67 research outputs found

    Applying evolutionary algorithms to materialized view selection in a data warehouse

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    [[abstract]]Effective analysis of genome sequences and associated functional data requires access to many different kinds of biological information. A data warehouse [14,16] plays an important role for storage and analysis for genome sequence and functional data. A data warehouse stores lots of materialized views to provide an efficient decision-support or OLAP queries. The view-selection problem addresses to select a fittest set of materialized views from a variety of MVPPs 0 forms a challenge in data warehouse research. In this paper, we present genetic algorithm to choose materialized views. We also use experiments to demonstrate the power of our approach

    Atomistic characterization of the active-site solvation dynamics of a model photocatalyst

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    The interactions between the reactive excited state of molecular photocatalysts and surrounding solvent dictate reaction mechanisms and pathways, but are not readily accessible to conventional optical spectroscopic techniques. Here we report an investigation of the structural and solvation dynamics following excitation of a model photocatalytic molecular system [Ir-2(dimen)(4)](2+), where dimen is para-diisocyanomenthane. The time-dependent structural changes in this model photocatalyst, as well as the changes in the solvation shell structure, have been measured with ultrafast diffuse X-ray scattering and simulated with Born-Oppenheimer Molecular Dynamics. Both methods provide direct access to the solute-solvent pair distribution function, enabling the solvation dynamics around the catalytically active iridium sites to be robustly characterized. Our results provide evidence for the coordination of the iridium atoms by the acetonitrile solvent and demonstrate the viability of using diffuse X-ray scattering at free-electron laser sources for studying the dynamics of photocatalysis.1

    The complete sequence of the Acacia ligulata chloroplast genome reveals a highly divergent clpP1 gene

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    Legumes are a highly diverse angiosperm family that include many agriculturally important species. To date, 21 complete chloroplast genomes have been sequenced from legume crops confined to the Papilionoideae subfamily. Here we report the first chloroplast genome from the Mimosoideae, Acacia ligulata, and compare it to the previously sequenced legume genomes. The A. ligulata chloroplast genome is 158,724 bp in size, comprising inverted repeats of 25,925 bp and single-copy regions of 88,576 bp and 18,298 bp. Acacia ligulata lacks the inversion present in many of the Papilionoideae, but is not otherwise significantly different in terms of gene and repeat content. The key feature is its highly divergent clpP1 gene, normally considered essential in chloroplast genomes. In A. ligulata, although transcribed and spliced, it probably encodes a catalytically inactive protein. This study provides a significant resource for further genetic research into Acacia and the Mimosoideae. The divergent clpP1 gene suggests that Acacia will provide an interesting source of information on the evolution and functional diversity of the chloroplast Clp protease comple

    Isotocin controls ion regulation through regulating ionocyte progenitor differentiation and proliferation

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    The present study using zebrafish as a model explores the role of isotocin, a homolog of oxytocin, in controlling ion regulatory mechanisms. Double-deionized water treatment for 24 h significantly stimulated isotocin mRNA expression in zebrafish embryos. Whole-body Cl−, Ca2+, and Na+ contents, mRNA expressions of ion transporters and ionocyte-differentiation related transcription factors, and the number of skin ionocytes decreased in isotocin morphants. In contrast, overexpression of isotocin caused an increase in ionocyte numbers. Isotocin morpholino caused significant suppression of foxi3a mRNA expression, while isotocin cRNA stimulated foxi3a mRNA expressions at the tail-bud stage of zebrafish embryos. The density of P63 (an epidermal stem cell marker)-positive cells was downregulated by isotocin morpholinos and was upregulated by isotocin cRNA. Taken together, isotocin stimulates the proliferation of epidermal stem cells and differentiation of ionocyte progenitors by regulating the P63 and Foxi3a transcription factors, consequently enhancing the functional activities of ionocytes

    AMP-activated protein kinase inhibits NF-κB signaling and inflammation: impact on healthspan and lifespan

