One-pot Selective Formylation and Claisen Rearrangement on Calix[4]arenes

A versatile synthon with formyl and allyl groups at the upper rim of calix[4]arene has been synthesized in two steps. Selective formylation of 25,27-diallyloxy-26,28-dihydroxycalix[4]arene, along with the Claisen rearrangement of the allyl groups, was achieved by reaction with hexamethylenetetraamine (hexamine) in glacial acetic acid. A control reaction of the dipropyl analogue shows that the selective formylation takes place independently of the Claisen rearrangement. The crystal structure of the dimethylacetal derivative of 5,17-diformyl-11,23-diallylcalix[4]arene is reported

Does training with amplitude modulated tones affect tone-vocoded speech perception?

Temporal-envelope cues are essential for successful speech perception. We asked here whether training on stimuli containing temporal-envelope cues without speech content can improve the perception of spectrally-degraded (vocoded) speech in which the temporal-envelope (but not the temporal fine structure) is mainly preserved. Two groups of listeners were trained on different amplitude-modulation (AM) based tasks, either AM detection or AM-rate discrimination (21 blocks of 60 trials during two days, 1260 trials; frequency range: 4Hz, 8Hz, and 16Hz), while an additional control group did not undertake any training. Consonant identification in vocoded vowel-consonant-vowel stimuli was tested before and after training on the AM tasks (or at an equivalent time interval for the control group). Following training, only the trained groups showed a significant improvement in the perception of vocoded speech, but the improvement did not significantly differ from that observed for controls. Thus, we do not find convincing evidence that this amount of training with temporal-envelope cues without speech content provide significant benefit for vocoded speech intelligibility. Alternative training regimens using vocoded speech along the linguistic hierarchy should be explored

Does Capital Regulation Matter for Bank Behavior? Evidence for German Savings Banks

The aim of this paper is to assess how German savings banks adjust capital and risk under capital regulation. We estimate a modified version of the model developed by Shrieves and Dahl (1992). In comparison to former research, we impose fewer restrictions with regard to the impact of regulation on capital and risk adjustments. Besides, we complement our analysis with dynamic panel data techniques and a rolling window approach. We find evidence that the coordination of capital and risk adjustments depends on the amount of capital the bank holds in excess of the regulatory minimum (the so-called capital buffer). Banks with low capital buffers try to rebuild an appropriate capital buffer by raising capital and simultaneously lowering risk. In contrast, banks with high capital buffers try to maintain their capital buffer by increasing risk when capital increases

Fire Sale Bank Recapitalizations

status: accepte

Human Decision Making Based on Variations in Internal Noise: An EEG Study

Perceptual decision making is prone to errors, especially near threshold. Physiological, behavioural and modeling studies suggest this is due to the intrinsic or ‘internal’ noise in neural systems, which derives from a mixture of bottom-up and top-down sources. We show here that internal noise can form the basis of perceptual decision making when the external signal lacks the required information for the decision. We recorded electroencephalographic (EEG) activity in listeners attempting to discriminate between identical tones. Since the acoustic signal was constant, bottom-up and top-down influences were under experimental control. We found that early cortical responses to the identical stimuli varied in global field power and topography according to the perceptual decision made, and activity preceding stimulus presentation could predict both later activity and behavioural decision. Our results suggest that activity variations induced by internal noise of both sensory and cognitive origin are sufficient to drive discrimination judgments

Control of macrostructure in deformation processing of metal/metal laminates

A study was carried out on model systems deformed under plane-strain. Finite element analysis was used to examine continuously and discontinuously layered models, in which the reinforcement to matrix flow stress ratio, r(s), was varied within the range 1.5 < r(s) < 10. It was found that, for homogeneous refinement of continuously reinforced laminates, the critical value of r(s) is approximately 2. This value, valid for the ideal plastic case, can be increased to a maximum value of r(s) approximate to5 with work hardening. For discontinuously layered systems, similar results were found. It is therefore concluded that macrostructural control is possible in metal/ metal svstems either in the form of homogeneous refinement of the continuous structures or in the form of structures with thin, long, closely spaced reinforcements, provided that the flow strength of the reinforcement is not more than five times that of the matrix. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

