) potrebu za širim i interdisciplinarnim pristupom opisa pisane jezične prakse, (ii) nedovoljnost opisa školske razine pravopisnih priručnika za suvremeno pisanje, kao i na (iii) nedostatnost postojeće kroatističke kodifikacije obaju terminoloških smjerova. Da bi se pravopisni priručnici mogli nazvati znanstveno utemeljenim djelima, u znatnijoj bi mjeri trebali opisati računalno pisanje i na razini interpunkcije uvesti razlikovanje znaka i grafema. Jedno od takvih mjesta opisa prema kojima bi pravopisi mogli unaprijediti svoju tehnološku suvremenost jest pitanje pisanja spojnice na početku prelomljena retka o čemu se iznijelo osam argumenata za odbacivanje aktualne tradicije. Raščlamba je pokazala da ima opravdanosti da se crtna kodifikacija temelji na trima ili četirima znakovima koji se iz 11 unikodnih latiničnih znakova svode uspostavljanjem osnovnih skupina središnjih crta, radno nazvanih c1, c2, c3 i c4 kao najkraća, srednje duga, duga i jako duga središnja crta.
U hrvatskoj jezikoslovnoj tradiciji element se formalni je pokazatelj pripadnosti pojedinoga glagola skupini povratnih glagola. Taj se element dosad smatrao zamjenjivim zamjenicom sebe u tzv. pravih povratnih glagola. U ovome se radu na temelju postavaka više autora (Zec 1985, Sells, Zaenen i Zec 1987, Moskovljević 1997, Medová 2009, Oliva 2010) pokušava dokazati neistovjetnost elemenata se i sebe. Slobodna zamjena tih dvaju elemenata rezultira promjenom značenja i gramatičkom neovjerenošću. Iz toga proizlazi i drugačija podjela povratnih glagola. U radu će se usporedbom nekoliko povratnih glagola i njihovih prijelaznih parnjaka iznijeti drugačiji pristup povratnim glagolima.
“Institutional Overburdening” to a large extent was a consequence of the “Great Moderation”. This term indicates that it was a period in which inflation had come down from rather high levels. Growth and employment were at least satisfying and variability of output had substantially declined. It was almost unavoidable that as a consequence expectations on future actions of central banks and their ability to control the economy reached an unprecedented peak which was hardly sustainable. Institutional overburdening has two dimensions. One is coming from exaggerated expectations on what central banks can achieve (“expectational overburdening”). The other dimension is “operational overburdening” i.e. overloading the central bank with more and more responsibilities and competences.
U radu se daje analiza i prikaz tvorbenoga sustava umanjenica u kajkavskome narječju. Analiza je provedena na primjerima iz objavljenih dijalektoloških opisa govora, kajkavskih rječnika te iz vlastite građe. U tvorbenome se opisu polazi sa sinkronijskoga stanovišta, a povijesnojezične se napomene donose tek sporadično. Navode se svi u građi potvrđeni sufiksi za tvorbu umanjenica muškoga, srednjega i ženskoga roda. Uz svaku se tvorbenu kategoriju navode i jezične značajke koje se odnose na glasovne promjene na granici osnove i sufiksa.
The loss and restoration of the phoneme /j/ plays a major role in the development of Proto-Slavic. After vowel contraction in posttonic syllables, Dybo’s law, and the rise of new /j/ in east, South, and West Slavic, contracted and uncontracted forms may have coexisted during a considerable period of time. After Dybo’s law we have *voļȃ < *vòlja "will" but *rolьjà < *orlь̀ja "plowland", after contraction *roļá in Slovincian rolåu, Old Polish rolå. The loss of distinctive tone yielded merger of the two paradigms, as a result of which most nouns of the former type adopted the accentuation of the latter. Slavic deverbal ja-stems are original proterodynamic ī/jē-stems. The proterodynamic nouns *dūšà (c) "soul" and *zorjà (c) "dawn" have probably preserved the original accentuation. The other proterodynamic jā-stems evidently adopted the accent pattern of the deverbal ā-stems.
