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Recently we identified the VRC01-like antibody DRVIA7(A7) from an HIV-1 B' subtype-infected individual (DRVI01) with broad neutralization activity, and almost all viruses from the individual were resistant to both VRC01 and A7 lineage antibodies. Here, we identified and characterized a panel of HIV-1 variants with resistance to VRC01 and A7 using site-directed mutagenesis and swapping amino acid fragments of gp120. Site-directed mutagenesis revealed that E279D/R282K/N460A/T464N of gp120 from DRVI01 produced VRC01-susceptible variants. Multiple mutations significantly increased the neutralization sensitivity to VRC01. Residues N464 located at the tip of the V5 loop were considered irrelevant to the neutralization of VRC01. For DRVI01-derived viruses, the single N464T change fully produced VRC01-resistant variants; conversely, a single T464N mutation generated VRC01-susceptible variants. Alanine scanning revealed that the N464 residue plays a vital role in binding with VRC01. Neutralizing assays against A7 lineage antibodies showed that DRVI01-derived viruses with multiple mutations could be neutralized by A7 lineage antibodies with different neutralizing breadths. Combining the changes in loops D and V5 produced variants that were totally sensitive variants to A7 lineage antibodies.

The identification of immunogens is crucial for human immunodeficiency virus type 1 (HIV-1) vaccine development. In our previous study, we demonstrated that HIV-1 envelope glycoprotein mutants based on the equine infectious anemia virus (EIAV)attenuated vaccine enhance immunogenicity, both for DNA immunization alone and as a combined DNA prime-vaccinia boost immunization. An RV144 clinical trial has demonstrated that an envelope protein boost may provide some degree of protection against HIV-1 infection. In order to explore the antibody immune responses to two HIV-1 envelope glycoprotein mutants based on the EIAV vaccine and wild-type envelope glycoprotein, mice and guinea pigs were immunized using a DNA prime-protein boost immunization strategy. The result showed, compared with wild-type gp140, gp140 2M (which contained 2 sites amino acid mutations) and gp140 5M (which contained 5 sites amino acid mutations) increased env-specific IgG and IgG3 binding antibody titers.Gp140 2M resulted in a slight improvement in the neutralizing antibody response against sensitive HIV-1 isolates compared with gp140. These findings have implications for HIV-1 vaccine development based on the HIV-1 CN54 envelope glycoprotein.

This paper presents modeling random drift by traditional time series method. In the modeling process, the real time average algorithm is proposed which can extract the constant drift of the MEMS gyroscope effectively to get random drift, and a modified recursive extended least squares (RELS) method for parameter estimation of the autoregressive moving average models (ARMA) is presented. The modified RELS algorithm consists of two-stage RLS algorithm which can on line be implemented, and has the fast convergence rate. After modeling, the corresponding Kalman filter is designed to make compensation for gyroscope random drift. The compensation results for the practical testing data of the MEMS gyroscope show that the model established can reflect the gyroscope random drift tendency with reasonable accuracy, and the gyroscope random drift can be effectively reduced by the filtering method presented.

Combined with the characteristics of multibeam bathymetric data and grey scale image, this paper proposed an algorithm of mutlibeam data registration based on false grey scale double-zone matching. By analyzing the original grey normalized matching algorithm, this paper improved the original algorithm by adding another matching zone, and then deals the mutlibeam data with the algorithm of false grey scale and the new method this paper proposed. Finally, verified the new algorithm both on theory and simulation, and evaluated the running speed of the algorithm. The simulation results showed that the algorithm did improve the speed of program, which meets the requirement of real-time in multibeam data matching better.

A compressed sensing (CS) recognition algorithm for sonar image based on non-negative matrix factorization and adjacency spectra (A-NMF) feature extraction is proposed in this paper. The feature vector of the tradition CS recognition algorithm is random Gaussian matrix, which causes the identification rate unstable. The stable feature vector which is extracted by the A-NMF feature extraction is used in this algorithm. The feature and structure of the original data can be expressed more accurately by this feature vector. Then the sonar images are classified under the compressed sensing framework. Experimental results show that the sonar image recognition is high, efficient and stable.

