371 research outputs found

    Descripción del Modelo de Lorenz con aplicaciones

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    Los contenidos y métodos de los sistemas dinámicos son de gran interés en la matemática aplicada actual; tanto por el soporte científico como por la necesidad de interactuar con los modelos matemáticos de fenómenos de diversas disciplinas. En este trabajo, esta preocupación se centra en estudiar el origen, la interpretación dinámica, el caos y la sincronización del modelo de Lorenz. La motivación surge del curso de ecuaciones diferenciales, orientado por el profesor Mauro Montealegre Cárdenas, a quien agradecemos su colaboración durante la elaboración de esta tesis.65 p.Contenido parcial: Historia de la mecánica de fluidos -- Descripción del caos en el sistema Lorenz -- Sincronización de sistemas caóticos

    Educación para la prevención del abuso sexual en la institución educativa el Pensil, Betania y el Hogar infantil La Argentina, del Municipio de La Argentina del departamento del Huila

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    Imagenes, Tablas, DiagramasLa educación en la prevención del abuso sexual infantil en la Institución Educativa el pensil Betania , y el colegio sueños y sonrisas del Municipio de La Argentina del Departamento del Huila, se abordó en su gran mayoría población estudiantil entre los 5 a 16 años, pero asimismo se contó con la participación de docentes y padres de familia, utilizando una metodología activa participativa dinámica desarrollando actividades reflexivas como talleres, charlas, videos, dinámicas, concursos, y espacios de esparcimiento etc. Dando a los estudiantes docentes y padres de familia herramientas para la prevención del abuso sexual.Education on prevention of child sexual abuse in the hanging Bethany Educational Institution, and college dreams and smiles of the Municipality of La Argentina Huila Department, addressed the vast majority student population between 5-16 years, but also counted with the participation of teachers and parents, using a participatory dynamic developing reflective activities such as workshops, lectures, videos, dynamic, competitions, and recreational areas etc active methodology. Giving students teachers and parents tools to prevent sexual abuse

    Organizing refugee camps: 'respected space' and 'listening posts'

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    We examine an organizational form that has received little attention despite its social significance – the refugee camp. From an in-depth case study of the Dadaab refugee camp in Kenya we explain how these organizations maintain social stability even though refugees live for decades in them and are deprived of the freedom to move or work outside the camp’s boundaries. Our analysis finds that refugee camps are characterized by a parallel organizational structure in which the institutional worlds of (primarily Western) camp officials and (in our case, primarily Somali) refugees coexist. Mutual dependence between camp officials and refugees enables the use of a respected space of reciprocal tolerance and minimal intrusion, and a listening post that is perceived as a legitimate communication arrangement and that acts as a safety valve. These complementary mechanisms provide the means by which to allay the otherwise high potential of severe discontent

    IRX-2, a Novel Immunotherapeutic, Enhances Functions of Human Dendritic Cells

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    Background: In a recent phase II clinical trial for HNSCC patients, IRX-2, a cell-derived biologic, promoted T-cell infiltration into the tumor and prolonged overall survival. Mechanisms responsible for these IRX-2-mediated effects are unknown. We hypothesized that IRX-2 enhanced tumor antigen-(TA)-specific immunity by up-regulating functions of dendritic cells (DC). Methodology/Principal Findings: Monocyte-derived DC obtained from 18 HNSCC patients and 12 healthy donors were matured using IRX-2 or a mix of TNF-α, IL-1β and IL-6 ("conv. mix"). Multicolor flow cytometry was used to study the DC phenotype and antigen processing machinery (APM) component expression. ELISPOT and cytotoxicity assays were used to evaluate tumor-reactive cytotoxic T lymphocytes (CTL). IL-12p70 and IL-10 production by DC was measured by Luminex® and DC migration toward CCL21 was tested in transwell migration assays. IRX-2-matured DC functions were compared with those of conv. mix-matured DC. IRX-2-matured DC expressed higher levels (p<0.05) of CD11c, CD40, CCR7 as well as LMP2, TAP1, TAP2 and tapasin than conv. mix-matured DC. IRX-2-matured DC migrated significantly better towards CCL21, produced more IL-12p70 and had a higher IL12p70/IL-10 ratio than conv. mix-matured DC (p<0.05 for all). IRX-2-matured DC carried a higher density of tumor antigen-derived peptides, and CTL primed with these DC mediated higher cytotoxicity against tumor targets (p<0.05) compared to the conv. mix-matured DC. Conclusion: Excellent ability of IRX-2 to induce ex vivo DC maturation in HNSCC patients explains, in part, its clinical benefits and emphasizes its utility in ex vivo maturation of DC generated for therapy. © 2013 Schilling et al

