844 research outputs found

    Sensitivity analysis and optimal treatment control for a mathematical model of human papillomavirus infection

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    Human papillomavirus (HPV) is one of the most common sexually transmitted viruses, and is a causal agent of cervical cancer. We aimed to develop a mathematical model of HPV natural history and qualitatively analyzed the stability of disease-free equilibrium, non-existence of limit cycle and existence of forward bifurcation. We performed sensitivity analysis to identify key epidemiological parameters. The Partial Rank Correlation Coefficient (PRCC) values for basic reproduction number shows that controlling contact rate plays an important role in disturbing equilibrium of HPV infection. Moreover, the increase of medical level is the most effective measure to prevent new HPV infections. Optimal treatment problem is solved and theoretical analysis is verified by numerical simulation

    Comparative performance of sustainable anode materials in microbial fuel cells (MFCs) for electricity generation from wastewater

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    Microbial fuel cells (MFCs) are a promising technology to generate electricity from wastewater and reduce the organic content. Whilst there has been a significant enhancement in MFC efficiency arising from the introduction of novel materials and cell designs, challenges remain with respect to the performance, cost, and sustainability of anode materials. This paper reports the development of single chamber MFCs with a focus on novel, cost-effective, and recycled carbon-based anode materials, including Recycled Water Filter Block/Powder (RWFB/RWFP), Recycled Chopped Carbon Fibre (RCCF), Carbon Felt (CF) and Graphite Flexible powder (GFG). Anodes prepared from GFG were shown to provide high power density (342.8 mW/m2), followed by RCCF, CF, RWFP, RWFB and CF (77.6, 71.8, 59.0 and 57.9 mW/m2, respectively). Chemical Oxygen Demand (COD) reduction was measured initially and at day 30, with GFG anodes observed to remove 83% of the initial load, compared to RCCF, RWFB, RWFP and CF anodes, where COD reductions of 69%, 61%, 65% and 73% were observed, respectively. Electrochemical analysis and biofilm imaging confirmed recycled materials were colonised by microorganisms and performed to high standards. GFG offers significant promise as an anode material, with excellent performance supported by a reduction in capital cost of up to 90% in comparison to CF. The use of recycled carbon material as MFC anodes shows promise, but requires additional work to improve the stability and durability of systems to permit scale-up

    Metabolomics of the interaction between PPAR-α and age in the PPAR-α-null mouse

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    Regulation between the fed and fasted states in mammals is partially controlled by peroxisome proliferator-activated receptor-α (PPAR-α). Expression of the receptor is high in the liver, heart and skeletal muscle, but decreases with age. A combined 1H nuclear magnetic resonance (NMR) spectroscopy and gas chromatography-mass spectrometry metabolomic approach has been used to examine metabolism in the liver, heart, skeletal muscle and adipose tissue in PPAR-α-null mice and wild-type controls during ageing between 3 and 13 months. For the PPAR-α-null mouse, multivariate statistics highlighted hepatic steatosis, reductions in the concentrations of glucose and glycogen in both the liver and muscle tissue, and profound changes in lipid metabolism in each tissue, reflecting known expression targets of the PPAR-α receptor. Hepatic glycogen and glucose also decreased with age for both genotypes. These findings indicate the development of age-related hepatic steatosis in the PPAR-α-null mouse, with the normal metabolic changes associated with ageing exacerbating changes associated with genotype. Furthermore, the combined metabolomic and multivariate statistics approach provides a robust method for examining the interaction between age and genotype

    PoolHap: Inferring Haplotype Frequencies from Pooled Samples by Next Generation Sequencing