To optimize the immunization strategy against HIV-1, a DNA vaccine was combined with a recombinant vaccinia virus (rTV) vaccine and a protein vaccine. Immune responses against HIV-1 were detected in 30 female guinea pigs divided into six groups. Three groups of guinea pigs were primed with HIV-1 DNA vaccine three times, boosted with rTV at week 14, and then boosted with gp140 protein at intervals of 4, 8 or 12 weeks. Simultaneously, the other three groups of animals were primed with rTV vaccine once, and then boosted with gp140 after 4, 8 or 12 weeks. The HIV-1 specific binding antibody and neutralizing antibody, in addition to the relative affinity of these antibodies, were detected at different time points after the final administration of vaccine in each group. The DNA-rTV-gp140 immune regimen induced higher titers and affinity levels of HIV-1 gp120/gp140 antibodies and stronger V1V2-gp70 antibodies than the rTV-gp140 regimen. In the guinea pigs that underwent the DNA-rTV-gp140 regimen, the highest V1V2-gp70 antibody was induced in the 12-week-interval group. However, the avidity of antibodies was improved in the 4-week-interval group. Using the rTV-gp140 immunization strategy, guinea pigs boosted at 8 or 12 weeks after rTV priming elicited stronger humoral responses than those boosted at 4 weeks after priming. In conclusion, this study shows that the immunization strategy of HIV-1 DNA vaccine priming, followed by rTV and protein vaccine boosting, could strengthen the humoral response against HIV-1. Longer intervals were better to induce V1V2-gp70-specific antibodies, while shorter intervals were more beneficial to enhance the avidity of antibodies.

This paper aims at finding a solution to the problem aroused in complex system simulation, where a specific functional federation is coupled with other simulation systems. In other words, the communication information within the system may be received by other federates that participated in this united simulation. For the purpose of ensuring simulation system unitary character, a hierarchical federation architecture (HFA) is taken. Also considering the real situation, where federates in a complicated simulation system can be made simpler to an extent, a multi-resolution modeling (MRM) method is imported to implement the design of hierarchical level By utilizing the multiple resolution entity (MRE) modeling approach, MRE for federates are designed out. When different level training simulation is required, the appropriate MRE at corresponding layers can be called. The design method realizes the reuse feature of the simulation system and reduces simulation complexity and improves the validity of system Simulation Cost (SC). Taking submarine voyage training simulator (SVTS) for instance, a HFA for submarine is constructed in this paper, which approves the feasibility of studied approach.

In this paper, a robust digital watermarking method against shearing based on Haar orthogonal function system was introduced. The proposed method adopted the complete generalized orthogonal properties of Haar orthogonal function system to achieve the piece — based orthogonal transform on the image. The significant middle frequency coefficients in the transformation matrix are picked up, based on characteristics of the image visual system and the Haar orthogonal transform. The watermark is adoptively weighed to the middle frequency matrix. The method improves the validity of watermarking and shows excellent advantage against shearing attack. Experimental results show that the Haar orthogonal function system based watermark approach can provide an excellent protection under geometric attacks.

Three-dimension electronic chart display information system (ECDIS) is one of the new developing directions of electronic navigation chart, and its real-time quality is one of the important requirements. In this paper the algorithm of simplifying triangle surface using edge contraction, which can ensure the real-time display of objects in seabed environment, was put forward. The optimum contraction point was determined by the Lagrange matrix, so that the algorithm ensures that the contraction point locates on the original model, meanwhile meets the demands of least deviation. This algorithm can improve the plotting speed, and preserve the boundary character by using the fewer triangles to simulate objects.

A new algorithm is proposed for underwater vehicles multi-path planning. This algorithm is based on fitness sharing genetic algorithm, clustering and evolution of multiple populations, which can keep the diversity of the solution path, and decrease the operating time because of the independent evolution of each subpopulation. The multi-path planning algorithm is demonstrated by a number of two-dimensional path planning problems. The results show that the multi-path planning algorithm has the following characteristics: high searching capability, rapid convergence and high reliability.

Delaunay refinement is a technique for generating unstructured meshes of triangles for sensor network configuration engineering practice. A new method for solving Delaunay triangulation problem is proposed in this paper, which is called endpoint triangle’s circumcircle model (ETCM). As compared with the original fractional node refinement algorithms, the proposed algorithm can get well refinement stability with least time cost. Simulations are performed under five aspects including refinement stability, the number of additional nodes, time cost, mesh quality after intruding additional nodes, and the aspect ratio improved by single additional node. All experimental results show the advantages of the proposed algorithm as compared with the existing algorithms and confirm the algorithm analysis sufficiently.

A generation method of underwater terrain was brought forward in which the electric chart was used as the data source. Laplace interpolation was used in data interpolation of the water depth on the electronic chart to generate three-dimensional environment. The Roam-based LOD algorithm was improved and data storage structure of the Roam algorithm was redesigned, and a height factor was introduced when distinguishing resolution. The improved model LOD algorithm reduced the geometry complexity while ensuring the accuracy of the simplified model, and was very effective in computing and storage. The simulation results showed that the method was effective.

