Formant and Voice Source Characteristics of Vowels in Chinese National Singing and Bel Canto. A Pilot Study.

BACKGROUND: There have been numerous reports on the acoustic characteristics of singers' vowel articulation and phonation, and these studies cover many phonetic dimensions, such as fundamental frequency (F0), intensity, formant frequency, and voice quality. METHOD: Taking the three representative vowels (/a/, /i/, /u/) in Chinese National Singing and Bel Canto as the research object, the present study investigates the differences and associations in vowel articulation and phonation between Chinese National Singing and Bel Canto using acoustic measures, for example, F0, formant frequency, long-term average spectrum (LTAS). RESULTS: The relationship between F0 and formant indicates that F1 is proportional to F0, in which the female has a significant variation in vowel /a/. Compared with the male, the formant structure of the female singing voice differs significantly from that of the speech voice. Regarding the relationship between intensity and formant, LTAS shows that the Chinese National Singing tenor and Bel Canto baritone have the singer's formant cluster when singing vowels, while the two sopranos do not. CONCLUSIONS: The systematic changes of formant frequencies with voice source are observed. (i) F1 of the female vowel /a/ has undergone a significant tuning change in the register transition, reflecting the characteristics of singing genres. (ii) Female singers utilize the intrinsic pitch of vowels when adopting the register transition strategy. This finding can be assumed to facilitate understanding the theory of intrinsic vowel pitch and revise Sundberg's hypothesis that F1 rises with F0. A non-linear relationship exists between F1 and F0, which adds to the non-linear interaction of the formant and vocal source. (iii) The singer's formant is affected by voice classification, gender, and singing genres.

Spotted fever group Rickettsia in Yunnan Province, China.

Information about spotted fever group (SFG) rickettsiae in southern China remains sparse. A specific and sensitive real-time PCR assay for detection of SFG rickettsiae was established and used to detect the prevalence rate of SFG rickettsiae in Yunnan Province, China. The limit of detection (LOD) of our real-time PCR was 200 copies per reaction, which is more sensitive than the previously developed nested PCR assays for Rickettsia. We tested 265 blood samples (127 goats, 78 dogs, and 60 cattle) collected from Yunnan Province using the real-time PCR assay and revealed that the prevalence of SFG rickettsiae among dogs, cattle, and goats were 14.10%, 23.33%, and 24.41%, respectively. The SFG rickettsiae detected in animals in Yunnan Province were classified into two genotypes: a unique group that is different from all known SFG rickettsiae species, and R. heilongjiangensis.

[Sero-epidemiological investigation on Rickettsia typhi, Bartonella henselae and Orientia tsutsugamushi in farmers from rural areas of Tianjin, 2007 - 2009].

OBJECTIVE: To study the sero-epidemiological status regarding Rickettsia (R.) typhi, Bartonella (B.) henselae and Orientia (O.) tsutsugamushi in farmers from rural areas of Tianjin. METHODS: Field epidemiological surveys were performed in 8 districts (county) of Tianjin city from 2007 to 2009. 886 farmers were randomly recruited and their serum samples collected to detect the specific antibodies of R. typhi, B. henselae and O. tsutsugamushi by micro-indirect immunofluorescence (IFA). RESULTS: The total antibody positive rates of R. typhi increased from 5.0% to 58.2% while B. henselae had an increase from 2.6% to 14.5% and O. tsutsugamushi increased from 1.8% to 39.8%. Geographic distribution showed that farmers living in the central and southeast areas were higher than that in other areas. CONCLUSION: Infections of both R. typhi, B. henselae and O. tsutsugamushi in farmers from Tianjin areas were popular and the antibody positive rates of R. typhi, B. henselae and O. tsutsugamushi had an annual increase.

[Meta-analysis on the association of G894T polymorphism in endothelial nitric oxide synthase gene and essential hypertension in Chinese population].

OBJECTIVE: To evaluate the relationship between G894T (Glu298Asp) polymorphism in the endothelial nitric oxide synthase (eNOS) gene and essential hypertension in Chinese population from different regions. METHODS: Odds ratios (ORs) of G894T genotype and allele distributions in essential hypertension patients against healthy controls were analyzed. All the relevant studies were screened with poor-qualified studies eliminated. Meta-analysis software MIX (Meta-analysis with interactive explanations-version 1.71), was applied for investigating and analyzing heterogeneity among individual studies and summarizing the effects across studies, and the risk of publication bias was evaluated. RESULTS: A total of 1900 cases and 1216 controls from 10 studies were included. The heterogeneity between studies was significant (P = 0.013; P = 0.011) and there were substantial sources of publication bias (P = 0.049; P = 0.038). The pooled OR (with 95%CI) of GT + TT vs. GG genotype was 1.79 (1.33 - 2.42) (Z = 3.83, P < 0.001), and the pooled OR (with 95%CI) of T vs. G allele was 1.73 (1.32 - 2.27) (Z = 3.92, P < 0.001). CONCLUSION: In Chinese population, mainly the Hans ethnic group, 894G-->T mutation in the eNOS appeared to be related to essential hypertension.