Correlation of the Nest Density and the Number of Workers in Bait Traps for Fire Ants (Solenopsis invicta) in Southern China

The relationship between Solenopsis invicta nest density and the number of fire ant workers in bait traps and percentages of traps capturing ants were investigated in the waste land of Wuchuan, Guangdong, South China. The results showed that fire ant nest density is positively correlated with the number of workers captured in traps, and could be described by N=60.53LnD +348.0D+421.1. The workers exceeded 200 and 300 in bait traps while the density of fire ant nests was over 0.023 and 0.084 ind./m2, respectively. The percentages of traps capturing ants were also positively correlated with fire ant nest density and fit by Pe=1/(1+e0.9694-309.85D). When the nest density was over 0.018 ind./m2, over 99% of traps captured fire ant workers. N=8.8796e0.0346Pe was the fitting line for worker amount and trap percentage. The workers per trap were about 50, 100, and 200 when the trap percentages were 50%, 70% and 90%, respectively

Performance analysis of statistical multiplexers and token ring networks with integrated data/voice traffic

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The Optimization Algorithm for Large-Scale In Situ Stress Field

In situ stress state is a predominant factor for the design and safe construction of geotechnical engineering. For a real construction site, the amount of calculation using a finite element method for in situ stress field increases dramatically with the increase of the calculation freedom due to large-scale uncertainties. In order to reduce the computing cost without losing the accuracy of the calculation, an optimization algorithm combined with a reduced order model, which is realized by the proper orthogonal decomposition algorithm (POD) for large-scale in situ stress field, is put forward in this paper. The POD algorithm produces a set of orthogonal bases through the extraction of the field variables, combining with the Galerkin finite element method to create a reduced order numerical model. The reduced order model is then calculated with a global optimization algorithm to inversely find the solution for the actual in situ stress field. In order to verify the accuracy and efficiency of the method, two examples are presented to simulate the inverse calculation of the in situ stress field. They showed that the computation time of the POD method could reach 1/10 of the ordinary computation time. Also, the results showed good accuracy with a minimum computational expense, which can provide a reference for inverse calculation of large-scale in situ stress field

Thicknesses of the retina and choroid in children with retinitis pigmentosa

Abstract Purpose To compare the retinal thicknesses (RT) and choroidal thicknesses (CT) in retinitis pigmentosa (RP) children with those of healthy children using enhanced depth imaging (EDI) optical coherence tomography (OCT). The RT and CT in different genetic subgroups of autosomal dominant RP (ADRP) and X-linked inheritance RP (XLRP) were further studied to investigate the characteristics of retinal and choroidal changes in the early stages of RP. Method A retrospective analysis was performed on a group of patients with RP who underwent EDI-OCT. Thirty-two children (64 eyes) with RP and 28 age- and refraction-matched healthy children (56 eyes) were included in the study. Seven of the 32 RP children (14 eyes) had X-linked inheritance RP, and 10 (20 eyes) had autosomal dominant inheritance RP. RT and CT were measured by optical coherence tomography and compared between the 32 children with RP and 28 controls and between 7 XLRP and 10 ADRP children. Result Among the 32 children with RP, there were 18 males and 14 females with an average age of 6.6 ± 2.4 years. The mean RT was smaller in the RP group than in the control group at all of the locations. The mean temporal CT was smaller in the RP group (243.76 ± 60.82 μm) than in the control group (275.23 ± 40.92 μm) (P = 0.001), while there was no significant thinning on the foveal or nasal side. The best-corrected visual acuity of the XLRP group (0.40 ± 0.19) was worse than that of the ADRP group (0.68 ± 0.21) (P = 0.001), but the disease duration was the same (P = 0.685). The mean foveal RT was smaller in the XLRP group (173.85 ± 22.87 μm) than in the ADRP group (192.20 ± 9.70 μm) (P = 0.003), while there was no significant thinning at the other locations we studied. The mean temporal CT was smaller in the XLRP group (211.21 ± 69.41 μm) than in the ADRP group (274.45 ± 57.91 μm) (P = 0.007); CT measurements in XLRP children showed a more severe reduction on the temporal side. Conclusion The choroid in RP children was preferentially smaller on the temporal side of the macula, and retinal thinning was relatively extensive. Children with RP have strong clinical and genetic heterogeneity. The XLRP children demonstrated greater RT reduction at the fovea and greater CT reduction at the temporal side of the macula than the ADRP children. Our findings also provide evidence that the changes in thicknesses may be indicative of the greater severity of XLRP versus ADRP in the early stage

Research on the Algorithm for Composite Lining of Deep Buried Water Conveyance Tunnel

Composite lining of deep buried water conveyance tunnel for bearing high internal water pressure is a new type of applicable structure. However, up to date, no effective method is available to calculate the stress of the structure. In this paper, a simplified algorithm, which can be used to calculate the stress distribution of composite lining accurately but costs little computational resource, is proposed. This algorithm, which is based on the elastic theory, takes the effect of internal water pressure and surrounding rock on the composite lining into consideration, respectively. Then, the stress distribution of composite lining in infinite body is derived on the basis of Lame solution. Finally, a case study is followed by choosing a typical section of the Eastern Canal in Beijing of the South-to-North Water Diversion Project (SNWDP). This case study was analysed by using the simplified algorithm and verified by finite element method with ABAQUS. The results show that the stress distribution of composite lining can be obtained quickly and accurately with the simplified algorithm, which can provide a reference for other engineering designs

Design of ₌׀₌ Shape Stub-Based Negative Group Delay Circuit

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NGD Analysis of Turtle-Shape Microstrip Circuit

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