The α -stable distribution is a very flexible tool to model NonGaussian data. Stable distributions can allow for modeling infinite variance, skewness and heavy tails, but gives rise to inferential problems related to the estimation of the stable distribution parameters. In this work, we study the estimation of α -stable distributions using numerical Bayesian sampling techniques such as Markov chain Monte Carlo (MCMC), which can simultaneously estimate the four parameters of the model with good performance. Metropolis-Hastings algorithm is used to update the parameters of α -stable distribution at every iteration. The simulation results show that our estimation method is capable of estimating all the parameters accurately.

To investigated the effect of estrogen on global myocardial ischemia/reperfusion (I/R) injury in ovariectomized (Ovx) rats.Sprague-Dawley rats were randomly repartitioned into three groups including sham-operated(Sham), ovariectomized (Ovx), or ovariectomized and then given 17beta-estradiol (Ovx + E2). Hearts were excised, mounted on the Langendorff. After the initial stabilization period, all of the three group hearts were randomly divided into normal perfusion subgroup (Control) and I/R perfusion subgroups. Control, perfused for 60 min after stabilization. I/R perfusion subgroups divided into 10 min I + 30 min R, 20 min I + 30 min R, 30 min I + 0 min R, 30 min I + 5 min R, 30 min I + 15 min R and 30 min I + 30 min R. And then, every group hearts were isolated into the single cardiomyocyte. The cardiomyocytes basal contraction and isoproterenol(ISO) stimulation contraction were measured. The viability and yield of cardiomyocytes were counted. LDH and CK concentrations in coronary effluent were assayed with assay kit.The viability and yield of cardiomyocytes were significantly decreased in the conditions of 30 min ischemia followed by different times of reperfusion. The releases of LDH and CK in coronary effluent were significantly increased in the conditions of 30 min ischemia followed by different times of reperfusion. Except the 10 min and 20 min ischemia, the releases of LDH and CK were significantly increased in Ovx during I/R. Ovx + E2 could abate the heart injury through decreasing the releases of LDH and CK. Besides the control and the 10 min I + 30 min R groups, the myocardial basal and ISO stimulation contraction were higher from Ovx than Sham, and the effect was reversed by Ovx + Ez.The results indicate estrogen plays a cardioprotective role in global myocardial ischemia/reperfusion injury in ovariectomized (Ovx) rats.

The relative position between magnetic target and the device installed on underwater vehicle, is determined by measuring magnetic field magnitude and gradients of target on condition that geomagnetic field anomaly can be viewed as a magnetic dipole target. The relationship between the errors of magnetic field magnitude, gradients and the variation of platform attitude and its effect on localization precision of vehicle are studied theoretically and simulated numerically. The results show that the effect of vehicle attitude variation on magnetic field magnitude and gradients are small and obvious, respectively. However, the distance between magnetic target and the device is not nearly varied. A new method calculating vehicle attitude variation by magnetic moments of the target is studied theoretically and simulated numerically. The results show the calculating precision for the novel method is higher in principle, which can be used to detect the attitude of underwater vehicle.

The accumulation of Enteromorpha prolifera in huge amount in the Yellow sea in June, 2008 draws the attention from all over the world. It is an urgent requirement to monitor the wide range of Enteromorpha prolifera distribution by remote sensing. As to the Enteromorpha prolifera floating on the sea surface, effective monitoring by optical remote sensing has been basically achieved. As far as the underwater suspended Enteromorpha prolifera is concerned, the present paper carried out the radiative transfer simulation research on the above water spectral response, its variation with the suspending depth, the water turbidity and environmental conditions. It was found that with the increase in Enteromorpha prolifera suspending depth and water turbidity as well as the decrease in the thickness of Enteromorpha prolifera, the Enteromorpha prolifera information contained in the surface spectra would decrease. The influence of environmental factors such as water-gas interface roughness, cloud cover extent and sun zenith angle on the underwater suspended Enteromorpha prolifera spectra can be ignored. The maximum Enteromorpha prolifera depth that can cause surface spectrum changes is about 30 m in clean water and about 1 m in turbidity water.

Vehicle mobile movement can cause dynamic error of the Platform inertial navigation system (PINS) which is widely used in underwater vehicle. Taking PINS as the research object, the space motion mathematical models of underwater vehicle are analyzed and established by reasonable simply. Through coordinate transformation relationship research of the fixed coordinate system, the moving coordinate system and the local present coordinate system, the underwater vehicle actual space motion can be embedded in the PINS. It can provide PINS the input information which contain the east and north acceleration real-timely by controlling vehicle motion and get the navigation which is more close to underwater actual motion. Thus the whole PHINS simulator based on underwater vehicle motion model are realized. Computer simulation result show the embeddedmethod is right and the PINS simulator can realized the actual simulation well. This is a new good method for the movement adaptability examination of INS.

