Fine structure in the large n limit of the non-hermitian Penner matrix model

In this paper we apply results on the asymptotic zero distribution of the Laguerre polynomials to discuss generalizations of the standard large $n$ limit in the non-hermitian Penner matrix model. In these generalizations $g_n n\to t$, but the product $g_n n$ is not necessarily fixed to the value of the 't Hooft coupling $t$. If $t>1$ and the limit $l = \lim_{n\rightarrow \infty} |\sin(\pi/g_n)|^{1/n}$ exists, then the large $n$ limit is well-defined but depends both on $t$ and on $l$. This result implies that for $t>1$ the standard large $n$ limit with $g_n n=t$ fixed is not well-defined. The parameter $l$ determines a fine structure of the asymptotic eigenvalue support: for $l\neq 0$ the support consists of an interval on the real axis with charge fraction $Q=1-1/t$ and an $l$-dependent oval around the origin with charge fraction $1/t$. For $l=1$ these two components meet, and for $l=0$ the oval collapses to the origin. We also calculate the total electrostatic energy $\mathcal{E}$, which turns out to be independent of $l$, and the free energy $\mathcal{F}=\mathcal{E}-Q\ln l$, which does depend of the fine structure parameter $l$. The existence of large $n$ asymptotic expansions of $\mathcal{F}$ beyond the planar limit as well as the double-scaling limit are also discussed

Spectral curves in gauge/string dualities: integrability, singular sectors and regularization

We study the moduli space of the spectral curves $y^2=W'(z)^2+f(z)$ which characterize the vacua of $\mathcal{N}=1$ U(n) supersymmetric gauge theories with an adjoint Higgs field and a polynomial tree level potential $W(z)$. It is shown that there is a direct way to associate a spectral density and a prepotential functional to these spectral curves. The integrable structure of the Whitham equations is used to determine the spectral curves from their moduli. An alternative characterization of the spectral curves in terms of critical points of a family of polynomial solutions $\mathbb{W}$ to Euler-Poisson-Darboux equations is provided. The equations for these critical points are a generalization of the planar limit equations for one-cut random matrix models. Moreover, singular spectral curves with higher order branch points turn out to be described by degenerate critical points of $\mathbb{W}$. As a consequence we propose a multiple scaling limit method of regularization and show that, in the simplest cases, it leads to the Painlev\`{e}-I equation and its multi-component generalizations.Comment: 29 pages, 4 figure

Have Spanish companies built greater entrepreneurship after privatization?

This study analyses some of the strategic and organizational changes experienced in public firms following privatization in its double facet: sale of companies and deregulation. Specifically, we analyse the process of innovation in terms of products, processes and organization. We also look into the development of new businesses and strategic renewal, which in the end shape the entrepreneurial capacity of a company. A sample of Spanish firms which were privatized between 1985 and 2000 shows that after privatization, these companies have experienced a significant increase in entrepreneurship. These changes are even more appreciable when a high sector competition is added to the ownership shift. Once they join the private sector, their level of product, process and organizational innovation is higher. They also develop new businesses at national level, reinforce their international activity and embark on strategic renewal processes by shedding the lesser profitable businesses and modifying their competitive strategy so as to gain efficiency

Innovation, exports and productivity.

We argue that the positive association found between firm productivity and exports in the literature relates to the firm's innovation decisions. Using a panel of Spanish manufacturing firms we find strong evidence that product innovation and not process innovation affects productivity and induces small non exporting firms to enter the export market.Innovación; Exportación; Productividad;

Influence of Body Composition on Arterial Stiffness in Middle-Aged Adults: Healthy UAL Cross-Sectional Study

Background and objectives: Several anthropometric and body composition parameters have been linked to arterial stiffness (AS) as a biomarker of cardiovascular disease. However, little is known about which of these closely related factors is more strongly associated with AS. The aim of the present study was to analyze the relationship of different anthropometric and body composition parameters with AS in middle-aged adults. Materials and Methods: This cross-sectional study included 186 middle-aged participants (85 women, 101 men; age = 42.8 ± 12.6 years) evaluated as part of the Healthy UAL study, a population study conducted at the University of Almería with the main purpose of analyzing the etiology and risk factors associated with cardio-metabolic diseases. Anthropometric measures included neck, waist, and hip circumferences, as well as the waist-to-height ratio (WHtr). Bioimpedance-derived parameters included fat-free mass index (FFMI), fat mass index (FMI), and percent of body fat (%BF). AS was measured by pulse wave velocity (PWV). The relationships of interest were examined through stepwise regression analyses in which age and sex were also introduced as potential confounders. Results: Neck circumference (in the anthropometric model; R2: 0.889; β: age = 0.855, neck = 0.204) and FFMI (in the bio-impedance model; R2: 0.891; β: age = 0.906, FFMI = 0.199) emerged as significant cross-sectional predictors of AS. When all parameters were included together (both anthropometry and bio-impedance), both neck circumference and FFMI appeared again as being significantly associated with AS (R2: 0.894; β: age = 0.882, FFMI = 0.126, neck = 0.093). Conclusion: It was concluded that FFMI and neck circumference are correlated with AS regardless of potential confounders and other anthropometric and bioimpedance-derived parameters in middle-aged adults

