Voltage-gated sodium channel gene mutation and P450 gene expression are associated with the resistance of Aphis spiraecola Patch (Hemiptera: Aphididae) to lambda-cyhalothrin.

Aphis spiraecola Patch is one of the most economically important tree fruit pests worldwide. The pyrethroid insecticide lambda-cyhalothrin is commonly used to control A. spiraecola. In this 2-year study, we quantified the resistance level of A. spiraecola to lambda-cyhalothrin in different regions of the Shaanxi province, China. The results showed that A. spiraecola had reached extremely high resistance levels with a 174-fold resistance ratio (RR) found in the Xunyi region. In addition, we compared the enzymatic activity and expression level of P450 genes among eight A. spiraecola populations. The P450 activity of A. spiraecola was significantly increased in five regions (Xunyi, Liquan, Fengxiang, Luochuan, and Xinping) compared to susceptible strain (SS). The expression levels of CYP6CY7, CYP6CY14, CYP6CY22, P4504C1-like, P4506a13, CYP4CZ1, CYP380C47, and CYP4CJ2 genes were significantly increased under lambda-cyhalothrin treatment and in the resistant field populations. A L1014F mutation in the sodium channel gene was found and the mutation rate was positively correlated with the LC50 of lambda-cyhalothrin. In conclusion, the levels of lambda-cyhalothrin resistance of A. spiraecola field populations were associated with P450s and L1014F mutations. Our combined findings provide evidence on the resistance mechanism of A. spiraecola to lambda-cyhalothrin and give a theoretical basis for rational and effective control of this pest species.

Seasonal dynamics of soil nitrogen mineralization and their influencing factors during shrub anthropogenic introduction in desert steppe.

We selected enclosed grassland, grazed grassland and shrublands with different planting years (3, 12, 22 years)/densities (intervals of 2, 6, 40 m) to investigate soil N mineralization dynamics in the growing season (April-October) and its influencing factors during the process of desert steppe-degradation-shrub introduction. The results showed that soil moisture at 0-200 cm layer was decreased with increases of shrub age and density, and that the variations of soil moisture at 0-10 cm layer coincided with seasonal change. Compared with grazed grassland and enclosed grassland, the positive effect of shrubs on soil carbon, nitrogen and phosphorus contents first increased and then decreased with the increases of age and density. Moreover, soil N mineralization significantly varied across months and sites. Soil NO3- content and microbial biomass carbon and nitrogen were significantly higher from June to August. The proportion of NO3- to inorganic nitrogen significantly increased from 30.5% in enclosed grassland to 69.5% in shrublands. NH4+ content was mainly affected by months compared with sites. In the process of steppe-degradation-shrub introduction, the increases of shrub age and density significantly enhanced seasonal differences of soil nitrification and ammonification, but not on the seasonal mineralization of microbial biomass carbon and nitrogen. Soil NH4+ and NO3- contents were significantly and positively correlated with total nitrogen, organic carbon and N/P. Soil stoichiometric ratios (C/N and N/P) directly regulated N mineralization process.

[Soil organic carbon dynamics and the prediction of their spatial changes in response to anthropogenically introduced shrub encroachment in desert steppe of the Eastern Ningxia, China.] / å®å¤ä¸œéƒ¨è’æ¼ è‰åŽŸçŒä¸›å¼•å ¥è¿‡ç¨‹ä¸­åœŸå£¤æœ‰æœºç¢³å˜åŒ–åŠå ¶ç©ºé—´æ ¼å±€é¢„æµ‹.

