961 resultados para country specific advantages


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Within a two-country model of international trade in which heterogeneous firms face firm-specific unions, we study the effects of different forms of trade liberalisation on market structure and competitive selection in the presence of inter-country asymmetries in size and labour market institutions. For given levels of trade openness, an increase in a country’s relative unions’ strength reduces the average productivity of its domestic producers but increases that of its exporters. Whilst an unfavourable union power differential, by increasing wages, weakens a country’s firms’ competitive position, the higher wages reinforce standard market access mechanisms to give rise to aggregate income effects. When the initial levels of trade openness are sufficiently low, this ‘expansionary’ aggregate effect can attract industry in the country with stronger unions and also result in an increase in the extensive margin of exports. For sufficiently large inter-country differences in the bargaining power of unions, trade liberalization can then result in a pro-variety effect, with an increase in the total availability of varieties to consumers in both countries, regardless of there being inter-country differences in size.

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Three Yersinia pestis strains isolated from humans and one laboratory strain (EV76) were grown in rich media at 28§C and 37§C and their outer membrane protein composition compared by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-Page). Several proteins with molecular weights ranging from 34 kDa to 7 kDa were observed to change in relative abundance in samples grown at different temperatures. At least seven Y. pestis outer membrane proteins showed a temperature-dependent and strain-specific behaviour. Some differences between the outer membrane proteins of full-pathogenic wild isolates and the EV76 strain could aldso be detected and the relevance of this finding on the use of laboratory strains as a reference to the study of Y. pestis biological properties is discuted.

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Single doses of drugs active aginst Trypanosoma cruzi (megazol, nifurtimox and benznidazole) induce a rapid clearence of the blood parasites in experimentally infected mice. Furthermore, the in vitro phagocytosis and intracellular destruction by mouse peritoneal macrophage of blood forms collected from the treatment animals is strongly enhanced as compared with parasites from untreated controls. The uptake of the blood forms by macrophages is significantly higher with megazol than with benznidazole and nifurtimox, a finding that concurs with data showing that megazol is also the most active compound in the living host. The possibility that macrophages participate in a synergic effect between the host immune response and chemotherapeutic effect is discussed.

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Genuine Savings has emerged as a widely-used indicator of sustainable development. In this paper, we use long-term data stretching back to 1870 to undertake empirical tests of the relationship between Genuine Savings (GS) and future well-being for three countries: Britain, the USA and Germany. Our tests are based on an underlying theoretical relationship between GS and changes in the present value of future consumption. Based on both single country and panel results, we find evidence supporting the existence of a cointegrating (long run equilibrium) relationship between GS and future well-being, and fail to reject the basic theoretical result on the relationship between these two macroeconomic variables. This provides some support for the GS measure of weak sustainability. We also show the effects of modelling shocks, such as World War Two and the Great Depression.

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We study how unionisation affects competitive selection between heterogeneous firms when wage negotiations can occur at the firm or at the profit-centre level. With productivity specific wages, an increase in union power has: (i) a selection-softening; (ii) a counter-competitive; (iii) a wage-inequality; and (iv) a variety effect. In a two-country asymmetric setting, stronger unions soften competition for domestic firms and toughen it for exporters. With profit-centre bargaining, we show how trade liberalisation can affect wage inequality among identical workers both across firms (via its effects on competitive selection) and within firms (via wage discrimination across destination markets).

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This investigation was performed to verify the effect of specific chemotherapy (Benznidazole or MK-346) on the inflammatory and fibrotic cardiac alterations in mice chronically infected with the strains 21 SF (Type II) and Colombian (Type III) of Trypanosoma cruzi. To obtain chronically infected mice, two groups of 100 Swiss mice each, were infected with either the 21 SF or the Colombian strain (2x 10 [raised to the power of] 4 and 5x 10 [raised to the power of] 4 blood forms respectively). The rate of morality in the acute phase was of 80% for both groups. Twenty surviving mice chronically infected with the 21 SF strain and 20 with the Colombian strain were then divided in treated and untreated groups. Excluding those that died during the course of treatment, 14 mice chronically infected with the 21 SF strain and 15 with the Colombian strain were evaluated in the present study. Chemotherapy was performed with Benznidazole (N-benzil-2-nitro-1-imidazolacetamide) in the dose of 100mg/k.b.w/day, for 60 days, or with the MK-436(3(1-methyl-5 nitroimidazol-2-yl) in two daily doses of 250 mg/k.b.w, for 20 days. Parasitological cure tests were performed (xenodiagnosis, haemoculture, subinovulation of the blood into newborn mice), and serological indirect immunofluorescence test. The treated and untreated mice as well as intact controls were killed at different periods after treatment and the heart were submitted to histopathological study with hematoxilineosin and picrosirius staining; ultrastructural study; collagen immunotyping, fibronectin and laminin identification by immunofluorescence tests. Results: the untreated controls either infected with 21 SF or Colombian strain, showed inflammatory and fibrotic alterations that were mild to moderate with the 21 SF strain and intense with the Colombian strain. Redpicrosirius staining showed bundles of collagen in the interstitial space and around cardiac fibers. Increased deposits of mitritial components and collagen fibers, macrophages and fibroblasts appeared at the ultra structural examination. Deposits of fibronectin, laminin, pro-III and IV collagens were seen, most intense in those infected with the Colombian strain. Treated nice, parasitologically cured, presented clear-cut regression of the inflammatory lesions and of the interstitial matrix thickening. Mice infected with the Colombian strain and treated with MK-436, was parasitologically cured in 5/6 cases and showed mild inflammatory infiltration and fibrosis. The mice treated with Benznidazole (Colombian strain) did not cure and showed moderate fibrosis and inflammation. Treatment of the nice infected with the 21 SF with Benznidazole determined parasitological cure of all animals, that showed mild inflammation and fibrosis of the myocardium. The cured mice of all groups and treated but uncured showed collagen degradation at electronmicroscopy and decrease of immunofluorescence pattern of the matrix.