Women with functional ovaries have a lower cardiovascular risk than men and postmenopausal women. However, oestrogen replacement therapy remains controversial. This study examined the effect of ovarian hormone deficiency and oestrogen replacement on ventricular myocyte contractile function and expression of beta-adrenoceptors (beta-ARs). Female Sprague-Dawley rats were subjected to bilateral ovariectomy (OVX) or sham operation (Sham). A subgroup of OVX rats received oestrogen (E2) replacement (40 microg kg(-1) day(-1)) for 4 weeks. Cardiomyocyte shortening was evaluated in basal conditions and in the presence of isoprenaline (ISO). The expression of beta-ARs was assessed by Western blotting. The presence of lactate dehydrogenase (LDH) activity in the coronary effluent was determined. Ovariectomy promoted body weight gain associated with reduced serum E2 and uterine weight, all of which were abolished by treatment with E2. Ovariectomy increased the amplitude of both basal and ISO-stimulated contractions, increased LDH release, upregulated beta1-AR expression and downregulated beta2-AR expression, all of which were restored by treatment with E2. A beta1-AR antagonist, CGP20712A, but not a beta2-AR antagonist, ICI118,551, significantly decreased the amplitude of ventricular myocyte shortening. Oestrogen decreased cardiomyocyte contraction and the expression of beta1-AR, and increased expression of beta2-AR, and all these effects were abolished by the E2 receptor antagonist, ICI182,780. These data suggest that oestrogen plays a cardioprotective role in female rat hearts subjected to ischaemia-reperfusion injury, and the effects of oestrogen are associated with decreased cardiomyocyte contraction and expression of beta1-AR, and increased expression of beta2-AR.

Fruit of elm has been a popular food in Chinese county for many years. With the rapid development of food nutrition and food safety, more and more people begin to pay attention to its content of trace elements and heavy metals. The wild fruit of elm was studied by ICP-MS/ICP-AES to detect the 22 trace elements. The results showed that the fruit of elm contained many trace elements which are necessary to human health: The concentrations of Mg, Ca, Mn, Fe, Cu, Zn, Sr and Rb were 224.57, 269.73, 9.23, 64.93, 1.68, 4.79, 7.68 and 2.21 microg x g(-1) (FW) respectively; while those of Li, B, V, Co, Ni, Se, Br, Mo and Sn were 318.43, 518.83, 265.52, 108.50, 411.21, 34.51, 51.72, 109.90 and 31.51 ng x g(-1) (FW), respectively. Except the wholesome trace elements, contents of heavy metals (As, Cr, Pb and Cd) are also the important standard to identify the quality of food, and the results showed that the concentrations of heavy metals, Pb, Cd, As, Hg and Cr were respectively 557.87, 8.81, 345.55, 0.78 and 347.97 ng x g(-1) (FW) in fruit of elm, which meet the national hygiene standards.

To express the Gag protein of HIV-1 strain CN54 in Pichia pastoris (P.pastoris), optimize fermentation parameters and purify Gag antigen.The Gag gene was subcloned into downstream of aox1 promoter of Pichia expression vector pPS1.0, an integrative vector which possesses an identical 5' untranslated region as the natural aox1 gene and employs both in vitro construction and in vivo selection for multi-copy integrants. The recombinant vector was introduced into P.pastoris strain GS115 by electroporation and selected with G418 for Gag gene integration. Super G418 resistant clones were selected and screened for Gag expression. The engineered P.pastoris was cultured to high cell density (300 A600 Units/ml) in a 5L fermentor. Through methanol induction, the expression level of Gag reached 120 mg/L. Intracellularly expressed Gag was released by high-pressure homogenization and purified through Sepharose FF and DEAE Sepharose FF column chromatography, the purity of Gag reached up to 90%.Western-blotting suggested that purified Gag expressed in P.pastoris could react specifically with serum from HIV infected individual.Gag antigen expressed in P.pastoris has provided a good basis for the development of a new generation of HIV vaccine candidates against some Chinese prevalent strains.

The aim of this study is to obtain Saccharomyces cerevisiae engineering strain with high gamma-linolenic acid (GLA, gamma-C18:3), which is a nutritionally important fatty acid that plays a vital role in biological structure and cell functions. As the first step,we cloned gamma6-desaturase gene from fungus mucor circinelloides by RT-PCR; delta6-desaturase is responsible for the transformation of linoleic acid into GLA. The PCR product was subcloned into yeast expression vector pYES2 to generate a recombinant plasmid pYES412. Transformation of S. cerevisiae strain INVSc1 was done by the lithium acetate method and the recombinant yeast cells were selected on a uracil-deficient medium. On appropriate medium and temperature,linoleic acid was provided as a substrate to yeast cultures,and the level of gamma-linolenic acid reached 50.07%. So far,the result we obtained is the best in terms of the level of expression of delta6-desaturase gene in Saccharomyces cerevisiae.