586 research outputs found

    EMD-based filtering (EMDF) of low-frequency noise for speech enhancement

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    An Empirical Mode Decomposition based filtering (EMDF) approach is presented as a post-processing stage for speech enhancement. This method is particularly effective in low frequency noise environments. Unlike previous EMD based denoising methods, this approach does not make the assumption that the contaminating noise signal is fractional Gaussian Noise. An adaptive method is developed to select the IMF index for separating the noise components from the speech based on the second-order IMF statistics. The low frequency noise components are then separated by a partial reconstruction from the IMFs. It is shown that the proposed EMDF technique is able to suppress residual noise from speech signals that were enhanced by the conventional optimallymodified log-spectral amplitude approach which uses a minimum statistics based noise estimate. A comparative performance study is included that demonstrates the effectiveness of the EMDF system in various noise environments, such as car interior noise, military vehicle noise and babble noise. In particular, improvements up to 10 dB are obtained in car noise environments. Listening tests were performed that confirm the results

    Apprenticeship pay survey 2011

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    Practical Approaches to USO Costing and Financing

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    In this paper we set out a holistic approach that incorporates recent developments in assessing the net cost of the USO and presents a robust methodology for practical implementation. We analyse the issues relating to assessing the net costs of the USO with particular focus on the benefits associated with USO and current empirical approaches to calculating the net costs. We then present an overview of approaches that have been applied in various countries and highlight their strengths and shortcomings in light of the necessarily theoretical aspects discussed in the first part of the paper. Finally, we present a practical approach that we believe assesses robustly the net cost of the USO.Regulation, Post, Universal service obligation, Financing

    N-Methylmesoporphyrin IX Fluorescence As A Reporter Of Strand Orientation In Guanine Quadruplexes

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    Guanine quadruplexes (GQ) are four-stranded DNA structures formed by guanine-rich DNA sequences. The formation of GQs inhibits cancer cell growth, although the detection of GQs invivo has proven difficult, in part because of their structural diversity. The development of GQ-selective fluorescent reporters would enhance our ability to quantify the number and location of GQs, ultimately advancing biological studies of quadruplex relevance and function. N-methylmesoporphyrin IX (NMM) interacts selectively with parallel-stranded GQs; in addition, its fluorescence is sensitive to the presence of DNA, making this ligand a possible candidate for a quadruplex probe. In the present study, we investigated the effect of DNA secondary structure on NMM fluorescence. We found that NMM fluorescence increases by about 60-fold in the presence of parallel-stranded GQs and by about 40-fold in the presence of hybrid GQs. Antiparallel GQs lead to lower than 10-fold increases in NMM fluorescence. Single-stranded DNA, duplex, or i-motif, induce no change in NMM fluorescence. We conclude that NMM shows promise as a turn-on\u27 fluorescent probe for detecting quadruplex structures, as well as for differentiating them on the basis of strand orientation

    Investigation Of The Interactions Between Pt(II) And Pd(II) Derivatives Of 5,10,15,20-Tetrakis (N-Methyl-4-Pyridyl) Porphyrin And G-Quadruplex DNA

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    G-quadruplexes are non-canonical DNA structures formed by guanine-rich DNA sequences that are implicated in cancer and aging. Understanding how small molecule ligands interact with quadruplexes is essential both to the development of novel anticancer therapeutics and to the design of new quadruplex-selective probes needed for elucidation of quadruplex biological functions. In this work, UV–visible, fluorescence, and circular dichroism spectroscopies, fluorescence resonance energy transfer (FRET) melting assays, and resonance light scattering were used to investigate how the Pt(II) and Pd(II) derivatives of the well-studied 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP4) interact with quadruplexes formed by the human telomeric DNA, Tel22, and by the G-rich sequences from oncogene promoters. Our results suggest that Pt- and PdTMPyP4 interact with Tel22 via efficient π–π stacking with a binding affinity of 106–107 M−1. Under porphyrin excess, PtTMPyP4 aggregates using Tel22 as a template; the aggregates reach maximum size at [PtTMPyP4]/[Tel22] ~8 and dissolve at [PtTMPyP4]/[Tel22] ≤ 2. FRET assays reveal that both porphyrins are excellent stabilizers of human telomeric DNA, with stabilization temperature of 30.7 ± 0.6 °C for PtTMPyP4 and 30.9 ± 0.4 °C for PdTMPyP4 at [PtTMPyP4]/[Tel22] = 2 in K+ buffer, values significantly higher as compared to those for TMPyP4. The porphyrins display modest selectivity for quadruplex vs. duplex DNA, with selectivity ratios of 150 and 330 for Pt- and PdTMPyP4, respectively. This selectivity was confirmed by observed ‘light switch’ effect: fluorescence of PtTMPyP4 increases significantly in the presence of a variety of DNA secondary structures, yet the strongest effect is produced by quadruplex DNA

