Phylogenetic Analysis of Some Species of the Anopheles hyrcanus Group (Diptera: Culicidae) in China Based on Complete Mitochondrial Genomes.

Some species of the Hyrcanus group are vectors of malaria in China. However, the member species are difficult to identify accurately by morphology. The development of sequencing technologies offers the possibility of further studies based on the complete mitochondrial genome. In this study, samples of mosquitoes of the Hyrcanus group were collected in China between 1997 and 2015. The mitochondrial genomes of ten species of the Hyrcanus group were analyzed, including the structure and base composition, codon usage, secondary structure of tRNA, and base difference sites in protein coding regions. Phylogenetic analyses using maximum-likelihood and Bayesian inference were performed based on mitochondrial genes and complete mitochondrial genomes The mitochondrial genome of 10 Hyrcanus group members ranged from 15,403 bp to 15,475 bp, with an average 78.23% (A + T) content, comprising of 13 PCGs (protein coding genes), 22 tRNAs, and 2 rRNAs. Site differences between some closely related species in the PCGs were small. There were only 36 variable sites between Anopheles sinensis and Anopheles belenrae for a variation ratio of 0.32% in all PCGs. The pairwise interspecies distance based on 13 PCGs was low, with an average of 0.04. A phylogenetic tree constructed with the 13 PCGs was consistent with the known evolutionary relationships. Some phylogenetic trees constructed by single coding regions (such as COI or ND4) or combined coding regions (COI + ND2 + ND4 + ND5 or ND2 + ND4) were consistent with the phylogenetic tree constructed using the 13 PCGs. The phylogenetic trees constructed using some coding genes (COII, ND5, tRNAs, 12S rRNA, and 16S rRNA) differed from the phylogenetic tree constructed using PCGs. The difference in mitochondrial genome sequences between An. sinensis and An. belenrae was very small, corresponding to intraspecies difference, suggesting that the species was in the process of differentiation. The combination of all 13 PCG sequences was demonstrated to be optimal for phylogenetic analysis in closely related species.

Seismological evidence for the earliest global subduction network at 2 Ga ago.

The earliest evidence for subduction, which could have been localized, does not signify when plate tectonics became a global phenomenon. To test the antiquity of global subduction, we investigated Paleoproterozoic time, for which seismic evidence is available from multiple continents. We used a new high-density seismic array in North China to image the crustal structure that exhibits a dipping Moho bearing close resemblance to that of the modern Himalaya. The relict collisional zone is Paleoproterozoic in age and implies subduction operating at least as early as ~2 billion years (Ga) ago. Seismic evidence of subduction from six continents at this age is interpreted as the oldest evidence of global plate tectonics. The sutures identified can be linked in a plate network that resulted in the assembly of Nuna, likely Earth's first supercontinent. Global subduction by ~2 Ga ago can explain why secular planetary cooling was not appreciable until Proterozoic time.

[Case-control study on different fixation methods for the treatment of tibial fractures in 96 patients].

OBJECTIVE: To compare the therapeutic effects of limited excision and locking plate fixation, interlocking intramedullary nailing and external fixation in treating tibial fractures. METHODS: From May 2007 to May 2011, 96 patients with tibial fractures were divided into three groups (Group A, Group B and Group C) and were treated with three kind of fixations including limited excision and locking plate fixation (36 cases in Group A, including 24 males and 12 females), interlocking intramedullary mailing (38 cases in Group B, including 22 males and 16 females) and external fixation (22 cases in Group C, including 12 males and 10 females). Operative time, healing time, weight-bearing time and complications were observed. Johner-Wruhs scoring was used to evaluate the function of lower limbs. RESULTS: All patients were followed up from 3 months to 30 months with an average of 13 months. In Group A, the operative time was (85.01 +/- 12.2) minutes; the healing time was (143.0 + 12.3) days; the weight-bearing time was (114.3 +/- 12.2) days; Complications occured in 3 patients. According to Johner-Wruhs scoring, the results were rated as excellent in 21 cases, good in 12 cases, moderate in 2 cases, and poor in 1 case; In Group B, the operative time was (90.0 +/- 14.6) minutes; the healing time was (132.0 +/- 14.6) days; the weight-bearing time was (46.0 +/- 12.2) days; Three patients occurred complications. According to Johner-Wruhs scoring,the results were rated as excellent in 24 cases, good in 11 cases, moderate in 2 cases, and poor in 1 case. In Group C, the operative time was (70.0 +/- 10.2) minutes; the healing time was (121.0 +/- 13.5) days; the weight-bearing time was (108.2 +/- 8.9) days; Two patients underwent complications. According to Johner-Wruhs scoring, the results were rated as excellent in 16 cases, good in 5 cases, moderate in 0 case, and poor in 1 case. There were no significant significance among three groups in operative time, healing time, complications and the lower limbs function recovered (P > 0.05). But weight-bearing time in interlocking intramedullary nailing was better than in limited excision and locking plate fixation and external fixation (P < 0.05). CONCLUSION: Different fixation methods have different advantages. Limited excision,closed reduction with locking plate fixation is an ideal method to treat the tibial fracture.