Search

We introduce the vertex weight into the spatial prisoners’ dilemma game to investigate the evolution of cooperation. Each player on a square lattice is assigned to a particular weight followed by three types of distributions, which include the exponential, power-law and uniform ones. Compared with the traditional version, we find that the cooperation level is markedly enhanced under the weighted square lattice. For most ranges of b , the highest cooperation level can be obtained under the uniform distribution, while power-law distribution usually leads to the lowest cooperation. The distributed weight can produce a heavy heterogeneity among the individuals’ payoff, some cooperators with higher weight will foster the cooperative clusters and even spread the cooperation strategy around the clusters, while defectors have no such advantages. In addition, we still investigate the impact of the amplitude of undulation of weight distribution on the cooperation, and the non-monotonic behavior about b is observed. Finally, the influence of noise on the cooperation is also studied for these types of distribution of weight. To some extent, our weighted scheme can characterize the difference or diversity of players, which will be beneficial to further understand the role of individuals during the evolution of cooperation.

We investigate the evolution of cooperation with evolutionary public goods games based on finite populations, where four pure strategies: cooperators, defectors, punishers and loners who are unwilling to participate are considered. By adopting approximate best response dynamics, we show that the magnitude of rationality not only quantitatively explains the experiment results in [Nature (London) 425 (2003) 390], but also it will heavily influence the evolution of cooperation. Compared with previous results of infinite populations, which result in two equilibriums, we show that there merely exists a special equilibrium and the relevant high value of bounded rationality will sustain cooperation. In addition, we characterize that loner's payoff plays an active role in the maintenance of cooperation, which will only be warranted for the low and moderate values of loner's payoff. It thus indicates the effects of rationality and loner's payoff will influence the cooperation. Finally, we highlight the important result that the introduction of voluntary participation and punishment will facilitate cooperation greatly.

Nineteen populations of Clintonia udensis Trautv. & Mey. were examined to quantify genetic diversity and genetic structure by chloroplast DNA microsatellites (cpSSR). Significant cpSSR genetic diversity (PPB = 63.64%) was detected in this species. Tetraploid populations demonstrated approximately the same level of genetic diversity as the diploid ones. A significant differentiation, however, was found between tetraploids and diploids. Most of the sixteen chloroplast haplotypes were limited to a single population. The level of haplotype diversity was high (Hd = 0.915). AMOVA, PCA and Bayesian clustering analysis revealed that there were significant genetic differences among populations. Inter-population genetic distances among population sites correlated significantly with geographic distances. These results indicate that the mixed-mating – breeding system, limited gene flow, environmental stress, and historical factors may be the main factors causing geographical differentiation in the genetic structure of C. udensis.

The genetic diversity of 17 populations of Clintonia udensis Trautv. et Mey. was studied by using 15 intersimple sequence repeat primers. The results revealed a relatively high genetic diversity, with percentage of polymorphic \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\mathrm{bands}\,=98.8\% $ \end{document} , Shannon’s information \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepa...

Using inter-simple sequence repeat (ISSR) markers, studies were performed to characterize the population genetic diversity and structure of Reaumuria soongorica (Pall.) Maxim. in the oasis–desert ecotone in Fukang, Xinjiang. Eleven primers were screened to amplify DNA sequences from 132 individuals, which corresponded to seven subpopulations. Totally, 176 loci, all of them polymorphic, were detected, and the percentage of polymorphic bands (PPB) was 100%, indicating a relatively high genetic diversity within the R. soongorica population. According to the hierarchical analysis of molecular variances (AMOVA), the analysis of Shannon's diversity and Nei's analysis of gene diversity, the percentages of genetic variation among subpopulations were 15.87%, 16.28% and 14.58%, respectively, which meant that 83.72–85.42% of total genetic variation occurred within subpopulations. Besides, POPGENE analysis also revealed a relatively high gene flow (Nm = 2.9290) among subpopulations. Correlation analysis showed that there existed no significant correlation between the ISSR-based genetic diversity of the seven R. soongorica subpopulations and their ecological factors (mainly in soil) (P > 0.05). However, on the other hand, Mantel test revealed a significant correlation between inter-subpopulation genetic distances and geographic distances (r = 0.637, P < 0.01), indicating that geographic distance was among the important factors affecting the population genetic structure of R. soongorica. Meanwhile, a comparative analysis was performed between the present ISSR-based and the previously published RAPD-based results, and revealed obvious discrepancies, implying the different evolutionary patterns of the genomic regions sampled by ISSR and RAPD markers.

