Near-infrared photoglottography for measuring multiple glottal events.

Near-infrared (NIR) photoglottography (PGG) is a non-invasive method for monitoring glottal activities which retains functionality of conventional PGG using visible light with more convenient accessibility. This paper is to investigate its performance in comparison with simultaneously recorded electroglottography (EGG) signals. Results showed that NIR PGG detects continuous transillumination for glottal aperture and vocal-fold contact. Glottal timing markers known as glottal closure and opening instants are detectable agreeing to the corresponding EGG-based instants. Further, it was inferred that variations of glottal waveforms based on NIR PGG reflect vertical vocal-fold edge motions.

Moderately Oxidizing Thioxanthylium Organophotoredox Catalysts for Radical-Cation Diels-Alder Reactions.

Moderately oxidizing thioxanthylium photoredox catalysts that operate under irradiation with green light have been developed. These catalysts exhibit relatively moderate excited-state reduction potentials [E1/2(C*/C•-) = 1.75-1.94 V vs saturated calomel electrode (SCE)] and can efficiently promote radical-cation Diels-Alder reactions under irradiation with green light. Interestingly, ß-halogenostyrenes (Ep/2 = 1.57-1.61 V vs SCE) are well tolerated, affording synthetically useful halocyclohexenes.

Visible-light-induced [4 + 2] cycloaddition of pentafulvenes by organic photoredox catalysis.

We have developed thioxanthylium photoredox catalyzed [4 + 2] cycloaddition of pentafulvenes at room temperature under green light irradiation, which affords tetrahydrocyclopenta[b]chromenes with high regioselectivities. The present reaction provides a sustainable approach to carry out the cycloaddition of pentafulvenes without the use of transition metal catalysts or high-temperature conditions. This procedure enables a mild and straightforward access to 1,3a,9,9a-tetrahydrocyclopenta[b]chromenes. The quantum yield of the reaction (Φ = 0.15) indicates that the reaction would mainly proceed via photocatalytic pathways.

Redox Potential Controlled Selective Oxidation of Styrenes for Regio- and Stereoselective Crossed Intermolecular [2 + 2] Cycloaddition via Organophotoredox Catalysis.

A redox potential controlled intermolecular [2 + 2] cross-cycloaddition has been developed in the presence of a thioxanthylium photoredox catalyst. Electron-rich styrenes such as ß-bromostyrene (Ep/2 = +1.61 V vs SCE) were selectively oxidized by a thioxanthylium photoredox catalyst (E1/2 (C*/C•-) = +1.76 V vs SCE) to styryl radical cations and reacted with styrene (Ep/2 = +1.97 V vs SCE) to furnish polysubstituted cyclobutanes in high yields. The present reaction can be successfully applied to intermolecular [2 + 2] cross-cycloaddition of ß-halogenostyrenes, which cannot be effectively achieved by the hitherto reported representative organophotoredox catalysts.

Friedel-Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts.

An efficient synthesis of methoxy-substituted thioxanthylium salts has been developed. The reaction of diaryl sulfides with benzoyl chlorides in the presence of TfOH smoothly proceeded to give the desired thioxanthylium salts in good yields. In their UV-vis spectra, the maximum absorption wavelengths of methoxy-functionalized thioxanthylium salts were observed at around 460 nm, which show a drastic red shift compared to the parent thioxanthylium salts. The present reaction provides a versatile access to functionalized thioxanthylium salts, and therefore it constitutes a promising tool for the synthesis of biologically and photochemically active molecules.

Access to Electron-Deficient 2,2-Disubstituted Chromanes: A Highly Regioselective One-Pot Synthesis via an Inverse-Electron-Demand [4 + 2] Cycloaddition of ortho-Quinone Methides.

