Viral infection of tobacco plants improves performance of Bemisia tabaci but more so for an invasive than for an indigenous biotype of the whitefly

The ecological effects of plant-virus-vector interactions on invasion of alien plant viral vectors have been rarely investigated. We examined the transmission of Tomato yellow leaf curl China virus (TYLCCNV) by the invasive Q biotype and the indigenous ZHJ2 biotype of the whitefly Bemisia tabaci, a plant viral vector, as well as the influence of TYLCCNV-infection of plants on the performance of the two whitefly biotypes. Both whitefly biotypes were able to acquire viruses from infected plants and retained t...     

改进的遗传算法在入侵检测中的应用

随着系统漏洞不断被发现,攻击不断发生,对入侵检测的效率提出了更高的要求。本文先采用改进的遗传算法,把关联规则应用在遗传算法的适应度函数的设计上,最后通过试验比较,得出该算法具有更好的检测效果。     

《雷雨》的戏剧意象及其象征性

曹禺对雷雨意象似乎情有独钟,雷雨意象在其作品中频繁出现,在其代表作《雷雨》中更是高度集中。曹禺利用这一独特意象,多方面展示了雷雨到来之前的特有氛围;从光与声两方面描绘雷雨的强大声势,强化雷雨意象的特征;随着剧情的逐渐推进,写出了雷雨由远及近、由弱到强、渐行渐进的到来过程。追根溯源,《雷雨》中雷雨意象出现的文化根源其实是一种集体无意识——雷雨崇拜,更具体地说是雷崇拜。受古代一系列关于雷雨击杀罪恶之人经验的影响,曹禺在利用雷雨意象烘托人物、渲染气氛的同时,更重要的表达了剧中人物罪的意识、灵魂的审视和救赎意识。     

Improved response surface method for anti-slide reliability analysis of gravity dam based on weighted regression

The aim of this study was to design and construct an improved response surface method （RSM） based on weighted regression for the anti-slide reliability analysis of concrete gravity dam. The limitation and lacuna of the traditional RSM were briefly analyzed. Firstly, based on small experimental points, research was devoted to an improved RSM with singular value decomposition techniques. Then, the method was used on the basis of weighted regression and deviation coefficient correction to reduce iteration times and experimental points and improve the calculation method of checking point. Finally, a test example was given to verify this method. Compared with other conventional algorithms, this method has some strong advantages： this algorithm not only saves the arithmetic operations but also greatly enhances the calculation efficiency and the storage efficiency.     

Effect of the geometric shapes of specimens on impact tensile tests

The geometric shapes of specimens are important in impact tensile tests because geometric shapes determine the stress states of the specimens, and precise geometric shapes can obtain proper material properties without non-material factors. The aim of this study was to investigate the 1D form of the stress by changing the length-to-diameter （L/D） ratios of specimens. The experiments were carried out on a split Hopkinson tensile bar （SHTB）-rotating disk indirect bar-bar tensile impact apparatus. The L/D ratios of the LY12CZ specimens used in the test ranged from 1 to 5. Results show that the specimens can be used to obtain exact parameters of materials under the proposed conditions when the L/D ratio is greater than 2. This is because the longer length will reduce or eliminate the effects of the interfaces.     

Quantitative evaluation of air pollution in transport strategic environmental assessment: a case study based on uncertainty analysis and graphic information system technology

Although the impact of road transport on urban air quality has achieved a high profile in China, still greater attention is required as it has not yet been considered fully even in relation to the road network linking cities and urban areas. Strategic environmental assessment （SEA） is a systematic and comprehensive process for evaluating the environmental impacts of a policy, plan or program in publicly accountable decision-making. Air pollution has been recognized as a significant issue in most transport SEA practices. The Strategic Environmental Assessment of the Hubei Road Network Plan （2002-2020） （HRNP） was introduced as one of the World Bank＇s pilot SEA projects. An effective framework was developed to investigate the functional relationship between the road network and its potential air pollutant emissions. In this study, two indicators were identified： emission intensity/ inventory of pollutants and the spatial distribution of the most polluted areas. Because strategic actions are inherently nebulous and data quality is often disappointing, three alternative scenarios were employed to address uncertainties and data/scale issues. Calculations were made using emission models and results were analyzed with the help of statistical tools and the geographic information system （GIS）. The results from the project implementation and the feedback from the World Bank have both shown that the proposed framework is effective in the transport SEA process.     