El Monasterio de Hosios Loukas

Reflexión crítica acerca de la visita al monasterio de Hosios Loukas, en Grecia, con los alumnos de la asignatura de Proyectos 3 y Proyectos 4 de Grado en Fundamentos de Arqutiectura, ETSA, Universidad Politécnica de Madrid

El párrafo como unidad discursiva : consideraciones de forma y contenido relativas a su demarcación y estructuración

In dealing with linguistics beyond the sentence the paragraph is considered as one of the intermediate units between the sentence and the text. Rather than a purely-orthographic unit, basically delimited by indentation, the paragraph is seen as a structural unit which exhibits certain formal features, largely, but also of content, which help set up its boundaries (cf. , among others, Brown & Yule 1983, Hinds 1977, Ji 2002, Longacre 1979). The study of such features, some of them depending on the specific text type, proves an interesting task in order to justify the importance of the paragraph as discourse unit. This paper intends to contribute to the study of these aspects, on the basis of a corpus of written texts from weekly news magazines in Spanish. From the point of the content of the paragraph but with relevance on its formal expression, a fundamental notion is that of discourse topic. Topic, and its hierarchy, is closely related to the organisation of discourse and affects other notions such as that of theme, thematic progression, topic-shift markers and the notion of episode, as a unit which can integrate various paragraphs. The paragraph is considered as a unit with internal coherence, on the one hand, and an adequate connection with the linguistic context, on the other. Depending on the communicative content of the paragraph, some studies distinguish different types of paragraph (cf. Siepmann et al. 2008) and others refer to an internal structure in the paragraph (cf. Hannay & Mackenzie 2002). In terms of types of paragraph and their characteristics, there are interesting differences in relation to the contrast among languages and text typology. Among the linguistic strategies that the corpus analysis suggests in terms of the paragraph transitions there are the following: a) adverbial expressions and connectors of different type and meaning, b) expressions reflecting the different patterns of thematic progression (cf. Daneš 1974, Fries 1983), c) focus constructions such as cleft and identifying constructions, d) evaluative and evidential expressions and e) the use of rhetorical questions.A la hora de hablar de una lingüística supraoracional se ha considerado el párrafo como una de las unidades intermedias entre oración y texto. Más que una unidad puramente ortográfica, delimitada básicamente por tabulación, el párrafo se entiende como unidad estructural a la que es posible asociar rasgos de forma, principalmente, aunque también de contenido, que ayudan a señalar su demarcación (cf. entre otros, Brown y Yule 1983, Hinds 1977, Ji 2002, Longacre 1979). El estudio de tales rasgos, algunos de ellos dependientes del tipo específico de texto, resulta interesante para ayudar a justificar la importancia del párrafo como unidad discursiva. Esta propuesta pretende contribuir al estudio de tales cuestiones, basándose en un corpus de textos escritos de revistas de noticias de actualidad en español. Desde el punto de vista del contenido del párrafo pero con incidencia en su expresión formal, una noción fundamental es la de tópico del discurso. El tópico, y su jerarquización, está estrechamente relacionado con la organización del discurso e incide sobre otras nociones como las de tema, progresión temática, marcadores de transición del tópico y la noción de episodio, como unidad que puede englobar varios párrafos. El párrafo se considera como una unidad con coherencia interna, por una parte, y con una conexión adecuada con el contexto lingüístico (que sigue y precede), por otra. Dependiendo del contenido comunicativo del párrafo, algunos estudios distinguen tipos de párrafos diferentes (cf. Siepmann et al. 2008) y otros hablan de una posible estructura interna del párrafo (cf. Hannay y Mackenzie 2002). En cuanto a tipos de párrafos y sus características, surgen diferencias interesantes en relación al contraste entre lenguas y a la tipología textual. Entre las estrategias lingüísticas que se observan en la transición de párrafos en los textos analizados destacan: a) el uso de expresiones adverbiales y conectores de distinta naturaleza y significado (solos o combinados con otras estrategias), b) expresiones que reflejan el principio de progresión temática lineal o escalonada o aquellas que reflejan el principio de progresión temática con temas derivados o continuos (cf. Daneš 1974, Fries 1983), c) perífrasis de relativo (oraciones escindidas) y otras construcciones de foco, d) expresiones evaluativas y marcas evidenciales y, finalmente, e) preguntas retóricas