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The author investigated the distribution of lectin receptors on Trypanosoma cruzi blood forms collected from mice inoculated with, respectively, the drug-resistant and drug-sensitive strains VL-10 and CL, and treated with the two standard active nitroheterocyclic compounds nifurtimox and benznidazole used for treatment of human Chagas' disease. Blood trypomastigotes purified in Fycoll-Hypaque were incubated with fluorescein-labelled lectins Con A, WGA, EE, WFA, TPA and PNA and then microscopically examined. Neither qualitative or quantitative differences in the fluorescence intensity could be detected between parasites from VL-10 and CL strains submitted or not to treatment. The results suggest that both strains do not differ in their surface membrane carbohydrate moieties. Moreover, the rapid clearance of blood forms the drug-sensitive strain in animals treated with singlo doses of both compounds is not likely to depend on membrane alterations expressed by changes in the carbohydrate components. furthermore, resistance or sensitivity to drugs is not apparently related to carbohydrate distribution on T. cruzi blood forms.

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During upper blepharoplasty, myocutaneous excess and fat pads are treated using an anterior approach. Eyelid malpositions such as involutional ptosis or lid retraction could be associated and should be treated with associated procedures. Aponeurotic surgery on the levator muscle can make use of the same anterior approach, with the major difficulty of dosage. In cases of ptosis with a positive epinephrine test or minor muscular retraction, the Muller muscle-conjunctival surgery via a posterior approach seems to be more reproducible. Double-approach techniques are described.

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Microarray transcript profiling and RNA interference are two new technologies crucial for large-scale gene function studies in multicellular eukaryotes. Both rely on sequence-specific hybridization between complementary nucleic acid strands, inciting us to create a collection of gene-specific sequence tags (GSTs) representing at least 21,500 Arabidopsis genes and which are compatible with both approaches. The GSTs were carefully selected to ensure that each of them shared no significant similarity with any other region in the Arabidopsis genome. They were synthesized by PCR amplification from genomic DNA. Spotted microarrays fabricated from the GSTs show good dynamic range, specificity, and sensitivity in transcript profiling experiments. The GSTs have also been transferred to bacterial plasmid vectors via recombinational cloning protocols. These cloned GSTs constitute the ideal starting point for a variety of functional approaches, including reverse genetics. We have subcloned GSTs on a large scale into vectors designed for gene silencing in plant cells. We show that in planta expression of GST hairpin RNA results in the expected phenotypes in silenced Arabidopsis lines. These versatile GST resources provide novel and powerful tools for functional genomics.

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We report the results of the Theravac-01 phase I trial, which was conducted to evaluate the safety and immunogenicity of a poxvirus-based vector, NYVAC, expressing Gag, Pol, Nef, and Env from an HIV clade B isolate. NYVAC-B vaccine was injected intra-muscularly into ten HIV-infected patients successfully treated with antiretroviral therapy, twice on day 0 and again at week 4. Safety and immunogenicity were monitored for 48 weeks. HIV-specific T-cell responses following immunization were quantitatively analyzed using an IFN-γ ELISPOT assay and qualitatively characterized for their functional profile (including multiple cytokines secretion plus cytotoxic and proliferation capacity) by polychromatic flow cytometry. Our results indicate that the NYVAC-B vaccine is safe and highly immunogenic, as indicated by increased HIV-specific T-cell responses in virtually all vaccinees. Interestingly, both an expansion of preexisting T-cell responses, and the appearance of newly detected HIV-specific CD4(+) and CD8(+) T-cell responses were observed. Furthermore, immunization mostly induced an increase in Gag-specific T-cell responses. In conclusion, NYVAC-B immunization induces broad, vigorous, and polyfunctional HIV-specific T-cell responses, suggesting that poxvirus-based vaccine regimens may be instrumental in the therapeutic HIV vaccine field.