We report the one-pot synthesis of 2,2-disubstituted chromanes with electron-withdrawing substituents. This reaction provides a simple yet efficient route to a wide range of electron-deficient chromanes in high yield and excellent regioselectivity. The reaction of salicylaldehyde with 1,1-disubstituted ethylenes smoothly furnishes these electron-deficient chromanes, which can be further transformed into functionalized chromanes or chromene. For example, BW683C was effectively synthesized from 5-chlorosalicylaldehyde with 4-chlorostyrene in two steps in excellent yield. The present reaction thus provides versatile access to functionalized electron-deficient chromanes and chromenes and therefore constitutes a promising tool for the synthesis of biologically and photochemically active molecules.

Organophotoredox-Catalyzed Intermolecular Oxa-[4+2] Cycloaddition Reactions.

An intermolecular oxa-[4+2] cycloaddition reaction promoted by a thioxanthylium photoredox catalyst under irradiation with green light has been developed. The reaction of ortho-quinone methides with styrenes smoothly affords the desired cycloadducts. Especially styrenes bearing electron-donating groups are efficiently transformed in this reaction. This method represents a sustainable way to carry out oxa-[4+2] cycloaddition reactions using only a catalytic amount of a photocatalyst and visible light.

Morphological characteristics of male and female hypopharynx: A magnetic resonance imaging-based study.

Studies with three-dimensional (3D) vocal tract visualization using magnetic resonance imaging (MRI) have suggested that hypopharyngeal cavities, i.e., laryngeal cavity and bilateral piriform fossa, may be the acoustic loci to express speaker characteristics in male speech sounds. Previous studies mainly investigated the hypopharynx in males but few for females. This study explored the hypopharynx morphological characteristics for the subjects in both genders by MRI. 3D numerical vocal tracts at vowels were reconstructed from the MRI datasets of three male and four female Chinese subjects. Geometrical measurements were conducted for the hypopharyngeal cavities. Morphological observations and statistical analyses revealed both commonalities and differences between the male and female subjects. The laryngeal cavity shapes in females were found similar to males resembling a Helmholtz resonator rather than a simple straight closed tube, and the bilateral piriform fossa cavities showed an asymmetry: the right is longer and wider than the left in both genders. As for the cavity size across vowels, for both the male and female subjects the laryngeal cavity and piriform fossa in /i/ were observed larger than those in /a/. To summarize gender characteristics, the female subjects were characterized by the smaller laryngeal cavity and piriform fossa compared with males.

Characterization of peach tree crown by using high-resolution images from an unmanned aerial vehicle.

In orchards, measuring crown characteristics is essential for monitoring the dynamics of tree growth and optimizing farm management. However, it lacks a rapid and reliable method of extracting the features of trees with an irregular crown shape such as trained peach trees. Here, we propose an efficient method of segmenting the individual trees and measuring the crown width and crown projection area (CPA) of peach trees with time-series information, based on gathered images. The images of peach trees were collected by unmanned aerial vehicles in an orchard in Okayama, Japan, and then the digital surface model was generated by using a Structure from Motion (SfM) and Multi-View Stereo (MVS) based software. After individual trees were identified through the use of an adaptive threshold and marker-controlled watershed segmentation in the digital surface model, the crown widths and CPA were calculated, and the accuracy was evaluated against manual delineation and field measurement, respectively. Taking manual delineation of 12 trees as reference, the root-mean-square errors of the proposed method were 0.08 m (R 2 = 0.99) and 0.15 m (R 2 = 0.93) for the two orthogonal crown widths, and 3.87 m2 for CPA (R 2 = 0.89), while those taking field measurement of 44 trees as reference were 0.47 m (R 2 = 0.91), 0.51 m (R 2 = 0.74), and 4.96 m2 (R 2 = 0.88). The change of growth rate of CPA showed that the peach trees grew faster from May to July than from July to September, with a wide variation in relative growth rates among trees. Not only can this method save labour by replacing field measurement, but also it can allow farmers to monitor the growth of orchard trees dynamically.

