Phase transition for the Maki-Thompson rumour model on a small-world network

We consider the Maki-Thompson model for the stochastic propagation of a rumour within a population. We extend the original hypothesis of homogenously mixed population by allowing for a small-world network embedding the model. This structure is realized starting from a $k$-regular ring and by inserting, in the average, $c$ additional links in such a way that $k$ and $c$ are tuneable parameter for the population architecture. We prove that this system exhibits a transition between regimes of localization (where the final number of stiflers is at most logarithmic in the population size) and propagation (where the final number of stiflers grows algebraically with the population size) at a finite value of the network parameter $c$. A quantitative estimate for the critical value of $c$ is obtained via extensive numerical simulations.Comment: 24 pages, 4 figure

Tears in Heaven: Religiously and Culturally Sensitive Laws for Preventing the Next Pandemic

In February 2016, the World Health Organization (WHO) declared a “public health emergency of international concern” due to the increased clusters of microcephaly, Guillain-Barré Syndrome, and other neurological disorders in areas affected by the Zika virus. That declaration came in the wake of the West Africa Ebola crisis. Back to back declarations by WHO of the highest threat level for an international public health emergency underscores how quickly pathogens can now spread and cause devastation across borders. It also highlights the need to implement lessons learned from each pandemic crisis without delay. These crises demonstrate that laws to curtail the spread of deadly contagious diseases need to be drafted and implemented in ways to maximize community acceptance. Without prudently crafted laws in place that are as consistent as possible with community mores, threats from deadly diseases may cause anxiety and panic, and governments may react to political and public pressures and mandate rules that may unnecessarily impinge on personal rights and deeply held religious beliefs. Infringing upon ideological or religious beliefs could lead to increased distrust of government and civil disobedience and could also, paradoxically, undermine the goal of preventing the spread of infectious disease. This article focuses on applying to future pandemics a critical lesson from prior crises — the need for public health officials to accommodate religious and cultural practices of the community to more effectively implement emergency measures. Further, the article proposes an interdisciplinary and proactive approach to development of laws and regulations to create a system that is adaptable, acceptable to the community, and scientifically sound

On Top of the Alveolar Epithelium: Surfactant and the Glycocalyx

Gas exchange in the lung takes place via the air-blood barrier in the septal walls of alveoli. The tissue elements that oxygen molecules have to cross are the alveolar epithelium, the interstitium and the capillary endothelium. The epithelium that lines the alveolar surface is covered by a thin and continuous liquid lining layer. Pulmonary surfactant acts at this air-liquid interface. By virtue of its biophysical and immunomodulatory functions, surfactant keeps alveoli open, dry and clean. What needs to be added to this picture is the glycocalyx of the alveolar epithelium. Here, we briefly review what is known about this glycocalyx and how it can be visualized using electron microscopy. The application of colloidal thorium dioxide as a staining agent reveals differences in the staining pattern between type I and type II alveolar epithelial cells and shows close associations of the glycocalyx with intraalveolar surfactant subtypes such as tubular myelin. These morphological findings indicate that specific spatial interactions between components of the surfactant system and those of the alveolar epithelial glycocalyx exist which may contribute to the maintenance of alveolar homeostasis, in particular to alveolar micromechanics, to the functional integrity of the air-blood barrier, to the regulation of the thickness and viscosity of the alveolar lining layer, and to the defence against inhaled pathogens. Exploring the alveolar epithelial glycocalyx in conjunction with the surfactant system opens novel physiological perspectives of potential clinical relevance for future research

Brenneria quercina and Serratia spp. isolated from Spanish oak trees: molecular characterization and PCR development

Brenneria quercina has been reported as one of the causal agents of oak decline in Spain. To investigate the bacterial variability of this pathogen from different Spanish oak forests, a collection of 38 bacterial isolates from seven geographic locations and from different oak species was analysed by sequencing 16S rDNA and rep-PCR fingerprinting. All Spanish isolates of B. quercina were grouped by rep-PCR into a homogenous cluster that differed significantly from B. quercina reference strains from California. 16S rDNA analysis revealed that 34 out of 38 isolates were Brenneria . However, four isolates belonged to the genus Serratia , suggesting that this bacterium could cause cankers in oak trees. The information obtained by rep-PCR fingerprint analysis was used to develop PCR primers for the sensitive and specific detection of B. quercina from infected plant tissues. Pathogenicity tests performed with Brenneria and Serratia isolates showed that both were able to grow and cause cankers in oak trees

Twisted bilayered graphenes at magic angles and Casimir interactions: correlation-driven effects

Twisted bilayered graphenes at magic angles are systems housing long ranged periodicity of Moir\'e pattern together with short ranged periodicity associated with the individual graphenes. Such materials are a fertile ground for novel states largely driven by electronic correlations. Here we find that the ubiquitous Casimir force can serve as a platform for macroscopic manifestations of the quantum effects stemming from the magic angle bilayered graphenes properties and their phases determined by electronic correlations. By utilizing comprehensive calculations for the electronic and optical response, we find that Casimir torque can probe anisotropy from the Drude conductivities in nematic states, while repulsion in the Casimir force can help identify topologically nontrivial phases in magic angle twisted bilayered graphenes.Comment: 9 pages, 6 figures (main), 7 pages, 7 figures (supplementary); provisionally accepted for publication in 2D Material