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    With the advance of next-generation sequencing (NGS) technologies, increasingly ambitious applications are becoming feasible. A particularly powerful one is the sequencing of polymorphic, pooled samples. The pool can be naturally occurring, as in the case of multiple pathogen strains in a blood sample, multiple types of cells in a cancerous tissue sample, or multiple isoforms of mRNA in a cell. In these cases, it's difficult or impossible to partition the subtypes experimentally before sequencing, and those subtype frequencies must hence be inferred. In addition, investigators may occasionally want to artificially pool the sample of a large number of individuals for reasons of cost-efficiency, e. g., when carrying out genetic mapping using bulked segregant analysis. Here we describe PoolHap, a computational tool for inferring haplotype frequencies from pooled samples when haplotypes are known. The key insight into why PoolHap works is that the large number of SNPs that come with genome-wide coverage can compensate for the uneven coverage across the genome. The performance of PoolHap is illustrated and discussed using simulated and real data. We show that PoolHap is able to accurately estimate the proportions of haplotypes with less than 2% error for 34-strain mixtures with 2X total coverage Arabidopsis thaliana whole genome polymorphism data. This method should facilitate greater biological insight into heterogeneous samples that are difficult or impossible to isolate experimentally. Software and users manual are freely available at http://arabidopsis.gmi.oeaw.ac.at/quan/poolhap/

    Vision-related quality of life and Appearance concerns are associated with anxiety and depression after eye enucleation: A cross-sectional study

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    © 2015 Ye et al. Aims: To investigate the association of demographic, clinical and psychosocial variables with levels of anxiety and depression in participants wearing an ocular prosthesis after eye enucleation. Methods: This cross-sectional study included 195 participants with an enucleated eye who were attending an ophthalmic clinic for prosthetic rehabilitation between July and November 2014. Demographic and clinical data, and self-reported feelings of shame, sadness and anger were collected. Participants also completed the National Eye Institute Visual Function Questionnaire, the Facial Appearance subscale of the Negative Physical Self Scale, and the Hospital Anxiety and Depression Scale. Regression models were used to identify the factors associated with anxiety and depression. Results: The proportion of participants with clinical anxiety was 11.8% and clinical depression 13.8%. More anxiety and depression were associated with poorer vision-related quality of life and greater levels of appearance concerns. Younger age was related to greater levels of anxiety. Less educated participants and those feeling more angry about losing an eye are more prone to experience depression. Clinical variables were unrelated to anxiety or depression. Conclusions: Anxiety and depression are more prevalent in eye-enucleated patients than the general population, which brings up the issues of psychiatric support in these patients. Psychosocialrather than clinical characteristics were associated with anxiety and depression. Longitudinal studies need to be conducted to further elucidate the direction of causality before interventions to improve mood states are developed. Copyright

    Prediction of Deleterious Non-Synonymous SNPs Based on Protein Interaction Network and Hybrid Properties

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    Non-synonymous SNPs (nsSNPs), also known as Single Amino acid Polymorphisms (SAPs) account for the majority of human inherited diseases. It is important to distinguish the deleterious SAPs from neutral ones. Most traditional computational methods to classify SAPs are based on sequential or structural features. However, these features cannot fully explain the association between a SAP and the observed pathophysiological phenotype. We believe the better rationale for deleterious SAP prediction should be: If a SAP lies in the protein with important functions and it can change the protein sequence and structure severely, it is more likely related to disease. So we established a method to predict deleterious SAPs based on both protein interaction network and traditional hybrid properties. Each SAP is represented by 472 features that include sequential features, structural features and network features. Maximum Relevance Minimum Redundancy (mRMR) method and Incremental Feature Selection (IFS) were applied to obtain the optimal feature set and the prediction model was Nearest Neighbor Algorithm (NNA). In jackknife cross-validation, 83.27% of SAPs were correctly predicted when the optimized 263 features were used. The optimized predictor with 263 features was also tested in an independent dataset and the accuracy was still 80.00%. In contrast, SIFT, a widely used predictor of deleterious SAPs based on sequential features, has a prediction accuracy of 71.05% on the same dataset. In our study, network features were found to be most important for accurate prediction and can significantly improve the prediction performance. Our results suggest that the protein interaction context could provide important clues to help better illustrate SAP's functional association. This research will facilitate the post genome-wide association studies