Most source number estimation methods based on the eigenvalues are decomposed by covariance matrix in MUSIC algorithm. To develop the source number estimation method which has lower signal to noise ratio and is suitable to both correlated and uncorrelated impinging signals, a new source number estimation method called beam eigenvalue method (BEM) is proposed in this paper. Through analyzing the space power spectrum and the correlation of the line array, the covariance matrix is constructed in a new way, which is decided by the line array shape when the signal frequency is given. Both of the theory analysis and the simulation results show that the BEM method can estimate the source number for correlated signals and can be more effective at lower signal to noise ratios than the normal source number estimation methods.

The risk of liver cancer in patients infected with the hepatitis B virus (HBV) and their clinical response to interferon alpha therapy vary based on the HBV genotype. The mechanisms underlying these differences in HBV pathogenesis remain unclear. In HepG2 cells transfected with a mutant HBV G2335A expression plasmid that does not transcribe the 2.2-kb doubly spliced RNA (2.2DS-RNA) expressed by wild-type HBV genotype A, the level of HBV pregenomic RNA (pgRNA) was higher than that in cells transfected with an HBV genotype A expression plasmid. By using cotransfection with HBV genotype D and 2.2DS-RNA expression plasmids, we found that a reduction of pgRNA was observed in the cells even in the presence of small amounts of the 2.2DS-RNA plasmid. Moreover, ectopic expression of 2.2DS-RNA in the HBV-producing cell line 1.3ES2 reduced the expression of pgRNA. Further analysis showed that exogenously transcribed 2.2DS-RNA inhibited a reconstituted transcription in vitro . In Huh7 cells ectopically expressing 2.2DS-RNA, RNA immunoprecipitation revealed that 2.2DS-RNA interacted with the TATA-binding protein (TBP) and that nucleotides 432 to 832 of 2.2DS-RNA were required for efficient TBP binding. Immunofluorescence experiments showed that 2.2DS-RNA colocalized with cytoplasmic TBP and the stress granule components, G3BP and poly(A)-binding protein 1 (PABP1), in Huh7 cells. In conclusion, our study reveals that 2.2DS-RNA acts as a repressor of HBV transcription through an interaction with TBP that induces stress granule formation. The expression of 2.2DS-RNA may be one of the viral factors involved in viral replication, which may underlie differences in clinical outcomes of liver disease and responses to interferon alpha therapy between patients infected with different HBV genotypes. IMPORTANCE Patients infected with certain genotypes of HBV have a lower risk of hepatocellular carcinoma and exhibit a more favorable response to antiviral therapy than patients infected with other HBV genotypes. Using cultured human hepatoma cells as a model of HBV infection, we found that the expression of 2.2DS-RNA caused a decrease in HBV replication. In cultured cells, the ectopic expression of 2.2DS-RNA obviously reduced the intracellular levels of HBV mRNAs. Our analysis of the 2.2DS-RNA-mediated suppression of viral RNA expression showed that 2.2DS-RNA inhibited transcription via binding to the TATA-binding protein and stress granule proteins. Our findings suggest that the 2.2DS-RNA acts as a suppressive noncoding RNA that modulates HBV replication, which may in turn influence the development of chronic hepatitis B.