Rad se bavi analizom svojstava, funkcija i markera konverzacijkih implikatura u SMS diskursu. U prvome dijelu članka utvrđuju se temeljni mehanizmi prijenosa implicitnih intencionalno enodiranih sadržaja u diskurs te se određuju obilježja jezične strukture i govorne produkcije tipična za dopisivanje putem SMS poruka. Diskurs SMS dopisivanja smatra se plodnim područjem za proučavanje implikatura zbog bogatstva implicitnim sadržajima (uvjetovanoga sažetošću SMS forme); posrednosti komunikacije koja iziskuje jezično ili znakovno markiranje implikatura te specifičnih načina prijenosa i signaliziranja implicitnih sadržaja. U drugome dijelu rada predstavljaju se paralingvistički i jezični markeri konverzacijskih implikatura koji su se temeljem analize korpusa SMS dopisivanja pokazali najzastupljenijima u upotrebi. Cilj je rada ukazati na specifičnosti SMS diskursa kada su u pitanju sredstva i mehanizmi enkodiranja, signaliziranja te uspješnoga dekodiranja implicitnih sadržaja.
This note discusses the basic economics of central clearing for derivatives and the need for a proper regulation, supervision and resolution of central counterparty clearing houses (CCPs). New regulation in the U.S. and in Europe renders the involvement of a central counterparty mandatory for standardized OTC derivatives’ trading and sets higher capital and collateral requirements for non-centrally cleared derivatives.
From a macrofinance perspective, CCPs provide a trade-off between reduced contagion risk in the financial industry and the creation of a significant systemic risk. However, so far, regulation and supervision of CCPs is very fragmented, limited and ignores two important aspects: the risk of consolidation of CCPs on the one side and the competition among CCPs on the other side. i) As the economies of scale of CCP operations in risk and cost reduction can be large, they provide an argument in favor of consolidation, leading at the extreme to a monopoly CCP that poses the ultimate default risk – a systemic risk for the entire financial sector. As a systemic risk event requires a government bailout, there is a public policy issue here. ii) As long as no monopoly CCP exists, there is competition for market share among existing CCPs. Such competition may undermine the stability of the entire financial system because it induces “predatory margining”: a reduction of margin requirements to increase market share.
The policy lesson from our consideration emphasizes the importance of a single authority supervising all competing CCPs as well as of a specific regulation and resolution framework for CCPs. Our general recommendations can be applied to the current situation in Europe, and the proposed merger between Deutsche Börse and London Stock Exchange.
U radu se donose rezultati deskriptivnog terminološkog opisa istraživanja provedenog na jednojezičnom korpusu predmetnog područja znanosti o kršu. Semaziološki orijentiranim pristupom provodi se distribucijska analiza terminoloških jedinica i njihovih supojavnica u diskursu. Oslanjajući se na leksičko-gramatički model, kreiraju se pojmovne klase na temelju dvojnosti sintagmatskih i paradigmatskih relacija. U opisu sintagmatskih jedinica posebna se pozornost posvećuje ulozi pridjevskih riječi kao kvalifikatora, ali i nositelja specijaliziranog značenja. Aktivna uloga pridjeva prikazuje se metodom parafraziranja značenja s obzirom na klase pojmova koje pridjev determinira. Analiza pridjeva u terminološkim sintagmama upućuje na višedimenzionalno dinamično strukturiranje pojmovnih struktura specijaliziranog područja znanja.
Die aktuelle Diskussion über eine Reform der gesetzlichen Rentenversicherung vermischt Fragen nach dem durchschnittlichen Rentenniveau mit Fragen der Umverteilung von Einkommen im Ruhestand zur Bekämpfung einer etwaigen Altersarmut. Dieser Beitrag kritisiert diesen Ansatz und befasst sich mit fünf Kernaussagen: (1) Die aktuell gültige Rentenformel darf unter keinen Umständen abgeschafft werden. (2) Das Renteneintrittsalter sollte an die durchschnittliche Restlebenserwartung nach dem Erreichen des 65. Lebensjahres gekoppelt werden. (3) Eine Integration der Flüchtlinge in den Arbeitsmarkt wird das Rentenniveau in den Jahren 2030 bis 2040 stützen. (4) Sollte trotz allem die Altersarmut steigen, so kann dem durch die Einführung einer Mindestrente begegnet werden. (5) Die private Altersvorsorge muss weiter gestützt werden.
