Semiconductor cavity QED: Bandgap induced by vacuum fluctuations

We consider theoretically a semiconductor nanostructure embedded in one-dimensional microcavity and study the modification of its electron energy spectrum by the vacuum fluctuations of the electromagnetic field. To solve the problem, a non-perturbative diagrammatic approach based on the Green's function formalism is developed. It is shown that the interaction of the system with the vacuum fluctuations of the optical cavity opens gaps within the valence band of the semiconductor. The approach is verified for the case of large photon occupation numbers, proving the validity of the model by comparing to previous studies of the semiconductor system excited by a classical electromagnetic field. The developed theory is of general character and allows for unification of quantum and classical descriptions of the strong light-matter interaction in semiconductor structures

Resolution of inflammation: an integrated view

O.S. is supported by the NWO (VIDI project 91712303), theDFG (SO876/3-1, SO876/6-1, FOR809, SFB914 TPB08), theGerman-Israeli Foundation, and the Else Kro¨ner FreseniusStiftung. M.P. is supported by the Wellcome Trust (program086867/Z/08), the Arthritis Research UK, the British HeartFoundation (PG/09/060 and PG/11/48/28981) and the MedicalResearch Council

BCS pairing in fully repulsive fermion mixtures

We consider a mixture of two neutral cold Fermi gases with repulsive interactions. We show that in some region of the parameter space of the system the effective attraction between fermions of the same type can appear due to the exchange of collective excitations. This leads to the formation of BCS pairing in the case where bare inter-atomic interactions are repulsive

Electron refraction at lateral atomic interfaces

We present theoretical simulations of electron refraction at the lateral atomic interface between a “homogeneous” Cu(111) surface and the “nanostructured” one-monolayer (ML) Ag/Cu(111) dislocation lattice. Calculations are performed for electron binding energies barely below the 1 ML Ag/ Cu(111) M-point gap (binding energy EB ¼53 meV, below the Fermi level) and slightly above its C -point energy (EB ¼160 meV), both characterized by isotropic/circular constant energy surfaces. Using plane-wave-expansion and boundary-element methods, we show that electron refraction occurs at the interface, the Snell law is obeyed, and a total internal reflection occurs beyond the critical angle. Additionally, a weak negative refraction is observed for EB ¼53 meV electron energy at beam incidence higher than the critical angle. Such an interesting observation stems from the interface phase-matching and momentum conservation with the umklapp bands at the second Brillouin zone of the dislocation lattice. The present analysis is not restricted to our Cu-Ag/Cu model system but can be readily extended to technologically relevant interfaces with spinpolarized, highly featured, and anisotropic constant energy contours, such as those characteristic for Rashba systems and topological insulators. Published by AIP Publishing.Peer ReviewedPostprint (published version

Fuzzy Networked Control Systems Design Considering Scheduling Restrictions

Nowadays network control systems present a common approximation when connectivity is the issue to be solved based on time delays coupling from external factors. However, this approach tends to be complex in terms of time delays. Therefore, it is necessary to study the behavior of the delays as well as the integration into differential equations of these bounded delays. The related time delays needs to be known a priory but from a dynamic real-time behavior. To do so, the use of priority dynamic Priority exchange scheduling is performed. The objective of this paper is to show a way to tackle multiple time delays that are bounded and the dynamic response from real-time scheduling approximation. The related control law is designed considering fuzzy logic approximation for nonlinear time delays coupling, where the main advantage is the integration of this behavior through extended state space representation keeping certain linear and bounded behavior and leading to a stable situation during events presentation by guaranteeing stability through Lyapunov

Large-scale gene expression study in the ophiuroid Amphiura filiformis provides insights into evolution of gene regulatory networks

BACKGROUND: The evolutionary mechanisms involved in shaping complex gene regulatory networks (GRN) that encode for morphologically similar structures in distantly related animals remain elusive. In this context, echinoderm larval skeletons found in brittle stars and sea urchins provide an ideal system. Here, we characterize for the first time the development of the larval skeleton in the ophiuroid Amphiura filiformis and compare it systematically with its counterpart in sea urchin. RESULTS: We show that ophiuroids and euechinoids, that split at least 480 Million years ago (Mya), have remarkable similarities in tempo and mode of skeletal development. Despite morphological and ontological similarities, our high-resolution study of the dynamics of genetic regulatory states in A. filiformis highlights numerous differences in the architecture of their underlying GRNs. Importantly, the A.filiformis pplx, the closest gene to the sea urchin double negative gate (DNG) repressor pmar1, fails to drive the skeletogenic program in sea urchin, showing important evolutionary differences in protein function. hesC, the second repressor of the DNG, is co-expressed with most of the genes that are repressed in sea urchin, indicating the absence of direct repression of tbr, ets1/2, and delta in A. filiformis. Furthermore, the absence of expression in later stages of brittle star skeleton development of key regulatory genes, such as foxb and dri, shows significantly different regulatory states. CONCLUSION: Our data fill up an important gap in the picture of larval mesoderm in echinoderms and allows us to explore the evolutionary implications relative to the recently established phylogeny of echinoderm classes. In light of recent studies on other echinoderms, our data highlight a high evolutionary plasticity of the same nodes throughout evolution of echinoderm skeletogenesis. Finally, gene duplication, protein function diversification, and cis-regulatory element evolution all contributed to shape the regulatory program for larval skeletogenesis in different branches of echinoderms