This paper demonstrates a proof-of-concept approach for encapsulating the insulin and Fe3O4 nanoparticles into size-controllable alginate microcapsules utilizing the electrostatic droplets (ESD) technique. We have established that the combination of ESD and external gelation is quite effective in producing uniform-sized polymer particles. In addition, using the external gelation technique, the droplets containing a sodium-alginate were gelled in situ by immersion in Ca(2+), Ba(2+), or Cu(2+) ions for a few minutes. The results show that different-type divalent cations caused various surface features to appear on the microcapsules (e.g., cracking, orange peel, pitting, splitting, wrinkling, etc.). The particle size can be adjusted from a few micrometers to ca. 1,000 μm by electrostatic force. The microcapsules can be made magnetic by incorporating a super-paramagnetic nanomaterial (e.g., Fe3O4 nanoparticles) during the preparation. The composite magnetic microcapsules are potential candidates for a magnetic-responsive drug delivery system. In addition, our results show that the encapsulation and in vitro release of a model drug, insulin, can enhance the effect of the controlled release. These microcapsules are addressable by an external magnetic field and are capable of loading a model drug and releasing it in a highly differential drug release profile. We have demonstrated that the appropriate magnetic field intensity for different release patterns is predictable, which enables a better application of microcapsules as a smart drug carrier.

Hepatitis B virus (HBV) is the smallest DNA virus and the major cause of acute and chronic hepatitis. The 3.2 kb HBV viral genome generates four major species of unspliced viral transcript as well as several alternatively spliced RNAs. A 2.2 kb singly-spliced RNA is the most abundant spliced RNA and is widely expressed among all HBV genotypes. The expression of the singly-spliced RNA, as well as that of its encoded protein HBSP, is strongly associated with hepatopathology during HBV infection. Here, we report a novel inhibitory role of a p21.5 protein, which is encoded by a 2.2 kb singly-spliced RNA, in the modulation of HBV replication. We show that overexpression of the singly-spliced RNA is able to efficiently inhibit HBV replication. Furthermore, a mutation in the ATG start codon of the precore region completely abolishes the inhibitory effect of the singly-spliced RNA, indicating that a viral protein (p21.5) derived from the singly-spliced RNA is the mediator of the inhibition. Furthermore, p21.5 is able to form a homodimer that interacts with core dimers forming hybrid viral assembly components. Sucrose gradient fractionation revealed that co-expression of p21.5 resulted in a spread distribution pattern of core proteins ranging from low to high sucrose densities. When compared with p22, p21.5 is almost ten times more efficient at destabilizing HBV nucleocapsid assembly in Huh7 cells overexpressing either p21.5 or p22 protein. Moreover, in vivo expression of p21.5 protein by tail vein injection was found to decrease the amount of nucleocapsid in the livers of HBV-expressing BALB/c mice. In conclusion, our study reveals that the HBV 2.2 kb singly-spliced RNA encodes a 21.5 kDa viral protein that significantly interferes with the assembly of nucleocapsids during HBV nucleocapsid formation. These findings provide a possible strategy for elimination of HBV particles inside cells.

To investigate the effect of premolar extraction on Bolton index overall ratios.Bolton index overall ratios were measured in 198 randomly chosen dental casts of three types of Angle's malocclusions before and after 4 combinations of hypothetical premolar extractions. The data was processed using SPSS 17.0 software package.The overall ratios decreased in each class of Angle's malocclusion after all combinations of premolars extraction, and the decreases in combinations of 5/5 and 5/4 extractions were significantly greater than that of 4/4 and 4/5 combinations (P0.05), but no significant difference was found between different types of malocclusion (P0.05).When formulating a treatment plan involving premolar extractions, orthodontists should consider that the Bolton overall ratios may decrease.

Generalized eruptive histiocytosis (GEH) is a rare generalized non-X histiocytosis, first described in 1963 by Winklemann and Muller 1 . Since then more than 20 patients with GEH, mainly adults but also a few children, have been reported. We report a case of GEH in a middle-aged woman with spontaneous regression, in which the ultrastructural findings of apoptosis were observed.