Searching for specific binding sites of the secretory glycoproteins of the subcommissural organ

The molecular organization of Reissner's fiber (RF), the structure of its proteins, and the permanent turnover of these proteins are all facts supporting the possibility that RF may perform multiple functions. There is evidence that CSF-soluble RF-glycoproteins may occur under physiological conditions. The present investigation was designed to investigate the probable existence within the CNS of specific binding sites for RF-glycoproteins. Three experimental protocols were used: (1) immunocytochemistry of the CNS of bovine fetuses using anti-idiotypic antibodies, raised against monoclonal antibodies developed against bovine RF-glycoproteins; (2) in vivo binding of the RF glycoproteins, perfusing into the rat CSF 125I-labeled RF-glycoproteins, or grafting SCO into a lateral ventricle of the rat; (3) in vitro binding of unlabeled RF-glycoproteins to rat and bovine choroid plexuses maintained in culture. One of the anti-idiotypic antibody generated by a Mab raised against RF-glycoproteins binds to choroidal cells. Furthermore, binding of RF-glycoproteins to the rat choroid plexus was obtained when: (1) the choroid plexus was cultured in the presence of unlabeled RF-glycoproteins; (2) the concentration of soluble RF-glycoproteins in the CSF was increased by isografting SCOs into a lateral ventricle; (3) radiolabeled glycoproteins were perfused into the ventricular CSF. This evidence suggests that the apical plasma membrane of the ependymal cells of the choroid plexus has specific binding sites for RF-glycoproteins, of unknown functional significance. The radiolabeled RF-glycoproteins perfused into the rat CSF also bound to the paraventricular thalamic nucleus, the floor of the Sylvian aqueduct and of the rostral half of the fourth ventricle, and title meninges of the brain and spinal cord. The labeling of the paraventricular thalamic nucleus points to a functional relationship between this nucleus and the SCO. The possibility that; the SCO may be a component of the circadian timing system is discussed. Microsc. Res. Tech. 52:541-551, 2001. (C) 2001 Wiley-Liss, Inc

Herramienta de soporte a la evaluación de la calidad docente de los estudios universitarios

Resumen: El proceso de monitorización y evaluación de un grado o máster oficial se fundamenta en un informe anual ajustado a los requerimientos dictaminados por las agencias externas de calidad docente, ya sean tanto europeas como nacionales, las cuales serán las responsables de evaluar dicha calidad. Teniendo en cuenta que estos informes se realizan a partir de un conjunto de indicadores que se deben recoger a partir de la docencia realizada, se propone la utilización de una herramienta de soporte al colectivo docente para mejorar de forma global la eficiencia del proceso y facilitar la evaluación de la calidad docente. En este artículo, se describe el proceso de evaluación que se utiliza en nuestro departamento y cómo la herramienta de soporte ayuda a optimizar este proceso de evaluación.Abstract: The monitoring process and evaluation of a degree or master is performed by an annual report based on a set of requirements defined by the quality agencies which are responsible to evaluate such quality. Taking into account that these reports are made up by a set of evidences that are gathered during the whole instructional process, we propose the use of a supportive tool. This tool will allow the improvement of the efficiency of the process and will facilitate the quality evaluation. This paper describes the evaluation process employed in our faculty and how the supportive tool helps to optimize the evaluation process

High Temperature Neutron Diffraction Study of the La1.4Sr1.6mn2o7 Bilayered Manganite

In this paper we present the results of a high temperature (300 K<T<800 K) neutron powder diffraction study of the La1.4Sr1.6Mn2O7 bilayered manganite. An unusual trend of the /Mn-Oequatorial parameter was found: it first decreases up to 500 K and then increases up to the highest T measured. At the same time, a significant shortening of the apical Mn-O(2) bond is observed in the range where the J-T distortion is reduced. The overall data gained by this study may suggest a shift of electronic density from axial to planar eg orbitals with T. This trend is explained considering of the presence of short range magnetic interaction well above TC.Comment: 18 pages, 6 figure

A Common Frame for Formal Imagination

In this paper, we review three influential theories of imagination in order to understand how the dynamics of imagination acts could be modeled using formal languages. While reviewing them, we notice that they are not detailed enough to account for all the mechanisms involved in creating and developing imaginary worlds. We claim those theories could be further refined into what we call the Common Frame for Imagination Acts, which defines a framework that can be used to study the dynamics of imagination using formal languages, and we support our claim by showing how the framework allows to model certain imagination acts step by step. Then, we introduce the Rhombus of Imagination, which is a visual tool that can be used in conjunction with our framework to study the procedural structure of different kinds of imagination acts and identify their dynamic properties

The Logic of Imaginary Scenarios

Imagining is something we use everyday in our lives, and in a wide variety of ways. In spite of the amount of works devoted to its study from both psychology and philosophy, there are only a few formal systems capable of modeling it; besides, almost all of those systems are static, in the sense that their models are initially predefined, and they fail to capture the dynamic process behind the creation of new imaginary scenarios. In this work, we review some influential theories of imagination and use their insights to distill an algorithm describing such process. Then, we use this algorithm to define a dynamic logical system built upon on a single-agent epistemic logic that provides the necessary tools to capture how the agent voluntarily creates new imaginary worlds; in other words, our system allows the model to be expanded dynamically at any time as a result of the agent performing an act of imagination. Furthermore, we provide an axiomatization and prove that the system is sound and complete