VC Units Research Articles

UNDERSTANDING THE QIEYUN RHYMES

This article shows that the Qieyun rhymes are not necessarily different VC units (VC = vowel and ending), as initially defined by Karlgren in his work Études sur la phonologie chinoise (1915–1926). Karlgren’s mistake creates a serious problem in the reconstruction of the vowel system of Middle Chinese. In the proposed reconstructions so far, excessive vocalic distinctions are required. This problem is well acknowledged but no explanations and solutions have been convincingly provided. Based on the information from the poetry rhyming before and at the same time of the Qieyun, our analyses of the Qieyun rhymes with the -ŋ ending indicate that 1) not all the Qieyun rhymes are different VCs, and 2) some Qieyun rhymes are the preservation of historical categories. With the new understanding of the nature of the Qieyun rhymes, the required main vowels of Middle Chinese can be significantly reduced. The twelve Qieyun rhymes with -ŋ require only six main vowels. The observation that not all the Qieyun rhymes are different VCs can be supported by the recent distribution analyses of the Qieyun rhymes. A fundamental viewpoint of this article is that in the study of the phonological history of Chinese, what should be reconstructed is the phonological system of Middle Chinese instead of the so-called “Qieyun system”. Because the phonological categories contained in the Qieyun are neither synchronically systematic nor phonologically consistent, the Qieyun does not represent a single phonological system of any historical period in the phonological history of Chinese.

Shark fossil diversity (Squalomorphii, Squatinomorphii, and Galeomorphii) from the Langhian of Brielas (Lower Tagus Basin, Portugal)

The fossiliferous marine Miocene sediments of the Lower Tagus Basin (Portugal) present a great diversity of Chondrichthyes forms. The current study focuses on the fossil sharks from the Langhian Vc unit of the Brielas section, located in the Setúbal Peninsula. A total of 384 isolated fossil teeth were analysed and ascribed to 17 species from the Orders Hexanchiformes, Squaliformes, Squatiniformes, Lamniformes, and Carcharhiniformes.Centrophorus granulosusandIago angustidensare described for the first time in Portuguese sediments, whereasPachyscyllium dachiardiiandRhizoprionodon ficheurirepresent only their second reported occurrence.Galeorhinus goncalvesiwas already known from the Portuguese uppermost Miocene (Alvalade Basin), but it is now recognized in older sediments. Furthermore, the new material seems to include the first reported occurrence ofHexanchuscf.agassiziin Miocene sediments. As a whole, these new findings support the previous palaeoenvironment characterization of a warm infralittoral setting gradually deepening to a circalittoral one, where seasonal upwelling phenomena could have occurred.

Langhian rays (Chondrichthyes, Batomorphii) from Brielas, Lower Tagus Basin, Portugal.

The Langhian Vc unit of Brielas section (Caparica road, Almada), in the marine Miocene of the Lower Tagus Basin (West Portugal), is rich in batoid species. In this study, batoids are represented by 149 isolated fossil teeth and a single fossil dental plate collected from a bulk sample of washed and sorted sediment. A total of 12 species belonging to the orders Rhinopristiformes, Rajiformes, Torpediniformes and Myliobatiformes were identified. All genera and some species are known to have extant representatives. Aetobatus cappettai Antunes and Balbino, 2006, is described now from Langhian material which suggests it is older than previously supposed. The biogeographic ranges, environmental constraints and behaviour of the species described in this study point out to an infralittoral environment characterized by the dominance of warm water conditions, where episodic upwelling contributed to the occurrence of different types of batoids coexisting in the same habitat.