The Intensifying Function of Modal Particles and Modal Elements in a Cross-Linguistic Perspective
(2015)
The aim of this paper is to analyze the intensifying function of German modal particles and equivalent modal expressions in Croatian and English. Our hypothesis is that some modal particles in German and their functional equivalents in Croatian and English can express different degrees of intensity and types of intensification. The presented study comprises two parts. First, the use of intensifying modal particles by a group of speakers of L1 Croatian and L2 German/English is investigated. On the basis of the results obtained, and by means of a previously conducted corpus analysis (cf. Kresić and Batinić 2014), an intensification scale with respect to the inventory of German modal particles and corresponding particles in Croatian as well as equivalent English expressions is suggested. Some German and Croatian modal particles and equivalent modal elements in English can be classified on the upper and partially on the lower part of the proposed intensification scale when compared to the norm, i.e. an utterance unmarked by a modal particle.
U ovom se radu prijevodi starogrčkih tragedija Bratoljuba Klaića promatraju u odnosu na njegove prethodnike te na zahtjeve onovremene recepcije antičkih dramskih tekstova. Na odabranim se primjerima iz Sofoklovih drama Antigona i Kralj Edip, a u usporedbi sa starijim prijevodima Kolomana Raca, analizira status Klaićeva prijevoda u odnosu na izvornik, određuju bitna načela njegove prevoditeljske metodologije te uočavaju strategije kojima rješava neke od problema interpretacije starogrčkoga teksta.
Pogled u radom ispunjen život Bratoljuba Klaića pokazuje širinu njegovih interesa i pobuđuje na misao o tom što bi hrvatsko jezikoslovlje moglo napraviti da je djelovalo u povoljnijim uvjetima. Svakako je književnost i kazalište izrazito privlačilo našeg proučavatelja, osobito hrvatska književnost, grčka i rimska, pa je prirodno njegovo sudjelovanje u ediciji Pet stoljeća hrvatske književnosti. Među hrvatskim piscima davnih stoljeća osobito su ga zanimali Hanibal Lucić, Petar Hektorović, Marin Držić i Ivan Gundulić, ali se je pozabavio i komedijom Ljubovnici, kao i novijim piscima Šenoom, Matošem, Ujevićem, Krležom, Kolarom i drugima. Znatnu je pozornost posvetio i folkloru tumačeći njegove jezične značajke. Na zanimljiv način bavio se je akcentom, osobito kad je riječ o akcentu starih pisaca hrvatskih i o naglasku u njihovim suvremenim izvedbama. Bratoljub Klaić bio je jedan od znanstvenika što su hrvatsku književnost tumačili kao prirodnu cjelinu pisaca raznih stoljeća, iz raznih predjela i različitih dijalekatnih osobina.
Metalepsa je u naratologiji definirana kao postupak prekoračenja granice između fikcije i stvarnosti, književnog i izvanknjiževnog (Genette 1972, 2004). Vodeći se tom definicijom što je uključuje K. Bagić (2012.) u smislu figure koja iziskuje novo promišljanje statusa granice u narativnom tekstu, u članku će se analizirati metalepsa unutar autoironijskog postupka poigravanja funkcijama književnog teksta u autobiografskoj humoresci "Priča o bezmesnom ručku" (Pripovijetke, 2009.) Bratoljuba Klaića. Poigravanje metanarativnim komentarima tzv. kanonske hrvatske književnosti prisutno je u drugoj humoresci iz iste zbirke, pod naslovom „Baba Lizino janješceˮ. Cilj rada je prikazati stilske i naratološke osobitosti Klaićeva proznog stvaralaštva, i to s naglaskom na postupcima kojima autor konstruira specifičan humoristični učinak utemeljen na obratu i odmaku od uspostavljenih unutartekstualnih i izvantekstualnih odnosa. Uključivanje metalepse, potkopavanje granice između fikcije i stvarnosti, književnog i neknjiževnog, metanarativnost, autoreferencijalnost, kao i samo ironiziranje funkcija književnosti te društva u kojemu ona nastaje i unutar kojega ostvaruje recepciju, ukazuju na to da se Klaićev izraz, unatoč prividnoj lakoći i jednostavnosti, mjestimice približava poetičkim odrednicama postmoderne. Istraživanje njegovih pripovjednih tekstova stoga može dati zanimljive rezultate i u ključu suvremenih spoznaja teorije pripovijedanja kad su u pitanju postupci ostvarivanja humora, pa čak i šire – kada je u pitanju tekstualno konstruiranje identiteta subjekta unutar autobiografskog diskursa.