The Mechanism and Representation of Korean Three-Way Phonation Contrast: External Photoglottography, Intra-Oral Air Pressure, Airflow, and Acoustic Data.

This paper aims to refine our understanding of the speech mechanism and laryngeal features involved in the Korean lenis (/p t k/), aspirated (/ph th kh/), and fortis (/p' t' k'/) plosives. For this purpose we made measurements using a new noninvasive technique called external lighting and sensing photoglottography (ePGG) as well as intra-oral air pressure (Pio) above the glottis, airflow, and acoustic data. From simultaneous recordings of the experimental data, we were ableto quantify the laryngeal-oral coordination of glottal opening and a consonant release, and the covariance of airflow peak and duration of aspiration with glottal opening. The phasing of glottal opening and the 3-way phonation contrast occurs in the order, from early to late, fortis, lenis < aspirated plosives, and the glottal opening peak ranges from low to high in the same order. We also found that a Pio peak, the durations of a high Pio plateau and an oral closure, and F0 are independent of the glottal opening mechanism, varying in the order lenis < aspirated and fortis plosives. From these findings, we propose that the 2 independent patterns are accounted for by the articulator-based features [±spread glottis] and [±tense], respectively.

Tandem Brook Rearrangement/Silicon Polonovski Reaction via Oxidative Generation of Ammonium Ylides.

A tandem Brook rearrangement/silicon Polonovski reaction has been achieved by in situ generation of ammonium ylides via the oxidation of α-silyl-tertiary amines. Furthermore, we found that the oxidation of N-(1-cyano-1-silyl)methyl-tertiary amines with peracids induced the tandem Brook rearrangement/silicon Polonovski reaction/fragmentation to give formamide derivatives in moderate yields.

A base-mediated self-propagative Lossen rearrangement of hydroxamic acids for the efficient and facile synthesis of aromatic and aliphatic primary amines.

A variety of aromatic and aliphatic hydroxamic acids were converted to the corresponding primary amines via base-mediated rearrangement. This rearrangement could proceed with less than 1 equiv. of K2CO3 in polar solvents under thermal conditions with no external reagents. This rearrangement has several features including no external activating agents needed for promoting the rearrangement, less than one equivalent of a base is sufficient for the reaction, and a clean reaction in which only carbon dioxide is produced as a by-product. A self-propagating mechanism via an isocyanate intermediate is proposed and elementary reaction steps, namely, chain propagation reactions are supported by experiments.

A study on transvelar coupling for non-nasalized sounds.

Previous studies have found that the velum in speech production may not only serve as a binary switch with on-off states for nasal and non-nasal sounds, but also partially alter the acoustic characteristics of non-nasalized sounds. The present study investigated the unique functions of the velum in the production of non-nasalized sounds by using morphological, mechanical, and acoustical measurements. Magnetic resonance imaging movies obtained from three Japanese speakers were used to measure the behaviors of the velum and dynamic changes in the pseudo-volume of the pharyngeal cavity during utterances of voiced stops and vowels. The measurements revealed no significant enlargements in the supraglottal cavity as subjects uttered voiced stops. It is found that the velum thickness varied across utterances in a way that depended on vowels, but not on consonants. The mechanical and acoustical observations in the study suggested that the velum is actively controlled to augment the voice bars of voiced stops, and nostril-radiated sound is one of the most important sources for voice bars, just as is laryngeal wall vibration. This study also proposed a two-layer diaphragm model that simulates transvelar coupling during the production of non-nasalized speech sounds. The simulation demonstrated that the model accurately represented the basic velar functions involved in speech production.

Stereoselective synthesis of bicyclo[3.1.1]heptane derivatives via intramolecular photocycloaddition reaction.