Gustatory modulation of the responses of trigeminal subnucleus caudalis neurons to noxious stimulation of the tongue in rats

Certain tastants inhibit oral irritation by capsaicin, whereas anesthesia of the chorda tympani (CT) enhances oral capsaicin burn. We tested the hypothesis that tastants activate the CT to suppress responses of trigeminal subnucleus caudalis (Vc) neurons to noxious oral stimuli. In anesthetized rats, we recorded Vc unit responses to noxious electrical, chemical (pentanoic acid, 200μm) and thermal (55°C) stimulation of the tongue. Electrically evoked responses were significantly reduced by a tastant mix and individually applied NaCl, monosodium glutamate (MSG), and monopotassium glutamate. Sucrose, citric acid, quinine and water (control) had no effect. Pentanoic acid-evoked responses were similarly attenuated by NaCl and MSG, but not by other tastants. Responses to noxious heat were not affected by any tastant. Transection and/or anesthesia of the CT bilaterally affected neither Vc neuronal responses to electrical or pentanoic acid stimulation, nor the depressant effect of NaCl and MSG on electrically evoked responses. Calcium imaging showed that neither NaCl nor MSG directly excited any trigeminal ganglion cells or affected their responses to pentanoic acid. GABA also had no effect, arguing against peripheral effects of GABA, NaCl or MSG on lingual nocicepive nerve endings. The data also rule out a central mechanism, as the effects of NaCl and MSG were intact following CT transection. We speculate that the effect is mediated peripherally by the release from taste receptor cells (type III) of some mediator(s) other than GABA to indirectly inhibit trigeminal nociceptors. The results also indicate that the CT does not exert a tonic inhibitory effect on nociceptive Vc neurons.

Vowel onset as a rhythmic marker in Japanese single and geminate stop distinctions

Hirata and Whiton (2005) found that the durational ratio of stop closure to a disyllabic word was the best parameter to distinguish singleton and geminate stops in spoken Japanese. However, given that vowel onset has perceptual and psychoacoustic importance as a temporal marker (Kato et al., 2003), the best unit may be from the first vowel onset of the target word to that of the following word in a carrier sentence (= Vword). In this study, 36 target disyllabic pairs including singletons and geminates (e.g. [buka] and [buk:a]) were embedded in the sentence [sokowa ____to jomimasu], spoken by four native Japanese speakers at three rates (Hirata and Whiton, 2005). The duration of Vword (e.g. the beginning of `u' in [buka] to the beginning of `o' in [to]) and of Vc(c) (e.g. `uk' from [buka] and `ukk' from [buk:a]) were measured, and the Vc(c)/Vword ratio was calculated. We examined how accurately this ratio classified singleton and geminate tokens across all rates and speakers. The classification accuracy was found to be 97.3-98.0%. This indicates that the duration of Vc(c) relative to Vword is a stable parameter for quantity distinction, and that the Vc(c) unit may constitute a meaningful rhythmic marker in production.

Cross-desensitization of responses of rat trigeminal subnucleus caudalis neurons to cinnamaldehyde and menthol

Most cold-sensitive subnucleus caudalis (Vc) neurons are also excited by the TRPM8 agonist menthol and the TRPA1 agonist cinnamaldehyde (CA). We investigated how interactions among menthol, CA and noxious cooling and heating of the tongue affected responses of superficial Vc units recorded in thiopental-anesthetized rats. Units responded to 1% CA which enhanced cold- and heat-evoked responses 5 min later. They responded more strongly to 10% CA which initially depressed cold responses, followed by enhancement at 5 min without affecting responses to heat. Following 10% CA, the mean response to 1% menthol was significantly lower than when menthol was tested first. After menthol, the subsequent response to CA was significantly weaker compared to the mean CA-evoked response when it was tested first. These results demonstrate mutual cross-desensitization between CA and menthol. The response to CA was enhanced following prior application of 10% ethanol (menthol vehicle). Prior application of menthol did not prevent the biphasic effect of 10% CA on cold-evoked responses, nor did prior application of CA prevent menthol enhancement of cold-evoked responses. Responses to noxious heat were unaffected by 10% CA and menthol regardless of the order of chemical presentation. These data indicate that superficial Vc neurons receive convergent input from primary afferents expressing TRPM8 and TRPA1. The mutual cross-desensitization between CA and menthol, and differential modulation of cold- vs. heat-evoked responses, suggests a direct inhibition of TRPM8 and TRPA1 expressed in peripheral nerve endings by CA and menthol, respectively, rather than a central site of interaction.