Već je i površnim pregledom u Klaićev Rječnik stranih riječi vidljivo da je Miroslav Krleža najcitiraniji književnik, a natuknice kod kojih se na njega upućuje su posuđenice, tuđice, strane riječi pa i cijeli rečenični citati na stranom jeziku. U radu se daje raščlamba natuknica koje Klaić povezuje s Krležom.
U radu se ukratko prikazuje Klaićev opis bizovačkoga govora i podjela donjopodravskih govora na dva međusobno ponešto različita tipa: valpovački akcenatski tip govora – okolica Bizovca do Donjega Miholjca – i šaptinovački akcenatski tip – od Donjega Miholjca prema Virovitici. Obilježja bizovačkoga govora uspoređuju se s govorom Podravskih Podgajaca.
U radu se ponajprije na temelju sklonidbe jednosložnih imenica o-osnova iznose temeljne razlike u uspostavi naglasnih tipova u Klaićevim djelima Rječnik stranih riječi i Naglasni sustav standardnoga hrvatskog jezika te Školskoga rječnika hrvatskoga jezika Instituta za hrvatski jezik i jezikoslovlje i Školske knjige. Zajednička je navedenim djelima dosljedna provedba novoštokavskih naglasnih pravila te nastojanje za usustavljivanjem naglašivanja. Razlike se odnose na odabir naglasnih tipova koji su u Klaićevim djelima utemeljeni na starijim jezičnim priručnicima i dijalektološkoj građi, a u Školskome su rječniku zasnovani na odrazima praslavenskih naglasnih paradigma. Iz rada je razvidno da bi Klaićev doprinos usustavljivanju naglašivanja u hrvatskome standardnom jeziku bio znatno veći da je njegov naglasni priručnik bio otisnut kad je nastao. U radu se navode i razlike u naglascima u suvremenim hrvatskim rječnicima koje su djelomično posljedicom nedostatka pravogovornih priručnika te selektivnoga odstupanja od novoštokavskih naglasnih pravila.
Članak analizira akcenatski sustav valpovačkoga podravskog govora na temelju Klaićeva opisa govora Bizovca. Usporedba njegova opisa s opisima drugih dijalektologa vodi do zaključka da su razlike između postojećih opisa valpovačke akcentuacije znatne te da je Klaićev opis od svih opisa najdetaljniji i najpouzdaniji. Drugi dio članka opisuje akcenatsku karakteristiku koja dijeli valpovački govor od ostalih slavonskih govora: povlačenje naglaska s dočetnoga sloga prozodijske riječi na početni slog. Navode se neke tipološke paralele iz drugih hrvatskih govora, zatim ruskoga i litavskoga jezika. Potvrđena je teza, koju je zastupalo više jezikoslovaca, da je povlačenje naglaska posljedica utjecaja mađarskog jezika na valpovački govor.
Brojni naglasni "tipovi" prvi put detaljno popisani u radovima Đ. Daničića bili su povod mnogim akcentološkim radovima u XX. st. Cilj im je prije svega bio učiniti naglasnu tipologiju jednostavnijom i preglednijom te upozoriti na (ne)aktualnosti naglasnih uzoraka koji su se dugo prepisivali i prenosili u literaturi. Šireuporabno neprimjenljiva Daničićeva naglasna tipologija bila je povod i Klaićevu (1963.) pokušaju smanjenja broja tipova, i to polazeći od proklize, osvrćući se na povijest jezika i na dijalekte. Prenošenje naglaska na proklitiku zahtijeva dobro poznavanje povijesti jezika tako da se to sažimanje ne doima šire uporabljivim, no svakako otvara pitanja kojima se i danas bavimo, a to je pitanje (ne)prenošenja naglaska na proklitiku i pitanje broja uzoraka promjenljivoga naglasnoga tipa. Analizom Klaićeve naglasne tipologije, koja se nameće iz njegovih radova, želimo pokazati koliko je odmaknula od Daničićeva tipologiziranja i koliko je bliska današnjim prikazima.
