Quantum Modelling of Electro-Optic Modulators

Many components that are employed in quantum information and communication systems are well known photonic devices encountered in standard optical fiber communication systems, such as optical beamsplitters, waveguide couplers and junctions, electro-optic modulators and optical fiber links. The use of these photonic devices is becoming increasingly important especially in the context of their possible integration either in a specifically designed system or in an already deployed end-to-end fiber link. Whereas the behavior of these devices is well known under the classical regime, in some cases their operation under quantum conditions is less well understood. This paper reviews the salient features of the quantum scattering theory describing both the operation of the electro-optic phase and amplitude modulators in discrete and continuous-mode formalisms. This subject is timely and of importance in light of the increasing utilization of these devices in a variety of systems, including quantum key distribution and single-photon wavepacket measurement and conformation. In addition, the paper includes a tutorial development of the use of these models in selected but yet important applications, such as single and multi-tone modulation of photons, two-photon interference with phase-modulated light or the description of amplitude modulation as a quantum operation.Comment: 29 pages, 10 figures, Laser and Photonics Reviews (in press

Artificial Contraception is Associated With Increased Numbers of Induced Abortions

Since the sexual revolution, it has been a widely accepted fact that contraceptives have been a necessity for our society. They seem to be the best way to prevent unwanted pregnancies that would otherwise result from sexual unions between two people unprepared for the commitment of raising any or additional children. It almost goes without saying that the more effective and available contraceptives become, the less likely women who wish to avoid pregnancy will become pregnant and the fewer induced abortions they will seek. In reality, the information available concerning abortions and the women who obtain them points to a different conclusion. The more effective and available contraceptives become in a society, the more widespread the practice of induced abortions becomes. On the other hand, natural family planning has been associated with fewer induced abortions when an unplanned pregnancy results. This paper will present a sample of the information available, attempt to draw conclusions, and discuss the possible reasons that contraceptives are unavoidably linked to increasing numbers of induced abortions and that, conversely, natural family planning is associated with very few or no induced abortions. </jats:p

Novel metaheuristic for parameter estimation in nonlinear dynamic biological systems

BACKGROUND: We consider the problem of parameter estimation (model calibration) in nonlinear dynamic models of biological systems. Due to the frequent ill-conditioning and multi-modality of many of these problems, traditional local methods usually fail (unless initialized with very good guesses of the parameter vector). In order to surmount these difficulties, global optimization (GO) methods have been suggested as robust alternatives. Currently, deterministic GO methods can not solve problems of realistic size within this class in reasonable computation times. In contrast, certain types of stochastic GO methods have shown promising results, although the computational cost remains large. Rodriguez-Fernandez and coworkers have presented hybrid stochastic-deterministic GO methods which could reduce computation time by one order of magnitude while guaranteeing robustness. Our goal here was to further reduce the computational effort without loosing robustness. RESULTS: We have developed a new procedure based on the scatter search methodology for nonlinear optimization of dynamic models of arbitrary (or even unknown) structure (i.e. black-box models). In this contribution, we describe and apply this novel metaheuristic, inspired by recent developments in the field of operations research, to a set of complex identification problems and we make a critical comparison with respect to the previous (above mentioned) successful methods. CONCLUSION: Robust and efficient methods for parameter estimation are of key importance in systems biology and related areas. The new metaheuristic presented in this paper aims to ensure the proper solution of these problems by adopting a global optimization approach, while keeping the computational effort under reasonable values. This new metaheuristic was applied to a set of three challenging parameter estimation problems of nonlinear dynamic biological systems, outperforming very significantly all the methods previously used for these benchmark problems

Open Strings in IIB Orientifold Reductions

We consider type IIB compactifications on a general 4D group manifold with different types of possible spacetime filling O-planes and the corresponding D-branes parallel to them. Once fluxes allowed by the associated orientifold projection are included, a 6D $\mathcal{N}=(1,1)$ gauged supergravity is obtained. In this paper we show how the consistent coupling to dynamical open strings living on the spacetime filling D-branes may be captured by the inclusion of extra vector multiplets and extra embedding tensor deformations on the gauged supergravity side. As a result, the quadratic constraints on the embedding tensor consistently reproduce the source corrected 10D Bianchi identities. Furthermore, the field strength modifications induced by the open string sector could potentially be understood as U-dual versions of the Green-Schwarz terms. Finally, the entire scalar potential of the theory exactly matches the one obtained from reduction of the bulk action plus the source contributions.Comment: 45 pages, 1 figur

