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We demonstrate that a multiple delayed feedback is a powerful tool to control coherence properties of autonomous self-sustained oscillators. We derive the equation for the phase dynamics in presence of noise and delay, and analyze it analytically. In Gaussian approximation a closed set of equations for the frequency and the diffusion constant is obtained. Solutions of these equations are in good agreement with direct numerical simulations.
It is shown that several polymers can form insoluble interfacial layers on a poly (ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) layer after annealing of the double-layer structure. The thickness of the interlayer is dependent on the characteristics of the underlying PEDOT.PSS and the molecular weight of the polymers. It is further shown that the electronic structures of the interlayer polymers have a significant effect on the properties of red-light-emitting polymer-based electrophosphorescent devices. Upon increasing the highest occupied molecular orbital and lowest unoccupied molecular orbital positions, a significant increase in current density and device efficiency is observed. This is attributed to efficient blocking of electrons in combination with direct injection of holes from the interlayer to the phosphorescent dye. Upon proper choice of the interlayer polymer, efficient red, polymer-based electrophosphorescent devices with a peak luminance efficiency of 5.5 cd A(-1) (external quantum efficiency = 6 %) and a maximum power-conversion efficiency of 5 Im W-1 can be realized.
The nanostructuring of ORMOCER (R) to form inverse opals is described. For this purpose a polymer opal is used as a template and infiltrated with liquid ORMOCER (R). After photopolymerization of the resin the host opal is dissolved in tetrahydrofuran and an ORMOCER (R) inverse opal is obtained. It shows excellent periodicity (by SEM) and optical properties to reveal a high degree of face centered cubic order. This replication process leads to a nanostructured photonic crystal with the outstanding mechanical properties of ORMOCER (R) and high temperature stability up to 350 degrees C.
One of the most important insights of Optimality Theory (Prince and Smolensky, 1993) is that phonological processes can be reduced to the interaction between faithfulness and universal markedness principles. In the most constrained version of the theory, all phonological processes should be thus reducible. This hypothesis is tested by alternations that appear to be phonological but in which universal markedness principles appear to play no role. If we are to pursue the claim that all phonological processes depend on the interaction of faithfulness and markedness, then processes that are not dependent on markedness must lie outside phonology. In this paper I will examine a group of such processes, the initial consonant mutations of the Celtic languages, and argue that they belong entirely to the morphology of the languages, not the phonology.
A new large set of reciprocal recombinant inbred lines (RILs) was created between the Arabidopsis accessions Col-0 and C24 for quantitative trait mapping approaches, consisting of 209 Col-0 x C24 and 214 C24 x Col-0 F-7 RI lines. Genotyping was performed using 110 evenly distributed framework single nucleotide polymorphism markers, yielding a genetic map of 425.70 cM, with an average interval of 3.87 cM. Segregation distortion (SD) was observed in several genomic regions during the construction of the genetic map. Linkage disequilibrium analysis revealed an association between a distorted region at the bottom of chromosome V and a non-distorted region on chromosome IV. A detailed analysis of the RILs for these two regions showed that an SD occurred when homozygous Col-0 alleles on chromosome IV coincided with homozygous C24 alleles at the bottom of chromosome V. Using nearly isogenic lines segregating for the distorted region we confirmed that this genotypic composition leads to reduced fertility and fitness.
The pollination biology of three mass flowering Utricularia species of the Indian Western Ghats, U. albocaerulea, U. purpurascens, and U. reticulata, was studied for the first time by extensive observation of flower visitors, pollination experiments, and nectar analyses. The ephemerality of the Utricularia habitats on lateritic plateaus, weather conditions adverse to insects, lack of observations of flower visitors to other Utricularia spp., and the predominance of at least. facultative autogamy in the few Utricularia species studied so far suggested that an autogamous breeding system is the common case in the genus. In contrast, we showed that the studied populations are incapable of autonomous selfing, or that it is an event of negligible rarity, although P/O was similarily low as in autogamous species investigated by other authors. In all three species the spatial arrangement of the reproductive organs makes an insect vector necessary for pollen transfer between and within flowers. However, U. purpurascens and U. reticulata are highly self-compatible, which allows for visitor-mediated auto-selfing and geitonogamy on inflorescence and clone level. Floral nectar is present in extremely small volumes in all three species, but sugar concentrations are high. More than 50 species of bees, butterflies, moths, hawk moths, and clipterans were observed to visit the flowers, and flower morphology facilitated pollination by all observed visitors. The results are discussed in the context of the phenological characteristics of the studied species, especially the phenomenon of mass flowering, and the environmental conditions of their habitats.
We investigate the effects of a time-delayed all-to-all coupling scheme in a large population of oscillators with natural frequencies following a bimodal distribution. The regions of parameter space corresponding to synchronized and incoherent solutions are obtained both numerically and analytically for particular frequency distributions. In particular, we find that bimodality introduces a new time scale that results in a quasiperiodic disposition of the regions of incoherence.
The small and large subunits of molybdopterin (MPT) synthase (MOCS2A and MOCS2B), are both encoded by the MOCS2 gene in overlapping and shifted open reading frames (ORFs), which is a highly unusual structure for eukaryotes. Theoretical analysis of genomic sequences suggested that the expression of these overlapping ORFs is facilitated by the use of alternate first exons leading to alternative transcripts. Here, we confirm the existence of these overlapping transcripts experimentally. Further, we identified a deletion in a molybdenum cofactor deficient patient, which removes the start codon for the small subunit (MOCS2A). We observed undisturbed production of both transcripts, while Western blot analysis demonstrated that MOCS2B, the large subunit, is unstable in the absence of MOCS2A. This reveals new insights into the expression of this evolutionary ancient anabolic system.