The multiregional core-periphery model: the role of the spatial topology

We use the multiregional core-periphery model of the new economic geography to analyze and compare the agglomeration and dispersion forces shaping the location of economic activity for a continuum of network topologies characterized by their degree of centrality, and comprised between two extremes represented by the homogenous (ring) and the heterogeneous (star) configurations. Resorting to graph theory, we systematically extend the analytical tools and graphical representations of the coreperiphery model for alternative spatial configurations, and study the stability of the alternative equilibria in terms of the sustain and break points. We study new phenomena such as the absence of any stable distribution of economic activity for some range of transport costs, and the infeasibility of the dispersed equilibrium in the heterogeneous space, resulting in the introduction of the concept pseudo flat-earth as a long run-equilibrium corresponding to an uneven distribution of economic activity between region

A rush of blood to the head: Temporal dimensions of retrenchment, environment and turnaround performance

In this work we test the general assumption in the turnaround literature that time is critical for firm survival, especially during the retrenchment stage.We study three time dimensions of change at this stage: timing, speed and rhythm. Drawing on the downward spiral and threat-rigidity perspectives, we posit that the positive impact these time dimensions have on turnaround performance is highly contingent on two types of environment. Our findings, based on a sample of 263 declining US firms over a 26-year period (1983e2009), demonstrate that an early timing of retrenchment has a positive impact on performance when the environment is munificent. On the contrary, an early timing has a negative impact when the environment is dynamic. We also note that a fast pace of retrenchment positively impacts firm performance in dynamic environments. Finally, we find that declining firms display better performances when following an irregular rhythm of retrenchment, both in highly munificent and highly dynamic environments. Our results indicate that, in general, declining firm performance improves with time-aggressive retrenchment actions in both types of environment. We discuss the contribution of our research to the turnaround literature, and the downward spiral and threat-rigidity perspective

A Panel Data Toolbox for MATLAB

Panel Data Toolbox is a new package for MATLAB that includes functions to estimate the main econometric methods of panel data analysis. The package includes code for the standard fixed, between and random effects estimation methods, as well as for the existing instrumental panel and new spatial panel. This paper describes the methodology and implementation of the functions and illustrates their use with well-known examples. We perform numerical checks against other popular commercial and free software in order to show the validity of the result

The measurement of profit, profitability, cost and revenue efficiency through data envelopment analysis: A comparison of models using BenchmarkingEconomicEfficiency.jl

We undertake a systematic comparison of existing models measuring and decomposing the economic efficiency of organizations. For this purpose we introduce the package BenchmarkingEconomicEfficiency.jl for the open-source Julia language including a set of functions to be used by scholars and professionals working in the fields of economics, management science, engineering, and operations research. Using mathematical programming methods known as Data Envelopment Analysis, the software develops code to decompose economic efficiency considering alternative definitions: profit, profitability, cost and revenue. Economic efficiency can be decomposed, multiplicative or additively, into a technical (productive) efficiency term and a residual term representing allocative (or price) efficiency. We include traditional decompositions like the radial efficiency measures associated with the input (cost) and output (revenue) approaches, as well as new ones corresponding to the Russell measures, the directional distance function, DDF (including novel extensions like the reverse DDF, modified DDF, or generalizations based on Hölder norms), the generalized distance function, and additive measures like the slack based measure, their weighted variants, etc. Moreover, regardless the underlying economic efficiency model, many of these technical inefficiency measures are available for calculation in a computer software for the first time. This article details the theoretical methods and the empirical implementation of the functions, comparing the obtained results using a common dataset on Taiwanese BanksJosé L. Zofío thanks the grant PID2019-105952 GB-I00 funded by Ministerìo de Ciencia e Innovación/ Agencia Estatal de Investigación /10.13039/50110001103

The Multiregional Core-periphery Model: The Role of the Spatial Topology

This version of the article has been accepted for publication and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s11067-015-9285-7We use the multiregional core-periphery model of the new economic geography to analyze and compare the agglomeration and dispersion forces shaping the location of economic activity for a continuum of network topologies — spatial or geographic configuration — characterized by their degree of centrality, and comprised between two extremes represented by the homogenous (ring) and the heterogeneous (star) configurations. Resorting to graph theory, we systematically extend the analytical tools and graphical representations of the core-periphery model for alternative spatial configuration, and study the sustain and break points. We study new phenomena such as the infeasibility of the dispersed equilibrium in the heterogeneous space, resulting in the introduction of the concept pseudo flat-earth as a long-run equilibrium corresponding to an uneven distribution of economic activity between region

