Absolute phase measurement method based on bidirectional coding patterns.

The stair-phase-coding patterns have been widely used to determine the fringe order for phase unwrapping of the wrapped phase in three-dimensional shape measurement. Although the special coding sequence algorithm can achieve with a large number of codewords, it needs the current codeword and its adjacent codewords to jointly determine the fringe order. If any codeword of the grouped adjacent codewords is incorrectly recognized, it will result in many false fringe orders. It increases the probability of fringe order error in the decoding process. And it is challenging to significantly increase the number of codewords. To solve this problem, we propose an absolute phase measurement method based on bidirectional coding patterns. The wrapped phase of the object is obtained by four-step phase-shifting patterns, and the fringe order is obtained by bidirectional coding patterns. When generating the bidirectional coding patterns, we code two groups of stair phase with different frequencies along the horizontal direction, which respectively represent local fringe order and partition information. Then, we alternately repeat the two groups of stair phase along the vertical direction in the whole pattern to obtain the bidirectional coding patterns. Each local fringe order information and the corresponding partition information in a small region jointly determine the fringe order of pixels in this small region. Fringe order errors in a small region do not affect other regions. To verify the effectiveness of our method, we performed simulations and experiments. Simulation and experimental results show that our method is effective for objects with different sizes and isolated objects.

High endemicity of alveolar echinococcosis in Yili Prefecture, Xinjiang Autonomous Region, the People's Republic of China: Infection status in different ethnic communities and in small mammals.

Alveolar echinococcosis (AE) is a life-threatening disease in humans caused by the larval stage of Echinococcus multilocularis. The tapeworm is transmitted between small mammals and dogs/foxes in the Northern Hemisphere. In this study 286 AE cases were reported from eight counties and one city in Yili Prefecture, Xinjiang Autonomous Region, the People's Republic of China from 1989 to 2015 with an annual incidence (AI) of 0.41/100,000. Among the patients, 73.08% were diagnosed in the last 11 years. Four counties in the high mountainous areas showed higher AI (0.51-1.22 cases/100,000 residents) than the four counties in low level areas (0.19-0.29/100,000 residents). The AI of AE in Mongolian (2.06/100,000 residents) and Kazak (0.93/100,000 residents) ethnic groups was higher than the incidence in other ethnic groups indicating sheep-farming is a risk for infection given this activity is mainly practiced by these two groups in the prefecture. A total of 1411 small mammals were captured with 9.14% infected with E. multilocularis metacestodes. Microtus obscurus was the dominant species in the mountain pasture areas with 15.01% of the voles infected, whereas Mus musculus and Apodemus sylvaticus were the dominant small mammals in the low altitude areas. Only 0.40% of A. sylvaticus were infected with E. multilocularis. PCR amplification and sequencing analysis of the mitochondrial cox1 gene showed that E. multilocularis DNA sequences from the small mammals were identical to isolates of local human AE cases. The overall results show that Yili Prefecture is a highly endemic area for AE and that the high-altitude pasture areas favorable for M. obscurus may play an important role in its transmission in this region.

Genetic variation of mitochondrial genes among Echinococcus multilocularis isolates collected in western China.

BACKGROUND: Alveolar echinococcosis (AE) is a life-threatening human disease caused by Echinococcus multilocularis transmitted between rodents and dogs/foxes in the Northern Hemisphere. The study aims to identify the genetic variation of the parasite in AE patients from China. METHODS: E. multilocularis isolates were collected from wild small mammals (n = 6) and AE patients (n = 56) from western China. Genomic DNA was extracted from different tissue samples including paraffin tissue blocks, ethanol fixed tissues and frozen tissues surgically removed. Two mitochondrial gene fragments (526 bp for cob and 474 bp for nad2) of E. multilocularis were amplified and sequenced. RESULTS: The parasite fragment sequences of cob fragments from AE patients showed two haplotypes, and nad2 gene fragment sequences had four haplotypes. The gene sequences from Microtus sp. were 100% identical to the sequences of some isolates from AE patients. These haplotypes were distributed in both Qinghai and Xinjiang provinces. Alignment analysis with the sequences from the GenBank databases showed five genotypes including three Asian genotypes, one from Europe and one from North America. CONCLUSIONS: Most AE patients harbored the Asian genotype 1 which may be an indication of its relative frequency in the definitive hosts and the environment or of its pathogenicity to humans, which calls for further research.

The complete mitochondrial genome sequence of Hemibagrus sp. (Siluriformes: Bagridae), molecular data for species identification.

In this study, we determined and described the complete mitogenome sequence of Hemibagrus sp. for the first time, which is 16,513 bp in length, and contains 37 genes, including 13 protein-coding genes, 2 rRNAs, 22 tRNAs, 1 origin of replication on the light-strand (OL) and a putative control region. The overall base composition was 31.1% A, 26.9% T, 26.9% C, 15.1% G, with a slight AT bias (58.0%). All protein-coding genes shared the start codon ATG, except for COI, which began with GTG. The tRNA-Ser(UGC) couldn't be folded into the typical cloverleaf secondary structure because its dihydrouridine arm is replaced by a simple loop. These results are expected to provide useful molecular data for species identification and further phylogenetic studies of Bagridae and Siluriformes.

