Intraday Evidence of the Informational Efficiency of the Yen/Dollar Exchange Rate

The informational efficiency of the yen/dollar exchange rate is investigated in five market segments within each business day from 1987 to 2007. Among the results, we first find that the daily exchange rate has a cointegrating relationship with the cumula-tive price change of the segment for which the London and New York markets are both open, but not with that of any other segments. Second, the cumulative price change of the London/N.Y. segment is the most persistent among the five market segments in the medium- and long-run. These results suggest that the greatest concentration of informed traders is in the London/N.Y. segment where intraday transactions are the highest. This is consistent with the theoretical prediction by Admati and Pfleiderer (1988) that prices are more informative when trading volume is heavier.Informational efficiency; Market segments; Yen/dollar exchange rate

An experimental study on the relation of T2-signal high intensity in MRI to histopathological changes in the kainic acid model of temporal lobe epilepsy in rats.

側頭葉てんかんでは，てんかん焦点に一致してMRI T2高信号領域が見られ，FLAIR法でこれがより明瞭になるが，このMRI所見と病理組織学的変化との関係は必ずしもはっきりしていない。そこで，Sprague－Dawleyラットにカイニン酸（KA）でけいれん発作重積状態を起こし，経時的にMRIを記録するとともに，ニッスル染色，GFAP免疫染色での病理組織学的変化を調べて両者の関係について検討した。KA群では，MRIで1～8週間後のいずれにおいてもpiriform cortexからentorhinal cortexにかけて不整形のT2高信号領域がみられたが，stage3のけいれん発作しか出現しなかったラットではstage4，5が出現したラットに比べて程度が弱かった。組織学的には，CA1，subiculum，piriform cortex，entorhinal cortexで神経細胞の消失，濃染細胞の増加と萎縮，GFAP免疫反応の増強が見られたが，piriform cortex，entorhinal cortexでの神経細胞消失の程度はT2信 号の程度と相関せず，GFAP免疫反応が増強した領域に一致して高信号がみられた。しかし，海馬のGFAP免疫反応増強はMRI所見に反映されず，これはMRIの解像度の限界にもよると考えられた。The relation of T2-signal high intensity areas observed in temporal lobe epilepsy to histopathological changes in limbic structures was examined in the rat kainic acid (KA) model of epilepsy. Male 8-week-old Sprague-Dawley rats were injected with 10mg/kg(i.p.) of KA or saline (control). Repetitive generalized convulsions (stage 3, or stage 4,5 seizures of amygdala kindled seizures) lasted for 3 to 4 hrs. were induced by KA injection in all rats. MRI was recorded on the day before the KA injection and 1, 2, 4, 8 weeks after the injection by fluid-attenuated inversion recovery method under deep pentobarbital anesthesia. Following the last MRI recording, rats were perfused with 4% paraformaldehyde (PFA) from left cardiac ventricle, post-fixed overnight in 4% PFA and brains were embedded in parafin. Coronal brain sections (6μm) were stained with cresyl violet, or mouse anti-GFAP antibody followed by biotinylated goat anti-mouse IgG and avidin-biotin-peroxidase (vectastain ABC kit). Irregularshaped moderate to severe high T2-signal areas were observed in bilateral piriform and entorhinal cortex in MRI. These high T2-signal areas were ovserved from 1 week after the KA injection to 8 weeks after the injection, and were more prominent in rats elicited stage 4 or 5 seizures than in rats elicited stage 3 seizures. Loss of pyramidal neurons and increased GFAP immunoreactivity were observed in piriform cortex, entorhinal cortex, CA1, subiculum, and hilus of dentate gyrus. The increase of GFAP immunoreactivity, but not the intensity of neuronal loss, in piriform and entorhinal cortex was almost correponded to the size and intensity of T2-signal. However, the increase of GFAP immunoreactivity in hippocampus was not detected as the increase of T2-signal in MRI. These findings indicate that astroglial reactions in piriform and entorhinal cortex are more sensitive to T2-weighted MRI than those in hippocampus

Medial prefrontal cortex and anterior cingulate cortex in the generation of alpha activity induced by transcendental meditation: a magnetoencephalographic study.