Baveći se (kao recenzentica) djelom Bratoljuba Klaića Naglasni sustav standardnoga hrvatskog jezika, Klaićev me način bilježenja naglasaka podsjetio i na nešto starije gramatike hrvatskoga jezika i na bilježenje naglasaka u tim gramatikama, pa se tim uspoređivanjem vrlo lako uočava razlika između pisanja naglasaka „nekad i sad”, premda to „nekad” i nije bilo tako davno. Kako su u hrvatskoj kroatistici akcentološka djela rijetka, prilika je da se na skupu posvećenu između ostaloga i akcentologu Bratoljubu Klaiću progovori nešto više o razlikama u bilježenju hrvatskih naglasaka u Klaićevo vrijeme (prije pedesetak godina) i u vrijeme bliže današnjemu, jer su te razlike od vremena pisanja Klaićeva djela do danas očite. U svojem izlaganju osvrnula sam se na poteškoće u novijem bilježenju hrvatskih standardnih naglasaka, poglavito na slogovima s dugim refleksom staroga glasa jata,te o razlozima koji su do njih doveli. Usredotočila sam se poglavito na Klaićevo i današnje pisanje naglasaka na nekadašnjoj tzv. dugoj (dvosložnoj) zamjeni jata – koliko god to neki lingvisti tretirali kao dvoglasnik ie, ipak se riječi kao snijeg, brijeg i sl. mogu rastaviti na slogove, dakle ipak su posrijedi dva sloga, a ne jedan – jer upravo u tome i jesu razlike između Klaićeva bilježenja naglasaka i onih današnjih u standardološkim djelima.
Rječnik stranih riječi Bratoljuba Klaića prepoznat je kao ozbiljan, pouzdan i relevantan priručnik ne samo u stručnim krugovima nego i u širokome krugu zainteresiranih korisnika. Razlogom je takve posvemašnje zainteresiranosti nedvojbeno njegova obavijesnost i preglednost, ali i prikladnost leksikografske obradbe. Dobar dio rječničkoga korpusa Klaićeva Rječnika čine glagolske natuknice koje se u rječničkome članku obrađuju kao polazna i kao izvedena natuknica. U radu se razmatraju glagolske natuknice obrađene u prvim četirima izdanjima (1 1951., 2 1958., 3 1962., 4 1966.) jer su to jedina izdanja s Klaićevim autorskim potpisom. Propituje se status glagolskih natuknica u rječničkoj makrostrukturi, ustroj rječničkoga članka s glagolskom natuknicom kao polaznom ili izvedenom natuknicom te osobito primarne i sekundarne podatke o natuknici koji prikazuju prozodijske, morfološke, rječotvorne, etimološke, stilske, terminološke i semantičke obavijesti o glagolskoj natuknici.
U radu se propituje status općeeuropskih frazema hrvatskoga jezika u izdanjima Rječnika stranih riječi Bratoljuba Klaića. Pod općeeuropskim se frazemima podrazumijevaju međunarodni frazemi potvrđeni u europskim jezicima s jednakim značenjem i velikom strukturnom podudarnošću. Za te je frazeme važno da najčešće imaju poznat zajednički izvor, tj. podrijetlo, ali postoje i općeeuropski frazemi kojima još nije utvrđeno točno podrijetlo, odnosno jezik i tekst iz kojega su uzeti i prošireni. Stoga je cilj rada utvrditi i opisati status općeeuropskih frazema u Klaićevu Rječniku stranih riječi. Naime, Bratoljub Klaić u njemu donosi vrijedne podatke o izvoru pojedinoga frazema, izreke ili poslovice. Pri tome su u Rječnik uključeni općeeuropski frazemi kojima je sastavnicom strano vlastito ime, strani apelativ ili termin ili je riječ o prevedenicama iz latinskoga i drugih jezika. Dolazi se do zaključka da Klaićev rječnik može, kao nezaobilazno polazište nekom budućem hrvatskom etimološkom frazeološkom rječniku, biti važnim izvorom proučavanju podrijetla frazema.