Meconio y exposición prenatal a neurotóxicos

6 pages, 1 figures, 2 tables.[ESP] Introducción. La ubicuidad con la que se encuentran la mayoría de las substancias neurotóxicas en el medio ambiente implica a los pediatras en la necesidad de desarrollar métodos para medir la magnitud de la exposición durante los periodos vulnerables del desarrollo. Una forma útil de abordar este problema consiste en analizar muestras biológicas que acumulen las substancias neurotóxicas o sus metabolitos durante el periodo fetal.Método. Revisión bibliográfica sistemática de los últimos 20 años obtenida principalmente de Medline; Science Citation Index y Embase sobre los estudios con meconio como matriz de exposición prenatal a substancias neurotóxicas. El perfil de búsqueda utilizado fue: meconium, prenatal exposure, biological markers, matrices, environmental pollutants, nervous system poisonings, neurotoxicity sindromes. Hemos seleccionado los trabajos más importantes y de sus referencias se han obtenido los más relevantes de los años previos a la búsqueda.Resultados. Tradicionalmente, los esfuerzos para determinar la exposición fetal se han centrado en el análisis de sangre de cordón u orina de la madre o el neonato. El meconio es fácilmente disponible, es inerte, acumula los neurotóxicos y/o sus metabolitos desde la semana 12 de gestación donde quedan “fosilizados” hasta el nacimiento. Puede constituir un instrumento muy importante para investigar la exposición fetal a los distintos contaminantes ambientales y en particular a neurotóxicos.Conclusiones. Las exposiciones fetales a los distintos neurotóxicos estudiados a través de sangre materna, de cordón, pelo, uña, placenta y orina parecen ser menos predictivas sobre los efectos neurológicos que las mediciones de los mismos realizadas en meconio. Son necesarios más estudios en este campo.Implementar y desarrollar la medida en meconio de una amplia gama de sustancias neurotóxicas ayudará en la práctica pediátrica a una intervención e identificación temprana mostrando las exposiciones que puedan provocar daño y facilitando el desarrollo de medidas preventivas y rehabilitadoras.[ENG] Brackground. The environmental ubiquity of most neurotoxicants implies the pediatricians in the development of methods for exposure measurement during the vulnerable periods of development. The analysis of biological samples able to accumulate the neurotoxicant substances or its metabolites during the fetal period is a useful approach to fulfil this objective.Material and methods. A systematic literature review of the last 20 years in Medline, Science Citation Index and Embase on the studies with meconium like womb of prenatal exposure to neurotoxicants has been undertaken. The search profile was: “meconium”, “prenatal exposure”, “biological markers”, “matrices”, “environmental pollutants”, “nervous system poisonings”, “neurotoxicity sindromes”. We selected the most relevant articles and retrieved more from their references.Results. Traditionally, the efforts to determine the fetal exposure have been centered in the analysis of cord blood, urinates of the mother or of the neonato. Meconium is easily available, inert, accumulates the neurotoxicants and/or its metabolitos from week 12 of gestation where they are "fossilized" until the birth. It can constitute a very important instrument for the investigation of the fetal exposure to the different environmental pollutants and in particular to neurotoxicants.Conclusions. Foetal exposure to different neurotoxicants monitored from maternal blood, cord blood, hair, fingernail, placenta and urinates seem to be less predictive for neurological effects than meconium. However, more studies are needed to confirm this hypothesis.Implementation and measurement in meconium of a wide range of neurotoxic substances will be of help in the pediatric practice for intervention and early identification as it will reveal harmful exposures and facilitate the implementation of preventive measures.Los autores quieren expresar su agradecimiento a los miembros de la red de Investigación Colaborativa INMA, y en especial a Amparo Quiles Latorre, Elena Romero Aliaga y Sandra Pérez Aliaga, por su apoyo y colaboración en la realización del trabajo de campo; al equipo de enfermería de la 7ª, 8ª y 9ª de la maternidad del Hospital Materno-Infantil Universitario La Fe y a los recién nacidos y sus felices padres que con su colaboración y entusiasmo hacen posible llevar a término estos estudios.Peer reviewe

Super Abrasive Machining of Integral Rotary Components Using Grinding Flank Tools

Manufacturing techniques that are applied to turbomachinery components represent a challenge in the aeronautic sector. These components require high resistant super-alloys in order to satisfy the extreme working conditions they have to support during their useful life. Besides, in the particular case of Integrally Bladed Rotors (IBR), usually present complex geometries that need to be roughed and finished by milling and grinding processes, respectively. In order to improve their manufacturing processes, Super Abrasive Machining (SAM) is presented as a solution because it combines the advantages of the use of grinding tools with milling feed rates. However, this innovative technique usually needed high tool rotary speed and pure cutting oils cooling. These issues implied that SAM technique was not feasible in conventional machining centers. In this work, these matters were tackled and the possibility of using SAM in these five-axis centers with emulsion coolants was achieved. To verify this approach, Inconel 718 single blades with non-ruled surfaces were manufactured with Flank-SAM technique and conventional milling process, analyzing cutting forces, surface roughness, and dimension accuracy in both cases. The results show that SAM implies a suitable, controllable, and predictable process to improve the manufacture of aeronautical critical components, such as IBR.FEDE