Optically active 1,3-bridged cyclobutanes 10 of the bicyclo[3.1.1]heptane ring system and 1,2-bridged cyclobutanes 11 of the bicyclo[3.2.0]heptane ring system were produced by UV irradiation of alpha,beta,gamma,delta-unsaturated esters 9a and 9c-f. The preference of endo-stereochemistry at C-6 bridged head was observed in cross-adducts 10. On the other hand, irradiation of conjugated dienol 9b led via only parallel cycloaddition to 1,2-bridged cyclobutane 11.

Visualisation of hypopharyngeal cavities and vocal-tract acoustic modelling.

The hypopharyngeal cavities consist of the laryngeal cavity and bilateral piriform fossa, constituting the bottom part of the vocal tract near the larynx. Visualisation of these cavities with magnetic resonance imaging (MRI) techniques reveals that during speech, the laryngeal cavity takes the form of a long-neck flask and the piriform fossa takes the form of a goblet of varying shapes: the former diminishes greatly in whispering and the latter disappears during deep inhalation. These cavities have been shown to exert significant acoustic effects at higher frequency spectra. In this study, acoustic experiments were conducted for male and female mechanical vocal tracts with the results that acoustic effects of those cavities determine the frequency spectra above 2 kHz, giving rise to peaks and zeros. An acoustic model of vowel production was proposed with three components: voice source, hypopharyngeal cavities and vocal tract proper, which provides effective means in controlling voice quality and expressing individual vocal characteristics.

Novel ellipsoid spatial analysis for determining malaria risk at the village level.

The distribution patterns of malaria incidence at a village level in Thailand were demonstrated with the use of a geographical information system (GIS), and provided the study of the malaria situation at a household level. Mosaic imageries from aerial photographs were used to create maps that contained X and Y coordinates. These digitized base maps were kept as computerized files. Standard Distance Ellipse (SDE) was used to measure the prevalence of dispersion around the mean center of malaria cases and points. Households in the SDE were at greater risk of malaria infection than those located outside the SDE. The spatial pattern of malaria incidence was investigated using spatial autocorrelation using Geary's ratio and Moran's index. Five of seven villages had a clustered spatial distribution of malaria incidence, the vector point of which had a 2-3km range from the patient's houses. Only one village had a significant clustered spatial distribution of malaria incidence (p<0.05). Control efforts should be focused on high-risk areas, especially those households with the heaviest caseloads. This approach would probably be more cost effective than the conventional malaria control methods. This SDE analytical technique would be a novel and useful epidemiological control method for use by public health administrators. The ellipsoidal areas required malaria control intervention.

Noh voice quality.

In Noh, a traditional performing art of Japan, extremely expressive voice quality is used to convey an emotional message. A periodicity of voice appears responsible for these special effects. Acoustic signals were recorded for selected portions of dramatic singing in order to study the acoustic effects of delicate voice control by a master of the Konparu school. Using a signal analysis-synthesis algorithm, TANDEM-STRAIGHT, to represent multiple candidates for pitch perception, signals deviating from the harmonic structure have been successfully displayed, corresponding to auditory impressions of pitch movements, even when narrow-band spectrograms failed to show the perceived events. Strong interaction between vocal tract resonance and vocal fold vibration seems to play a major role in producing these expressive voice qualities.

Base-mediated rearrangement of free aromatic hydroxamic acids (ArCO-NHOH) to anilines.

Without using activating agents, a variety of free aromatic hydroxamic acids could be rearranged to aromatic amines in the presence of base alone.

Fieldservers and Sensor Service Grid as Real-time Monitoring Infrastructure for Ubiquitous Sensor Networks.

The fieldserver is an Internet based observation robot that can provide an outdoor solution for monitoring environmental parameters in real-time. The data from its sensors can be collected to a central server infrastructure and published on the Internet. The information from the sensor network will contribute to monitoring and modeling on various environmental issues in Asia, including agriculture, food, pollution, disaster, climate change etc. An initiative called Sensor Asia is developing an infrastructure called Sensor Service Grid (SSG), which integrates fieldservers and Web GIS to realize easy and low cost installation and operation of ubiquitous field sensor networks.