Cycles Of Diversification Research Articles

Decisión de diversificación y decisión de Spin-off. Ciclos de expansión y ciclos de enfoque: Analisis retrospectivo de las evidencias del caso Bavaria

Esta propuesta utiliza el caso del Antigüo Grupo Empresarial Bavaria para analizar tres aspectos relacionados con la diversificación no relacionada y el proceso de spin off de las firmas. Primero se establece que las empresas con unidades de negocio caracterizadas por excesos de liquidez, se diversifican de manera no relacionada, debido a que la existencia de un mercado interno de capitales, les permite derribar sus restricciones de financiación e incrementar la rentabilidad corporativa. Segundo, se demuestra que la decisión de diversificación de un gerente corporativo es inversamente proporcional a la magnitud del costo esperado por la dilución de esfuerzo del gerente de la nueva unidad de negocio. Y finalmente, se muestra como la diversificación no relacionada presenta un límite en su contribución al incremento de la rentabilidad corporativa, en cuyo caso se puede inducir la decisión de realizar un spin off, para delimitar, especializar y mejorar la calidad de las decisiones de asignación de recursos. Se concluye que lo anterior puede explicar porque en algunos grupos económicos se observan ciclos de diversificación y ciclos de enfoque. Cuando el grupo económico desea incrementar la rentabilidad inicia su proceso de diversificación, una vez llega al umbral que hace que la probabilidad de acierto en sus decisiones de inversión se reduzca, entonces empieza nuevamente su proceso de enfoque, realizando separación de sus unidades no relacionadas. Este ciclo se puede repetir en el desarrollo histórico de un grupo empresarial.

A RAPD study of the Sarcostemma group of Cynanchum (Apocynaceae-Asclepiadoideae-Asclepiadeae)

One hundred and thirty-seven accessions of Cynanchum viminale and its relatives, formerly known as Sarcostemma, were studied using randomly amplified polymorphic DNA (RAPD). A fingerprinting technique was used because sequencing had failed to differentiate between morphologically separable groups. Chromosome counts were conducted to establish the ploidy level of the accessions. The banding patterns resulting from RAPD analysis were evaluated with Canonical Analysis of Principal Coordinates, Permanova and neighbour-joining. A strong geographic component was found in the structure of the group. Taxa considered species or subspecies based on morphology often formed coherent groups. The data are interpreted to reflect at least two cycles of diversification: the first one from Madagascar and the second one most likely from the East African–Arabian region, reaching Madagascar again. In mainland Africa, polyploidisation has occurred several times.

Monitored whole gene in vitro evolution of an anti-hRaf-1 affibody molecule towards increased binding affinity

The use of library technologies for the generation of affinity proteins often includes an affinity maturation step, based on the construction of secondary libraries from which second generation variants with improved affinities are selected. Here, we describe for the first time the affinity maturation of affibody molecules based on step-wise in vitro molecular evolution, involving cycles of error-prone PCR (epPCR) amplification for the introduction of diversity over the entire 58-residue three-helix bundle structure and ribosome display (RD) for the selection of improved variants. The model affibody molecule for the process was Z(RAF322), binding with a 1.9μm equilibrium dissociation constant (K(D)) to human Raf-1 (hRaf-1), a protein kinase of central importance in the MAPK/ERK proliferation pathway. The molecular evolution process was followed on both gene and protein levels via DNA sequencing and a biosensor-based binding analysis of pools of selected variants. After two cycles of diversification and selection, a significant increase in binding response of selected pools was seen. DNA sequencing showed that a dominant alanine to valine substitution had been effectively enriched, and was found in 83% of all selected clones, either alone or in combination with other enriched substitutions. The evolution procedure resulted in variants showing up to 26-fold increases in affinity to the hRaf-1 target. Noteworthy, for the two variants showing the highest affinities, substitutions were also found in affibody framework positions, corresponding to regions of the protein domain not addressed by traditional affibody molecule affinity maturation strategies. Interestingly, thermal melting point (T(m)) analyses showed that an increased affinity could be associated with both higher and lower T(m) values. All investigated variants showed excellent refolding properties and selective binding to hRaf-1, as analysed using a multiplexed bead-based binding assay, making them potentially valuable affinity reagents for cell biology studies.

The Dynamics of Land Development in Resort Communities: A Multiagent Simulation of Growth Regimes and Housing Choice

Over the past thirty years, recreation communities in many parts of the globe have gone through cycles of diversification and integration into complex recreation regions. As resort communities mature, they face increasing pressures on scarce recreational resources, demands for economic diversification, and changing attitudes toward tourism on the part of local residents. A variety of land-use management practices and economic development initiatives has emerged in resort towns in response to resource congestion and other growth issues. In this paper we explore alternative growth strategies through a simulation of housing decisions by primary actors in resort land markets. We use a multiagent system to model the dynamics of growth regimes, assess the influence of recreational and town amenities, and evaluate the effect of alternative growth processes on long-term development patterns. Our case study area is Steamboat Springs and surrounding parts of Routt County, a four-season recreational region in northwestern Colorado.