With the 14-year enclosed grassland and the grazed grassland as control, the impacts of anthropogenic shrublands (Caragana korshinskii) with the different planting years (3, 12, 22 a) and planting spaces (2, 8, 40 m) on soil organic carbon (SOC) contents were examined in the desert steppe of Eastern Ningxia, China. We further analyzed the spatial pattern and heterogeneity of SOC in 0-40 cm soil layer of the grassland area with introduced shrubs. The results showed that SOC in C. korshinskii shrublands had an increase trend with increased planting years and decreased spaces. The mean SOC with different planting years and spaces was 42.7% and 32.8% more than that in grazing land, respectively. There was no significant difference of SOC between shrublands and the 14-year enclosed grassland. The increase trend of SOC decreased by 27.0% in 22-year planting shrubland. The SOC content of 0-40 cm soil layer varied from 0.21 g·kg-1 to 26.04 g·kg-1 (with a mean of 3.75 g·kg-1), and the coefficient of SOC variation ranged from 90.9% to 114.7%. The SOC in 0-5 cm and 15-40 cm soil layers fitted the optimal theory formulation of Gaussian model, while that in 5-15 cm soil layer fitted a spherical model. The ranges (A0) of spatial autocorrelation in the 0-5 and 5-15 cm soil layers were smaller (3.11, 3.00 km) than that in 15-40 cm soil layer (10.10 km). The nugget/sill C0/(C0+C) of SOC in 0-5, 5-15 cm soil layer was 0.2% and 16.3%, indicating a strong spatial correlation, while that in 15-40 cm soil layer was 36.9%, with a moderate correlation. The shrub introdution could significantly accelerate the accumulation and fixation of SOC in top 40 cm soil layer in degraded desert steppe, but also intensified the spatial heterogeneity and SOC fragmentation. The SOC content in the anthropogenic shrublands had no significant difference from that in the enclosed desert steppe (14 years). The SOC spatial heterogeneity and the degree of fragmentation were weakened and decreased with the increasing soil layer depth.

[Spatial heterogeneity of soil water content under introduced shrub (Caragana korshinskii) in desert grassland of the eastern Ningxia, China]. / å®å¤ä¸œéƒ¨è’æ¼ è‰åŽŸçŒä¸›å¼•å ¥ä¸‹åœŸå£¤æ°´åˆ†ç©ºé—´å¼‚è´¨æ€§.

Combined with geographic information system (GIS) data, the spatial heterogeneity of soil water in the 0-200 cm soil layer of the desert steppe with the introduction of the shrub Caragana korshinskii in eastern Ningxia was studied by classical statistical and geostatistical methods. It was found that the soil water content of each soil layer in the 0-200 cm profile was relatively low, ranging from 0.6% to 19.0% (averaged 4.4%). The coefficient of soil water content variation ranged from 49.5% to 86.3%, which indicated moderate spatial heterogeneity. The variation of soil water content at the 0-60 cm and 80-120 cm soil layers fitted the spherical model, while that at the 60-80 cm soil layer fitted the exponential model and that at the 120-200 cm soil layer fitted the Gaussian model. Soil water content at different soil layers showed different degrees of spatial autocorrelation. The nugget/sill [C0/(C0+C)] of soil water content in the 0-40, 60-80, and 120-200 cm soil layers ranged from 26.1% to 49.9%, with moderate spatial correlations. The nugget/sill of soil water content in the 40-60 cm, 80-100 cm, and 100-120 cm soil layers ranged from 15.5% to 22.1%, with strong spatial correlations. The scale of spatial heterogeneity in soil water content (A0) varied among soil layers. The A0 was relatively large in the 0-20 and 20-40 cm soil layers (37.10-45.18 km) and small in the 40-200 cm soil layers (3.58-8.66 km). The results indicated that the introduction of C. korshinskii shrubs into desert grassland for vegetation recovery in recent decades have depleted soil water and accelerated the depletion of soil water in the deep layer (40-200 cm), leading to spatial heterogeneity and fragmentation of soil water (0-200 cm) with stronger effects at deep soil layer.

Large-diameter compression arteries as a possible facilitating factor for trigeminal neuralgia: analysis of axial and radial diffusivity.