Previous EEG studies have shown that transcendental meditation (TM) increases frontal and central alpha activity. The present study was aimed at identifying the source of this alpha activity using magnetoencephalography (MEG) and electroencephalography (EEG) simultaneously on eight TM practitioners before, during, and after TM. The magnetic field potentials corresponding to TM-induced alpha activities on EEG recordings were extracted, and we attempted to localize the dipole sources using the multiple signal classification (MUSIC) algorithm, equivalent current dipole source analysis, and the multiple spatio-temporal dipole model. Since the dipoles were mapped to both the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC), it is suggested that the mPFC and ACC play an important role in brain activity induced by TM.</p

13C-Metabolic Flux Analysis Reveals Effect of Phenol on Central Carbon Metabolism in Escherichia coli

Phenol is an important chemical product that can be used in a wide variety of applications, and it is currently produced from fossil resources. Fermentation production of phenol from renewable biomass resources by microorganisms is highly desirable for sustainable development. However, phenol toxicity hampers phenol production in industrial microorganisms such as Escherichia coli. In the present study, it was revealed that culturing E. coli in the presence of phenol not only decreased growth rate, but also biomass yield. This suggests that phenol affects the carbon flow of the metabolism, but the mechanism is unknown. To investigate the effect of phenol on the flux distribution of central carbon metabolism, 13C-metabolic flux analysis (13C-MFA) was performed on cells grown under different phenol concentrations (0, 0.1, and 0.15%). 13C-MFA revealed that the TCA cycle flux reduced by 25% increased acetate production from acetyl-CoA by 30% in the presence of 0.1% phenol. This trend of flux changes was emphasized at a phenol concentration of 0.15%. Although the expression level of citrate synthase, which catalyzes the first reaction of the TCA cycle, does not change regardless of phenol concentrations, the in vitro enzyme activity assay shows that the reaction was inhibited by phenol. These results suggest that the TCA cycle flux decreased due to phenol inhibition of citrate synthase; therefore, ATP could not be sufficiently produced by respiration, and growth rate decreased. Furthermore, since carbon was lost as acetate due to overflow metabolism, the biomass yield became low in the presence of phenol

Comparative analysis of seed and seedling irradiation with gamma rays and carbon ions for mutation induction in Arabidopsis

The molecular nature of mutations induced by ionizing radiation and chemical mutagens in plants is becoming clearer owing to the availability of high-throughput DNA sequencing technology. However, few studies have compared the induced mutations between different radiation qualities and between different irradiated materials with the same analysis method. To compare mutation induction between dry-seeds and seedlings irradiated with carbon ions and gamma rays in Arabidopsis, in this study we detected the mutations induced by seedling irradiation with gamma rays and analyzed the data together with data previously obtained for the other irradiation treatments. Mutation frequency at the equivalent dose for survival reduction was higher with gamma rays than with carbon ions, and was higher with dry-seed irradiation than with seedling irradiation. Carbon ions induced a higher frequency of deletions (2−99 bp) than gamma rays in the case of dry-seed irradiation, but this difference was less evident in the case of seedling irradiation. This result supported the inference that dry-seed irradiation under a lower water content more clearly reflects the difference in radiation quality. However, the ratio of rearrangements (inversions, translocations, and deletions larger than 100 bp), which are considered to be derived from the rejoining of two distantly located DNA breaks, was significantly higher with carbon ions than gamma rays irrespective of the irradiated material. This finding suggested that high-linear energy transfer radiation induced closely located DNA damage, irrespective of the water content of the material, that could lead to the generation of rearrangements. Taken together, the results provide an overall picture of radiation-induced mutation in Arabidopsis and will be useful for selection of a suitable radiation treatment for mutagenesis

Cold-induced metabolic conversion of haptophyte di- to tri-unsaturated C37 alkenones used as palaeothermometer molecules