Cecal Ligation and Puncture-Induced Sepsis Promotes Brown Adipose Tissue Inflammation Without Any Impact on Expression of Thermogenic-Related Genes

Background and Aims: The negative effects of chronic low-level inflammation on adipose tissue physiology have been extensively demonstrated, whereas the effects of acute inflammation are less studied. Here, we aimed to investigate the effects of sepsis-induced acute inflammation on gene expression markers of brown and white adipose tissue functionality. Methods: Brown adipose tissue (BAT) and perirenal white adipose tissue (prWAT) gene expression markers were analyzed in cecal ligation and puncture (CLP)-induced sepsis mice model. Results: CLP-induced sepsis attenuated expression of adipogenesis-related genes, in parallel to increased Tnf, Il6, and Ltf gene expression in prWAT. In contrast, CLP-induced sepsis resulted in increased expression of pro-inflammatory genes (Il6, Ltf, and Lbp) in BAT, without affecting expression of genes encoding for thermogenic activity. Conclusion: Sepsis promotes both prWAT and BAT inflammation, associated with reduced adipogenesis-related gene expression in prWAT, without significant effects on BAT thermogenic genes

Applying Model-Driven Paradigm for the Improvement of Web Requirement Validation

This paper proposes an approach for Web requirements validation by applying the model-driven paradigm in classical requirements validation techniques. In particular, we present how the Navigational Development Techniques (NDT) approach exploits the model-driven paradigm to improve its requirements validation task by exploring tool cases that systematize or even automate the application of requirements validation techniques. Our solution is validated by applying it in a real industrial environment. The results and the learned lessons are presented accordingly

Influencia de las condiciones ambientales en la germinación y supervivencia inicial del pino silvestre en el Valle del Lozoya(Madrid)

El objetivo de este estudio fue evaluar los factores micrometeorológicos que afectan a la regeneración del pino resinero en la Tierra de Pinares Segoviana. Se registró durante un período vegetativo completo la temperatura del suelo y la temperatura de la capa de aire más próximo al suelo. La temperatura del suelo alcanzó máximos de 56 ºC desde el mes de julio a septiembre, en períodos de más de 4 horas seguidas durante 2-5 días consecutivos y la temperatura del aire más próximo al suelo, donde viven las plántulas recién nacidas, alcanzó valores de hasta 56 ºC desde junio a septiembre, durante períodos de más de 4,5 horas en periodos de 7 días consecutivos. En las plántulas objeto de estudio se identificaron heridas en el cuello de la raíz lo que indica que las altas temperaturas producen cambios fisiológicos y morfológicos en las plántulas comprometiendo su supervivencia y la de la regeneración de estos montes. El análisis estadístico mostró que los puntos de muestreo seleccionados no presentaron grandes diferencias respecto a las variables microclimáticas consideradas

Present and future of Web content accessibility: An analysis

Web je stvoren kao univerzalna mreža znanja. Bio je to ogroman kvalitativni i kvantitativni skok u odnosu na pristup informacijama i njihovu obradu. Međutim, čak i danas, postoje znatne prepreke pristupu mreži velikog broja građana, uključujući osobe s invaliditetom i stare ljude smanjenih sposobnosti kao posljedice godina. Mogućnost pristupa je značajka kojom se olakšava pristup i uspješno korištenje web lokacije ili usluge što većem broju ljudi, bez obzira na njihova osobna ograničenja ili ograničenja nametnuta okolinom. Ovaj članak daje pregled osnovnih značajki mogućnosti pristupa mreži sada i u budućnosti, osvrćući se na uspješnu primjenu smjernica poznatih kao 2.0, kojima se osigurava podudaranje s postojećim zakonskim odredbama na nacionalnom i internacionalnom nivou.The Web was created as a universal network of knowledge. It represented a huge qualitative and quantitative leap in terms of acquisition and processing of information. However, even today, significant barriers make difficult the access of a large number of citizens to the web, including disabled users and old people with diminished skills as an effect of age. Accessibility is the feature which facilitates access to and successful usage of a web site or service for as many people as possible, regardless of their personal limitations or limitations imposed by their environment. This article reviews the main aspects of web accessibility and its future, passing through the effective implementation of guidelines known as 2.0, which ensure compliance with existing legislation at national and international level