553 research outputs found

    An Economy-wide Analysis of Impacts of WTO Tiered Formula for Tariff Reduction on Taiwan

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    In this study we use Taiwan as a case study to provide an economy-wide analysis of impacts on Taiwan of WTO tariff reduction schemes with different combinations of thresholds and reduction rates. The model we utilized in this study is Taiwan General Equilibrium Model with a WTO module (TAIGEM-WTO, hereafter) that is a multi-sectoral computable general equilibrium (CGE) model of the Taiwan's economy derived from Australian ORANI model (Dixon, Parmenter, Sutton and Vincent, 1982). Simulation results show that results are more sensitive to the scheme of tariff-reduction (i.e., Category 1, 2, and 3) than the tiered levels (i.e., A, B, C, and D) and as a strategy we should pay more attention to the arguments related to the amounts of tariff-reduction. Moreover, changes in nominal average tariff rates are more sensitive and shocks to the economy are more severe when we change the tariff reduction categories rather than the tiered levels. This conclusion also applies to the tiered reduction case when only sensitive products are considered. Finally, simulations with sector's bound rate calculated using arithmetic means have bigger effects than those using import values as weights. Therefore, sector's bound rate using import values as weights would be preferred.International Relations/Trade,

    Constructing HVS-Based Optimal Substitution Matrix Using Enhanced Differential Evolution

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    Least significant bit (LSB) substitution is a method of information hiding. The secret message is embedded into the last k bits of a cover-image in order to evade the notice of hackers. The security and stego-image quality are two main limitations of the LSB substitution method. Therefore, some researchers have proposed an LSB substitution matrix to address these two issues. Finding the optimal LSB substitution matrix can be conceptualized as a problem of combinatorial optimization. In this paper, we adopt a different heuristic method based on other researchers’ method, called enhanced differential evolution (EDE), to construct an optimal LSB substitution matrix. Differing from other researchers, we adopt an HVS-based measurement as a fitness function and embed the secret by modifying the pixel to a closest value rather than simply substituting the LSBs. Our scheme extracts the secret by modular operations as simple LSB substitution does. The experimental results show that the proposed embedding algorithm indeed improves imperceptibility of stego-images substantially

    Site-directed in vitro immunization leads to a complete human monoclonal IgG4λ that binds specifically to the CDR2 region of CTLA-4 (CD152) without interfering the engagement of natural ligands

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    <p>Abstract</p> <p>Background</p> <p>The ability to acquire fully human monoclonal antibodies (mAbs) with pre-defined specificities is critical to the development of molecular tags for the analysis of receptor function in addition to promising immunotherapeutics. Yet most of the arriving affinity maturated and complete human immunoglobulin G (IgG) molecules, which are actually derived from single human B cells, have not widely been used to study the conserved self antigens (Ags) such as CD152 (cytotoxic T lymphocyte antigen-4, CTLA-4) because proper hosts are lacking.</p> <p>Results</p> <p>Here we developed an optimized protocol for site-directed <it>in vitro </it>immunizing peripheral blood mononuclear cells (PBMC) by using a selected epitope of human CD152, an essential receptor involved in down-regulation of T cell activation. The resultant stable trioma cell lines constantly produce anti-CD152 mAb (γ4λhuCD152), which contains variable (V) regions of the heavy chain and the light chain derived from the VH3 and Vλ human germline genes, respectively, and yet displays an unusual IgG4 isotype. Interestingly, γ4λhuCD152 has a basic pI not commonly found in myeloid monoclonal IgG4λs as revealed by the isoelectric focusing (IEF) analysis. Furthermore, γ4λhuCD152 binds specifically, with nanomolar affinity, to an extracellular constituency encompassing the putative second complementarity determining region (CDR2) of CD152, whereby it can react to activated CD3<sup>+ </sup>cells.</p> <p>Conclusion</p> <p>In a context of specific cell depletion and conditioned medium,<it>in vitro </it>induction of human Abs against a conserved self Ag was successfully acquired and a relatively basic mAb, γ4λhuCD152, with high affinity to CDR2 of CD152 was thus obtained. Application of such a human IgG4λ mAb with designated CDR2 specificity may impact upon and prefer for CD152 labeling both <it>in situ </it>and <it>ex situ</it>, as it does not affect the binding of endogenous B7 ligands and can localize into the confined immunological synapse which may otherwise prevent the access of whole IgG1 molecules.</p