Heat shock protein 90 protects rat mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis via the PI3K/Akt and ERK1/2 pathways

Mesenchymal stem cell(MSC)transplantation has shown a therapeutic potential to repair the ischemic and infracted myocardium,but the effects are limited by the apoptosis and loss of donor cells in host cardiac microenvironment.The aim of this study is to explore the cytoprotection of heat shock protein 90(Hsp90)against hypoxia and serum deprivation-induced apoptosis and the possible mechanisms in rat MSCs.Cell viability was determined by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Apoptosis was assessed by Hoechst 33258nuclear staining and flow cytometric analysis with annexin V/PI staining.The gene expression of Toll-like receptor-4(TLR-4)and V-erb-b2 erythroblastic leukemia viral oncogene homolog 2(ErbB2)was detected by real-time polymerase chain reaction(PCR).The protein levels of cleaved caspase-3,Bcl-2,Bcl-xL,Bax,total-ERK,phospho-ERK,totaI-Akt,phospho-Akt,and Hsp90 were detected by Western blot.The production of nitric oxide was measured by spectrophotometric assay.Hsp90 improves MSC viability and protects MSCs against apoptosis induced by serum deprivation and hypoxia.The protective role of Hsp90 not only elevates Bcl-2/Bax and Bcl-xL/Bax expression and attenuates cleaved caspase-3 expression via down-regulating membrane TLR-4 and ErbB2 receptors and then activating their downstream PI3K/Akt and ERK1/2 pathways,but also enhances the paracrine effect of MSCs.These findings demonstrated a novel and effective treatment strategy against MSC apoptosis in cell transplantation.     

Effect of increased intra-abdominal pressure and decompressive laparotomy on aerated lung volume distribution

Increased intra-abdominal pressure(IAP) is common in intensive care patients,affecting aerated lung volume distribution.The current study deals with the effect of increased IAP and decompressive laparotomy on aerated lung volume distribution.The serial whole-lung computed tomography scans of 16 patients with increased IAP were retrospectively analyzed between July 2006 and July 2008 and compared to controls.The IAP increased from(12.1±2.3) mmHg on admission to(25.2±3.6) mmHg(P<0.01) before decompressive lap...     

Metachronous contralateral testicular and bilateral adrenal metastasis of chromophobe renal cell carcinoma: a case report and review of the literature

Chromophobe renal cell carcinoma(ChRCC) metastatic to the testis has not,to the best of our knowledge,been reported in the literature.Nor have there been reports of delayed bilateral adrenal metastasis of ChRCC.Here we report a case of metachronous contralateral testicular and bilateral adrenal metastasis of ChRCC in a 70-year-old man who underwent right radical nephrectomy for RCC six years ago.He was admitted to the hospital because of left intrascrotal enlargement of two-month duration.Ultrasonography re...     

Arachnoid cell involvement in the mechanism of coagulation-initiated inflammation in the subarachnoid space after subarachnoid hemorrhage

Objective: To assess if arachnoid cells have the capability to present antigen and activate T-lymphocytes after stimulation by bloody cerebrospinal fluid (CSF), and to illuminate the mechanism of coagulation-initiated inflammation in the subarachnoid space after subarachnoid hemorrhage (SAH). Methods: Arachnoid cells were cultured, characterized, and examined by immunofluorescence for the basal expression of human leukocyte antigen-DR (HLA-DR). Expression of HLA-DR, after co-culturing arachnoid cells in vitro with bloody CSF, was investigated by immunofluorescence and flow cytometry (FCM). The variation of arachnoid cells' ultrastructure was observed by transmission electron microscope (TEM). Arachnoid cells were co-cultured with peripheral blood mononuclear cells (PBMCs). The content of soluble interleukin-2 receptor (sIL-2r) in culture medium was detected by enzyme-linked immunosorbent assay (ELISA). Results: (1) Arachnoid cells were successfully cultured for many passages. The immunofluorescent staining was positive for HLA-DR in over 95% of the human arachnoid cells. The punctate HLA-DR was distributed in cytoplasm and not in the karyon. (2) After co-culturing arachnoid cells in vitro with bloody CSF, numerous particles with strong fluorescence appeared in the cytoplasm on Day 6. On Day 8, the quantity of particles and fluorescent intensity were maximal. FCM showed that the percentage of HLA-DR expressing cells was (2.5±0.4)% at the first 5 d, increasing to (60.8±3.6)% on Day 7. (3) After co-culturing arachnoid cells in vitro with bloody CSF, many lysosome and secondary lysosome particles were present in the cytoplasm. Hyperplasia of rough endoplasmic reticulum and enlarged cysts were observed, with numerous phagocytizing vesicles also observed at the edge of the arachnoid cells. (4) Arachnoid cells stimulated by bloody CSF were co-cultured in vitro with PBMCs. The content of sIL-2r in the culture medium, having been maintained at around 1.30 ng/ml during the first 3 d, had increased by Day 4. The content of sIL-2r peaked 7.53 ng/ml on Day 7 and then reduced gradually. Conclusions: (1) Basic HLA-DR expression is present in arachnoid cells. (2) After stimulation by bloody CSF, arachnoid cells have the potential to serve as antigen presenting cells (APCs) and the ability to activate T-lymphocytes, indicating that arachnoid cells are involved in the mechanism of coagulation-initiated inflammation in the subarachnoid space after SAH.