Neurons in Superficial Trigeminal Subnucleus Caudalis Responsive to Oral Cooling, Menthol, and Other Irritant Stimuli

The recent discoveries of cold-sensitive transient receptor potential (TRP) channels prompted us to investigate the responses of neurons in trigeminal subnucleus caudalis (Vc) to intraoral cooling and agonists of TRPM8 and TRPA1. Single units responsive to lingual cooling were recorded in superficial laminae of Vc in thiopental-anesthetized rats. All units responded to noxious heat and 88% responded to menthol. Responses increased with menthol concentration from 0.1 to 1% (6.4-64 mM) and plateaued at 10% (640 mM). Noxious cold-evoked responses were significantly enhanced after menthol in a concentration-dependent manner. Constant-flow application of 1% menthol elicited a phasic discharge that adapted over 2-8 min and significantly enhanced subsequent cold-evoked but not heat-evoked responses; vehicle (10% ethanol) was ineffective. Reapplication of menthol 15 min later elicited a significantly reduced response (self-desensitization). Vc units were similarly excited phasically by 1% menthol dissolved in 40% ethanol. The 40% ethanol briefly excited Vc units during the first minute and reduced subsequent responses to noxious heat and cold while exhibiting neither self-desensitization nor cross-desensitization to menthol. Menthol cross-desensitized Vc responses to 40% ethanol. Most menthol-responsive units also responded to the TRPA1 agonists cinnamaldehyde and mustard oil, and the TRPV1 agonist capsaicin. Units in superficial Vc receive convergent input from primary afferents that express TRPM8, TRPA1, and/or TRPV1 channels, either directly or indirectly via intersubnuclear pathways. The convergent nature of these units suggests a general role in signaling noxious stimuli.

음절수와 모음 열을 이용한 한국어 연결 숫자 음성인식

본 논문에서는 음절수와 모음 열 정보를 이용한 한국어 연속 숫자 인식을 제안하였다. 제안한 연속 숫자 인식기는 첫 단계로 발성된 연속 숫자 음성에서 음절수와 구간을 추출하고, 두 번째 단계로 모음 열을 인식한다. 이와 같이 인식된 모음 열 정보를 이용하여 인식 후보를 줄이게 된다. 인식후보 모델은 조음효과에 효과적으로 대처할 수 있는 CV(Consonant Vowel), VCCV, VC단위 HMM(Hidden Markov Model)을 사용하여 연속 숫자 음성인식기를 구성하였다. 실험결과 제안된 방법이 조음효과를 효과적으로 대처하고 연결 숫자 인식에 유효함을 확인하였다. In this paper, we present a new Korean connected digit recognition based on vowel string and number of syllables. There are two steps to reduce digit candidates. The first one is to determine the number and interval of digit. Once the number and interval of digit are determined, the second is to recognize the vowel string in the digit string. The digit candidates according to vowel string are recognized based on CV (consonant vowel), VCCV and VC unit HMM. The proposed method can cope effectively with the coarticulation effects and recognize the connected digit speech very well.

Complexing properties and structural characteristics of thermally sensitive copolymers of N-vinylpyrrolidone and N-vinylcaprolactam