    Primary Cardiac Lymphoma

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    Primary cardiac lymphoma (PCL) has rarely been reported in Chinese populations. PCL mostly occurs in the right atrium. The clinical manifestations may be variable and are attributed to its location, the presence of congestive heart failure, pericardial effusion, arrhythmia, and cardiomegaly. The prognosis is usually poor because it is usually found too late and therefore, clinicians should be aware of PCL. Imaging examinations are the best methods for initial diagnosis and include echocardiography, computed tomography (CT) scan, magnetic resonance imaging (MRI), and radioisotope scan. However, the final diagnosis is made by pathology, such as cytologic examination of the effusive fluid and tissue biopsy. Because the tumors are difficult to resect, the main treatment for the disease is chemotherapy, which can be successful. Here, we report a 58-year-old man who had a tumor measuring 8 × 5 cm in the right atrium. By clinical staging, including chest X-ray, echocardiography, CT scan of the abdomen, MRI of the heart, whole body tumor Gallium scan, and gastrointestinal series, no metastatic lesion or involvement was found in other parts of the body. Pathologic findings including cytology of pericardial effusion and heart tumor biopsy revealed the case as a diffuse large B-cell lymphoma. After chemotherapy with COP (cyclophosphamide + vincristine + prednisone) and CHOPBE (COP + doxorubicin + bleomycin + etoposide) regimens, the intracardiac tumor had disappeared, but the patient survived for 12 months in total, despite additional radiotherapy over the pericardial lesions. It was presumed that because the tumor was very large and involved all 3 layers of the heart, it did not respond as well to the therapy as expected

    Urban-Rural Disparity of Generics Prescription in Taiwan: The Example of Dihydropyridine Derivatives

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    The aim of the current study was to investigate the urban-rural disparity of prescribing generics, which were usually cheaper than branded drugs, within the universal health insurance system in Taiwan. Data sources were the cohort datasets of National Health Insurance Research Database with claims data in 2010. The generic prescribing ratios of dihydropyridine (DHP) derivatives (the proportion of DHP prescribed as generics to all prescribed DHP) of medical facilities were examined against the urbanization levels of the clinic location. Among the total 21,606,914 defined daily doses of DHP, 35.7% belonged to generics. The aggregate generic prescribing ratio rose from 6.7% at academic medical centers to 15.3% at regional hospitals, 29.4% at community hospital, and 66.1% at physician clinics. Among physician clinics, the generic prescribing ratio in urban areas was 63.9 ± 41.0% (mean ± standard deviation), lower than that in suburban (69.6 ± 38.7%) and in rural (74.1% ± 35.3%). After adjusting the related factors in the linear regression model, generic prescribing ratios of suburban and rural clinics were significantly higher than those of urban clinics (β=0.043 and 0.077; P=0.024 and 0.008, resp.). The generic prescribing ratio of the most popular antihypertensive agents at a clinic was reversely associated with the urbanization level

    Repeated Small Perturbation Approach Reveals Transcriptomic Steady States

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    The study of biological systems dynamics requires elucidation of the transitions of steady states. A “small perturbation” approach can provide important information on the “steady state” of a biological system. In our experiments, small perturbations were generated by applying a series of repeating small doses of ultraviolet radiation to a human keratinocyte cell line, HaCaT. The biological response was assessed by monitoring the gene expression profiles using cDNA microarrays. Repeated small doses (10 J/m2) of ultraviolet B (UVB) exposure modulated the expression profiles of two groups of genes in opposite directions. The genes that were up-regulated have functions mainly associated with anti-proliferation/anti-mitogenesis/apoptosis, and the genes that were down-regulated were mainly related to proliferation/mitogenesis/anti-apoptosis. For both groups of genes, repetition of the small doses of UVB caused an immediate response followed by relaxation between successive small perturbations. This cyclic pattern was suppressed when large doses (233 or 582.5 J/m2) of UVB were applied. Our method and results contribute to a foundation for computational systems biology, which implicitly uses the concept of steady state

    Functional phosphoproteomic profiling of phosphorylation sites in membrane fractions of salt-stressed Arabidopsis thaliana

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    <p>Abstract</p> <p>Background</p> <p>Under conditions of salt stress, plants respond by initiating phosphorylation cascades. Many key phosphorylation events occur at the membrane. However, to date only limited sites have been identified that are phosphorylated in response to salt stress in plants.</p> <p>Results</p> <p>Membrane fractions from three-day and 200 mM salt-treated Arabidopsis suspension plants were isolated, followed by protease shaving and enrichment using Zirconium ion-charged magnetic beads, and tandem mass spectrometry analyses. From this isolation, 18 phosphorylation sites from 15 <it>Arabidopsis </it>proteins were identified. A unique phosphorylation site in 14-3-3-interacting protein AHA1 was predominately identified in 200 mM salt-treated plants. We also identified some phosphorylation sites in aquaporins. A doubly phosphorylated peptide of PIP2;1 as well as a phosphopeptide containing a single phosphorylation site (Ser-283) and a phosphopeptide containing another site (Ser-286) of aquaporin PIP2;4 were identified respectively. These two sites appeared to be novel of which were not reported before. In addition, quantitative analyses of protein phosphorylation with either label-free or stable-isotope labeling were also employed in this study. The results indicated that level of phosphopeptides on five membrane proteins such as AHA1, STP1, Patellin-2, probable inactive receptor kinase (At3g02880), and probable purine permease 18 showed at least two-fold increase in comparison to control in response to 200 mM salt-stress.</p> <p>Conclusion</p> <p>In this study, we successfully identified novel salt stress-responsive protein phosphorylation sites from membrane isolates of abiotic-stressed plants by membrane shaving followed by Zr<sup>4+</sup>-IMAC enrichment. The identified phosphorylation sites can be important in the salt stress response in plants.</p
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