Highly-efficient noise-assisted energy transport in classical oscillator systems

Photosynthesis is a biological process that involves the highly-efficient transport of energy captured from the sun to a reaction center, where conversion into useful biochemical energy takes place. Even though one can always use a quantum perspective to describe any physical process, since everything follows the laws of Quantum Mechanics, is the use of quantum theory imperative to explain this high efficiency? Making use of the quantum-classical correspondence of electronic energy transfer recently introduced by Eisfeld and Briggs [Phys. Rev. E 85, 046118 (2012)], we show here that the highly-efficient noise-assisted energy transport described by Rebentrost et al. [New J. Phys. 11, 033003 (2009)], and Plenio and Huelga [New J. Phys. 10, 113019 (2008)], as the result of the interplay between the quantum coherent evolution of the photosynthetic system and noise introduced by its surrounding environment, it can be found as well in purely classical systems. The wider scope of applicability of the enhancement of energy transfer assisted by noise might open new ways for developing new technologies aimed at enhancing the efficiency of a myriad of energy transfer systems, from information channels in micro-electronic circuits to long-distance high-voltage electrical lines.Comment: 4 pages, 3 figure

Fluorescence energy transfer enhancement in aluminum nanoapertures

Zero-mode waveguides (ZMWs) are confining light into attoliter volumes, enabling single molecule fluorescence experiments at physiological micromolar concentrations. Among the fluorescence spectroscopy techniques that can be enhanced by ZMWs, F\"{o}rster resonance energy transfer (FRET) is one of the most widely used in life sciences. Combining zero-mode waveguides with FRET provides new opportunities to investigate biochemical structures or follow interaction dynamics at micromolar concentration with single molecule resolution. However, prior to any quantitative FRET analysis on biological samples, it is crucial to establish first the influence of the ZMW on the FRET process. Here, we quantify the FRET rates and efficiencies between individual donor-acceptor fluorophore pairs diffusing in aluminum zero-mode waveguides. Aluminum ZMWs are important structures thanks to their commercial availability and the large literature describing their use for single molecule fluorescence spectroscopy. We also compare the results between ZMWs milled in gold and aluminum, and find that while gold has a stronger influence on the decay rates, the lower losses of aluminum in the green spectral region provide larger fluorescence brightness enhancement factors. For both aluminum and gold ZMWs, we observe that the FRET rate scales linearly with the isolated donor decay rate and the local density of optical states (LDOS). Detailed information about FRET in ZMWs unlocks their application as new devices for enhanced single molecule FRET at physiological concentrations

Nanophotonic enhancement of the F\"orster resonance energy transfer rate on single DNA molecules

Nanophotonics achieves accurate control over the luminescence properties of a single quantum emitter by tailoring the light-matter interaction at the nanoscale and modifying the local density of optical states (LDOS). This paradigm could also benefit to F\"orster resonance energy transfer (FRET) by enhancing the near-field electromagnetic interaction between two fluorescent emitters. Despite the wide applications of FRET in nanosciences, using nanophotonics to enhance FRET remains a debated and complex challenge. Here, we demonstrate enhanced energy transfer within single donor-acceptor fluorophore pairs confined in gold nanoapertures. Experiments monitoring both the donor and the acceptor emission photodynamics at the single molecule level clearly establish a linear dependence of the FRET rate on the LDOS in nanoapertures. These findings are applied to enhance the FRET rate in nanoapertures up to six times, demonstrating that nanophotonics can be used to intensify the near-field energy transfer and improve the biophotonic applications of FRET

Auxiliary Companies of the Horticultural Sector as a Competitiveness Element: The Case of Almeria (Spain)

The horticultural model of Almeria (Spain) based on the operation of greenhouses is an international reference and has been considered as an economic miracle. Alongside this agricultural development has been the deployment of the diverse productive activity of auxiliary companies. The objective of this article is to understand how these companies operate and analyze their factors of competitiveness, competing needs, and future competitive improvements, taking as reference four of the most important subsectors (machinery, greenhouse infrastructure, plastics, and seeds). The Delphi method was used and through a panel of experts the conditioning factors of each of the variables to be analyzed (factors, needs, and competitiveness improvements) was chosen. Of the 120 companies that were sent questionnaires, 72 participated. The sectors that make up the auxiliary companies are heterogeneous and therefore the results obtained have differed among them. The synergies between the greenhouse crops and the auxiliary companies are an example of diversification of productive activity that can be extrapolated to other production areas worldwide. The future of the auxiliary companies is linked to that of the intensive agriculture and the key variables must be underscored by competitiveness and sustainability

The elder community, traffic accidents and Social Work

S i se cumple la proyección sobre población para 2050 aportada por la OMS, en España el 35% de sus habitantes tendrán más de 65 años. La rapidez con que nos acercamos a esa cifra, aparentemente lejana, obliga a redefinir, en muchos aspectos, las variables económicas, sociales y culturales desde las que se ha construido el modelo de vida y las prioridades presupuestarias. Un aspecto de esa sociología de la vida cotidiana de “los mayores” está marcado por su situación asimétrica con el tráfico de vehículos y la pandemia que suponen los accidentes de tráfico, con muertes y lesiones, tanto en carretera como en ciudad, tanto en su rol de conductores como en su papel de peatones. Según los últimos datos de la DGT, los +65 son los que menos se benefician de la reducción de accidentes que se ha producido en España en los últimos años. El hecho de que no exista una edad límite para retirar el carné de conducir y que los Centros de Reconocimiento de Conductores no cumplan con su cometido de disuasión legal, por establecer una competencia a la baja en busca del cliente, impiden la funcionalidad del sistema. Con este panorama, en que las carreteras se encuentran y se encontrarán crecientemente utilizadas por conductores septuagenarios, octogenarios y nonagenarios, aparecen dos figuras fundamentales por su situación relacional con los mayores, que pueden aportar un gran servido a la colectividad, el médico de cabecera y el trabajador social. Involucrarse o no en esta tarea puede ser decisivo. Se abre, así, un nuevo ámbito de intervención social: mayores vulnerables ante el tráfico._______________________________________According to the OMS 35% of the Spanish population will be over 65 years in the year 2050. These circumstances imply a redefinition of economic, social and cultural variables. Last data from the Spanish DGT (Traffic General Office) indicate that people over 65 are the segment of population that less advantages obtain as a consecuence of reductions in road accidents. Since there is neither age limit nor driver health control to cancel the driving licence in Spain, the system that rules driving is not functional. Under this perspective, an increasing number of drivers over 70, 80, and 90 will increasingly be filling up Spanish roads and highways. Therefore, two figures will become relevant to face this situation; the social worker and the physician. Also, a new area of social intervention is open: traffic-vulnerable elders

Descripción de las fiestas de cañas y toros : celebradas en Jerez de la Frontera el año 1630 con motivo del nacimiento del Príncipe D. Baltasar Carlos

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 201