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    Adenosine monophosphate-activated protein kinase (AMPK) is a crucial regulator of energy metabolic homeostasis and thus a major survival factor in a variety of metabolic stresses and also in the aging process. Metabolic syndrome is associated with a low-grade, chronic inflammation, primarily in adipose tissue. A low-level of inflammation is also present in the aging process. There are emerging results indicating that AMPK signaling can inhibit the inflammatory responses induced by the nuclear factor-κB (NF-κB) system. The NF-κB subunits are not direct phosphorylation targets of AMPK, but the inhibition of NF-κB signaling is mediated by several downstream targets of AMPK, e.g., SIRT1, PGC-1α, p53, and Forkhead box O (FoxO) factors. AMPK signaling seems to enhance energy metabolism while it can repress inflammatory responses linked to chronic stress, e.g., in nutritional overload and during the aging process. AMPK can inhibit endoplasmic reticulum and oxidative stresses which are involved in metabolic disorders and the aging process. Interestingly, many target proteins of AMPK are so-called longevity factors, e.g., SIRT1, p53, and FoxOs, which not only can increase the stress resistance and extend the lifespan of many organisms but also inhibit the inflammatory responses. The activation capacity of AMPK declines in metabolic stress and with aging which could augment the metabolic diseases and accelerate the aging process. We will review the AMPK pathways involved in the inhibition of NF-κB signaling and suppression of inflammation. We also emphasize that the capacity of AMPK to repress inflammatory responses can have a significant impact on both healthspan and lifespan

    Lung epithelium as a sentinel and effector system in pneumonia – molecular mechanisms of pathogen recognition and signal transduction

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    Pneumonia, a common disease caused by a great diversity of infectious agents is responsible for enormous morbidity and mortality worldwide. The bronchial and lung epithelium comprises a large surface between host and environment and is attacked as a primary target during lung infection. Besides acting as a mechanical barrier, recent evidence suggests that the lung epithelium functions as an important sentinel system against pathogens. Equipped with transmembranous and cytosolic pathogen-sensing pattern recognition receptors the epithelium detects invading pathogens. A complex signalling results in epithelial cell activation, which essentially participates in initiation and orchestration of the subsequent innate and adaptive immune response. In this review we summarize recent progress in research focussing on molecular mechanisms of pathogen detection, host cell signal transduction, and subsequent activation of lung epithelial cells by pathogens and their virulence factors and point to open questions. The analysis of lung epithelial function in the host response in pneumonia may pave the way to the development of innovative highly needed therapeutics in pneumonia in addition to antibiotics

    Regular inhaled corticosteroids in adult-onset asthma and the risk for future cancer: a population-based cohort study with proper person-time analysis

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    Victor C Kok,1,2 Jorng-Tzong Horng,2,3 Hsu-Kai Huang,3 Tsung-Ming Chao,4 Ya-Fang Hong5 1Division of Medical Oncology, Department of Internal Medicine, Kuang Tien General Hospital, Taichung, Taiwan; 2Department of Biomedical Informatics, Asia University Taiwan, Taichung, Taiwan; 3Department of Computer Science and Information Engineering, National Central University, Jhongli, Taiwan; 4Statistics Unit, Department of Applied Geomatics, Chien Hsin University, Jhongli, Taiwan; 5Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan Background: Recent studies have shown that inhaled corticosteroids (ICS) can exert anti-inflammatory effects for chronic airway diseases, and several observational studies suggest that they play a role as cancer chemopreventive agents, particularly against lung cancer. We aimed to examine whether regular ICS use was associated with a reduced risk for future malignancy in patients with newly diagnosed adult-onset asthma. Methods: We used a population-based cohort study between 2001 and 2008 with appropriate person-time analysis. Participants were followed up until the first incident of cancer, death, or to the end of 2008. The Cox model was used to derive an adjusted hazard ratio (aHR) for cancer development. Kaplan–Meier cancer-free survival curves of two groups were compared. Results: The exposed group of 2,117 regular ICS users and the nonexposed group of 17,732 non-ICS users were assembled. After 7,365 (mean, 3.5 years; standard deviation 2.1) and 73,789 (mean, 4.1 years; standard deviation 2.4) person-years of follow-up for the ICS users and the comparator group of non-ICS users, respectively, the aHR for overall cancer was nonsignificantly elevated at 1.33 with 95% confidence interval (CI), 1.00–1.76, P=0.0501. The Kaplan–Meier curves for overall cancer-free proportions of both groups were not significant (log-rank, P=0.065). Synergistic interaction of concurrent presence of regular ICS use was conducted using “ICS-negative and chronic obstructive pulmonary disease (COPD)-negative” as the reference. The aHR for the group of “ICS-positive, COPD-negative” did not reach statistically significant levels with aHR at 1.38 (95% CI, 0.53–3.56). There was a statistically significant synergistic interaction of concurrent presence of regular ICS use and COPD with aHR at 3.78 (95% CI, 2.10–6.81). Conclusion: The protective effect of regular ICS use in the studied East Asian patients with adult-onset asthma was not detectable, contrary to reports of previous studies that ICS might prevent the occurrence of future cancer. Keywords: immortal time bias, NHIRD, population-based study, retrospective cohort study, risk of cance