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BACKGROUND/OBJECTIVES: There is little objective information regarding nutrition transition in African countries. We assessed trends in nutrition patterns in the Seychelles between 1989 and 2011. SUBJECTS/METHODS: Population-based samples were obtained in 1989, 1994 and 2011 and participants aged 25-44 are considered in this study (n=493, 599 and 471, respectively). Similar, although not identical, food frequency questionnaires (FFQs) were used in each survey and the variables were collapsed into homogenous categories for the purpose of this study. RESULTS: Between 1989 and 2011, consumption frequency of fish (5+/week) decreased from 93 to 74%, whereas the following increased: meat (5+/week) 25 to 51%, fruits (1+/week) 48 to 94%, salty snacks (1+/week) 22 to 64% and sweet snacks (1+/week) 38 to 67% (P<0.001 for all). Consumption frequency decreased for home-brewed alcoholic drinks (1+/week) 16 to 1%, but increased for wine (1+/week) 5 to 33% (both P<0.001). Between 2004 and 2011, consumption frequency decreased for rice (2/day) 62 to 57% and tea (1+/day) 72 to 68%, increased for poultry (1+/week) 86 to 96% (all P<0.01), and did not change for vegetables (70.3 to 69.8%, P=0.65). CONCLUSIONS: Seychelles is experiencing nutrition transition characterized by a decreased consumption frequency of traditional staple foods (fish, polished rice), beverages (tea) and of inexpensive home brews, and increased consumption frequency of meat, poultry and snacks. Food patterns also became more varied along with a broader availability of products in the 22-year interval. The health impact of these changes should be further studied.

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Cytotoxic T cells (CTL) recognize short peptides that are derived from the proteolysis of endogenous cellular proteins and presented on the cell surface as a complex with MHC class I molecules. CTL can recognize single amino acid substitutions in proteins, including those involved in malignant transformation. The mutated sequence of an oncogene may be presented on the cell surface as a peptide, and thus represents a potential target antigen for tumour therapy. The p21ras gene is mutated in a wide variety of tumours and since the transforming mutations result in amino acid substitutions at positions 12, 13 and 61 of the protein, a limited number of ras peptides could potentially be used in the treatment of a wide variety of malignancies. A common substitution is Val for Gly at position 12 of p21ras. In this study, we show that the peptide sequence from position 5 to position 14 with Val at position 12-ras p5-14 (Val-12)-has a motif which allows it to bind to HLA-A2.1. HLA-A2.1-restricted ras p5-14 (Val-12)-specific CTL were induced in mice transgenic for both HLA-A2.1 and human beta2-microglobulin after in vivo priming with the peptide. The murine CTL could recognize the ras p5-14 (Val-12) peptide when they were presented on both murine and human target cells bearing HLA-A2.1. No cross-reactivity was observed with the native peptide ras p5-14 (Gly-12), and this peptide was not immunogenic in HLA-A2.1 transgenic mice. This represents an interesting model for the study of an HLA-restricted CD8 cytotoxic T cell response to a defined tumour antigen in vivo.

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Immunology-based interventions have been proposed as a promising curative chance to effectively attack postoperative minimal residual disease and distant metastatic localizations of prostate tumors. We developed a chimeric antigen receptor (CAR) construct targeting the human prostate-specific membrane antigen (hPSMA), based on a novel and high affinity specific mAb. As a transfer method, we employed last-generation lentiviral vectors (LV) carrying a synthetic bidirectional promoter capable of robust and coordinated expression of the CAR molecule, and a bioluminescent reporter gene to allow the tracking of transgenic T cells after in vivo adoptive transfer. Overall, we demonstrated that CAR-expressing LV efficiently transduced short-term activated PBMC, which in turn were readily stimulated to produce cytokines and to exert a relevant cytotoxic activity by engagement with PSMA+ prostate tumor cells. Upon in vivo transfer in tumor-bearing mice, CAR-transduced T cells were capable to completely eradicate a disseminated neoplasia in the majority of treated animals, thus supporting the translation of such approach in the clinical setting.

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Very little is known about early molecular events triggering epithelial cell differentiation. We have examined the possible role of tyrosine phosphorylation in this process, as observed in cultures of primary mouse keratinocytes after exposure to calcium or 12-O-tetradecanoylphorbol-13-acetate (TPA). Immunoblotting with phosphotyrosine-specific antibodies as well as direct phosphoamino acid analysis revealed that induction of tyrosine phosphorylation occurs as a very early and specific event in keratinocyte differentiation. Very little or no induction of tyrosine phosphorylation was observed in a keratinocyte cell line resistant to the differentiating effects of calcium. Treatment of cells with tyrosine kinase inhibitors prevented induction of tyrosine phosphorylation by calcium and TPA and interfered with the differentiative effects of these agents. These results suggest that specific activation of tyrosine kinase(s) may play an important regulatory role in keratinocyte differentiation.