Magneto-Optical Activity in High Index Dielectric Nanoantennas

The magneto-optical activity, namely the polarization conversion capabilities of high- index, non-absorbing, core-shell dielectric nanospheres is theoretically analyzed. We show that, in analogy with their plasmonic counterparts, the polarization conversion in resonant dielectric particles is linked to the amount of electromagnetic field probing the magneto-optical material in the system. However, in strong contrast with plasmon nanoparticles, due to the peculiar distribution of the internal fields in resonant dielectric spheres, the magneto-optical response is fully governed by the magnetic (dipolar and quadrupolar) resonances with little effect of the electric ones

Fluctuations of the electromagnetic local density of states as a probe for structural phase switching

We study the statistics of the fluorescence decay rates for single quantum emitters embedded in a scattering medium undergoing a phase transition. Under certain circumstances, the structural properties of the scattering medium explore a regime in which the system dynamically switches between two different phases. While in that regime the light-scattering properties of both phases are hardly distinguishable, we demonstrate that the lifetime statistics of single emitters with low diffusivity is clearly dependent on the dynamical state in which the medium evolves. Hence, lifetime statistics provides clear signatures of phase switching in systems where light scattering does not

Kerker Conditions Upon Lossless, Absorption, and Optical Gain Regimes

The directionality and polarization of light show peculiar properties when the scattering by a dielectric sphere can be described exclusively by electric and magnetic dipolar modes. Particularly, when these modes oscillate in-phase with equal amplitude, at the so-called first Kerker condition, the zero optical backscattering condition emerges for non-dissipating spheres. However, the role of absorption and optical gain in the first Kerker condition remains unexplored. In this work, we demonstrate that either absorption or optical gain precludes the first Kerker condition and, hence, the absence of backscattered radiation light, regardless of the size of the particle, incident wavelength, and incoming polarization. Finally, we derive the necessary prerequisites of the second Kerker condition of the zero forward light scattering, finding that optical gain is a compulsory requirement

Self-diffusion and structural properties of confined fluids in dynamic coexistence

Self-diffusion and radial distribution functions are studied in a strongly confined Lennard-Jones fluid. Surprisingly, in the solid–liquid phase transition region, where the system exhibits dynamic coexistence, the self-diffusion constants are shown to present up to three-fold variations from solid to liquid phases at fixed temperature, while the radial distribution function corresponding to both the liquid and the solid phases are essentially indistinguishable

Resonant radiation pressure on neutral particles in a waveguide

A theoretical analysis of electromagnetic forces on neutral particles in an hollow waveguide is presented. We show that the effective scattering cross section of a very small (Rayleigh) particle can be strongly modified inside a waveguide. The coupling of the scattered dipolar field with the waveguide modes induce a resonant enhanced backscattering state of the scatterer-guide system close to the onset of new modes. The particle effective cross section can then be as large as the wavelength even far from any transition resonance. As we will show, a small particle can be strongly accelerated along the guide axis while being highly confined in a narrow zone of the cross section of the guide.Comment: RevTeX,4 pages,3 PS figure

Dynamical and temporal characterization of the total ozone column over Spain

As the ozone is one of the most relevant variables in the climate system, to get further in its long-term characterization is a critical issue. In this study, measurements of total ozone column (TOC) from five well-calibrated Brewer spectrophotometers placed in the Iberian Peninsula are analyzed. The temporal trend rate for TOC is +9.3 DU per decade for the period 1993–2012 in Central Iberian Peninsula. However, the low TOC levels during 2011 and 2012 over the study region notably reduce this rate. Empirical linear relationships are established between TOC and pressure, height, and temperature of the tropopause. The linear fits showed seasonal and latitudinal dependence, with stronger relationships during winter and spring. Events with the presence of a double tropopause (DT) are proved to be characteristic of the study region. The decrease in TOC levels when these anomalous events occur is quantified around 10 % in winter and spring with respect to the usual cases with a single tropopause. The total weight of the DT events with respect to the annual values is about 20 %, with a negligible occurrence in summer and autumn and being latitudinal-dependent. The North Atlantic Oscillation (NAO) index explains 30 % of the total ozone variability in winter. The DT events are found to be more frequent during phases with positive NAO.This work was partially supported the Ministerio de Ciencia e Innovación through project CGL2011-29921-C02-01

Doñana, diversidad y ciencia

144 páginasLa biodiversidad es más que la suma de los elementos que componen el mundo vivo; también son biodiversidad las relaciones entre esos elementos, los procesos ecológicos que hacen posible su existencia y los procesos evolutivos que los han originado. […] Los seres humanos necesitamos a la biodiversidad más que ella a nosotros, ya que es la responsable de que la Tierra funcione de una manera satisfactoria. […] El entramado de la vida se ocupa de regular la composición de la atmósfera (y con ella, el clima), de depurar el aire y el agua, de hacer fértil al suelo, de evitar riadas y avalanchas, de polinizar las cosechas, de reducir las plagas, etc. Por todo ello es indispensable conservar la biodiversidad, hoy amenazada.” (Miguel Delibes) Doñana, diversidad y ciencia es un paseo conceptual por el espacio natural más emblemático de Europa. La esencia de un mito a través de decenas de fotografías… Un acercamiento respetuoso a la diversidad de sus conceptos, un paseo por la esencia de su historia y una curiosa aproximación a la ciencia que genera hoy en día. En este recorrido descubriremos el carácter distintivo de algunos de los parajes de la reserva, sus matices más interesantes, las texturas y las formas más sorprendentes de la naturaleza, sus colores y conjuntos, sus transformaciones en las últimas décadas y la influencia de la presencia humana en el privilegiado ecosistema de la Reserva Biológica de Doñana

AURKA, BIRC5 and PLK1 as potential biomarkers of response in radiation-resistant colorectal cancer

The study demonstrated that AURKA, BIRC5 and PLK1 proteins are hyper-expressed in patients affected by colon and rectum adenocarcinoma resistant to radiotherapy. The validation of the expression levels in patient samples shows that they are conserved in tumor stages I-IV, suggesting their potential as possible biomarkers

Regulation of AURKA, BIRC5 and PLK1 protein expression in colorectal cancer

AURKA, BIRC5 and PLK1 proteins show multiple regulatory transcription factors, highlighting E2F7, DRAP1 and ZNF511. The regulation of these protein is important to modulate the progression of cell cycle, cell proliferation, apoptosis and resistance to treatment

A network analysis to identify mediators of germline-driven differences in breast cancer prognosis.

Identifying the underlying genetic drivers of the heritability of breast cancer prognosis remains elusive. We adapt a network-based approach to handle underpowered complex datasets to provide new insights into the potential function of germline variants in breast cancer prognosis. This network-based analysis studies ~7.3 million variants in 84,457 breast cancer patients in relation to breast cancer survival and confirms the results on 12,381 independent patients. Aggregating the prognostic effects of genetic variants across multiple genes, we identify four gene modules associated with survival in estrogen receptor (ER)-negative and one in ER-positive disease. The modules show biological enrichment for cancer-related processes such as G-alpha signaling, circadian clock, angiogenesis, and Rho-GTPases in apoptosis