Unter der Leitung des Gothaer Medailleurs Christian Wermuth (1661-1739) wurden zugleich drei Medaillen geschaffen und zum freien Verkauf angeboten, die an die poetische Krönung von Sidonia Hedwig Zäunemann (1711-1740) erinnern. Von der als Universität der Aufklärung konzipierten Göttinger Universität literarisch ausgezeichnet, war die Erfurter Autorin die neunte von insgesamt 21 kaiserlich gekrönten Dichterinnen. Die treibenden Kräfte hinter dem Verleihungsakt standen unter dem Eindruck der durch die Universität Wittenberg vorgenommenen exzeptionellen Ehrung von Zäunemanns Vorgängerin Christiana Mariana von Ziegler (1695-1760). Den hohen Prestigewert der Göttinger Krönung belegen neben Lobgedichten und Berichten in Zeitungen und gelehrten Journalen auch die Krönungsmedaillen. Deren kulturpolitische Signalfunktion erschließt sich aus dem Sinn und Zweck, der den zwei Frauenkrönungen auf Seiten ihrer Initiatoren zugedacht war. Ein in Gotha entstandenes Werbeblatt zu den "curieuse[n] und wohl inventierte[n] Medaillen", datiert auf den 19. September 1738, gibt Aufschluss über die kreativen Köpfe, die als Nicht-Medailleure zum Gelingen dieses wohl auch unter kompetitiven Gesichtspunkten außergewöhnlichen künstlerischen Projektes unter Mitarbeit eines Medaillenverfertigers namens Grauel beitrugen. Eine aus den Quellen gearbeitete Zeittafel zum Krönungsjahr und die Mitteilung einer in der Wermuth-Forschung unbekannten Variante der kleinen Zäunemann-Medaille runden den literatur-, kunst- und kulturwissenschaftlich perspektivierten Beitrag ab.
The neural crest gives rise to the neurons and glial cells of the peripheral nervous system (PNS) (Bronner-Fraser and Fraser, 1989; Frank and Sanes, 1991). Self-renewing neural crest-derived stem cells (NCSCs) are present in migratory neural crest and various postmigratory locations, including peripheral ganglia (Duff et al., 1992; Morrison et al., 1999; Kruger er al., 2002). It is demonstrated that NCSCs from embryonic mouse dorsal root ganglia (DRG) are reprogrammed in neurosphere (NS) cultures in the presence of EGF and FGF. Reprogrammed NCSCs (rNCSCs) generate exclusively central nervous system (CNS) progeny, both in vitro and upon transplantation into the mouse brain (Binder et al., 2011). In this study the timing and mechanisms underlying the reprogramming were addressed. Most of the cells acquire CNS characteristics at passage 2, reaching a stable proportion of >90% of Olig2-positive cells at passage 3, which is maintained at least up to passage 10. The PNS marker p75 is completely lacking from passage 3 onwards. Furthermore, it was shown that the reprogramming does not involve a transient pluripotency state. This suggests a direct reprogramming of NCSCs to cells with CNS identity. The reprogramming leads to a stable CNS identity as shown by delayed BMP4 application. This result is in agreement with the previous observation that rNCSCs only generate CNS progeny, in particular mature myelinating oligodendrocytes, upon transplantation into embryonic, postnatal and lesioned adult mouse brains (Binder et al., 2011). Genome wide gene expression profiles of rNCSC NS demonstrates already in culture a complete switch to a (spinal cord stem cell) SCSC CNS identity. These results demonstrate a complete reprogramming of PNS progenitors to CNS identity without genetic modification and imply PNS cells as a source for stem cell-based CNS therapy.
The reprogramming of NCSCs is completely blocked in the presence of BMP4 in NS cultures, as shown by the expression of neural crest markers p75 and Sox10. In addition, BMP4 NCSCs generate PNS neurons (Tuj1/Phox2b- and Peripherin/Tuj1-coexpressing cells) and Schwann cells (O4/p75-coexpressing cells). Genome wide gene expression profiles of BMP NCSCs demonstrate that BMP NCSCs express genes at high levels which are characteristic for neural crest/neural crest derivatives, mesenchymal derivatives of neural crest and perivascular pericytes/MSCs. On the other hand CNS marker genes are restricted to rNCSCs and are only expressed at background or undetectable levels in BMP NCSCs. These findings imply that the CNS versus PNS identity is controlled by antagonistic functions of FGF and BMP4.
