14,993 research outputs found
Interaction Effects on the Magneto-optical Response of Magnetoplasmonic Dimers
The effect that dipole-dipole interactions have on the magneto-optical (MO)
properties of magnetoplasmonic dimers is theoretically studied. The specific
plasmonic versus magnetoplasmonic nature of the dimer's metallic components and
their specific location within the dimer plays a crucial role on the
determination of these properties. We find that it is possible to generate an
induced MO activity in a purely plasmonic component, even larger than that of
the MO one, therefore dominating the overall MO spectral dependence of the
system. Adequate stacking of these components may allow obtaining, for specific
spectral regions, larger MO activities in systems with reduced amount of MO
metal and therefore with lower optical losses. Theoretical results are
contrasted and confirmed with experiments for selected structures
Optical bistability in subwavelength apertures containing nonlinear media
We develop a self-consistent method to study the optical response of metallic
gratings with nonlinear media embedded within their subwavelength slits. An
optical Kerr nonlinearity is considered. Due to the large E-fields associated
with the excitation of the transmission resonances appearing in this type of
structures, moderate incoming fluxes result in drastic changes in the
transmission spectra. Importantly, optical bistability is obtained for certain
ranges of both flux and wavelength.Comment: 4 pages, 4 figure
A Meiotic Checkpoint Alters Repair Partner Bias to Permit Inter-sister Repair of Persistent DSBs
Accurate meiotic chromosome segregation critically depends on the formation of inter-homolog crossovers initiated by double-strand breaks (DSBs). Inaccuracies in this process can drive aneuploidy and developmental defects, but how meiotic cells are protected from unscheduled DNA breaks remains unexplored. Here we define a checkpoint response to persistent meiotic DSBs in C. elegans that phosphorylates the synaptonemal complex (SC) to switch repair partner from the homolog to the sister chromatid. A key target of this response is the core SC component SYP-1, which is phosphorylated in response to ionizing radiation (IR) or unrepaired meiotic DSBs. Failure to phosphorylate (syp-16A) or dephosphorylate (syp-16D) SYP-1 in response to DNA damage results in chromosome non-dysjunction, hyper-sensitivity to IR-induced DSBs, and synthetic lethality with loss of brc-1BRCA1. Since BRC-1 is required for inter-sister repair, these observations reveal that checkpoint-dependent SYP-1 phosphorylation safeguards the germline against persistent meiotic DSBs by channelling repair to the sister chromatid.Cancer Research UK FC0010048UK Medical Research Council FC0010048Wellcome Trust FC0010048Ministerio de EconomĂa y Competitividad BFU2016-75058-PEuropean Research Council ERC2014 AdG669898 TARLOO
Screening of nuclear pairing in nuclear and neutron matter
The screening potential in the and pairing channels in
neutron and nuclear matter in different approximations is discussed. It is
found that the vertex corrections to the potential are much stronger in nuclear
matter than in neutron matter.Comment: 11 pages, 8 figures, revtex4 styl
Applying clustering based on rules on WHO-DAS II for knowledge discovery on functional disabilities
The senior citizens represent a fast growing proportion of the population in Europe and other developed areas. This increases the proportion of persons with disability and reducing quality of life. The concept of disability itself is not always precise and quantifiable. To improve agreement on the concept of disability, the World Health Organization (WHO) developed a clinical test WHO Disability Assessment Schedule, (WHO-DASII) that is understood to include physical, mental, and social well-being, as a generic measure of functioning. From the medical point of view, the purpose of this work is to extract knowledge on the performance of the test WHO-DASII on the basis of a sample of neurological patients from an Italian hospital. This Knowledge Discovery problem has been faced by using clustering based on rules, a technique stablished on 1994 by Gibert which combines some Inductive Learning (from AI) methods with Statistics to extract knowledge on ill-structured domains (that is complex domains where consensus is not achieved, like is the case). So, in this paper, the results of applying this technique to the WHO-DASII results is presented.Postprint (published version
Solving quantum master equations in phase space by continued-fraction methods
Inspired on the continued-fraction technique to solve the classical
Fokker--Planck equation, we develop continued-fraction methods to solve quantum
master equations in phase space (Wigner representation of the density matrix).
The approach allows to study several classes of nonlinear quantum systems
subjected to environmental effects (fluctuations and dissipation), with the
only limitations that the starting master equations may have. We illustrate the
method with the canonical problem of quantum Brownian motion in periodic
potentials.Comment: 7 pages, 3 figure
InAs/InP single quantum wire formation and emission at 1.5 microns
Isolated InAs/InP self-assembled quantum wires have been grown using in situ
accumulated stress measurements to adjust the optimal InAs thickness. Atomic
force microscopy imaging shows highly asymmetric nanostructures with average
length exceeding more than ten times their width. High resolution optical
investigation of as-grown samples reveals strong photoluminescence from
individual quantum wires at 1.5 microns. Additional sharp features are related
to monolayer fluctuations of the two dimensional InAs layer present during the
early stages of the quantum wire self-assembling process.Comment: 4 pages and 3 figures submitted to Applied Physics Letter
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