The interaction of thermally sensitive copolymers of N-vinylpyrrolidone (VP) and N-vinylcaprolactam (VC) with small molecules having different chemical structures (8-anilinonaphthalene-1-sulphonic acid magnesium salt dihydrate, acridine orange, phenol, and sodium dodecyl sulphate) in aqueous solutions was studied by luminescent methods. The interaction of these copolymers with acridine orange was studied at different temperatures. It was established that the complexing ability of VP–VC copolymers even at a low content of VC units exceeds that of poly- N-vinylpyrrolidone. At a high content of VC units, and a low content of VC units, the complexing ability of VP–VC copolymers was found to be higher than that of poly- N-vinylcaprolactam. It is shown that the change in functional characteristics of VP–VC copolymers is determined by changes in the structural organization of VP–VC macromolecules and by increasing intramacromolecular interactions between nonpolar groups. Intramacromolecular structurization occurring during temperature increase and complexation is manifested very distinctly by changes in nanosecond dynamics of macromolecules. Nanosecond relaxation times characterizing intramolecular mobility of macromolecules with increasing temperature and in complexation with phenol and surfactant ions were determined.

Sensitization, desensitization and stimulus-induced recovery of trigeminal neuronal responses to oral capsaicin and nicotine.

Repeated application of capsaicin at a 1-min interstimulus interval (ISI) to the tongue induces a progressively increasing irritant sensation (sensitization), followed after a rest period by reduced sensitivity to further capsaicin (desensitization). Sequential reapplication of capsaicin induces irritation that eventually increases to initial levels: stimulus-induced recovery (SIR). In contrast, repeated application of nicotine elicits a declining irritant sensation across trials. To investigate possible neural correlates of these phenomena, we recorded from single units in superficial laminae of the dorsomedial trigeminal subnucleus caudalis (Vc) that responded to noxious thermal (54 degrees C) and chemical (1 M pentanoic acid) stimulation of the tongue of anesthetized rats. We then recorded responses to either capsaicin (330 microM) or nicotine (0.6 M), delivered either once, repeatedly at 1-min ISI, or continually by constant flow. After the initial capsaicin application and a rest period, the capsaicin was reapplied in the identical manner to test for SIR. The mean response of 14 Vc units to sequential application of pentanoic acid did not vary significantly across trials, indicating lack of tachyphylaxis or sensitization. The averaged response of 11 Vc units to repeated capsaicin increased significantly across the first eight trials and then plateaued. Following the rest period, spontaneous firing had returned to the precapsaicin level. With capsaicin reapplication, the averaged response increased again after a significant delay (due to desensitization), but did not reattain the peak firing rate achieved in the initial series (partial SIR). Constant-flow application of capsaicin induced an identical sensitization followed by nearly complete SIR. A single application of capsaicin induced a significant rise in firing in eight other units, but the rate of rise and maximal firing rate were both much lower compared with repetitive or constant-flow capsaicin. When capsaicin was reapplied once after the rest period, there was no change in firing rate indicating absence of SIR. These results indicate that maintenance of the capsaicin concentration induces a progressive increase in neuronal response that parallels sensitization. With recurrent capsaicin application, desensitization can be overcome to result in a delayed recovery of Vc responses similar to SIR. In contrast, the averaged response of 17 Vc units to repeated or constant-flow application of nicotine increased only over the first 3 min, and then decreased to spontaneous levels even as nicotine was still being applied. These results are consistent with the decrease in the perceived irritation elicited by sequential application of nicotine in humans.

Some Aspects of theThermal Degradation of Poly(Vinyl Chloride)

The kinetic perculiarities and mechanism of the nonautocatalytic thermal degradation of PVC with effective removal of HCl are discussed. The papers which are concerned with the mathematical models of the initial stage of the nonautocatalytic thermal dehydrochlorination of idealized PVC, i.e., PVC having no abnormal fragments, the polymer, containing VC units and abnormal groups and the polymer having macromolecules with various stereoregularity, are considered. Mechanism of the autocatalytic thermal degradation of PVC in the presence of HCl is discussed.

