Otolith microstructure analysis based on wild young fish and its application in confirming the first annual increment in Tibetan Gymnocypris selincuoensis

Otolith microstructural features of larval and juvenile fish, and especially the confirmation of the first annulus, are important for studying the early life history of fish. In this study, otolith microstructure analysis was performed on 318 young Gymnocypris selincuoensis (99 larvae and 219 juveniles) collected from Lake Siling Co from May 2010 to June 2011. The time of the first annulus formation of otoliths in juveniles was confirmed. The results showed that lapilli were the most suitable otoliths for age determination of G. selincuoensis among the three pairs of otoliths. By comparing the microstructure features of the otolith edge of the wild juveniles before and after overwintering, the first annulus formation time of the lapilli of the 2010 generation of juveniles was confirmed to be from April 17 to May 3, 2011 using the daily increment analysis. On the lapillus, an opaque band was formed from mid-April through early November (the growing season of G. selincuoensis), and a translucent band (i.e., the annulus) was formed from early November to mid-April of the following year (the slow growth stage). The first daily increment outside of the first annulus was formed at an average water temperature of 1.69 degrees C, which is the lowest reported water temperature at which fish were able to form daily increments. Our proposed method to determine the time of the first annulus formation through otolith daily increment analysis provides a referential way for confirming annulus formation in fish. The high temporal resolution (at day level) of this method in estimating annulus formation time highlights its application potentials in studies of growing season length estimation and fish response to water temperature change, which can assist with fish population management and conservation challenges arising from climate and environmental changes.</p

Phylogeographic studies of schizothoracine fishes on the central Qinghai-Tibet Plateau reveal the highest known glacial microrefugia

Pleistocene climatic oscillations have greatly influenced the evolutionary history and distribution pattern of most extant species. However, their effects on species on the Qinghai-Tibet Plateau (QTP) are not well understood. To investigate the effects of past climatic shifts, particularly the Last Glacial Maximum (LGM), on plateau fish, we analysed the phylogeographic structure and demographic history of five closely related taxa of the subfamily Schizothoracinae, a representative endemic taxon of the QTP, from nine endorheic lakes on the central QTP and three peripheral exorheic rivers using the mitochondrial control region (D-loop) sequence and 12 microsatellite (SSR) markers. Phylogram from D-loop haplotypes revealed two well-supported lineages (North and South) separated by the Tanggula Mountains. The results from the D-loop and SSR revealed that endorheic populations possess high genetic diversity and a unique genetic structure. The most recent demographic expansion occurred post-LGM for most endorheic populations and in the last interglacial period for Siling Co and all exorheic populations. Phylogeographic structure, together with species distribution modelling, supports the scenario of multiple glacial refugia on the QTP during the LGM and suggests that Siling Co (4540 m asl) is a cryptic glacial microrefugia for plateau fish, which would be the highest glacial microrefugia known.</p

Safety-Risk Assessment for TBM Construction of Hydraulic Tunnel Based on Fuzzy Evidence Reasoning

Due to multiple factors influencing the construction safety of TBM hydraulic tunnels, risk assessment is a critical point of a construction management plan to avoid possible risks. In this paper, a safety-risk evaluation index system of TBM construction for hydraulic tunnels is built based on the identification and analysis of possible sources of risk in techniques, geologic, equipment, management, and accidents. Considering the influence of factors such as the experience level and the expertise of decision makers, a combination assignment method of index weights is proposed based on binary semantics. On the basis of a fuzzy normal distribution used as the subordinate function distribution of fuzzy evaluation levels, the subordinate function distribution of fuzzy evaluation levels under multi-level intersection situations is introduced, and a comprehensive evaluation model of safety risks for TBM tunnel construction is built. The validity and practicality of the evaluation model is examined with the combination of a long-distance water conveyance tunnel project. Results show that the construction safety-risk of the TBM hydraulic tunnel project belongs to the middle-high level, and the safety accident risk belongs to the low level. The study provides guidance of evaluation and control of risks for this tunneling construction being successfully completed

Albuminuria Is Associated with Left Ventricular Hypertrophy in Patients with Early Diabetic Kidney Disease

Aims. Left ventricular hypertrophy (LVH) and albuminuria are both markers for cardiovascular diseases (CVDs) in patients with type 2 diabetes mellitus (T2DM). We speculate that albuminuria in T2DM patients with early diabetic kidney disease (DKD) could predict LVH. Methods. 333 diabetic patients (219 non-DKD and 114 early DKD) were enrolled. The association between albuminuria and LVMI was examined using multivariate linear regression and logistic regression. Results. The rate of LVH was significantly higher in patients with early DKD versus those without DKD (57.0% versus 32.9%; P<0.001). Multivariate linear regression analysis demonstrated that albuminuria status (no, micro-, and macroalbuminuria; P<0.001), age (P<0.001), systolic blood pressure (P=0.0578), and the use of ACEI/ARB drug (P<0.001) were independently associated with LVMI. The risks were substantially higher for LVH in the microalbuminuria group (odds ratio 2.473 (95% confidence interval 1.370–4.464)) and macroalbuminuria group (odds ratio 3.940 (95% confidence interval 1.553–9.993)) compared with that in non-DKD group. Concentric hypertrophy was the most common geometric pattern in patients with early DKD (36.0%), followed by eccentric hypertrophy (21.0%). Conclusions. Albuminuria is associated with higher LVMI and higher rate of LVH in patients with early phase DKD