Hydrogels composed of assembled colloids is a material class that is currently receiving much interest and shows great promise for use in biomedical applications. This emerging material class presents unique properties derived from the combination of nanosized domains in the form of colloidal particles with a continuous gel network and an interspersed liquid phase. Here we developed an amphiphilic chitosanbased, thermogelling, shear-reversible colloidal gel system for improved glaucoma treatment and addressed how preparation procedures and loading with the anti-glaucoma drug latanoprost and commonly used preservative benzalkonium chloride influenced the mechanical properties of and drug release from the colloidal gels. The results highlight that incorporated substances and preparation procedures have effects both on mechanical properties and drug release, but that the release of drug loaded in the colloidal carriers is mainly limited by transport out of the carriers, rather than by diffusion within the gel. The developed colloidal chitosan based gels hold outstanding biomedical potential, as confirmed by the ease of preparation and administration, low cytotoxicity in MTT assay, excellent biocompatibility and lowering of intraocular pressure for 40 days in a rabbit glaucoma model. The findings clearly justify further investigations towards clinical use in the treatment of glaucoma. Furthermore, the use of this shear-reversible colloidal gel could easily be extended to localized treatment of a number of critical conditions, from chronic disorders to cancer, potentially resulting in a number of new therapeutics with improved clinical performance. Refereed/Peer-reviewed

Microbubble particles have been extensively utilized as temporal templates for various biomedical applications. This study proposes a facile strategy to obtain microbubble-containing alginate particles (i.e., microbubbles inside alginate gel particles, called alginate microbubbles). The chemical reaction of sodium bicarbonate and hydrogen peroxide to produce gaseous carbon dioxide and oxygen was utilized to form microbubbles within alginate particles. Uniform alginate particles were obtained by a stable needle-based droplet formation process. Kinetic reaction of gas formation was monitored for 2% alginate particles. The gas formation increased with the concentrations of sodium bicarbonate (1–5 wt%) and hydrogen peroxide (0–36.5 wt%).

Background Gastric cancer is the second most common cause of death from cancer worldwide. Epidemiologic studies have examined the possible association between tomato products consumption and gastric cancer, but the relationship between tomato products and the risk of gastric cancer is controversial. We performed a meta-analysis of cohort and case–control studies to analyze this association. Methods We systematically searched MEDLINE and EMBASE and contacted authors to identify potential studies published from January 1966 to June 2012. We pooled the relative risks from individual studies using a random-effects model and performed heterogeneity and publication bias analyses. Results Twenty-one studies were eligible for our inclusion criteria, in a pooled analysis of all studies, consumption of large amounts of tomato products (in a comparison of the highest and lowest consumption groups) reduced the risk for gastric cancer (odds ratio, 0.73; 95% confidence interval, 0.60–0.90). The pooled OR of lycopene consumption and serum lycopene was 0.88 (95% CI = 0.67–1.16) and 0.79 (95% CI = 0.59–1.07), respectively. Conclusions Consumption of large amounts of tomato products is associated with a reduced risk of gastric cancer. However, because of potential confounding factors and exposure misclassification, further studies are required to establish these findings.

The Potential Geographic Analysis and Prediction of Acer tataricum subsp. Ginnala in China As a versatile and highly ornamental tree species, Acer tataricum subsp. ginnala is widely distributed in the contemporary ages (1950- 2000). Predicting its potential geographic distribution not only has great significance for its protection, but also provides theoretical support for forecasting other endangered species geographic distribution. In this study, MaxEnt model combined the GIS spatial analysis techniques were used to predict the potential geographic distribution of Acer tataricum subsp. ginnala from the 2030s to the 2070s. The reasons for the changes of geographic distribution were analyzed based on the future climate characteristics of China. The present results showed that Acer tataricum subsp. ginnala had different levels of distribution in China from 2030s to 2070s. The geographic distribution of Acer tataricum subsp. ginnala was mainly in the Northeast and North China. However, the mainly geographic distribution of Acer tataricum subsp. ginnala had changed because of the effects of temperature, precipitation and other climatic factors. In special, the distribution was moved to eastern parts of Shandong, parts of Hubei, the bordering parts of Jiangsu and Anhui provinces. Acer tataricum subsp. ginnala suitable areas in the country had shown a obviously reduction trend with the advance of years, And the future climate of China will be not conducive to the growth of Acer tataricum subsp. ginnala. The information got in this study will be usefull for the Acer tataricum subsp. ginnala protection in China...