Genetic differentiation between red deer from different sample sites on the Tianshan Mountains (Cervus elaphus), China.

About 273 individuals were identified from 471 fecal samples from six different red deer populations in China. The genetic structure showed that the red deer from the western and eastern Tianshan Mountains was different. A total number of 12 haplotypes were defined by 97 variable sites by the control region (CR), and 10 haplotypes were defined by 34 variable sites by cytochrome b. There was no haplotype sharing between red deer populations from western and eastern Tianshan Mountains by the CR and the cytochrome b. The red deer populations from west were clade with wapiti from North American and red deer from Siberia, while red deer populations from east were clade with red deer from Crimea in Pleistocene rather than west at present. The result of NETWORK also showed that red deer populations from western and eastern Tianshan Mountains were different. The haplotype and the Fst value between western and eastern Tianshan red deer were significantly different. The AMOVA analysis showed that 97.34% and 1.14% of the total genetic variability were found within populations and among populations within groups, respectively, by microsatellite. AMOVA for mitochondria showed that most of the variance was explained among-group. The Fst, pairwise distance, and phylogenetic relationship result showed that red deer between western and eastern Tianshan were more different than some of the red deer from North-Asia, South-Asia, East-Asia, and wapiti. All data from this study do support that the genetic characteristics of red deer between western and eastern Tianshan Mountains by microsatellite, control region, and cytochrome b were different.

Allele frequencies of 12 Y-chromosomal STRs in Chinese Tuvans in the Altay region.

Allele and haplotype frequencies of 12 Y-chromosomal short tandem repeats (STRs) included in the PowerPlex(®) Y Systems (Promega) were determined in a sample of 150 unrelated healthy male individuals of Chinese Tuvans living in the Altay region of Xinjiang Uygur Autonomous Region. Allele frequencies and gene diversity for each Y-STR locus were determined. The observed haplotype diversity value was 0.9708. The present results can be used as Chinese Tuvan genetic information resources in routine population study and forensic analysis.

Brief communication: Y-chromosome haplogroup analysis indicates that Chinese Tuvans share distinctive affinity with Siberian Tuvans.

Tuvans are mainly distributed in Siberia (the Republic of Tuva), Mongolia, and China. The genetic origin of Chinese Tuvans remains controversial. The Tuvans in China were classified as Mongolians in the early 1950s by the National Ethnic Affairs Commission of China, but they defined themselves as a separate group. To resolve this dispute and determine their genetic relationships with the peoples in Central Asia, we randomly selected 150 male subjects from the Tuvans in the Altai region of Xinjiang Uygur Autonomous Region in China. Fourteen Y chromosomal markers were genotyped using the RFLP method or direct sequencing. These haplogroup data were combined with public data for 15 populations in South Siberia and Central Asia. Tuvans in both China and the Republic of Tuva had the highest frequencies of haplogroups K-M9 and Q-M242. Principal component analysis demonstrated that the Tuvans in China were of a distinct cluster, separated from their neighbors, the Mongolians and Kazakhs, which finding was consistent with the Analysis of Molecular Variances. Further population tree analysis revealed that Tuvans were on a far-separated cluster from their neighbors. Based on these results, we propose that the Tuvans (in both China and the Republic of Tuva) constitute a group distinct from Mongolians and from other Central Asia populations. However, the genetic results might be the consequence of some evolutionary forces like genetic drift and founder effect, and do not necessarily reflect their ultimate origin.

[Genetic relationships between Tuva population and the neighboring populations in the Altai Region of Xinjiang Uygur Autonomous Region].

In the Hanasi scenic spot of the Altai Region, Xinjiang Uygur Autonomous Region, China, there is a special population known as Xinjiang Tuvinians for short. These Tuvinians were classified as Mongolians in the early 1950s by the National Ethnic Affairs Commission of China, but they claimed that they have an independent origin. To resolve this dispute and their genetic relationships with the people in the neighboring regions, we randomly selected 150 male Tuvinians in the Altai Region. Fourteen Y chromosomal markers were genotyped and eleven haplogroups were constructed. The frequencies of the haplogroups K-M9 and Q-M242 were higher in Xinjiang Tuvinians or Tuvinians in the Tuva Republic than those in the other populations (e.g., Mongolians and Kazakh). Principal component analysis , multi-dimensional scaling analysis and further phylogenetic tree analysis revealed that the Xinjiang Tuvinians were far separated from Mongolians and Kazakh. Based on these results, we proposed that Xinjiang Tuvinians are genetically distinct from Mongolians and Kazakh.