220 research outputs found

    Integrated surveillance of leishmaniases vectors in the Americas

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    We developed integrated vector surveillance (IVS) proposals, both for cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL) in the Americas, based on eco-epidemiological studies conducted by researchers of the Leishmaniasis Research Network of Argentina-REDILA. For CL, the transmission was explained in the framework of the edge effect, the increase of vectors and risk of exposure at ecotones and environmental interfaces, and typified as ephemeral, transient, or permanent edges. This approach supports a cost-effective IVS strategy for early warning of CL outbreaks, through an environmental modification alert network, which includes multiple sources of information and actors.Para acceder a la videoconferencia completa, hacer clic en "Enlace externo".Sociedad Latinoamericana de Ecología de Vectore

    Distributed feedback lasers based on dichromated poly(vinyl alcohol) reusable surface-relief gratings

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    A simple, low-cost and versatile holographic method to produce reusable surface-relief gratings on dichromated poly(vinyl alcohol) (DCPVA) films, with periods Λ ≥ 270 nm and modulation depths up to 300 nm, is reported. DCPVA presents processing advantages with respect to other photoresists, such as dichromated gelatine, i.e. higher light sensitivity, simpler fabrication process and better batch to batch reproducibility. The successful use of these DCPVA relief gratings as distributed feedback (DFB) laser resonators is demonstrated. Second-order DFB devices emitting in the wavelength range 577-614 nm have been easily prepared by coating a dye-doped polymer film on top of the resonators.We thank the Spanish Government (MINECO) and the European Union (FEDER) for grant no. MAT2011-28167-C02

    Gender diversity, inclusive innovation and firm performance

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    This study delves into intra-organizational dimensions that might impact inclusive innovation. Based on the expectation states theory, we explore how gender diversity in management positions and on the board of directors affects inclusive innovation. Furthermore, drawing on the signaling theory, we examine the relationship between inclusive innovation and a firm's performance. Using a comprehensive panel data of European manufacturing companies for a period of 10 years, we provide evidence that gender diversity in management positions and the presence of at least one woman on the board of directors have a positive effect on inclusive innovation. Our results also reveal the economic value of such strategy, showing that inclusive innovation positively influences performance. Implications for theory and managerial practice are discussedMinisterio de Ciencia e Innovaci on, Grant/Award Number: PID2020-117313RB-I00Ministerio de Ciencia e Innovaci on, Grant/Award Number: PID2020-117313RB-I00Programa Operativo Andalucia FEDER 2012-202

    Perylenediimide-based distributed feedback lasers with holographic relief gratings on dichromated gelatine

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    One dimensional second-order distributed feedback (DFB) lasers consisting of polystyrene (PS) films doped with a perylenediimide laser dye, deposited over dichromated gelatine (DCG) photoresist layers with solvent resistant relief gratings recorded by holographic lithography, are reported. The advantage of using the grating on DCG in the final device is that the fabrication process is simplified and the grating pattern better preserved, since no etching methods to transfer the grating to another substrate are needed. A very simple model, proposed to explain the experimental waveguide properties, has allowed identifying the waveguide mode at which DFB emission appears, which was the key to optimize the device performance. In the frame of this model, the thickness of the PS and DCG films could be adjusted in order to minimize the laser threshold and to control its wavelength tuneability. The performance of these lasers is comparable to that of recently reported devices based on the same active material, but deposited over high-quality DFB gratings engraved on SiO2 by nanoimprint lithography.We thank support from the Spanish Government (MINECO) and the European Community (FEDER) through Grant Nos. MAT2008-06648-C02 and MAT-2011-28167-C02, as well as to the University of Alicante. M.G.R. was supported by a CSIC fellowship within the program JAE

    Sub-400 nm film thickness determination from transmission spectra in organic distributed feedback lasers fabrication

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    The design and fabrication of thin-film based organic optoelectronic devices require knowledge of the film optical properties. A low-cost and non-destructive method often used for optical characterization of films is the well-established spectrophotometric envelope method. However, this method is typically limited to thickness above 400 nm, a value often higher than that of the films involved in these devices. This paper studies a procedure to obtain the thickness of sub-400 nm active films from their spectrophotometric trace when the refractive index is previously known. The proposed procedure is based on comparing the experimental transmission spectrum in the transparent spectral window with that obtained by simulation. The capabilities of the proposed method are demonstrated here by its application in the fabrication of organic distributed feedback lasers, for which a fine control of film thickness is important to obtain an optimized and reproducible response. Results are verified with other techniques, such as ellipsometry and profilometry. Thus, with the proposed method, film thickness can be easily determined down to 40 nm maintaining an accuracy of about 5 nm even for films with low refractive index (1.5–1.7). Different methods to determine refractive index of these films are also discussed.Spanish Ministry of Economy and Competitivity (MINECO) and European Community (FEDER) through grant no. MAT2015-66586-R

    Two-dimensional distributed feedback lasers with thermally-nanoimprinted perylenediimide-containing films

