Bi-Objective Community Detection (BOCD) in Networks using Genetic Algorithm

A lot of research effort has been put into community detection from all corners of academic interest such as physics, mathematics and computer science. In this paper I have proposed a Bi-Objective Genetic Algorithm for community detection which maximizes modularity and community score. Then the results obtained for both benchmark and real life data sets are compared with other algorithms using the modularity and MNI performance metrics. The results show that the BOCD algorithm is capable of successfully detecting community structure in both real life and synthetic datasets, as well as improving upon the performance of previous techniques.Comment: 11 pages, 3 Figures, 3 Tables. arXiv admin note: substantial text overlap with arXiv:0906.061

Genetic algorithm with a local search strategy for discovering communities in complex networks

In order to further improve the performance of current genetic algorithms aiming at discovering communities, a local search based genetic algorithm GALS is here proposed. The core of GALS is a local search based mutation technique. In order to overcome the drawbacks of traditional mutation methods, the paper develops the concept of marginal gene and then the local monotonicity of modularity function Q is deduced from each nodes local view. Based on these two elements, a new mutation method combined with a local search strategy is presented. GALS has been evaluated on both synthetic benchmarks and several real networks, and compared with some presently competing algorithms. Experimental results show that GALS is highly effective and efficient for discovering community.Thanks are due to the referees for helpful comments. This work was supported by National Natural Science Foundation of China (60873149, 60973088, 61133011, 61202308), Scholarship Award for Excellent Doctoral Student granted by Ministry of Education (450060454018), Program for New Century Excellent Talents in University (NCET-11-0204), and Jilin University Innovation Project (450060481084)

A Statistical Response Surface Study of the Tellurium Electrowinning Process

Statistical methods have been used to design an efficient experimental study of the tellurium electrowinning process where current density, electrolyte flow rate, temperature, free NaOH and initial Te concentration were varied simultaneously. Regression analysis was used to quantify the relative impact of each process operating parameter on the purity of electrowon Te. Empirical models show that significant interactions between process parameters allow for the minimization of Se and Pb co-deposition. Behaviour predicted by the models has been substantiated with voltametric and amperochronometric observations, confirming that statistical design of experiments effectively mapped the process responses

Strategies for Optimal Operation of the Tellurium Electrowinning Process

Empirical models predicting the purity of electrowon tellurium have been developed using data from 36 pilot-plant trials. Based on these models, a numerical optimization of the process was performed to identify conditions which minimize the total contamination in Pb and Se while reducing electrical consumption per kilogram of electrowon tellurium. Results indicate that product quality can be maintained and even improved while operating at the much higher electroplating production rates obtained at high current densities. Using these same process settings, the electrical consumption of the process can be reduced by up to 10 pct by operating at midrange temperatures of close to 50 °C. This is particularly attractive when waste heat is available at the plant to help preheat the electrolyte feed. When both Pb and Se are present as contaminants, the most energy-efficient strategy involves the use of a high current density, at a moderate temperature with high flow, for low concentrations of TeO2. If Pb is removed prior to the electrowinning process, the use of a low current density and low electrolyte feed concentration, while operating at a low temperature and moderate flow rates, provides the most significant reduction in Se codeposition

Molecular underpinnings of enzalutamide resistance

\u3cp\u3eProstate cancer (PCa) is among the most common adult malignancies, and the second leading cause of cancer-related death in men. As PCa is hormone dependent, blockade of the androgen receptor (AR) signaling is an effective therapeutic strategy for men with advanced metastatic disease. The discovery of enzalutamide, a compound that effectively blocks the AR axis and its clinical application has led to a significant improvement in survival time. However, the effect of enzalutamide is not permanent, and resistance to treatment ultimately leads to development of lethal disease, for which there currently is no cure. This review will focus on the molecular underpinnings of enzalutamide resistance, bridging the gap between the preclinical and clinical research on novel therapeutic strategies for combating this lethal stage of prostate cancer.\u3c/p\u3

PIAS1 is a determinant of poor survival and acts as a positive feedback regulator of AR signaling through enhanced AR stabilization in prostate cancer

Novel drugs like Abiraterone or Enzalutamide, which target androgen receptor (AR) signaling to improve androgen deprivation therapy (ADT), have been developed during the past years. However, the application of these drugs is limited because of occurrence of inherent or acquired therapy resistances during the treatment. Thus, identification of new molecular targets is urgently required to improve current therapeutic prostate cancer (PCa) treatment strategies. PIAS1 (protein inhibitor of activated STAT1 (signal transducer and activator of transcription-1)) is known to be an important cell cycle regulator and PIAS1-mediated SUMOylation is essential for DNA repair. In this context, elevated PIAS1 expression has already been associated with cancer initiation. Thus, in the present study, we addressed the question of whether PIAS1 targeting can be used as a basis for an improved PCa therapy in combination with anti-androgens. We show that PIAS1 significantly correlates with AR expression in PCa tissue and in cell lines and demonstrate that high PIAS1 levels predict shorter relapse-free survival. Our patient data are complemented by mechanistic and functional in vitro experiments that identify PIAS1 as an androgen-responsive gene and a crucial factor for AR signaling via prevention of AR degradation. Furthermore, PIAS1 knockdown is sufficient to decrease cell proliferation as well as cell viability. Strikingly, Abiraterone or Enzalutamide treatment in combination with PIAS1 depletion is even more effective than singledrug treatment in multiple PCa cell models, rendering PIAS1 as a promising target protein for a combined treatment approach to improve future PCa therapies

Tracking aging of bitumen and its saturate, aromatic, resin, and asphaltene fractions using high-field fourier transform ion cyclotron resonance mass spectrometry.

Bitumen is a widely used material, but its aging behavior is only understood at a macroscopic level as hardening and embrittlement over time. To assess bitumen aging behavior in the long run, the pressure aging vessel (PAV) testing procedure was developed. However, this procedure including high-pressure and high-temperature oxidation of the bitumen has not yet been understood on a molecular level. Here, a bitumen sample and its SARA fractions, i.e., saturates, aromatics, resins, and asphaltenes, were investigated in comparison with their aged samples to study changes of their chemical compositions. Negative electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry [ESI(-)] FT-ICR-MS was used to analyze samples. The effect of aging was characterized using the aromaticity equivalent (X-c, double bond equivalent (DBE), and van Krevelen plots. It was found that aging induces reduction of condensed aromatic compounds to alicyclic and open chain aliphatic compounds, while small aromatic compounds have been found to be relatively stable (or altered only slightly). Abundant alterations were detected in unaged bitumen. These changes can be assigned to resins and asphaltenes as compared to saturates and aromatics. Overall, alterations of highly condensed compounds were found to be related to aging. Furthermore, molecular series of CHO, CHNO, and CHOS fragments were more susceptible to oxygenation in bitumen, aromatics, resins, and asphaltenes as compared to saturates. In addition, molecular changes in asphaltenes showed a significant difference from classical assessment with high content of condensed aromatic compounds. Rather, the most abundant compounds in asphaltenes appear to be more saturated and apolar