Developmental knowledge of inter- and intraword boundaries: Evidence from American and Mandarin Chinese speaking beginning readers

AbstractThis article addresses native monolingual American and Mandarin Chinese incipiently bilingual children's ability to detect and identify inter- and intraword boundaries. Two hypotheses are reported: first, that young children will demonstrate similar patterns in their segmentation behavior, and that there will be a developmental progression in this behavior; and second, that Mandarin Chinese subjects learning to read Chinese and English simultaneously will segment English words more readily into syllables than American subjects, treating them as Chinese monosyllables (C)V(C). Although results partially support the first hypothesis, no group main effect was found. However, when the same subjects' intraword segmentation patterns were further analyzed to probe their awareness of adult phonological constraints while spontaneously segmenting words into (C)VC or CV(C) units, there was evidence of difference in group segmentation patterns. With time, though, the bilingual subjects appear to develop nativeike phonological constraints.

Desalination technology in the Canary Islands, 1990

The total production capacity of desalination plants in the Canary Islands is 212,000 m 3/d. Brackish water plants, with 39,000 m 3/d capacity, use membrane units of different sizes. Sea water plants include MSF, VC and RO units. Sizes range from small units for tourist resorts to large plants for urban water supply. New sea water plants, being built under a Regional Desalination Scheme, will mainly use RO or VC technologies due to their small to medium size.

Response Properties of Periodontal Mechanosensitive Neurons in the Trigeminal Spinal Tract Nucleus of the Cat

Periodontal mechanosensitive (PM) units were recorded from the trigeminal spinal tract nucleus (Vst) of the cat. The Vst is divided into three subnuclei: oralis (Vo), interpolaris (Vi), and caudalis (Vc). The receptive fields of PM units in Vo and Vi were arranged in a dorsoventral sequence in the mandibular to maxillary divisions, and those in Vc were arranged in a mediolateral sequence. The majority of Vo units were single-tooth ones, whereas more than half the Vi units and all the Vc ones were multitooth units. The PM units in each subnucleus were predominantly responsive to canine tooth stimulation. Most of the PM units in Vo and Vi gave sustained responses to pressure applied to the tooth, were directionally selective, and were most actively excited by canine tooth stimulation in the caudomedial or rostrolateral direction. Vc units, however, were transient. The threshold intensity for firings by canine tooth stimulation was less than 0.05 N. These findings indicate that only the response properties of PM units in the rostral part of Vst resemble those of the trigeminal main sensory nucleus neurons and primary afferent nerves.

Not all nonwords are alike: Implications for reading development and theory

Three experiments were designed to examine children's and adults' ability to pronounce consonant-vowel-consonant (CVC) nonsense words. Some of the nonwords, like tain and goach, shared their VC unit with a number of real words. Other nonwords, like goan and taich, shared their VC unit with few or no real words. Pooling across items, the very same grapheme-phoneme correspondences occurred in the two types of nonwords. First graders, good and poor third grade readers, and adults all performed better on the nonwords with the more common VC units than on the nonwords with the less common VC units. Although readers appeared to use VC units in the pronunciation of nonwords, we did not find evidence for use of initial CV units. Implications of the results for reading development, dyslexia, and models of nonword pronunciation are discussed.

A Japanese text‐to‐speech conversion system using pitch‐controlled residual wave excitation

A Japanese text‐to‐speech conversion system was developed that could generate fluent speech by concatenating CV and VC units. A new synthesis method was proposed, where residual waves were used as excitation signals for an LPC synthesis filter in all portions of each unit. LPC filter coefficients were calculated by approximating spectral envelopes extracted by the improved cepstral analysis method, which was less affected by pitch frequency than the conventional LPC method. Therefore, the synthetic speech generated by the proposed method had extremely high quality, even when pitch frequencies of the residual waves were widely changed. Moreover, in order to realize natural rhythms, phoneme duration was determined by new rules. The rules were created by taking into account the various contexts (such as preceding and following phonemes and the position of a phoneme in a phrase), and by statistically analyzing a large speech database. A comprehension test using 1000 phonetic balanced words showed that the proposed system achieved 97.4% of high accuracy rate.

