300 research outputs found

    ¿Qué está haciendo el científico? : análisis de la actividad científica descrita por alumnos secundarios chilenos de 11° y 12° grado de distintos tipos de establecimientos educacionales

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    Con el objetivo de conocer la representación de estudiantes secundarios chilenos de distintos tipos de establecimientos acerca de los científicos y la actividad que estos realizan, se aplicó a una muestra de 438 estudiantes de 11° y 12° grado el Draw-a-Scientist-Test, en la versión de Türkmen (2008). En ella, los alumnos son invitados a describir de manera escrita la actividad que realiza el científico que dibujaron. Dichas narraciones fueron analizadas en función de los procesos científicos relatados, propósitos y consecuencia de la actividad descrita. Los procesos científicos más frecuentemente mencionados fueron “experimentar” y “observar”. “Formular modelos”, proceso fundamental en la actividad científica, prácticamente no fue mencionado. En relación a propósitos y consecuencias la mayoría de los alumnos tiene una imagen positiva de la actividad científica

    Breast cancer cutaneous metastases are associated to uMUC1 and sialyl Lewis x and to highly malignant primary tumors

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    Breast cancer spreading to different organs have been related to different molecules and mechanisms, but cutaneous metastasis remains unexplored. Increasing evidence showed that MUC1 and some of its carbohydrate associated antigens may be implicated in breast cancer metastasis. In this study we analyzed these tumor markers in order to identify breast cancer cutaneous metastatic profiles. A cohort of 26 primary tumors from breast cancer patients with cutaneous metastases were included; also, cutaneous and lymphatic node metastatic samples and primary tumors from breast cancer patients without metastases were analysed. Immunohistochemical (IHC) studies demonstrated that both underglycosylated MUC1 (uMUC1) and sialyl Lewis x (sLex) to be positively associated with cutaneous metastatic primary tumors (p < 0.05). Notably, a high percentage of tumors with cutaneous metastases were characterized as triple negative and Her2+ tumors (37.5 % and 29 %, respectively). Some discordant results were found between primary tumors and their matched cutaneous metastases. To determine if MUC1 variants may be carriers of carbohydrate antigens, subcellular fractions from a cutaneous metastatic lesion were obtained, immunoprecipitated and analyzed by Western blot. We found that the isolated uMUC1 with a molecular weight of>200 kDa was also the site for binding of antisLex MAb; in coincidence, a high correlation of positive IHC expression of both markers was observed. Our findings confirm that breast cancer cutaneous metastases were associated to highly malignant primary tumors and sustain the hypothesis that u-MUC1 and sLe x may drive breast cancer cutaneous metastases.Centro de Investigaciones Inmunológicas Básicas y Aplicada

    Metástasis cutáneas de cáncer de mama

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    El objetivo de este estudio es identificar perfiles correspondientes a la metástasis cutánea en el cáncer de mama mediante el análisis de marcadores tumorales tales como MUC1 y antígenos carbohidratos asociados.Facultad de Ciencias Médica

    Metástasis cutáneas de cáncer de mama

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    El objetivo de este estudio es identificar perfiles correspondientes a la metástasis cutánea en el cáncer de mama mediante el análisis de marcadores tumorales tales como MUC1 y antígenos carbohidratos asociados

    Linking learning with governance in networks and clusters: key issues for analysis and policy

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    In this paper we analyse the relationship between governance and learning in clusters and networks. In particular, we see these two key elements as interdependent, suggesting that, under particular circumstances, such interdependence may drive clusters and networks towards a dynamic development trajectory. A pure ‘governance perspective’ makes the development of any locality dependent on the system of powers which exists within the locality or across the global value chain. In parallel, a pure ‘competence-based approach’ focuses mainly on the capabilities of actors to learn and undertake activities. In contrast, we open the prospects for an interdependent relation that may change the actual competences of actors as well as the governance settings and dynamics in networks and clusters. When supported by public policies, the learning process may have the potential to modify the governance environment. Simultaneously, the learning process is intrinsically influenced by economic power, which may seriously affect the development prospects of clusters and networks. This is why an intertwined consideration of both aspects is necessary to promote specific approaches to learning and to design appropriate policies. In this paper we offer two preliminary case studies to clarify some of these dynamics: the first taken from the computers cluster in Costa Rica and the second from an Italian bio-pharmaceutical firm and its production network. The first case study refers to the software cluster that was created from scratch in Costa Rica thanks to an enlightened government policy in coordination with new local enterprises and an important foreign direct investor; while the second reflects on the ability of an individual company to create a network of relationships with large transnational companies in order to acquire new competences without falling into a subordinate position with respect to its larger partners

    International Risk-Taking, Volatility, and Consumption Growth

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    We show that countries that take on more international risk are rewarded with higher expected consumption growth. International risk is defined as the beta of a country's consumption growth with world consumption growth. High-beta countries hold more foreign assets, as predicted by the theory. Despite the positive effects of beta, a country's idiosyncratic volatility is negatively correlated with expected consumption growth. Therefore, uninsured shocks affect not only current growth, but also future consumption growth. High-volatility countries have worse net foreign asset positions, suggesting that solvency constraints limit their future growth
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