The use of rNCSCs for cell therapies requires an accessible source of these cells in the adult organism. Since the DRG is not an easily approachable tissue source, the adult mouse palate, containing NCSCs, was chosen. These results suggest that pNCSCs arise from Sox10-positive neural crest-derived stem cells, that downregulate PNS marker gene expression, such as Sox10 and p75, in NS culture. Contrary to rNCSCs, CNS marker upregulation was not observed. Notably, genome wide gene expression profiles of pNCSCs demonstrate an enrichment of genes expressed by mesenchymal derivatives and perivascular pericytes/mesenchymal stem cells. Since the cranial crest gives rise, besides PNS neural progeny and melanocytes, to mesenchymal derivatives, the results demonstrate that pNCSCs have a restricted developmental potential in comparison to rNCSCs and acquire mostly normal fates of the cranial neural crest.
Taken together, the results demonstrate that rNCSCs acquire a SCSC identity in the presence of EGF and FGF and that the reprogramming can be efficiently blocked by BMP4. On the other hand, NCSCs derived from adult palate rather acquire mesenchymal fates and do not acquire a CNS identity under the conditions used.
This is the ninth post in the blog series „Movements and Institutions“.
This article disputes the conceptualization of institutionalization as a one-way process. Instead, it argues that social movement organizations can make use of contentious tactics while being institutionalized. The environmental NGO Birdlife Malta provides an example to illustrate this argument
n traditional portfolio theory, risk management is limited to the choice of the relative weights of the riskless asset and a diversified basket of risky securities, respectively. Yet in industry, risk management represents a central aspect of asset management, with distinct responsibilities and organizational structures. We identify frictions that lead to increased importance of risk management and describe three major challenges to be met by the risk manager. First, we derive a framework to determine a portfolio position's marginal risk contribution and to decide on optimal portfolio weights of active managers. Second, we survey methods to control downside risk and unwanted risks since investors frequently have non-standard preferences which make them seek protection against excessive losses. Third, we point out that quantitative portfolio management usually requires the selection and parametrization of stylized models of financial markets. We therefore discuss risk management approaches to deal with parameter uncertainty, such as shrinkage procedures or re- sampling procedures, and techniques of dealing with model uncertainty via methods of Bayesian model averaging.
Tulasnella species (Tulasnellaceae, Cantharellales, Basidiomycota) form inconspicuous basidiomata on rotten branches or trunks of trees, difficult to find and recognize in nature. However, according to ultrastrucural and molecular data, species of Tulasnellaceae are the most frequent mycorrhriza forming fungi (mycobionts) of green, photosynthetic orchids worldwide. Species of Tulasnellaceae were also found as prominent mycobionts of the extraordinary diverse orchids in tropical montane rainforest of Southern Ecuador. Orchids obligately depend on mycobionts during the juvenile stage when the fungi have to deliver carbon to the non-photosynthetic protocorm and thus the fungi substantially influence the establishment of orchids in the wild. Species of Tulasnellaceae can acquire carbon from decaying bark or wood by specific saprotrophic capabilities as was recently proven through comparative genomics that included data on decay enzymes from Tulasnella cf. calospora isolated from orchid mycorrhizae (Anacamptis laxiflora, Italy). Thus, species of Tulasnellaceae can be saprotrophs and symbionts simultaneously.
It is currently under discussion, whether specific species of Tulasnella are required for seed germination and establishment of distinct terrestrial and epiphytic orchids in nature or if species of Tulasnella are generalists concerning their association with orchids. The inconsistences in species concepts and taxonomy of Tulasnella spp., however, strongly impede progress in this field of research. The aim of the present study was, therefore, to revise the species concepts by combining, for the first time, morphological and molecular data from basidiomata.
Specimens were collected in tropical Andean forest in Southern Ecuador and in temperate forests in Germany. Additional specimens were loaned from fungaria. In total, 205 specimens, corresponding to 16 own samples and 189 specimens from fungaria were analyzed. The mycobiont relationships of Tulasnella spp. with orchids from the sampling area in Ecuador were studied in populations of Epidendrum rhopalostele. The basis for molecular-phylogenetic analysis was completed by data obtained from own previous investigations on mycobionts from the investigation area and Tulasnella isolates from Australia.