    Cancer risk in patients aged 30 years and above with type 2 diabetes receiving antidiabetic monotherapy: a cohort study using metformin as the comparator

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    Yu-Ching Chen,1 Victor C Kok,1,2 Ching-Hsuan Chien,1 Jorng-Tzong Horng,1,3 Jeffrey J P Tsai11Department of Biomedical Informatics, Asia University, Taichung, 2Department of Internal Medicine, Kuang Tien General Hospital, Taichung, 3Department of Computer Science and Information Engineering, National Central University, Jhongli, TaiwanIntroduction: Accumulating evidence suggests that metformin reduces incident cancer development. Few cohort studies have evaluated the risk of subsequent cancer development in diabetic cohorts receiving antidiabetic monotherapy. We conducted a population-based study in patients with new-onset type 2 diabetes treated with antidiabetic monotherapy.Methods: We identified a cohort of patients with type 2 diabetics aged ≥30 years receiving hypoglycemic monotherapy (n=7,325) from the 1998–2007 Longitudinal Health Insurance Dataset. Patients were grouped according to the antidiabetic therapy they received into metformin (n=2,223), sulfonylurea (n=3,965), glitazone (n=53), meglitinide (n=128), acarbose (n=150), and insulin (n=806) groups. Patients with preexisting cancer were excluded. All patients were followed up until cancer development, dropout, death, or until December 31, 2008. Cox’s model was used to estimate multivariable hazard ratios (HRs) adjusted for age, sex, Charlson comorbidity index, smoking-related comorbidities, alcohol use disorders, morbid obesity, pancreatitis, hypertension, monthly income, and urbanization level. The log-rank test was used to compare cumulative cancer incidence. Two-sided P-values <0.05 were required to reject the null hypothesis.Results: The overall median follow-up duration was 2.5 years (interquartile range, 3.6 years). Totally, 367 and 124 cancers developed in the sulfonylurea and metformin groups, respectively, representing an adjusted HR of 1.36 (95% confidence interval [CI], 1.11–1.67; P<0.005). No significant differences were observed between other groups. Increased adjusted HRs were observed for colorectal cancer (adjusted HR, 1.94; 95% CI, 1.15–3.27; P<0.05) and lung cancer (adjusted HR, 1.76; 95% CI, 1.00–3.07; P<0.05).Conclusion: Metformin monotherapy may be associated with a reduction in the risk for cancer development compared with sulfonylurea monotherapy. Moreover, the use of an average defined daily dose of >0.25 of metformin when compared to lower dose will contribute to a reduction of 80% risk.Keywords: type 2 diabetes, antidiabetic drug, monotherapy, metformin, sulfonylureas, cancer risk, NHIR

    BPR2-D2 targeting viral ribonucleoprotein complex-associated function inhibits oseltamivir-resistant influenza viruses.

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    OBJECTIVES: The emergence of oseltamivir-resistant viruses raised the global threat with regard to influenza virus infection. To develop alternative antiviral agents against influenza virus infection is significant and urgent. METHODS: A neutralization test was applied as a screening assay and a plaque reduction assay was used for confirmation. Expression plasmids for viral ribonucleoproteins (RNPs) and a plasmid that allowed expression of a pseudoviral reporter RNA were transfected into cells to investigate the effects of a novel antiviral compound on viral RNA synthesis. RESULTS: BPR2-D2 was identified as a novel inhibitor against influenza virus from a hit obtained from high throughput screening of 20 000 or more compounds. BPR2-D2 exhibited an excellent antiviral efficacy for the oseltamivir-resistant virus (EC(50) ranging from 0.021 to 0.040 microM). No resistant virus was produced throughout 20 passages in the presence of BPR2-D2, whereas oseltamivir-resistant virus was generated at passage 8 using the same experimental system. A molecular target other than neuraminidase (NA) was found because BPR2-D2 inhibited the synthesis of viral RNA that was driven by influenza viral RNP in a transfection assay. BPR2-D2 also exhibited a broad antiviral spectrum against various strains of influenza A and influenza B viruses. CONCLUSIONS: BPR2-D2 was identified as a novel inhibitor of influenza virus. It may target viral RNPs that are responsible for viral RNA synthesis. Targeting different molecules compared with NA allows BPR2-D2 to inhibit oseltamivir-resistant viruses.link_to_subscribed_fulltex
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