Postvocalic consonantal voicing and constancy of syllable duration

In American English, a vowel preceding a voiced consonant has frequently been shown to be of longer duration than one preceding a voiceless consonant. However, Port [J. Acoust. Soc. Am. 69, 262–274 (1981)] reported no effect of postvocalic consonant voicing on the total duration of the VC unit. Port attributed this finding to an inverse relationship between vowel and consonant durations. Our study replicates and extends this work to the entire CVC syllabic unit across changes in speaking rate. Syllable and segmental durations were measured for /pVC/ target syllables. The target syllables used eight vowels and voiced or voiceless cognates of the final consonant, which was either stop or fricative. Syllables were produced in sentence contexts at three speaking rates by four female and four male native American English speakers. [Work supported in part by NIH.]

Thermal and photodegradation of vinyl chloride/vinyl bromide copolymers

AbstractVinyl chloride/vinyl bromide (VC/VBr) copolymers have been synthesized by radical copolymerization in bulk. Conversion increases and molecular weight of the copolymers decreases with increasing VBr in the feed. This indicates that VBr is a chain transfer agent in VC/VBr copolymerization systems. In accordance with the lower thermal stability of the vinylbromide homopolymer (PVBr), thermal degradation experiments show that the stability of the copolymers significantly decreases with increasing VBr content. It has been found that the initial rate of dehydrohalogenation is an exponential function of VBr content during thermal degradation of VC/VBr copolymers. In separate experiments, HBr evolved during degradation has been determined by a bromide selective electrode. The initial dehydrobromination rates of VC/VBr copolymers containing higher fractions of VBr are markedly higher than the initial dehydrochlorination rates. This clearly indicates the lower thermal stability of VBr monomer units compared with VC units. UV and visible spectra of degraded VC/VBr copolymers show that the absorption and the average length of polyenes are higher for samples with higher VBr content.Dehydrohalogenation curves obtained during photodegradation of VC/VBr copolymers show a faster initial phase followed by a slower stationary phase. The initial rate of dehydrohalogenation is higher for copolymers containing higher fractions of VBr, whereas these copolymers reach the slower stationary phases at lower extents of dehydrohalogenation.

Serial ordering units for speech production: segments or other syllabic subunits

Serial ordering errors in spontaneous speech often involve individual phoneme-like segments, but seldom larger syllabic components containing both consonants and vowels. This observation suggests that syllabic structure provides a framework for the serial ordering of individual phonemic segments, while larger subsyllabic units and entire syllables do not themselves undergo such ordering during normal production planning (Shattuck-Hufnagel 1979; Shattuck-Hufnagel and Klatt 1979). When speakers repeated syllable sequences constructed by alternating pairs of consonants in conflicting patterns (e.g., PAN FILL FUN POLL, where initial /p, f/ alternate in the pattern ABBA, final /n, l/ in ABAB), 95% of the errors involved a change in a single segment and only 5% involved a CV, VC, or CVC unit. These findings support the view that speech production planning involves the serial ordering of phoneme-like segments, and not of larger syllabic components. Further questions about the nature of position constraints on segments interacting in errors, and about the role of word stress in constraining single-segment errors, are also being explored using this method.

NMR study of vinyl chloride–vinylidene chloride copolymer

AbstractA study of the proton magnetic resonance spectra of poly(vinyl chloride) (PVC), poly(vinylidene chloride) (PVDC), and vinyl chloride–vinylidene chloride (VC–VDC) copolymer has resulted in a clearer understanding of the copolymer NMR spectra. Comparison of the homopolymer spectra with the copolymer spectra, including information obtained from decoupling experiments, indicated that the chain structure of the eight copolymers studied were of two different types. The simplest type copolymer chain contained head‐to‐tail VDC sequences, head‐to‐head or tail‐to‐tail VDC sequences, and VC‐VDC sequences. The second type copolymer contained all of the sequences of type I copolymers and, in addition, contained VC sequences. The average length of these VC sequences was less than four VC units. The composition of seven of the copolymers was determined by chlorine analysis and by an NMR method of analysis which was based on the above conclusions. The agreement between the results of the two methods of analysis was quite good.