Studies on the Spatial Distribution of Aphis-eating Ladybirds in Soybean Fields

- Seven-spot ladybird (Coccinella septempunctata Linnaeus), Akebia leaflike moth (Adonia variegate goeze), Ash bark beetle (Leis axyridis Pallas) and bifid tongued bees (Propylaea japonica Thunberg) are principal predators of soybean aphids (Aphis glycineOriginating text in Chinese.Citation: Wang, Xiaoqi, Ding, Xiuyun, Huang, Feng. (1991). Studies on the Spatial Distribution of Aphis-eating Ladybirds in Soybean Fields. Journal of Shenyang Agricultural University, 22(1), 13-16

There exists no tetravalent half-arc-transitive graph of order 2p2

AbstractA graph is half-arc-transitive if its automorphism group acts transitively on its vertex set, edge set, but not arc set. In this paper, we show that there is no tetravalent half-arc-transitive graph of order 2p2

Studies on the Spatial Distribution Pattern of Soybean Aphid and Sampling Techniques

The results of our studies on the spatial distribution patterns of aphid populations and of the aphid infested plants in the field showed a spatial distribution pattern of aphids aggregated at certain density levels. Characteristics of aphid behavior, such as mutual attraction between individual aphids, were the cause for aggregation of soybean aphids. The basic elements of distribution are individual aphid colonies. The aphid infested soybean plants were either uniformly or randomly distributed when infestation rates were low, and uniform distribution prevailed as the infested rates increased to higher levels. Sampling methods such as parallel, chessboard and “Z” pattern sampling, were all applicable in the investigation of aphid population density. In addition, by referring to the linear regression equation between average crowdedness and mean proposed by Iwao and applying the ? and ? values from the equation to the formulae of theoretical sampling numbers and sequential sampling, we may obtain the theoretical sampling numbers and results of sequential sampling for the investigation of both aphid density and the aphid infestationrate of soybean plants.Originating text in Chinese.Citation: Huang, Feng, Ding, Xiuyun, Wang, Xiouqi, Huang, Zhanghai. (1992). Studies on the Spatial Distribution Pattern of Soybean Aphid and Sampling Techniques. Journal of Shenyang Agricultural University, 23(2), 81-87

Analysis of the expression profile of Dickkopf-1 gene in human glioma and the association with tumor malignancy

<p>Abstract</p> <p>Background</p> <p>Gliomas represent the most common primary malignant brain tumors, yet little is known about the molecular pathogenesis of these tumors. The highly-regulated Wnt signal transduction pathway is essential for normal developmental processes, and defects in the pathway are closely linked to oncogenesis. Dickkopf-1 (DKK-1) is a secreted protein that acts as a potent inhibitor of the Wnt pathway. The aim of this study was to examine the expression profile of DKK-1 gene in human glioma and its association with tumor malignancy.</p> <p>Methods</p> <p>We determined the expression levels of DKK-1 transcript and protein in 12 glioblastoma cell lines, medulloblastoma cells, low-grade glioma cells, and human astrocyte cells by semiquantitative RT-PCR and ELISA. A total of 47 tumor biopsy specimens and 11 normal brain tissue samples from patients with cerebral trauma internal decompression were embedded in paraffin blocks and used for immunostaining. Twenty-six primary tumors and 7 corresponding brain samples were stored in liquid nitrogen and used for RT-PCR. We further examined serologic concentrations and cerebral fluid levels of DKK-1 in patients with tumors.</p> <p>Results</p> <p>DKK-1 could only be detected in 12 human glioblastoma cell lines, not in a panel of other tumor and normal cell lines. The difference between glioma patients and healthy individuals was significant. Kendall's tau-c association analysis also revealed the increased DKK-1 protein expression in tumor tissues of higher pathologic classification. The levels of cerebral fluid DKK-1 protein were significantly higher in glioma patients than in healthy donors or in neuronal benign tumor patients, suggesting that the DKK-1 molecule in cerebral fluids can be applicable to detect the presence of glioma and be developed as a novel prognostic treatment.</p> <p>Conclusion</p> <p>The Wnt antagonist DKK-1 gene may have important roles in glioma tumorigenesis and act as a novel biomarker in human malignant glioblastoma.</p

Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia

Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK) for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes) who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2–5 mm; and mid-peripheral, 5-6 mm) preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET) and postoperative Q-value changes (ΔQ) was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69±4.2, 5.19±3.8, and 6.23±3.9 μm at the center, paracenter, and mid-periphery, resp., P<0.01). A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r=0.438, 0.580, and 0.504, resp., P<0.01). Conclusions. Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia

An adaptive acoustoelectric signal decoding algorithm based on Fourier fitting for brain function imaging

Acousticelectric brain imaging (ABI), which is based on the acoustoelectric (AE) effect, is a potential brain function imaging method for mapping brain electrical activity with high temporal and spatial resolution. To further enhance the quality of the decoded signal and the resolution of the ABI, the decoding accuracy of the AE signal is essential. An adaptive decoding algorithm based on Fourier fitting (aDAF) is suggested to increase the AE signal decoding precision. The envelope of the AE signal is first split into a number of harmonics by Fourier fitting in the suggested aDAF. The least square method is then utilized to adaptively select the greatest harmonic component. Several phantom experiments are implemented to assess the performance of the aDAF, including 1-source with various frequencies, multiple-source with various frequencies and amplitudes, and multiple-source with various distributions. Imaging resolution and decoded signal quality are quantitatively evaluated. According to the results of the decoding experiments, the decoded signal amplitude accuracy has risen by 11.39% when compared to the decoding algorithm with envelope (DAE). The correlation coefficient between the source signal and the decoded timing signal of aDAF is, on average, 34.76% better than it was for DAE. Finally, the results of the imaging experiment show that aDAF has superior imaging quality than DAE, with signal-to noise ratio (SNR) improved by 23.32% and spatial resolution increased by 50%. According to the experiments, the proposed aDAF increased AE signal decoding accuracy, which is vital for future research and applications related to ABI