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    Two-dimensional (2D) distributed feedback (DFB) lasers with gratings imprinted by thermal nanoimprint lithography on the active film are reported. They show thresholds for lasing of ∼10 kW/cm2, similar to the most efficient imprinted DFB lasers reported; and long operational lifetimes (under ambient conditions) of ∼12 × 104 pump pulses. The key for their successful operation has been the selection of a highly efficient and stable dye, perylene orange (PDI-O), and a proper matrix to host it, the fluoro-modified thermoplastic resist mr-I7030R, which has enabled 2D imprinting while preserving the dye optical properties. The use of the UV-curable resist SU8 as an alternative matrix for PDI-O to be imprinted by combined nanoimprint and photolithography was also investigated, and was concluded to be unsuccessful due to severe photoluminescence quenching. By replacing PDI-O with Rhodamine 6G, lasers with reasonable thresholds, but with significantly inferior operational lifetimes in comparison to PDI-O/mr-I7030R devices, were obtained.We thank support from the Spanish Government (MINECO) and the European Community (FEDER) through Grants MAT2011-28167-C02 and MAT2015-66586-R, as well as to the University of Alicante. M.M-V. has been partly supported by a MINECO FPI fellowship (no. BES-2009-020747) and by a Junta de Castilla y León grant (no. SA046U16)

    Distributed feedback lasers based on perylenediimide dyes for label-free refractive index sensing

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    The refractive index sensing capabilitity of distributed feedback (DFB) lasers based on highly photostable (under ambient conditions) perylenediimide-based active films, are reported. The sensor bulk sensitivity is determined from changes in the laser emission wavelength upon exposure to different liquids. The role of the active film thickness (hf) on the sensor sensitivity and on the laser parameters is studied. Sensors based on very thin films (hf = 160 nm) show the highest sensitivities, but their laser thresholds are relatively high and their operational durabilities moderate. The use of thicker films (hf = 850 nm) allows reducing the laser threshold and increasing the durability by two orders of magnitude. In this case, a higher sensitivity is achieved when the sensor operates at the wavelength corresponding to the first-order TE1 mode, instead of at the TE0 one. Finally, it is also shown that the inclusion of a high refractive index TiO2 layer on top of the sensor structure improves the sensitivity by around two times.This work was supported by the Spanish Government (MINECO) and the European Community (FEDER) through grant no. MAT-2011–28167-C02. This work was partially funded by the Basque Government within the framework of the Etortek Program (Grant No. IE13-360). M. Morales-Vidal has been partly supported by a MINECO FPI fellowship (no. BES-2009-020747)

    1,7-Bay-Substituted Perylenediimide Derivative with Outstanding Laser Performance

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    Efficient ASE at wavelengths >620 nm from PS films doped with a bay-substituted perylenediimide (PDI) derivative is reported. The maximum PDI content is around 40 times larger than in prior studies. The ability to introduce large dye amounts into the film without photoluminescence (PL) quenching allows very high PL and ASE efficiencies with low thresholds. A distributed feedback (DFB) laser device using one of the best-performing films is fabricated and characterized.We thank support from the Spanish Government (MINECO), the European Community (FEDER) and the Generalitat Valenciana through MAT-2011–28167-C02, CTQ2011–26455, PROMETEO 2012/010 and ISIC/2012/008, as well as to the University of Alicante and the University Miguel Hernández de Elche

    Dating the Anthropocene in deep-sea sediments: a gamma spectrometric approach

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    1 poster presented at the International meeting of Sedimentology 2017 in Toulouse, France, from October 10th to 13thUtilizando muestras de sedimentos superficiales obtenidas durante la campaña OVIDE/BOCATS 2016 y una innovadora técnica para establecer cronologías absolutas, se ha obtenido una primera estimación cuantitativa de los flujos de carbono hacia sedimentos profundos en la cuenca subpolar de Irminger. La geocronología basada en espectrometría gamma de alta resolución y bajo fondo con dos detectores simultáneos de germanio hiper-puro (HPGe) es una técnica suficientemente precisa y sensible como para datar sedimentos pelágicos profundos. El papel cuantitativo del Irminger como sumidero de carbono durante el Antropoceno se evaluó combinando una cronología basada en el radionúclido natural 210Pb junto a análisis sedimentológicos y de composición elemental. La tasa media de sedimentación para el canal central del Irminger es de 0.83±0.14 mm·yr-1. Los cálculos de flujos de carbono concluyen que durante el Antropoceno 32±14 g·Cinorg·m-2·año-1 y 4.5±3 g·Corg·m-2·año-1 sedimentan en la cuenca del Irminger, suponiendo un considerable sumidero de carbono en el área cuantificado en más de 22 Tg-C·año−1N

    Phlebotominae (Diptera: psycodidae) fauna in the Chaco region and Cutaneous Leishmaniasis transmission patterns in Argentina

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    In Argentina, the incidence of American Cutaneous Leishmaniasis (ACL) has shown a steady increase over the last few decades. In the Chaco biogeographical region, specifically, several outbreaks of ACL were recently reported in addition to the usual time-space scattering of ACL cases. However, little is known about the sandfly composition in the eastern, humid Chaco (HC) region or the western, dry Chaco (DC) region. Therefore, phlebotomine captures were performed throughout this region and an analysis of the distribution of reported ACL cases was conducted in order to assess the vector diversity in ACL endemic and epidemic scenarios in the Chaco region. The results support the hypothesis of two distinct patterns: (1) the DC, where Lutzomyia migonei was the most prevalent species, had isolated ACL cases and a zoonotic cycle; (2) the HC, where Lutzomyia neivai was the most prevalent species, had an increase in ACL incidence and outbreaks and an anthropozoonotic cycle. The epidemic risk in the Chaco region may be associated with the current climate trends, landscape modification, connection with other ACL foci, and Lu. neivai predominance and abundance. Therefore, changes in sandfly population diversity and density in the Chaco region are an indicator of emergent epidemic risk in sentinel capture sites.Facultad de Ciencias Naturales y Muse
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