Diseño de un modelo de dirección por competencias básicas distintivas para las pymes exportadoras de la ciudad de medellín

El presente trabajo permite reconocer el modelo de dirección por competencias básicas distintivas (DCBD),como herramienta para que las pymes exportadoras de Medellín puedan medir su competitividad internacional,a partir de los recursos, competencias y capacidades existentes en su estructura administrativa y organizacional.Para ello se diseña un modelo de tipo cualitativo no probabilístico que combina escalas de medición de linkertcon otras de diferencial semántico, cuyo producto es una matriz que permite clasificar la competencia esencialen tres categorías: valiosa, rara y exclusiva. De esta manera, las empresas pueden conocer qué tan preparadasse encuentran, en términos de sus recursos y capacidades, para internacionalizarse. El factor innovador deesta herramienta consiste en adicionar a los modelos de competencias básicas distintivas la orientación haciala internacionalizació

Reconstruction of topological graphs and their Hilbert bimodules

We show that the Hilbert bimodule associated to a compact topological graph can be recovered from the C*-algebraic triple consisting of the Toeplitz algebra of the graph, its gauge action and the commutative subalgebra of functions on the vertex space of the graph. We discuss connections with work of Davidson-Katsoulis and of Davidson-Roydor on local conjugacy of topological graphs and isomorphism of their tensor algebras. In particular, we give a direct proof that a compact topological graph can be recovered up to local conjugacy from its Hilbert bimodule, present an example of nonisomorphic locally conjugate compact topological graphs with isomorphic Hilbert bimodules. We also give an elementary proof that for compact topological graphs with totally disconnected vertex space the notions of local conjugacy, Hilbert bimodule isomorphism, isomorphism of C*-algebraic triples, and isomorphism all coincide.Comment: V2: 24 pages. Added references to earlier work, especially of Davidson-Katsoulis, Davidson-Roydor for the origin of local conjugacy of topological graphs and related results/examples, and of Bruce-Takeishi on reconstruction of discrete graphs; apologies for our oversight. Thanks to Adam Dor-On and an anonymous referee for alerting us, and Davidson and Katsoulis for helpful discussion

High-throughput continuous dielectrophoretic separation of neural stem cells.

We created an integrated microfluidic cell separation system that incorporates hydrophoresis and dielectrophoresis modules to facilitate high-throughput continuous cell separation. The hydrophoresis module consists of a serpentine channel with ridges and trenches to generate a diverging fluid flow that focuses cells into two streams along the channel edges. The dielectrophoresis module is composed of a chevron-shaped electrode array. Separation in the dielectrophoresis module is driven by inherent cell electrophysiological properties and does not require cell-type-specific labels. The chevron shape of the electrode array couples with fluid flow in the channel to enable continuous sorting of cells to increase throughput. We tested the new system with mouse neural stem cells since their electrophysiological properties reflect their differentiation capacity (e.g., whether they will differentiate into astrocytes or neurons). The goal of our experiments was to enrich astrocyte-biased cells. Sorting parameters were optimized for each batch of neural stem cells to ensure effective and consistent separations. The continuous sorting design of the device significantly improved sorting throughput and reproducibility. Sorting yielded two cell fractions, and we found that astrocyte-biased cells were enriched in one fraction and depleted from the other. This is an advantage of the new continuous sorting device over traditional dielectrophoresis-based sorting platforms that target a subset of cells for enrichment but do not provide a corresponding depleted population. The new microfluidic dielectrophoresis cell separation system improves label-free cell sorting by increasing throughput and delivering enriched and depleted cell subpopulations in a single sort

Presence of cytochrome P-450-dependent monooxygenase in intimal cells of the hog aorta

Cytochrome P-450-dependent mixed function oxidase activity is present in vascular tissue; however, as far as we could determine, the distribution of monooxygenase activity across the blood vessel wall has not previously been assessed. The aryl-hydrocarbon hydroxylase activity was examined by metabolism of benzo[a]pyrene in microsomes prepared from intimal and smooth muscle cell scrapings of the hog thoracic aorta. Microsomes of intimal cells comprising 95% endothelial cells showed an approximately 2.5-fold increase in aryl-hydrocarbon hydroxylase activity compared with that in microsomes prepared from medial smooth muscle cells. Michaelis-Mentin kinetics for the intimal enzyme yielded an apparent Km value of 11.11 microM and an apparent Vmax of 3-OH benzo[a]pyrene of 40 pmol/mg protein/10 min. Aryl-hydrocarbon hydroxylase activity was dependent on nicotinamide adenine dinucleotide phosphate and was inhibited by 7,8 benzoflavone, SKF 525A, and carbon monoxide. The localization of cytochrome P-450-dependent mixed function oxidase primarily to the intimal surface of the aorta may indicate a role for this enzyme system in vasoregulation and the pathogenesis of atherosclerosis

The Hospitals/Residents Problem with Couples: complexity and integer programming models

The Hospitals / Residents problem with Couples (hrc) is a generalisation of the classical Hospitals / Residents problem (hr) that is important in practical applications because it models the case where couples submit joint preference lists over pairs of (typically geographically close) hospitals. In this paper we give a new NP-completeness result for the problem of deciding whether a stable matching exists, in highly restricted instances of hrc, and also an inapproximability bound for finding a matching with the minimum number of blocking pairs in equally restricted instances of hrc. Further, we present a full description of the first Integer Programming model for finding a maximum cardinality stable matching in an instance of hrc and we describe empirical results when this model applied to randomly generated instances of hrc

Diseño de un modelo de dirección por competencias básicas distintivas para las pymes exportadoras de la ciudad de medellín

El presente trabajo permite reconocer el modelo de dirección por competencias básicas distintivas (DCBD),como herramienta para que las pymes exportadoras de Medellín puedan medir su competitividad internacional,a partir de los recursos, competencias y capacidades existentes en su estructura administrativa y organizacional.Para ello se diseña un modelo de tipo cualitativo no probabilístico que combina escalas de medición de linkertcon otras de diferencial semántico, cuyo producto es una matriz que permite clasificar la competencia esencialen tres categorías: valiosa, rara y exclusiva. De esta manera, las empresas pueden conocer qué tan preparadasse encuentran, en términos de sus recursos y capacidades, para internacionalizarse. El factor innovador deesta herramienta consiste en adicionar a los modelos de competencias básicas distintivas la orientación haciala internacionalizació