81 research outputs found

    Improved support vector machine classification for imbalanced medical datasets by novel hybrid sampling combining modified mega-trend-diffusion and bagging extreme learning machine model

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    To handle imbalanced datasets in machine learning or deep learning models, some studies suggest sampling techniques to generate virtual examples of minority classes to improve the models' prediction accuracy. However, for kernel-based support vector machines (SVM), some sampling methods suggest generating synthetic examples in an original data space rather than in a high-dimensional feature space. This may be ineffective in improving SVM classification for imbalanced datasets. To address this problem, we propose a novel hybrid sampling technique termed modified mega-trend-diffusion-extreme learning machine (MMTD-ELM) to effectively move the SVM decision boundary toward a region of the majority class. By this movement, the prediction of SVM for minority class examples can be improved. The proposed method combines α-cut fuzzy number method for screening representative examples of majority class and MMTD method for creating new examples of the minority class. Furthermore, we construct a bagging ELM model to monitor the similarity between new examples and original data. In this paper, four datasets are used to test the efficiency of the proposed MMTD-ELM method in imbalanced data prediction. Additionally, we deployed two SVM models to compare prediction performance of the proposed MMTD-ELM method with three state-of-the-art sampling techniques in terms of geometric mean (G-mean), F-measure (F1), index of balanced accuracy (IBA) and area under curve (AUC) metrics. Furthermore, paired t-test is used to elucidate whether the suggested method has statistically significant differences from the other sampling techniques in terms of the four evaluation metrics. The experimental results demonstrated that the proposed method achieves the best average values in terms of G-mean, F1, IBA and AUC. Overall, the suggested MMTD-ELM method outperforms these sampling methods for imbalanced datasets

    WWP-1 Is a Novel Modulator of the DAF-2 Insulin-Like Signaling Network Involved in Pore-Forming Toxin Cellular Defenses in Caenorhabditis elegans

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    Pore-forming toxins (PFTs) are the single largest class of bacterial virulence factors. The DAF-2 insulin/insulin-like growth factor-1 signaling pathway, which regulates lifespan and stress resistance in Caenorhabditis elegans, is known to mutate to resistance to pathogenic bacteria. However, its role in responses against bacterial toxins and PFTs is as yet unexplored. Here we reveal that reduction of the DAF-2 insulin-like pathway confers the resistance of Caenorhabditis elegans to cytolitic crystal (Cry) PFTs produced by Bacillus thuringiensis. In contrast to the canonical DAF-2 insulin-like signaling pathway previously defined for aging and pathogenesis, the PFT response pathway diverges at 3-phosphoinositide-dependent kinase 1 (PDK-1) and appears to feed into a novel insulin-like pathway signal arm defined by the WW domain Protein 1 (WWP-1). In addition, we also find that WWP-1 not only plays an important role in the intrinsic cellular defense (INCED) against PFTs but also is involved in innate immunity against pathogenic bacteria Pseudomonas aeruginosa and in lifespan regulation. Taken together, our data suggest that WWP-1 and DAF-16 function in parallel within the fundamental DAF-2 insulin/IGF-1 signaling network to regulate fundamental cellular responses in C. elegans

    Spinocerebellar ataxia type 8 larger triplet expansion alters histone modification and induces RNA foci

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    <p>Abstract</p> <p>Background</p> <p>Spinocerebellar ataxia type 8 (SCA8) involves the expression of an expanded CTG/CAG combined repeats (CR) from opposite strands producing CUG expansion transcripts (ataxin 8 opposite strand, ATXN8OS) and a polyglutamine expansion protein (ataxin 8, ATXN8). The pathogenesis of SCA8 is complex and the spectrum of clinical presentations is broad.</p> <p>Results</p> <p>Using stably induced cell models expressing 0, 23, 88 and 157 CR, we study the role of ATXN8OS transcripts in SCA8 pathogenesis. In the absence of doxycycline, the stable ATXN8OS CR cell lines exhibit low levels of ATXN8OS expression and a repeat length-related increase in staurosporine sensitivity and in the number of annexin positive cells. A repeat length-dependent repression of ATXN8OS expression was also notable. Addition of doxycycline leads to 25~50 times more ATXN8OS RNA expression with a repeat length-dependent increase in fold of ATXN8OS RNA induction. ChIP-PCR assay using anti-dimethyl-histone H3-K9 and anti-acetyl-histone H3-K14 antibodies revealed increased H3-K9 dimethylation and reduced H3-K14 acetylation around the ATXN8OS cDNA gene in 157 CR line. The repeat length-dependent increase in induction fold is probably due to the increased RNA stability as demonstrated by monitoring ATXN8OS RNA decay in cells treated with the transcriptional inhibitor, actinomycin D. In cells stably expressing ATXN8OS, RNA FISH experiments further revealed ribonuclear foci formation in cells carrying expanded 88 and 157 CR.</p> <p>Conclusion</p> <p>The present study demonstrates that the expanded CUG-repeat tracts are toxic to human cells and may affect ATXN8OS RNA expression and stability through epigenetic and post-transcriptional mechanisms.</p

    Terahertz master-oscillator power-amplifier quantum cascade laser with a grating coupler of extremely low reflectivity