In this paper, a method for evaluating elastic deflection of acetabulum is given, which is developed from the finite element analysis. The lubrication quantities are nondimensionalized. To eliminate the divergency often encountered at high pressure or low film thickness, the authors applied an efficient numerical solution composed of damping Newton method and direct method to solve the problem of elastohydrodynamic lubrication squeeze film. An applied method for evaluating the progressive variation of minimum film thickness in hip prostheses is presented which offers an optimum selection of the parameters of hip prostheses with no need for a complicated EHL calculation. Effects of joint size, elastic modulus and biological factors on lubrication nature are also taken into account. Presented at the 44th Annual Meeting in Atlanta, Georgia May 1–4, 1989

Along with the fast development of networking technologies, more and more group-oriented applications and services emerge in wireless networks. Nevertheless, due to the lack of security mechanism, a certain level of security must be achieved before the deployment of group communications. A number of group key management algorithms and architectures have been proposed, however, inefficiency is a bottle-neck of performance to these approaches. In this paper, we design a new group key management approach based on the currently proposed cluster-based group key management scheme, which can significantly improve the efficiency of group key management in wireless networks.

Acer grosseri, an economically and ecologically important maple species, is mainly distributed in North China. Based on Sequence Related Amplified Polymorphism (SRAP) markers and morphological characters, A. grosseri shows rich genetic diversity. Less genetic differentiation occurred between than within natural populations. All studied populations of A. grosseri formed two main clusters. There was no significant correlation between genetic and geographical distances among populations. The biological characters, mating system, gene exchange, and selective pressure from environmental heterogeneity are the main factors affecting the genetic population structure of A. grosseri., Knowledge of the genetic diversity and structure of tree species across their geographic ranges is essential for sustainable use and management of forest ecosystems. Acer grosseri Pax., an economically and ecologically important maple species, is mainly distributed in North China. In this study, the genetic diversity and population differentiation of 24 natural populations of this species were evaluated using sequence-related amplified polymorphism markers and morphological characters. The results show that highly significant differences occurred in 32 morphological traits. The coefficient of variation of 34 characters was 18.19 %. Principal component analysis indicated that 18 of 34 traits explained 60.20 % of the total variance. The phenotypic differentiation coefficient (VST) was 36.06 % for all morphological traits. The Shannon–Wiener index of 34 morphological characters was 6.09, while at the population level, it was 1.77. The percentage of polymorphic bands of all studied A. grosseri populations was 82.14 %. Nei's gene diversity (He) and Shannon's information index (I) were 0.35 and 0.50, respectively. Less genetic differentiation was detected among the natural populations (GST = 0.20, ΦST = 0.10). Twenty-four populations of A. grosseri formed two main clusters, which is consistent with morphological cluster analysis. Principal coordinates analysis and STRUCTURE analysis supported the UPGMA-cluster dendrogram. There was no significant correlation between genetic and geographical distances among populations. Both molecular and morphological data suggested that A. grosseri is rich in genetic diversity. The high level of genetic variation within populations could be affected by the biological characters, mating system and lifespan of A. grosseri, whereas the lower genetic diversity among populations could be caused by effective gene exchange, selective pressure from environmental heterogeneity and the species' geographical range.

In this paper the vertex weight is introduced into a snowdrift game to study the evolution of cooperative behavior. Compared with the snowdrift game in a traditional square lattice without any weight, cooperation can be promoted under three types of weight distribution: uniform, exponential and power-law distribution. For an intermediate cost-to-benefit ratio (r), in particular, the facilitation effect of cooperation is obvious. Moreover, the influence of undulation amplitude of weight distribution and the noise strength of strategy selection on cooperative behavior are also investigated. They exhibit a nontrivial phenomenon as a function of r. The results are helpful in analyzing and understanding the emergence of collective cooperation that is found widely in many natural and social systems.