    Study of J/ψ→ppˉJ/\psi\to p\bar{p} and J/ψ→nnˉJ/\psi\to n\bar{n}

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    The decays J/ψ→ppˉJ/\psi\to p\bar{p} and J/ψ→nnˉJ/\psi\to n\bar{n} have been investigated with a sample of 225.2 million J/ψJ/\psi events collected with the BESIII detector at the BEPCII e+e−e^+e^- collider. The branching fractions are determined to be B(J/ψ→ppˉ)=(2.112±0.004±0.031)×10−3\mathcal{B}(J/\psi\to p\bar{p})=(2.112\pm0.004\pm0.031)\times10^{-3} and B(J/ψ→nnˉ)=(2.07±0.01±0.17)×10−3\mathcal{B}(J/\psi\to n\bar{n})=(2.07\pm0.01\pm0.17)\times10^{-3}. Distributions of the angle Ξ\theta between the proton or anti-neutron and the beam direction are well described by the form 1+αcos⁥2Ξ1+\alpha\cos^2\theta, and we find α=0.595±0.012±0.015\alpha=0.595\pm0.012\pm0.015 for J/ψ→ppˉJ/\psi\to p\bar{p} and α=0.50±0.04±0.21\alpha=0.50\pm0.04\pm0.21 for J/ψ→nnˉJ/\psi\to n\bar{n}. Our branching-fraction results suggest a large phase angle between the strong and electromagnetic amplitudes describing the J/ψ→NNˉJ/\psi\to N\bar{N} decay.Comment: 16 pages, 13 figures, the 2nd version, submitted to PR

    Search for the Lepton Flavor Violation Process J/ψ→eÎŒJ/\psi \to e\mu at BESIII

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    We search for the lepton-flavor-violating decay of the J/ψJ/\psi into an electron and a muon using (225.3±2.8)×106(225.3\pm2.8)\times 10^{6} J/ψJ/\psi events collected with the BESIII detector at the BEPCII collider. Four candidate events are found in the signal region, consistent with background expectations. An upper limit on the branching fraction of B(J/ψ→eÎŒ)<1.5×10−7\mathcal{B}(J/\psi \to e\mu)< 1.5 \times 10^{-7} (90% C.L.) is obtained

    First observation of the M1 transition ψ(3686)→γηc(2S)\psi(3686)\to \gamma\eta_c(2S)

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    Using a sample of 106 million \psi(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: \psi(3686)\to\gamma\eta_c(2S). Analyses of the processes \psi(2S)\to \gamma\eta_c(2S) with \eta_c(2S)\to \K_S^0 K\pi and K^+K^-\pi^0 gave an \eta_c(2S) signal with a statistical significance of greater than 10 standard deviations under a wide range of assumptions about the signal and background properties. The data are used to obtain measurements of the \eta_c(2S) mass (M(\eta_c(2S))=3637.6\pm 2.9_\mathrm{stat}\pm 1.6_\mathrm{sys} MeV/c^2), width (\Gamma(\eta_c(2S))=16.9\pm 6.4_\mathrm{stat}\pm 4.8_\mathrm{sys} MeV), and the product branching fraction (\BR(\psi(3686)\to \gamma\eta_c(2S))\times \BR(\eta_c(2S)\to K\bar K\pi) = (1.30\pm 0.20_\mathrm{stat}\pm 0.30_\mathrm{sys})\times 10^{-5}). Combining our result with a BaBar measurement of \BR(\eta_c(2S)\to K\bar K \pi), we find the branching fraction of the M1 transition to be \BR(\psi(3686)\to\gamma\eta_c(2S)) = (6.8\pm 1.1_\mathrm{stat}\pm 4.5_\mathrm{sys})\times 10^{-4}.Comment: 7 pages, 1 figure, 1 tabl
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