30 morphospecies are illustrated and delimited by a morphological key based on traditional species concepts. Tulasnella andina from Ecuador and Tulasnella kirschneri from China are presented as species new to science. Tulasnella cruciata is described from herbarium material for the first time. Tulasnella aff. eichleriana and T. violea are reported for the first time from Ecuador. Molecular sequences of two Tulasnella spp. isolated from mycobionts of Epidendrum rhopalostele cannot be related to any morphological species concept. Statistical analyses suggest that conventional diagnostic using morphological characteristics is ambiguous for delimiting morphologically similar species.
For the first time sequences of the ITS-5.8S rDNA region were obtained after cloning from fresh basidiomata. Extraction of DNA from herbarium specimens was, however, unsuccessful. Sequences from 16 fresh basidiomata, six pure cultures, and sequences of orchids mycorrhizae (e.g. from Epidendrum rhopalostele) available in the database GenBank were analyzed. Proportional
variability of ITS-5.8S rDNA sequences within and among cultures and within and among specimens were used to designate morphospecies. Results suggest an intragenomic variation of less than 2 %, an intraspecific variation of up to 4 % and an interspecific divergence of more than 9 % for Tulasnella spp.
Four percent of intraspecific divergence was defined as a minimum threshold for delimiting phylogenetic species. This threshold corroborates the so far used 3 % to 5 % divergence in delimitation of operational taxonomic units of Tulasnella mycobionts.
Quite a number of sequences of Tulasnella are available in GenBank, mostly obtained from direct PCR amplification from orchid mycorrhizae. By including closely related sequences in the phylogenetic analysis, several morphological cryptic species of Tulasnella, mostly from Ecuador, were found. Arguments are given for molecular support of the new species Tulasnella andina and the established species Tulasnella albida, T. asymmetrica, T. eichleriana, T. tomaculum, and T. violea. Thus, by combining molecular and morphological data species concepts in Tulasnella are improved. The definitions of Tulasnella calospora and T. deliquescens, however, remain phylogenetically inconsistent.
The present investigation is a first step to expand our knowledge on the intraand interspecific morphological and molecular variability of Tulasnella spp. and to delimit species relevant for studies on ecology and communities of orchids and Tulasnellaceae.
The recent financial crisis has demonstrated that a failure of Systemically Important Financial Institutions (SIFIs) could seriously damage the stability of the financial system. A precise and consistent definition of a SIFI is pivotal to ensure efficient and effective regulation of the global financial sector. This paper proposes a threefold test logic that allows to classify Financial Institutions as systemically important across the various industry segments.
We provide a comprehensive analysis of the determinants of trading in the sovereign credit default swaps (CDS) market, using weekly data for single-name sovereign CDS from October 2008 to September 2015. We describe the anatomy of the sovereign CDS market, derive a law of motion for gross positions and their components, and identify the key factors that drive the cross-sectional and time-series properties of trading volume and net notional amounts outstanding. While a single principal component accounts for 54 percent of the variation in sovereign CDS spreads, the largest common factor explains only 7 percent of the variation in sovereign CDS net notional amounts outstanding. Moreover, unlike for CDS spreads, common global factors explain very little of the variation in sovereign CDS trading and net notional amounts outstanding, suggesting that it is driven primarily by idiosyncratic country risk. We analyze several local and regional channels that may explain the trading in sovereign CDS: (a) country-specific credit risk shocks, including changes in a country's credit rating and related outlook changes, (b) the announcement and issuance of domestic and international debt, (c) macroeconomic sentiment derived from conventional and unconventional monetary policy, macro-economic news and shocks, and (d) regulatory channels, such as changes in bank capital adequacy requirements. All our findings suggest that sovereign CDS are more likely used for hedging than for speculative purposes.
Using novel monthly data for 226 euro-area banks from 2007 to 2015, we investigate the determinants of changes in banks’ sovereign exposures and their effects during and after the crisis. First, public, bailed out and poorly capitalized banks responded to sovereign stress by purchasing domestic public debt more than other banks, with public banks’ purchases growing especially in coincidence with the largest ECB liquidity injections. Second, bank exposures significantly amplified the transmission of risk from the sovereign and its impact on lending. This amplification of the impact on lending does not appear to arise from spurious correlation or reverse causality.