In this study the effects of total saponins of Panax notoginseng (TSPN) and electroacupuncture (EA) were compared. Liquid paraffin was intraperitoneally injected (0.1 ml/mouse) to establish the animal model with inflammation. The mice were randomly divided into 4 groups with different treatments for 7 days: EA group, TSPN group (100 mg.kg intraperitoneal administration), Naloxone (Nx) plus TSPN group and EA plus TSPN group. The pain threshold was measured by a detector (EQ-9E) and the nitroblue tetrazolium test (NBT) for polymorphonuclear neutrophil (PMN) bacteriocidal activity and the alpha-naphthyl acetate esterase (ANAE) histochemical staining for detection of the focal pattern lymphocyte subpopulation and the toluidine blue histochemical staining for detection of degranulation rate peritoneal mast cells were performed. The results showed that in TSPN, EA and EA plus TSPN group the pain threshold was elevated significantly, the enumeration of NBT positive PMN and the ANAE-F lymphocyte subpopulation was enhanced. All the above effects could be partially inhibited by naloxone. Between TSPN group and Nx group the degranulation rate of peritoneal mast cells had no significant difference. Since the TSPN and EA have similar effects e.g. anti-inflammatory, analgesic and immunomodulatory action, it suggested that the TSPN might be somewhat agonist of the opioid like peptide receptor without addiction side reactions.

In this paper we will give a wear analysis and a life estimation of the XHP series Rock bit bearing system with the three-body abrasive wear equation developed by the authors. The result of the estimation indicates that it is possible to increase the service life by about eighty-six percent due to using the mechanical seal instead of the O-ring rubber seal.

Wear tests on the main bearings of 8.5 inch XHP 3 rock bits were performed, from which it is concluded that the way to improve the drilling effectiveness for the rock bits is to set drilling pressure and rotary speed properly, and to develop a new type of grease for rock bits which can bear a higher temperature than conventional grease. In addition, it is also shown that an inexpensive copper alloy can take the place of expensive Ag85Mn15 as an anti-wear material in the bearing, so that the production cost for the rock bits can be reduced.

We studied the evolution of cooperation in the prisoner’s dilemma game on a square lattice where the size of the interaction neighborhood is considered. Firstly, the effects of noise and the cost-to-benefit ratio on the maintenance of cooperation were investigated. The results indicate that the cooperation frequency depends on the noise and cost-to-benefit ratio: cooperation reaches a climax as noise increases, but it monotonously decreases and even vanishes with the ratio increasing. Furthermore, we investigated how the size of the interaction neighborhood affects the emergence of cooperation in detail. Our study demonstrates that cooperation is remarkably enhanced by an increase in the size of the interaction neighborhood. However, cooperation died out when the size of the interaction neighborhood became too large since the system was similar to the mean-field system. On this basis, a cluster-forming mechanism acting among cooperators was also explored, and it showed that the moderate range of the neighborhood size is beneficial for forming larger cooperative clusters. Finally, large-scale Monte Carlo simulations were carried out to visualize and interpret these phenomena explicitly.

Background MicroRNAs are a class of small non-coding RNAs that play an important role in various human tumor initiation and progression by regulating gene expression negatively. The aim of this study was to investigate the effect of miR-214 on cell proliferation, migration and invasion, as well as the functional connection between miR-214 and PTEN in gastric cancer. Methods miR-214 and PTEN expression was determined in gastric cancer and matched normal tissues, and human gastric cancer cell lines by quantitative real-time PCR. The roles of miR-214 in cell proliferation, migration and invasion were analyzed with anti-miR-214 transfected cells. In addition, the regulation of PTEN by miR-214 was evaluated by Western blotting and luciferase reporter assays. Results miR-214 was noted to be highly overexpressed in gastric cancer tissues and cell lines using qRT-PCR. The expression level of miR-214 is significantly associated with clinical progression and poor prognosis according to the analysis of the clinicopathologic data. We also found that the miR-214 levels are inversely correlated with PTEN in tumor tissues. And PTEN expression level is also associated with metastasis and invasion of gastric cancer. In addition, knockdown of miR-214 could significantly inhibit proliferation, migration and invasion of gastric cancer cells. Moreover, we demonstrate that PTEN is regulated negatively by miR-214 through a miR-214 binding site within the 3’-UTR of PTEN at the posttranscriptional level in gastric cancer cells. Conclusions These findings indicated that miR-214 regulated the proliferation, migration and invasion by targeting PTEN post-transcriptionally in gastric cancer. It may be a novel potential therapeutic agent for gastric cancer.