STRAIN PARTITIONING AND PLASTIC-FLOW IN SOME METAL-METAL LAMINATES

An investigation is carried out into the plane strain deformation of model laminates incorporating a single hard layer. A total of four laminates based on Al alloy(5053)-steels and Cu-W are investigated in which the relative hardness of the constituent layers, r(h), are in the range between 2 and 13. It is found that the deformation is uniform in the initial stages of plane-strain, the strain being partitioned equally between the constituent layers. The regime of uniform deformation is prolonged in samples with low r(h), and nonexistent in Cu-W (r(h) = 13). End of uniform deformation is marked first by necking and then the rupture of the hard layers into platelets leading to the so-called boudin structure. The deformation then becomes grossly inhomogeneous. The platelets deform less than the matrix and moreover volumes evolve in the matrix rhombic in shape in the immediate vicinity of the platelets into which deformation penetrates less. With continued deformation the platelets rupture further, whereby releasing parts of the constrained volumes. The relative hardness of the constituents layers are modified and the range initially as wide as 2 < r(h) < 1 3 narrows down with increasing strain and seems to move to a common value of around r(h) = 2.5

Dynamic scheduling of voter checks in FPGA-based TMR systems

SRAM-based Field-Programmable Gate Arrays (FPGAs) are susceptible to radiation-induced Single Event Upsets (SEUs). Techniques for partially reconfiguring corrupted modules of Triple Modular Redundant (TMR) FPGA-based designs have been described in the literature. Most of these techniques require some form of network-on-chip for aggregating voter error messages from the system's TMR components to a central reconfiguration controller in order to trigger the partial reconfiguration of modules when they become faulty. The frequency at which TMR components fail in the system depends on their soft-error vulnerability. However, most error recovery techniques adopt a static voter error checking schedule, which leads to delays in checking TMR components with high failure probability. In this paper we propose a Voter Scheduling Engine (VSE) for dynamically prioritizing and managing TMR voter checks so as to minimize the error detection time in the system and to thereby maximize the system's reliability. Software and hardware implementations of the VSE are proposed. Moreover, we have implemented the classic static voter checking schedule and the VSE on a real TMR system and evaluated the reliabilities of both approaches for varying radiation environments. Results demonstrate that the likelihood of system failure can be decreased by up to 50% when the VSE, rather than static voter checking, is incorporated into the TMR system.4 page(s

The effect of HDL-bound and free PON1 on copper-induced LDL oxidation

Oxidative modification of LDL plays an important role in the development of atherosclerosis. High density lipoprotein (HDL) confers protection against atherosclerosis and the antioxidative properties of paraoxonase 1 (PON1) has been suggested to contribute to this effect of HDL. The PON1 exist in two major polymorphic forms (Q and R), which regulate the concentration and activity of the enzyme and alter its ability to prevent lipid oxidation. However, the association of Q192R polymorphism with PON1's capacity to protect against LDL lipoperoxidation is controversial. The aim of this study was to evaluate the effects of the purified PON1 Q192R and the partially purified HDL-bound PON1 Q192R isoenzymes (HDL-PON1 Q192R) on LDL oxidation, with respect to their arylesterase/homocysteine thiolactonase (HTLase) activities. Cupric ion-induced LDL oxidation was reduced up to 48% by purified PON1 Q192, but only 33% by an equivalent activity of PON1 R192. HDL-PON1 Q192 isoenzyme caused a 65% reduction, whereas HDL-PON1 R192 isoenzyme caused only 46% reduction in copper ion-induced LDL oxidation. These findings reflect the fact that PON1 Q and PON1 R allozymes may have different protective characteristics against LDL oxidation. The protection against LDL oxidation provided by HDL-PON1 Q192R isoenzymes is more prominent than the purified soluble enzymes. Inhibition of the Ca+2-dependent PON1 Q192R arylesterase/HTLase by the metal chelator EDTA, did not alter PON1's ability to inhibit LDL oxidation. These studies indicate that the active site involvement of the purified enzyme is not similar to the HDL-bound one, in terms of both PON1 arylesterase/HTLase activity and the protection of LDL from copper ion-induced oxidation. Moreover, PON1's ability to protect LDL from oxidation does not seem to require calcium. (C) 2016 Elsevier Ireland Ltd. All rights reserved