Experimental evidence of a Neotropical pest insect moderately tolerant to complete freezing.

Due to climate change, many regions are experiencing progressively milder winters. Consequently, pest insects from warm regions, particularly those with some tolerance to low temperatures, could expand their geographic range into these traditionally colder regions. The palm borer moth (Paysandisia archon) is a Neotropical insect that in recent decades has reached Europe and Asia as one of the worst pests of palm trees.

Morphological and biochemical responses of a neotropical pest insect to low temperatures.

As traditionally cold areas become warmer due to climate change, temperature could no longer be a barrier to the establishment of non-native insects. This is particularly relevant for pest insects from warm and tropical areas, mainly those with some tolerance to moderately low temperatures, which could expand their range into these new locations. From this perspective, in this work we studied the morphological and biochemical responses of the Neotropical pest Paysandisia archon to low temperatures, as part of a possible strategy to colonize new areas.

Morphological response of the red palm weevil, Rhynchophorus ferrugineus, to a transient low temperature analyzed by computer tomography and holographic microscopy.

The red palm weevil (RPW), Rhynchophorus ferrugineus, is one of the worst palm pests worldwide. Our study aims to assess its internal and external morphological response to a sudden but transient decrease in the environmental temperature. Wild pre-pupae were subjected for 7 days to either low (5.

Multifunctional hybrid materials for combined photo and chemotherapy of cancer.

Combined chemo and photothermal therapy in in vitro testing has been achieved by means of multifunctional nanoparticles formed by plasmonic gold nanoclusters with a protecting shell of porous silica that contains an antitumor drug. We propose a therapeutic nanoplatform that associates the optical activity of small gold nanoparticles aggregates with the cytotoxic activity of 20(S)-camptothecin simultaneously released for the efficient destruction of cancer cells. For this purpose, a method was used for the controlled assembly of gold nanoparticles into stable clusters with a tailored absorption cross-section in the vis/NIR spectrum, which involves aggregation in alkaline medium of 15 nm diameter gold colloids protected with a thin silica layer.

Coupled wave analysis of holographically induced transparency (HIT) generated by two multiplexed volume gratings.

We present a holographic system that can be used to manipulate the group velocity of light pulses. The proposed structure is based on the multiplexing of two sequential holographic volume gratings, one in transmission and the other in reflection geometry, where one of the recording beams must be the same for both structures. As in other systems such as grating induced transparency (GIT) or coupled-resonator-induced transparency (CRIT), by using the coupled wave theory it is shown that this holographic structure represents a classical analogue of the electromagnetically induced transparency (EIT).

Nonparaxial diffraction analysis of Airy and SAiry beams.

We theoretically analyze Airy beams by solving the exact vectorial Helmholtz equation using boundary conditions at a diffraction aperture. As result, the diffracted beams are obtained in the whole space; thus, we demonstrate that the parabolic trajectories are larger than those previously reported, showing that the Airy beams start to form before the Fourier plane. We also demonstrate the possibility of using a new type of Airy beams (SAiry beams) with finite energy that can be generated at the focal plane of the lens due to diffraction by a circular aperture of a spherical wave modified by a cubic phase.

Full characterization of holographic reflection gratings recorded on BB640 emulsions.

A complete characterization of unslanted holographic reflection gratings with high diffraction efficiency recorded on ultrafine grain emulsion BB640 has been achieved. By use of a wavelength-dependent absorption coefficient, the diffraction efficiency, the replay wavelength, and the spectral bandwidth of each recording has been obtained. Corresponding index modulation, absorption, and effective thickness have been obtained with high accuracy by fitting the experimental data with Kogelnik's theory.

Multiple band holographic reflection gratings recorded in new ultra-fine grain emulsion BBVPan.

We present the results obtained using the new panchromatic ultra-fine grain emulsion BBVPan, manufactured by Colourholographics Ltd., to produce multiple band holographic reflection gratings, multiplexed on a single layer of material. Three different laser systems were used: He-Cd, frequency-doubled Nd-YAG and He-Ne.

Nonlinear effects on holographic reflection gratings recorded with BB640 emulsions.

Nonlinear recording effects on holographic re ection gratings recorded on BB640 emulsions have been studied. Using an analytical approach to the characteristic curve of this emulsions, the density profiles recorded in the developed emulsions that correspond to the original light pattern generated by the holographic setup have been obtained. The final spatial profiles of the refraction index resulting from different exposure levels and different bleaching processes have been evaluated studying the experimental diffraction efficiency and comparing it with Kogelnik's theory.

Comparison of direct, rehalogenating, and solvent bleaching processes with BB-640 plates.

Bleaching is one of the key processes in the production of phase holograms with fine grain silver halide emulsions. This step was widely studied for discontinued Kodak, Agfa, and Ilford emulsions, and most of those results have been optimized with small changes for presently available holographic emulsions. A study of the different bleaching techniques with BB-640 holographic emulsions is presented.