The cosmopolitan marine haptophyte alga Emiliania huxleyi accumulates very long-chain (C37-C40) alkyl ketones with two to four trans-type carbon-carbon double bonds (alkenones). These compounds are used as biomarkers of haptophytes and as palaeothermometers for estimating sea-surface temperatures in biogeochemistry. However, the biosynthetic pathway of alkenones in algal cells remains enigmatic, although it is well known that the C37 tri-unsaturated alkenone (K37:3) becomes dominant at low temperatures, either by desaturation of K37:2 or by a separate pathway involving the elongation of tri-unsaturated alkenone precursors. Here, we present experimental evidence regarding K37:3 synthesis. Using the well-known cosmopolitan alkenone producer E. huxleyi, we labelled K37:2 with 13C by incubating cells with 13C-bicarbonate in the light at 25 °C under conditions of little if any K37:3 production. After stabilisation of the 13C-K37:2 level by depleting 13C-bicarbonate from the medium, the temperature was suddenly reduced to 15 °C. The 13C-K37:2 level rapidly decreased, and the 13C-K37:3 level increased, whereas the total 13C-K37 level—namely [K37:2 + K37:3]—remained constant. These 13C-pulse-chase-like experimental results indicate that 13C-K37:2 is converted directly to 13C-K37:3 by a desaturation reaction that is promoted by a cold signal. This clear-cut experimental evidence is indicative of the existence of a cold-signal-triggered desaturation reaction in alkenone biosynthesis

Rationally controlled helical organization of a multiple-hydrogen-bonding oligothiophene: guest-induced transition of helical-to-twisted ribbonswz

A cyanuric acid-functionalized quaterthiophene self-aggregates to form helical ribbons which are transformed into twisted ribbons upon complexing with a complementary bismelamine receptor. Nanostructures formed by the self-assembly of p-conjugated oligomers through noncovalent interactions are attracting enormous attention as novel materials being developed in the nanoscale. 1 The further development of this research field requires a precise control of self-assembled nanostructures by rational molecular designs based on specific noncovalent interactions. 2 Among various self-assembled nanostructures, helical architectures have attracted special attention in view of their chirooptical properties, supramolecular chiral chemistry and supramolecular electronics

Viewing Targets in Infantile Nystagmus

The aim of this study was to propose a new pathophysiological hypothesis for involuntary eye oscillation in infantile nystagmus (IN): patients with IN exhibit impaired gaze fixation, horizontal smooth pursuit and optokinetic nystagmus (OKN) and use saccadic eye movements for these underlying impairments. In order to induce saccades, they make enough angle between gaze and target by precedent exponential slow eye movements. IN consists of the alternate appearance of the saccade and the slow eye movements. Unlike most previous theories, IN is therefore considered a necessary strategy allowing for better vision and not an obstacle to clear vision. In five patients with IN, eye movements were analyzed during the smooth pursuit test, saccadic eye movement test, OKN test and vestibulo-ocular reflex (VOR) test. Their gaze fixation, horizontal smooth pursuit, OKN and the last half of the slow phase of VOR were impaired. The lines obtained by connection of the end eye positions of fast phase of nystagmus coincided with the trajectories of targets. The findings indicate that patients followed the target by the fast but not the slow phase of nystagmus, which supports our hypothesis. By setting the direction of slow phase of nystagmus opposite to the direction of the OKN stimulation, enough angle can be effectively made between the gaze and target for the induction of saccade. This is the mechanism of reversed OKN response. In darkness and when eyes are closed, IN weakens because there is no visual target and neither the saccade for catching up the target or slow phase for induction of the saccade is needed

Clinical relevance of impaired consciousness in accidental hypothermia: a Japanese multicenter retrospective study

[Aim] This study aimed to investigate the association between level of impaired consciousness and severe hypothermia (<28°C) and to evaluate the association between level of impaired consciousness and inhospital mortality among accidental hypothermia patients. [Methods] This was a multicenter retrospective study using the J-Point registry database, which includes data regarding patients whose core body temperature was 35.0°C or less and who were treated as accidental hypothermia in emergency departments between April 1, 2011 and March 31, 2016. We estimated adjusted odds ratios of the level of impaired consciousness for severe hypothermia less than 28°C and inhospital mortality using a logistic regression model. [Results] The study included 505 of 572 patients in the J-Point registry. Relative to mildly impaired consciousness (Glasgow Coma Scale [GCS] 13–15), the adjusted odds ratios for severe hypothermia less than 28°C were: moderate (GCS 9–12), 3.26 (95% confidence interval [CI], 1.69–6.25); and severe (GCS < 9), 4.68 (95% CI, 2.40–9.14). Relative to mildly impaired consciousness (GCS 13–15), the adjusted odds ratios for inhospital mortality were: moderate (GCS9–12), 1.65 (95% CI, 0.95–2.88); and severe (GCS < 9), 2.10 (95% CI, 1.17–3.78). [Conclusion] The level of impaired consciousness in patients with accidental hypothermia was associated with severe hypothermia and inhospital mortality