    What do we have to know about PD-L1 expression in prostate cancer? A systematic literature review. part 4: Experimental treatments in pre-clinical studies (cell lines and mouse models)

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    In prostate cancer (PC), the PD-1/PD-L1 axis regulates various signaling pathways and it is influenced by extracellular factors. Pre-clinical experimental studies investigating the effects of various treatments (alone or combined) may discover how to overcome the immunotherapyresistance in PC-patients. We performed a systematic literature review (PRISMA guidelines) to delineate the landscape of pre-clinical studies (including cell lines and mouse models) that tested treatments with effects on PD-L1 signaling in PC. NF-kB, MEK, JAK, or STAT inhibitors on human/mouse, primary/metastatic PC-cell lines variably down-modulated PD-L1-expression, reducing chemoresistance and tumor cell migration. If PC-cells were co-cultured with NK, CD8+ Tcells or CAR-T cells, the immune cell cytotoxicity increased when PD-L1 was downregulated (opposite effects for PD-L1 upregulation). In mouse models, radiotherapy, CDK4/6-inhibitors, and RB deletion induced PD-L1-upregulation, causing PC-immune-evasion. Epigenetic drugs may reduce PD-L1 expression. In some PC experimental models, blocking only the PD-1/PD-L1 pathway had limited efficacy in reducing the tumor growth. Anti-tumor effects could be increased by combining the PD-1/PD-L1 blockade with other approaches (inhibitors of tyrosine kinase, PI3K/mTOR or JAK/STAT3 pathways, p300/CBP; anti-RANKL and/or anti-CTLA-4 antibodies; cytokines; nitroxoline; DNA/cell vaccines; radiotherapy/Radium-223)

    Accurate reconstruction of insertion-deletion histories by statistical phylogenetics

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    The Multiple Sequence Alignment (MSA) is a computational abstraction that represents a partial summary either of indel history, or of structural similarity. Taking the former view (indel history), it is possible to use formal automata theory to generalize the phylogenetic likelihood framework for finite substitution models (Dayhoff's probability matrices and Felsenstein's pruning algorithm) to arbitrary-length sequences. In this paper, we report results of a simulation-based benchmark of several methods for reconstruction of indel history. The methods tested include a relatively new algorithm for statistical marginalization of MSAs that sums over a stochastically-sampled ensemble of the most probable evolutionary histories. For mammalian evolutionary parameters on several different trees, the single most likely history sampled by our algorithm appears less biased than histories reconstructed by other MSA methods. The algorithm can also be used for alignment-free inference, where the MSA is explicitly summed out of the analysis. As an illustration of our method, we discuss reconstruction of the evolutionary histories of human protein-coding genes.Comment: 28 pages, 15 figures. arXiv admin note: text overlap with arXiv:1103.434

    What do we have to know about PD-L1 expression in prostate cancer? A systematic literature review. Part 3: PD-L1, intracellular signaling pathways and tumor microenvironment

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    The tumor microenvironment (TME) includes immune (T, B, NK, dendritic), stromal, mesenchymal, endothelial, adipocytic cells, extracellular matrix, and cytokines/chemokines/soluble factors regulating various intracellular signaling pathways (ISP) in tumor cells. TME influences the survival/progression of prostate cancer (PC), enabling tumor cell immune-evasion also through the activation of the PD-1/PD-L1 axis. We have performed a systematic literature review according to the PRISMA guidelines, to investigate how the PD-1/PD-L1 pathway is influenced by TME and ISPs. Tumor immune-escape mechanisms include suppression/exhaustion of tumor infiltrating cytotoxic T lymphocytes, inhibition of tumor suppressive NK cells, increase in immune-suppressive immune cells (regulatory T, M2 macrophagic, myeloid-derived suppressor, dendritic, stromal, and adipocytic cells). IFN-γ (the most investigated factor), TGF-β, TNF-α, IL-6, IL-17, IL-15, IL-27, complement factor C5a, and other soluble molecules secreted by TME components (and sometimes increased in patients’ serum), as well as and hypoxia, influenced the regulation of PD-L1. Experimental studies using human and mouse PC cell lines (derived from either androgen-sensitive or androgen-resistant tumors) revealed that the intracellular ERK/MEK, Akt-mTOR, NF-kB, WNT and JAK/STAT pathways were involved in PD-L1 upregulation in PC. Blocking the PD-1/PD-L1 signaling by using immunotherapy drugs can prevent tumor immune-escape, increasing the anti-tumor activity of immune cells
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