Spherical harmonics to quantify cranial asymmetry in deformational plagiocephaly

[EN] Cranial deformation and deformational plagiocephaly (DP) in particular affect an important percentage of infants. The assessment and diagnosis of the deformation are commonly carried by manual measurements that provide low interuser accuracy. Another approach is the use of three-dimensional (3D) models. Nevertheless, in most cases, deformation measurements are carried out manually on the 3D model. It is necessary to develop methodologies for the detection of DP that are automatic, accurate and take profit on the high quantity of information of the 3D models. Spherical harmonics are proposed as a new methodology to identify DP from head 3D models. The ideal fitted ellipsoid for each head is computed and the orthogonal distances between head and ellipsoid are obtained. Finally, the distances are modelled using spherical harmonics. Spherical harmonic coefficients of degree 2 and order - 2 are identified as the correct ones to represent the asymmetry characteristic of DP. The obtained coefficient is compared to other anthropometric deformation indexes, such as Asymmetry Index, Oblique Cranial Length Ratio, Posterior Asymmetry Index and Anterior Asymmetry Index. The coefficient of degree 2 and order - 2 with a maximum degree of 4 is found to provide better results than the commonly computed anthropometric indexes in the detection of DP.This article was funded by Instituto de Salud Carlos III and European Regional Development Fund (FEDER) (Grant no. PI18/00881).Grieb, J.; Barbero-García, I.; Lerma, JL. (2022). Spherical harmonics to quantify cranial asymmetry in deformational plagiocephaly. Scientific Reports. 12(1):1-10. https://doi.org/10.1038/s41598-021-04181-z11012

Estudios estructurales en la histona H1 de ceratitis capitata

Tesis - Universidad Complutense de Madrid, 1981.Depto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEProQuestpu

A reduced basis for a local high definition wind model

In this paper we present an application of the reduced basis method to a local high definition adjusted wind model. The model provides a precise description of the wind in 3D and takes into account topography and thermal gradients on the surface by solving only 2D linear equations; the buoyancy forces, slope effects, and mass conservation are also considered. The wind field is adjusted to the point measurements through an optimal control problem in which the wind flux acts as a control on the boundary. In order to use a reduced basis method, we consider an affine decomposition in terms of the parameter related to the friction coefficient and the wind measures at some given observation points. We also design an a posteriori error estimator that is needed to conduct our reduced basis process. Finally, two numerical examples are presented: a test problem and a real-data scenario, we corroborate the correct behavior of the method in both cases.Ministerio de Economía y Competitividad del Gobierno de España; FONDECYT N1140392, CONICYT; Basal CMM U. de Chile

Turnaround Strategy and ownsership structure in declining firms: diferences between family and non-family businesses

El presente trabajo analiza la influencia de la estructura de propiedad en las estrategias de reestructuración en empresas en crisis, específicamente, en el caso de las pequeñas y medianas empresas. En concreto, nos centramos en el estudio de las diferencias entre empresas familiares y no familiares a la hora de afrontar y reaccionar ante resultados decrecientes. Sobre una muestra de 1.807 empresas españolas (PYMEs), de las que 947 están controladas por una persona o familia, hemos encontrado que las empresas familiares con resultados negativos tienden a mantener o aumentar puestos de trabajo al tiempo que reducen sus activos a través de procesos de desinversión. Asimismo, hemos comprobado que esta relación se da con mayor intensidad en el caso de las empresas familiares de menor tamaño y edad. Finalmente, el nivel de concentración de la propiedad también parece ejercer un papel moderador.The present paper analyzes the influence of the ownership structure on turnaround strategies in declining firms, especially in the case of small and medium-sized businesses. Concretely, we focus on the study of the differences between family and non-family businesses when they react to decreasing financial results during few years. Using a sample of 1,807 Spanish firms (SMEs), 947 of them controlled by a single person or a family, we have found that family-owned businesses with negative results tend to maintain or increase the number of employees while they reduce their assets, by divestments operations. We have also confirmed that this relationship is more intense in the case of smaller and younger family-owned businesses. Finally, we have considered concentration of ownership structure as an additional moderator variable in the study