BACKGROUND: Neurovascular compression (NVC) of the trigeminal nerve is associated with trigeminal neuralgia (TN). Some arteries that compress the trigeminal nerve are large, while others are small. This study evaluated the influence of diameter of compression arteries (DCA) on NVC with and without TN using axial diffusivity (AD) and radial diffusivity (RD) of magnetic resonance (MR) imaging. METHODS: Fifty TN patients with unilateral NVC, 50 asymptomatic patients with unilateral NVC, and 50 healthy controls (HC) were divided into three groups (NVC with TN, NVC without TN, and HC). The three groups were imaged with a 3.0-T MR system using three-dimensional fast imaging employing steady-state acquisition (3D FIESTA) and diffusion tensor imaging (DTI). We compared the mean size of DCA between NVC with and without TN. The mean values of AD and RD at the site of NVC were compared between the three groups. Correlation analyses were performed between the DCA and the diffusion metrics (AD and RD) in NVC patients with and without TN. RESULTS: The mean DCA in NVC patients with TN (1.58 ± 0.34 mm) was larger than that without TN (0.89 ± 0.29 mm). Compared with NVC without TN and HC, the mean values of RD at the site of NVC with TN were significantly increased; however, no significant changes of AD were found between the groups. Correlation analysis showed that DCA positively correlated with RD in NVC patients with and without TN (r = 0.830, p = 0.000). No significant correlation was found between DCA and AD (r = 0.178, p = 0.077). CONCLUSIONS: Larger-diameter compression arteries may increase the chances of TN, and may be a possible facilitating factor for TN.

Field trial of a quantum secured 10 Gb/s DWDM transmission system over a single installed fiber.

We present results from the first field-trial of a quantum-secured DWDM transmission system, in which quantum key distribution (QKD) is combined with 4 × 10 Gb/s encrypted data and transmitted simultaneously over 26 km of field installed fiber. QKD is used to frequently refresh the key for AES-256 encryption of the 10 Gb/s data traffic. Scalability to over 40 DWDM channels is analyzed.

[Diagnostic value of serum anti-cyclic citrullinated peptide antibodies in patients with rheumatoid arthritis].

OBJECTIVE: To explore the diagnostic value of serum anti-cyclic citrullinated peptide (Anti-CCP) antibodies in patients with rheumatoid arthritis (RA). METHODS: Anti-CCP antibodies were detected in the serum samples of 120 RA patients, 71 non-RA patients with various rheumatic diseases, and 50 normal controls by enzyme-linked immunosorbent assay (ELISA) using domestic and imported commercial detection kits. Rheumatoid factors (RF) were assayed by immune-nephelometry. The correlation between Anti-CCP and RF in RA diagnosis was analyzed by calculating the area under curve of the receiver operating characteristic (ROC) curve. RESULTS: The positive rates for Anti-CCP, detected using both domestic and imported kits, were 61.7% (74/120) and 69.2% (83/120) in RA group, significantly higher than those in the non-RA group (9.9%, 7/71 and 7.0%, 5/71) and normal control group (both 0, P<0.001). The sensitivities for Anti-CCP and RF were 69.2% and 64.2%, and the specificities were 92.9% and 67.6%, respectively. The positive predictive value was 94.3% for Anti-CCP and 77.0% for RF, whereas the negative predictive value was 64.1% for Anti-CCP and 52.7% for RF. The likelihood ratio (LR) was 9.82 for anti-CCP and 1.98 for RF. The area under curve of ROC for Anti-CCP was 0.829 and 0.740 for RF. Anti-CCP antibodies had greater diagnostic value than RF in RA diagnosis, and Anti-CCP showed significant correlation with RF (r=0.29, P=0.001). CONCLUSION: Anti-CCP antibodies are an excellent serological marker for RA, which shows high diagnostic specificity at early stage, and can increase its diagnostic value when combined with RF detection, but the role of Anti-CCP in the occurrence and prognosis of RA remains to be further investigated.