7,397 research outputs found

    Is Africa Integrated in the Global Economy?

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    The popular impression that Africa has not integrated into world trade, as suggested by the evolution in simple indicators, has been called into question recently by more formal analysis. This paper refines and generalizes this analysis and lends support to the popular view of disintegration, but only for countries in Francophone Africa. These countries are currently underexploiting their trading opportunities and have witnessed disintegration over time, a trend that is most pronounced in their trade with technologically advanced countries. There is some evidence, on the other hand, that countries in Anglophone Africa are reversing the trend of disintegration, particularly in their trade with advanced countries. Copyright 2003, International Monetary Fund

    Pulsed source of spectrally uncorrelated and indistinguishable photons at telecom wavelengths

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    We report on the generation of indistinguishable photon pairs at telecom wavelengths based on a type-II parametric down conversion process in a periodically poled potassium titanyl phosphate (PPKTP) crystal. The phase matching, pump laser characteristics and coupling geometry are optimised to obtain spectrally uncorrelated photons with high coupling efficiencies. Four photons are generated by a counter- propagating pump in the same crystal and anlysed via two photon interference experiments between photons from each pair source as well as joint spectral and g^(2) measurements. We obtain a spectral purity of 0.91 and coupling efficiencies around 90% for all four photons without any filtering. These pure indistinguishable photon sources at telecom wavelengths are perfectly adapted for quantum network demonstrations and other multi-photon protocols

    Mathematical Development Program for Calculation of Fatty Acid Composition Blend of Vegetable Oils

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    The method of solution of the problem of polyunsaturated fatty acids (PUFA) lack in milk products is offered in the work. It is offered to create the milk-containing products (sour cream product) with adjusted fatty acid composition. The possibility of replacement of the mass part of milk fat (50 %) by the blend of natural vegetable oils was studied. For the solution of this problem the program within MatLab mathematical package was elaborated. The recommended fatty acids (FA) ratio [3] is selected as optimization parameter. The optimized blend was created using the elaborated program. The data, received by mathematical calculations, were experimentally proved using the method of gas-liquid chromatography [7]. On the based of the results, received at the studies, it can be stated, that 50 % replacement of mass part of fat (m.p.f.) in milk products (sour cream product) by elaborated blend, allows partially adjust its FA composition

    Desecration

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    Deacon Christopher, a soon-to-be-ordained Catholic priest, is faced with the reality of the sex scandals in the wake of his upcoming ordination

    Akibat Hukum Kepailitan terhadap Kreditor Pemegang Hak Tanggungan dalam Eksekusi Hak Tanggungan

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    Tujuan-The purpose of this study was to how did the legal consequences of bankruptcy to creditors as holders of guaranty rights in executing guaranty rights of debitors. This was a descriptive and normative business law research.Metode-Data were collected from primary, secondary, and tertiary business law materials. Data were analyzed and discussed to draw conclusions qualitatively to answer the research problems.Results-showed that the causes why separate creditors had exclusive authorities upon bankruptcy was that to provide legal security upon guaranty to return credits had been granted to debtors, because without legal security on the credits, there would be no institutions (both individual or legal entity) willing to provide credits to debtors. Creditor rights as holders of guaranty rights were in form of parate eksekusi and execution based on execution power to the Certificate of Guaranty rights which was limited by Act of bankruptcy.Originality

    Expression of Tumor Assosiated and Epithelial-mesenchymal Transition Markers in 2d and 3d Cell Cultures of Mcf-7

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    The target effects on the expression of epithelial-mesenchymal transition regulation molecules are promising for cancer therapy, including breast cancer. 3D cell culture is a model for studying epithelial-mesenchymal transition in vitro and may become a test system for anticancer therapy.Aim of research. The aim of this research was to evaluate and compare the expression of tumor associated and epithelial-mesenchymal transition markers in tumor cells of breast adenocarcinoma (MCF-7 cell line) in 2D and 3D cell culture.Methods. For realization of the aim MCF-7 cell line (breast adenocarcinoma) was chosen as an experimental model in vitro. The monolayer cell culture was cultured in standard conditions (37 0C, 5 % CO2, humidity 95 %). The initial density of inoculated cells was 2 x 104 cells/cm2. The cells were incubated for two days before their use in the experiment. For the initial generation of spheroids the monolayer cell culture was removed off the substrate after the four days of incubation, using 0,25 % Trypsin-EDTA, and placed in nutrient medium with 5 % carboxymethyl cellulose (Bio-Rad, USA) at concentration of 5 x 105 cells/ml. Then the plates were incubated on an orbital shaker (Orbital shaker, PSU-10i, Biosan, Latvia) at 50 rpm for 3–5 hours. Half of culture medium was replenished every 3 days. A spheroid culture was maintained for 14 days. Detection of markers (ER, p53, EpCAM, vim, AE1/AE3, panCK, EGFR) in 2D and 3D cell culture was performed using immunohistochemistry method with primary monoclonal antibodies. Histological samples of cells were photographed to compare the morphological characteristics and the expression of proteins in monolayer and spheroid cultureResults. The results demonstrated that the percentage of tumor marker positive cells (ER+, EGFR+, EpCAM+, panCK+, AE1/AE3+) in monolayer culture is 1.25–2 times than more in spheroid culture. In contrast, tumor spheroids consist of fewer cells with the expression of epithelial markers such as EpCAM and AE1/AE3, but they contain a large number of cells that expressed mesenchymal marker vimentin by 5 % and p53 by 10 %. This may indicate that the cells acquire a mesenchymal phenotype. However, tumor cells of monolayer cell culture were not expressed vimentin.Conclusions. Our results demonstrated the differences of expression of tumor associated and epithelial-mesenchymal transition markers in 2D and 3D breast cancer cell cultures. Thus, the percentage of epithelial markers (Cytokeratines and epithelial cell adhesion molecule) in tumor spheroids is less than in cells of monolayer however spheroids cells begin expressing a mesenchymal marker – vimentin. In 3D cell culture only the outer cell layers expressed tumor associated proteins unlike 2D cell culture in which all of cells showed equally expression. Reduced of manifestation of tumor associated markers in 3D cell culture may indicate an increase of stem properties. These data showed that 3D cell culture more than 2D cell culture characterized processes of epithelial-mesenchymal transition
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