Toy model to describe the effect of positional blocklike disorder in metamaterials composites

We study theoretically the effect of a new type of blocklike positional disorder on the effective electromagnetic properties of one-dimensional chains of resonant, high-permittivity dielectric particles, where particles are arranged into perfectly well-ordered blocks whose relative position is a random variable. This creates a finite order correlation length that mimics the situation encountered in metamaterials fabricated through self-assembled techniques, whose structures often display short-range order between near neighbors but long-range disorder, due to stacking defects. Using a spectral theory approach combined with a principal component statistical analysis, we study, in the long-wavelength regime, the evolution of the electromagnetic response when the composite filling fraction and the block size are changed. Modifications in key features of the resonant response (amplitude, width, etc.) are investigated, showing a regime transition for a filling fraction around 50%.

Changes in Diadenosine Polyphosphates during Alignment-Fit and Orthokeratology Rigid Gas Permeable

Purpose.: To evaluate the levels of dinucleotides diadenosine tetraphosphate (Ap4A) and diadenosine pentaphosphate (Ap5A) in tears of patients wearing rigid gas permeable (RGP) contact lenses on a daily wear basis and of patients wearing reverse-geometry RGP lenses overnight for orthokeratology treatment. Methods.: Twenty-two young volunteers (10 females, 12 males; 23.47 ± 4.49 years) were fitted with an alignment-fit RGP lens (paflufocon B) for a month, and after a 15-day washout period they were fitted with reverse-geometry RGP lenses for corneal reshaping (paflufocon D) for another month. During each period, tears were collected at baseline day 1, 7, 15, and 28. Ap4A and Ap5A were measured by high-pressure liquid chromatography (HPLC). Additionally, corneal staining, break-up time (BUT), Schirmer test, and dryness symptoms were evaluated. Results.: Ap4A concentrations increased significantly from baseline during the whole period of daily wear of RGP lenses (P < 0.001); concentration was also significantly higher than in the orthokeratology group, which remained at baseline levels during the study period except at day 1 (P < 0.001) and day 28 (P = 0.041). While BUT and Schirmer remained unchanged in both groups, discomfort and dryness were significantly increased during alignment-fit RGP daily wear but not during the orthokeratology period. Conclusions.: Daily wear of RGP lenses increased the levels of Ap4A due to mechanical stimulation by blinking of the corneal epithelium, and this is associated with discomfort. Also, orthokeratology did not produce symptoms or signs of ocular dryness, which could be a potential advantage over soft contact lenses in terms of contact lens-induced dryness.

A Bayesian approach to study the risk variables for tuberculosis occurrence in domestic and wild ungulates in South Central Spain

BACKGROUND Bovine tuberculosis (bTB) is a chronic infectious disease mainly caused by Mycobacterium bovis. Although eradication is a priority for the European authorities, bTB remains active or even increasing in many countries, causing significant economic losses. The integral consideration of epidemiological factors is crucial to more cost-effectively allocate control measures. The aim of this study was to identify the nature and extent of the association between TB distribution and a list of potential risk factors regarding cattle, wild ungulates and environmental aspects in Ciudad Real, a Spanish province with one of the highest TB herd prevalences. RESULTS We used a Bayesian mixed effects multivariable logistic regression model to predict TB occurrence in either domestic or wild mammals per municipality in 2007 by using information from the previous year. The municipal TB distribution and endemicity was clustered in the western part of the region and clearly overlapped with the explanatory variables identified in the final model: (1) incident cattle farms, (2) number of years of veterinary inspection of big game hunting events, (3) prevalence in wild boar, (4) number of sampled cattle, (5) persistent bTB-infected cattle farms, (6) prevalence in red deer, (7) proportion of beef farms, and (8) farms devoted to bullfighting cattle. CONCLUSIONS The combination of these eight variables in the final model highlights the importance of the persistence of the infection in the hosts, surveillance efforts and some cattle management choices in the circulation of M. bovis in the region. The spatial distribution of these variables, together with particular Mediterranean features that favour the wildlife-livestock interface may explain the M. bovis persistence in this region. Sanitary authorities should allocate efforts towards specific areas and epidemiological situations where the wildlife-livestock interface seems to critically hamper the definitive bTB eradication success.

Populismos y democracias defectuosas en El Ecuador (1996-2012): continuidades y diferencia

From 1995 to 2015, Ecuador experienced one of its longest periods of deep political, social and economic crisis. During this interval, three democratically elected governments (Bucaram, 1997; Mahuad, 2000 and Gutiérrez, 2005) were overthrown and a critical juncture arose in 2006 as a result. Since 2007, and as a consequence of these chaotic circumstances, new populist strongmen ascended and, amid the biggest bonanza of oil revenues in Ecuadorian history, established a defective democracy. The gradual escalation of authoritarian tendencies during the three consecutive terms in which Rafael Correa has acted as President, have resulted in the severe weakening of the country’s democratic institutions, since Correa’s has strived to perpetuate himself in power through continual re-election into office, instead of building an institutional quality-democracy. This study aims to clarify the historical foundations of the recurrence of caudillistas, populist and authoritarian governments in Ecuador, revealing the basis of the specific path dependence of Ecuadorian politics. We also explore the Jungian theory, specifically the “pseudo-hero myth”, as the political narrative which Correa’s regime successfully employed to establish its hegemony. Additionally, we perform a psychological-political case analysis by examining the social psychology components underlying the Ecuadorian path dependence towards authoritarian and populist caudillos: Specifically, our case study is framed within historical institutionalism, which focuses on methodological individualism to attend various political science and psychological-political theories...

Prácticas artísticas contextuales y comunitarias: cuatro casos en Colombia, 1991-2012

Desde mediados del siglo XX se manifiestan en el universo artístico propuestas caracterizadas por la falta de reflexión y la ausencia de compromiso con el entorno social y político. Prevalece en los artistas una actitud individualista y el desprendimiento de un interés por lo social, lo que ha significado un ejercicio de construcción estética desde su propio universo subjetivo. De otro lado, el conjunto de relaciones que determinan y gobiernan las prácticas artísticas configuran una institucionalidad fuertemente cimentada, desde donde se imponen modos de producción y circulación del arte que favorecen la persistencia de un distanciamiento entre el artista y su acontecer. Mayoritariamente la formalización de la obra artística transita de forma obligada hacia la mera circulación y exhibición en espacios institucionales, es destinada a un espectador recogido y silencioso. La obra en estos casos busca sustraer al espectador de su entorno habitual para contactarlo pasivamente con las obras presentadas. Sin embargo, contrarias a estos planteamientos, asoman actitudes en cierta comunidad artística que defiende la necesidad de socializar sus prácticas y de alimentar un intercambio directo con el conglomerado social, principalmente con comunidades urbanas, llegando incluso a proponer la promoción de las cualidades sociales en los individuos...

Conflicto ético, diálogo e intervención social: la propuesta de “diálogos morales” de Amitai Etzioni

Este artículo reflexiona sobre el concepto de “diálogos morales” que introduce Amitai Etzioni con la finalidad de buscar vías para acometer con éxito la solución de conflictos sociales que afectan a valores. En principio, todo el mundo acepta que los demás disfruten de sus derechos, salvo que el ejercicio de los derechos de otros colisione con los nuestros. En ese caso es cuando podría aparecer el conflicto. Etzioni propone reglas para conseguir que los conflictos sociales relacionados con valores puedan convertirse en un diálogo fecundo con resultados.