427 research outputs found

    Protein sequences classification based on weighting scheme

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    We present a new technique to recognize remote protein homologies that rely on combining probabilistic modeling and supervised learning in high-dimensional feature spaces. The main novelty of our technique is the method of constructing feature vectors using Hidden Markov Model and the combination of this representation with a classifier capable of learning in very sparse high-dimensional spaces. Each feature vector records the sensitivity of each protein domain to a previously learned set of sub-sequences (strings). Unlike other previous methods, our method takes in consideration the conserved and non-conserved regions. The system subsequently utilizes Support Vector Machines (SVM) classifiers to learn the boundaries between structural protein classes. Experiments show that this method, which we call the String Weighting Scheme-SVM (SWS-SVM) method, significantly improves on previous methods for the classification of protein domains based on remote homologies. Our method is then compared to five existing homology detection methods

    Establishment and characterization of two human breast carcinoma cell lines by spontaneous immortalization: Discordance between Estrogen, Progesterone and HER2/neu receptors of breast carcinoma tissues with derived cell lines

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    Background: Breast cancer is one of the most common cancers among women throughout the world. Therefore, established cell lines are widely used as in vitro experimental models in cancer research.Methods: Two continuous human breast cell lines, designated MBC1 and MBC2, were successfully established and characterized from invasive ductal breast carcinoma tissues of Malaysian patients. MBC1 and MBC2 have been characterized in terms of morphology analysis, population doubling time, clonogenic formation, wound healing assay, invasion assay, cell cycle, DNA profiling, fluorescence immunocytochemistry, Western blotting and karyotyping.Results: MBC1 and MBC2 exhibited adherent monolayer epithelial morphology at a passage number of 150. Receptor status of MBC1 and MBC2 show (ER+, PR+, HER2+) and (ER+, PR-, HER2+), respectively. These results are in discordance with histopathological studies of the tumoral tissues, which were triple negative and (ER-, PR-, HER2+) for MBC1 and MBC2, respectively. Both cell lines were capable of growing in soft agar culture, which suggests their metastatic potential. The MBC1 and MBC2 metaphase spreads showed an abnormal karyotype, including hyperdiploidy and complex rearrangements with modes of 52-58 chromosomes per cell.Conclusions: Loss or gain in secondary properties, deregulation and specific genetic changes possibly conferred receptor changes during the culturing of tumoral cells. Thus, we hypothesize that, among heterogenous tumoral cells, only a small minority of ER+/PR+/HER2+ and ER+/PR-/HER2+ cells with lower energy metabolism might survive and adjust easily to in vitro conditions. These cell lines will pave the way for new perspectives in genetic and biological investigations, drug resistance and chemotherapy studies, and would serve as prototype models in Malaysian breast carcinogenesis investigations. © 2012 Kamalidehghan et al.; licensee BioMed Central Ltd

    Larson Miller Parameter for the Prediction of the Creep Life of Unweld and Welded P91 Steel

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    For structural components that operate at elevated temperatures, martensitic P91 steel is preferable. It is widely used in steam generators in the fossil-fired thermal and nuclear power generation sectors due to its creep endurance and corrosion resistance. Several creep laws, such as Monkman-Grant, Theta project, Wilshire and Sinh model, Omega technique, and the Larson Miller Parameter (LMP),   have been developed over time to predict and failure of materials susceptible to the creep phenomenon. However, only the Omega Law and Larson-Miller Parameter are the only two methods approved in API 579-1. In this work, the creep test for welded and unwelded P91were conducted at temperatures of 600°C under stresses of 165, 175 MPa, and 190 MPa. In comparison to the welded specimens, the unwelded specimens displayed a continuously more substantial development of creep strain with time, resulting in a higher steady-state creep rate and a shorter rupture life. The increased magnitude of creep-rupture data has been observed to impact the dependability of creep life. Because of more significant changes in service temperature and stress conditions, the dependability of P91 steel has deteriorated, as well as an increase in creep life. The rupture life has been predicted using the LMP method, which utilizes the constant C parameter. At the same stress, the predicted creep life for weld material shows a higher value than that of the parent material, which is consistent with the experimental result

    History of Islamic political movements in Turkey

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    This article investigates the history of Islamic political movements in Turkey. The time period of the article cover the time after the establishment of the Republic of Turkey in 1923 to the year 2000. It is argued in the article that Islamic movements were largely suppressed in the period between 1923-1945 when the country was ruled with a single party regime led by the Republican Peoples Party. With the introduction of multi-party political system in 1945, political Islam found the opportunity for political activism in the body of Democrat Party. But the political Islam found a more organized opportunity with the establishment of National Order Party in 1970 and National Salvation Party in 1971 by Necmettin Erbakan. Based on a programme of National View, the Turkish political Islam was known for its aim to support material development with a parallel moral and spiritual development with a reaction to the west in interstate relations. Turkish political Islam expressed itself with Welfare Party in 1983 to function until 1998 with some clear changes in its programme particularly in its agreement with contemporary political institutions and later support for Turkey’s integration with the west. Turkish political Islam experienced its first great electoral success during the WP period. However, the WP is closed down in 1998 by the Constitutional Court due to allegations about anti-secularism and driven to a process of breakdown. © 2015, Canadian Center of Science and Education. All rights reserved

    Larson Miller Parameter for the Prediction of the Creep Life of Unweld and Welded P91 Steel