    Estimating State and Local Tax Exporting Between 1999 and 2012

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    In fiscal year 2012, state and local governments collected $1.4 trillion in taxes. Using various data sources, this paper presents state-by-state estimates of the amount that each state is able to export of its tax burden to non-residents, including the export effects of federal deductibility. Overall, based on the economic incidence assumptions outlined in this paper, between 12.5 percent and 45 percent of state and local tax collections were ultimately borne by out-of-state residents in FY 2012. This large range is the result of the uncertainty pertaining to the economic incidence of the property tax

    Stakeholder Perception of the Ethics of an Industry: The Case of Organic Food in South India

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    <p class="03ABSTRACT"><strong>Abstract</strong></p><p class="03ABSTRACT">Increasing reliance on artificial and non-sustainable methods of agriculture had resulted in negatively affecting both the soil and the health of agriculturists. Organic agriculture abhors such conventional agricultural practices and inculcates the implementation of safer, socially responsible and environmentally sustainable agricultural practices. This paper analyses the stakeholders’ perception of responsibility and environmental sustainability by conducting qualitative research using case studies of several organic food supply chains based in Kerala, a state in the south of India. The interviews with key stakeholders along the supply chain network illustrate that the rationale for organic agriculture is based on principles of fairness, responsibility and sustainability. Furthermore, the results depict that perceptions of ethics vary amongst stakeholder groups. Thoughthe literature is extensive on business ethics and sustainability, research on stakeholder perception along the entire industry is minimal within academic literature and the paper contributes to this area. Furthermore, from a managerial perspective, this paper sheds light on the influence of business ethics within an industry and exhibits the importance and influence of social responsibility and environmental sustainability within an industry.</p><p class="04KEYWORD"> Keywords: Ethics, food, sustainability, responsibility, agriculture, organic</p

    The 2017 Failed Outburst of GX 339-4: Relativistic X-ray Reflection near the Black Hole Revealed by NuSTAR and Swift Spectroscopy

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    We report on the spectroscopic analysis of the black hole binary GX 339−4 during its recent 2017–2018 outburst, observed simultaneously by the Swift and NuSTAR observatories. Although during this particular outburst the source failed to make state transitions, and despite Sun constraints during the peak luminosity, we were able to trigger four different observations sampling the evolution of the source in the hard state. We show that even for the lowest-luminosity observations the NuSTAR spectra show clear signatures of X-ray reprocessing (reflection) in an accretion disk. Detailed analysis of the highest signal-to-noise spectra with our family of relativistic reflection models RELXILL indicates the presence of both broad and narrow reflection components. We find that a dual-lamppost model provides a superior fit when compared to the standard single lamppost plus distant neutral reflection. In the dual-lamppost model two sources at different heights are placed on the rotational axis of the black hole, suggesting that the narrow component of the Fe K emission is likely to originate in regions far away in the disk, but still significantly affected by its rotational motions. Regardless of the geometry assumed, we find that the inner edge of the accretion disk reaches a few gravitational radii in all our fits, consistent with previous determinations at similar luminosity levels. This confirms a very low degree of disk truncation for this source at luminosities above ~1% Eddington. Our estimates of R_(in) reinforce the suggested behavior for an inner disk that approaches the innermost regions as the luminosity increases in the hard state

    BreakTrans: Uncovering the genomic architecture of gene fusions

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    Producing gene fusions through genomic structural rearrangements is a major mechanism for tumor evolution. Therefore, accurately detecting gene fusions and the originating rearrangements is of great importance for personalized cancer diagnosis and targeted therapy. We present a tool, BreakTrans, that systematically maps predicted gene fusions to structural rearrangements. Thus, BreakTrans not only validates both types of predictions, but also provides mechanistic interpretations. BreakTrans effectively validates known fusions and discovers novel events in a breast cancer cell line. Applying BreakTrans to 43 breast cancer samples in The Cancer Genome Atlas identifies 90 genomically validated gene fusions. BreakTrans is available at http://bioinformatics.mdanderson.org/main/BreakTran

    International Trade

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