Complete mitochondrial genome of the Cyclemys dentata and phylogenetic analysis of the major family Geoemydidae

In the present study, the complete mitochondrial (mt) genome of Cyclemys dentata was determined using PCR reactions. The structural organization and gene order of C. dentata were equivalent to those of most other vertebrates. The mt genome was 16,489 bp in length, has rich A+T content, consisting of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region (D-loop). All protein-coding genes started with ATG, many genes have complete stop codons, except ND2, COX3, ND3, and cyt-b genes had incomplete stop codons of T. The light-strand replication origin (OL) of C. dentata might fold into a stable stem-loop secondary structure, and its loop had 2 nt less than that of the Cyclemys atripons OL sequence. The D-Loop of C. dentata contained a central domain (CD), 2 extended termination associated sequences (ETAS1, ETAS2) and 3 conserved sequence blocks (CSB1, CSB2, CSB3). The average length of 20 turtles' mt genomes was 16,692.5 bp, including 34.1% A, 27.0% T, 26.0% C and 12.9% G. The C. dentata mitochondrial genome could provide useful data for further studies on phylogenetics and conservation genetics of this species. The phylogenetic relationships of the family Geoemydidae were analyzed by maximum-likelihood (ML) and neighbor-joining (NJ) based on concatenated sequences of 13 protein-coding genes from 20 turtle species. The ML and NJ trees had homologous topologies. The results support the existing classification of the genera of Geoemydidae, that C. dentata was a sister species of C. atripons, Pyxidea nested in Cuora, and Chinemys was synonymous with Mauremys.

[Etiological investigation on diarrhoeal diseases in the rural area of Suixian county, Yu Dong plain in China]

To study the etiology of diarrhoeal diseases in the rural area, we carried out a study on diarrhoeal diseases in two natural villages. 15 kinds of diarrhoeal pathogens including 172 strains were isolated from 318 patients with diarrhoea making the isolation rate 49.37%; 12 kinds of diarrhoeal pathogens and 69 strains were isolated from 310 healthy controls and the isolation rate was 22.26%; 6 kinds of diarrhoeal pathogens and 44 strains were isolated in 405 samples obtained from the envronmenfal samples. The major pathogens isolated from various samples were ETEC (LT) and proteus, followed by Shigella, Rotavirus. Analysis on the pathogenetic agents and preventive measurements were also carried out.

[Study of etiology on inpatients with diarrhea in Suixian county of east Henan]

To study the etiology of inpatients with diarrhoea, 372 inpatients with diarrhoea were studied in Suixian county in 1990. Three causative agents as diarrhoeagenic bacteria, rotavirus and diarrhoeagenic parasites were isolated. 12 kinds of diarrhoeal pathogens with 237 strains were isolated. The overall isolation rate was 63.71%, including diarrhoeagenic bacteria 44.35%, rotaviruses 12.1% and diarrhoeagenic parasites 7.26%. The main pathogens were Salmonella typhimurium and Rotavirus (44.3% and 18.9% of total pathogens isolated). Inpatients with diarrhoea between 0-1 years (67.1% of total pathogens isolated) had the highest rates. The isolation rates in the third quarter and the fourth quarter were not significantly higher than that of the others seasons. Analysis on epidemiological characteristics clinical diagnosis and infectious agents was also carried out.

Relative duration as a perceptual cue to stress in Mandarin

Perceptual tests were carried out to examine (1) whether F0 is necessary to perceive stress in Mandarin, and (2) if not, which cue, duration or intensity, is more important. The results indicate that stress can be identified on the basis of duration and intensity alone; duration is a more important cue than intensity. Acoustical analyses of both natural and reiterant speech revealed that both duration and intensity were correlates of stress. There was a ratio of approximately 3:2 between the durations of stressed and unstressed vowels of the same quality, and a difference of nearly 8 dB between their intensities. In addition, segmental changes, such as consonant and vowel reduction, laryngealization, and vowel devoicing, may enhance the perception of the absence of stress.