    Get PDF
    For structural components that operate at elevated temperatures, martensitic P91 steel is preferable. It is widely used in steam generators in the fossil-fired thermal and nuclear power generation sectors due to its creep endurance and corrosion resistance. Several creep laws, such as Monkman-Grant, Theta project, Wilshire and Sinh model, Omega technique, and the Larson Miller Parameter (LMP),   have been developed over time to predict and failure of materials susceptible to the creep phenomenon. However, only the Omega Law and Larson-Miller Parameter are the only two methods approved in API 579-1. In this work, the creep test for welded and unwelded P91were conducted at temperatures of 600°C under stresses of 165, 175 MPa, and 190 MPa. In comparison to the welded specimens, the unwelded specimens displayed a continuously more substantial development of creep strain with time, resulting in a higher steady-state creep rate and a shorter rupture life. The increased magnitude of creep-rupture data has been observed to impact the dependability of creep life. Because of more significant changes in service temperature and stress conditions, the dependability of P91 steel has deteriorated, as well as an increase in creep life. The rupture life has been predicted using the LMP method, which utilizes the constant C parameter. At the same stress, the predicted creep life for weld material shows a higher value than that of the parent material, which is consistent with the experimental result

    Factors affecting the accumulation of 9-methoxycanthin-6-one in callus cultures of Eurycoma longifolia.

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    A study was conducted to improve 9-methoxycanthin-6-one productivity (potential anti-tumour compound) from callus cultures of Eurycoma longifolia (Tongkat Ali). Several factors affecting 9-methoxycanthin-6-one production in callus cultures such as different medium compositions and physical factors were investigated and analyzed. Results show that a higher production of 9-methoxycanthin-6-one (3.84 mg'g-1 DW (Dry Weight)) is obtained from callus cultured in ¼ MS basal media. At fructose of 2% (w/v), the production of 9-methoxycanthin-6-one (4.59 mg'g-1 DW) is promoted to gain the highest yield, compared to other carbon sources tested. The addition of 2.0-mg'L-1 dicamba also increases 9-methoxycanthin-6-one production (12.3 mg'g-1 DW). Higher production of 9-methoxycanthin-6-one was obtained at pH 5.5 (1.53 mg'g-1 DW). Production of 9-methoxycanthin-6-one (2.34 mg'g-1 DW) in callus cultures is also increased when the medium is added with 1×10-1 μM phenylalanine. This study suggests that the successful production of 9-methoxycanthin-6-one in vitro cultures has a potential in large-scale production using bioreactor technology

    Potential and Electric Field Characteristics of Broken Porcelain Insulator

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    Overhead line insulators can be damaged for various reasons during their service life. Porcelain or glass insulators once damaged can affect the reliability of power system networks. This paper presents the study of voltage and electric characteristics along the surface of a broken porcelain insulator located in a string of 10 unit insulators. Three models of broken porcelain insulators were being proposed and the analysis results on voltage and electric characteristics were individually collected. The broken porcelain insulator with the most significant effect were then being investigated in the strings of 10 unit insulators. The finite element software of Quickfield was used to analyze the voltage and electric characteristics. Form the presented results, it is proven that the single porcelain insulators with broken shed at the nearest to the electrode terminal gave the most significant effect of voltage and electric field distribution pattern along the creepage distance. However, when this type of broken insulator was included in a string of 10 unit insulators, maximum average value of voltage achieved once the broken insulator was located at the HV terminal. Meanwhile, the highest electric field strength was recorded when the broken insulator was located in the middle of the string

    Optical properties of diamond like carbon films prepared by DC-PECVD

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    Diamond-like carbon (DLC) thin films were deposited at different substrate temperatures using methane and hydrogen gas in DC-PECVD at 2x10-1Torr. From the light transmission using UV-VIS spectroscopy it was found that the optical transition had changed from allowed indirect transition to allowed direct transition as the substrate temperature increased. The Optical gap increased with temperature, highest of 3.034 eV was observed at 573 K, beyond which it dropped. Colour of the film changed from light brownish to a colourless transparent film in the higher temperature. The Urbach energy decreased from 1.25 eV to 0.75 eV with increasing substrate temperature till 573 K and a slight increase after it. This trend is attributed to change in sp3/sp2 ratio or change in structure. The cluster size decreases with temperature, resulting in larger band gap and the structure more ordered. Similar pattern is also witnessed in the emission spectrum of the photoluminescence

    Potential field methods and their inherent approaches for path planning

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    Path Planning is one of the vital aspects in autonomous system. In path planning, safety is important issue that should be taken into account in order to ensure a robot reaches at the target location without collision with surrounding obstacles. Moreover, there are important aspects that need to be addressed in path planning; computational time, optimal path and completeness. One of the popular methods for path planning is Potential field. Potential filed method is capable to overcome unknown scenario, taking into account the realities of the current environment of the robot motion. Two type of forces involved in potential field method; attractive force generated by goals and repulsive force generated by obstacles. However, this method has a major drawback due to local minima problem. This paper reviews the traditional artificial potential field theory that has been modified with variety of algorithms based on potential field method that have been implemented to upgrade the potential function performance in obstacle avoidance and local minima problem

    Predictability of complex modulus using rheological models

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    The objective of this study was to investigate the advantages and disadvantages of several linear visco-elastic rheological models applied to the unmodified and polymer-modified bitumens. It was found that all the models studied can be used to predict the linear visco-elastic of unmodified bitumens, aged and unaged samples reasonably well. In contrary, this condition was not really applicable on polymer-modified bitumens particularly for the unaged samples. The measured and predicted data was assessed using the discrepancy ratio (Ri), Mean Normalized Error (MNE) and Average Geometric Deviation (AGD) goodness of fitting statistical analysis. From the study, the modified Sigmoidal and Generalized Logistic Sigmoidal models were observed to be the most outstanding models, followed by the Christensen Anderson and Marasteanu (CAM), Christensen and Anderson (CA) and 2S2P1D (2 springs, 2 parabolic elements and 1 spring) models. The presence of semi-crystalline waves and elastomeric structures in the mixtures render the breakdown of time temperature equivalency principle
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