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    A terahertz master-oscillation power-amplifier quantum cascade laser (THz-MOPA-QCL) is demonstrated where a grating coupler is employed to efficiently extract the THz radiation. By maximizing the group velocity and eliminating the scattering of THz wave in the grating coupler, the residue reflectivity is reduced down to the order of 10−3. A buried DFB grating and a tapered preamplifier are proposed to improve the seed power and to reduce the gain saturation, respectively. The THz-MOPA-QCL exhibits single-mode emission, a single-lobed beam with a narrow divergence angle of 18° × 16°, and a pulsed output power of 136 mW at 20 K, which is 36 times that of a second-order DFB laser from the same material

    A Meta-analysis of Gene Expression Signatures of Blood Pressure and Hypertension

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    Genome-wide association studies (GWAS) have uncovered numerous genetic variants (SNPs) that are associated with blood pressure (BP). Genetic variants may lead to BP changes by acting on intermediate molecular phenotypes such as coded protein sequence or gene expression, which in turn affect BP variability. Therefore, characterizing genes whose expression is associated with BP may reveal cellular processes involved in BP regulation and uncover how transcripts mediate genetic and environmental effects on BP variability. A meta-analysis of results from six studies of global gene expression profiles of BP and hypertension in whole blood was performed in 7017 individuals who were not receiving antihypertensive drug treatment. We identified 34 genes that were differentially expressed in relation to BP (Bonferroni-corrected p&lt;0.05). Among these genes, FOS and PTGS2 have been previously reported to be involved in BP-related processes; the others are novel. The top BP signature genes in aggregate explain 5%–9% of inter-individual variance in BP. Of note, rs3184504 in SH2B3, which was also reported in GWAS to be associated with BP, was found to be a trans regulator of the expression of 6 of the transcripts we found to be associated with BP (FOS, MYADM, PP1R15A, TAGAP, S100A10, and FGBP2). Gene set enrichment analysis suggested that the BP-related global gene expression changes include genes involved in inflammatory response and apoptosis pathways. Our study provides new insights into molecular mechanisms underlying BP regulation, and suggests novel transcriptomic markers for the treatment and prevention of hypertension

    Hypertension and Dentistry

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    Being as a dental profession, the essence of providing medical and dental care for the patient is to treat the entirety as human being not just on the scale of their own teeth. As a result, the tight link between the primary medical condition of the patient such as hypertension and the dental care provided is certainly a non negligible issue. Providing blood pressure monitoring for certain patients and ensuring their vital signs are magnificent tasks for carrying on the dental care under safe condition. The integration of the medical condition of the patient with the dental treatment plan create a holistic system of dental care.egységes, osztatlanfogorvosangolVÁg

    The Interdependence of Powerful Local Families and Government In the Han Dynasty——The Case of the Cheng-Yang Chung Family

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    本文試圖分析漢代地方大姓的特性,探討他們與中央或地方政府的互動,指出大姓與政府之間主要的關係不是壓制、對抗,而是相互依存。 第一章回顧士族、豪族等與地方大姓相關研究成果,展望可進一步研究的空間。 第二章結合漢代家族史的研究成果,論證漢代的「宗族」一般是指親族關係,而非嚴密組織。所謂的地方大姓,是以某地在政治、經濟或社會上具有勢力的某一家庭為中心,凝聚同地同姓家庭而形成。地方大姓也會吸引非同姓的賓客、部曲等,而構成足以支配某地政治、經濟、社會資源的勢力。 第三章說明漢代地方大姓因擔任鄉里事務的領袖,影響鄉里百姓的生活。不過由於鄉里常據仕宦、德望、財力等推選領袖,因此地方大姓之間也會形成競爭。 第四章以碑刻史料對成陽仲氏進行個案研究。首先整理諸碑的年代與著錄,並加注釋作為進一步討論的基礎。碑刻中的成陽仲氏,以為漢求福的名義,得到政府支持修建堯廟與堯母靈臺,從而建立鄉里聲望,使族人得到仕途發展。形成他們與漢廷利益與共,相互依存的局面。 第五章總結前述,認為漢代是多元、成熟的社會,因此大姓需要政府的支持,以在激烈的競爭中維持社會地位

    Exploring Quality of Life, Stress, and Risk Factors Associated with Irritable Bowel Syndrome for Female University Students in Taiwan

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    Irritable bowel syndrome (IBS) is a common recurrent functional gastrointestinal disorder that impacts on patients physically and mentally. Studies on IBS have focused on adults, yet few studies have examined IBS among female university students. The aim of this study was to investigate the prevalence of IBS for female university students and its related factors. Using a cross-sectional study design, a total of 2520 female university students were recruited in southern Taiwan. The structured questionnaires, including the Rome III IBS diagnostic questionnaire, IBS symptom severity scale, Perceived Stress Scale, and World Health Organization Quality of Life BREF questionnaire (WHOQOL-BREF) were used for data collection. A total of 1894 female students complete the questionnaires. The response rate was 75.15%. The results indicated 193 female students with IBS and the prevalence of IBS was 10.1%. IBS female students had higher levels of stress and lower QOL than non-IBS female students. The risk factors for female university students developing IBS were dysmenorrhea, food avoidance, class absenteeism, and the lower physical domain of QOL. It is advised to consider these factors when providing students with counselling and relevant services in the expectation of alleviating their IBS symptoms, reducing the incidence rate of IBS, and further improving their QOL
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