The adaptive maintenance of flower color variation is frequently attributed to pollinators partly... more The adaptive maintenance of flower color variation is frequently attributed to pollinators partly because they preferentially visit certain flower phenotypes. We tested whether Gentiana lutea-which shows a flower color variation (from orange to yellow) in the Cantabrian Mountains range (north of Spain)-is locally adapted to the pollinator community. We transplanted orange-flowering individuals to a population with yellow-flowering individuals and vice versa, in order to assess whether there is a pollination advantage in the local morph by comparing its visitation rate with the foreign morph. Our reciprocal transplant experiment did not show clear local morph advantage in overall visitation rate: local orange flowers received more visits than foreign yellow flowers in the orange population, while both local and foreign flowers received the same visits in the yellow population; thus, there is no evidence of local adaptation in Gentiana lutea to the pollinator assemblage. However, some...
Objetivo: Revisar las indicaciones de las histerectomias postparto en el Hospital Universitario J... more Objetivo: Revisar las indicaciones de las histerectomias postparto en el Hospital Universitario Joan XXIII de Tarragona. Material y metodos: Estudio retrospectivo de las 18 histerectomias postparto realizadas en el Hospital Universitario Joan XXIII de Tarragona, en el periodo comprendido entre enero de 1999 a diciembre de 2005. Resultados: La frecuencia de histerectomias postparto en el periodo de 7 anos, es de 1,5%. La causa mas frecuente fue atonia uterina en 13 pacientes, placenta acreta en 3 pacientes, placenta previa oclusiva en 1 paciente y desgarro uterino en 1 paciente. La edad media es de 30,2 anos. Las complicaciones fueron 5 pacientes coagulacion intravascular diseminadas, 2 shock hipovolemicos, 2 lesiones de cupula vesical, 2 reintervenciones, 2 muertes maternas (un caso por embolia de liquido amniotico y otro por traumatismo craneoencefalico y sospecha de embolismo pultmonar), 1 hematoma de cupula vaginal, 1 absceso pelvico y 1 hipotension intraoperativa.
Angiosperms diversification was primarily driven by pollinator agents, but non-pollinator agents ... more Angiosperms diversification was primarily driven by pollinator agents, but non-pollinator agents also promoted floral evolution.Gentiana luteashows pollinator driven flower color variation in NW Spain. We test whether insect herbivores and livestock, which frequently feed inG.lutea, play a role inG. luteaflower color variation, by answering the following questions: (i) Do insect herbivores and grazing livestock show flower color preferences when feeding onG. lutea? (ii) Do mutualists (pollinators) and antagonists (seed predators, insect herbivores and livestock) jointly affectG. luteareproductive success? Insect herbivores fed more often on yellow flowering individuals but they did not affect seed production, whereas livestock affected seed production but did not show clear color preferences. Our data indicate that flower color variation ofG. luteais not affected by insect herbivores or grazing livestock.
Here, we propose a method to estimate misalignment losses that is based on the calculation of the... more Here, we propose a method to estimate misalignment losses that is based on the calculation of the radiated angular power distribution as light propagates through space using the fiber far field pattern (FFP) and simplifying and speeding calculations with the Hankel transform. This method gives good estimates for combined transversal and longitudinal losses at short, intermediate and long offset distances. In addition, the same methodology can be adapted to describe not only scalar loss but also its angular dependence caused by misalignments. We show that this approach can be applied to upgrade a connector matrix included in a propagation model that is integrated into simulation software. This way, we assess the effects of misalignments at different points in the link and are able to predict the performance of different layouts at system level.
2013 15th International Conference on Transparent Optical Networks (ICTON), 2013
ABSTRACT Structural health monitoring (SHM) is a cost-effective approach to meet operational requ... more ABSTRACT Structural health monitoring (SHM) is a cost-effective approach to meet operational requirements, and to reduce maintenance costs in aircrafts. Besides, fiber optic sensor technology is a mature technology which can be used to monitor physical parameters of wing leading-edge surfaces and fuselage sections made of composites carbon fiber-reinforced plastic (CFRP) materials. This paper deals with some applications of plastic and glass optical fiber based sensors for SHM. Among other, we will describe the results we have obtained for damage detection, impact location, strain and deformation measurements. We will also show some results of the blade tip timing and tip clearance in aircraft turbines. These are two of the main parameters governing the efficiency of turbine engine.
In this chapter the deployment of plastic optical fibers in short-range (in-building) networks is... more In this chapter the deployment of plastic optical fibers in short-range (in-building) networks is examined. The application is evaluated in the context of the problem of modeling optical power propagation through the fiber when it is deployed in peculiar environments such as those inside a house. A fast and versatile matrix method is developed to model optical power transmission throughout the fiber. This method is flexible in incorporating the effects of localized disturbances over transmission and compact in facilitating integration in commercial software packages.
The aim of the present paper is to provide a comprehensive analysis of the coupling losses in mul... more The aim of the present paper is to provide a comprehensive analysis of the coupling losses in multi-step index (MSI) fibres. Their light power acceptance properties are investigated to obtain the corresponding analytical expressions taking into account longitudinal, transverse, and angular misalignments. For this purpose, a uniform power distribution is assumed. In addition, we perform several experimental measurements and computer simulations in order to calculate the coupling losses for two different MSI polymer optical fibres (MSI-POFs). These results serve us to validate the theoretical expressions we have obtained.
ABSTRACT The time-dependent power flow equation is employed to calculate frequency response and b... more ABSTRACT The time-dependent power flow equation is employed to calculate frequency response and bandwidth in addition to mode coupling and mode-dependent attenuation in step-index plastic optical fibers. Frequency response is specified in the paper as a function of fiber length. Results are found to match reported measurements better than the existing analytical solution does. Mode-dependent attenuation and mode dispersion and coupling are known to be strong in plastic optical fibers, leading to major implications for their frequency response.
Pure and Applied Optics: Journal of the European Optical Society Part A, 1998
We present an experimental method to obtain the point spread function (PSF) of human eyes, based ... more We present an experimental method to obtain the point spread function (PSF) of human eyes, based on two techniques: the conventional symmetric double-pass method and the recently introduced asymmetric one-and-a-half-pass method. The symmetric double-pass method provides the autocorrelation of the retinal PSF and thus, the modulation transfer function (MTF). Here, we show that the double-pass MTF can be combined with partial phase information provided by the one-and-a-half-pass method to estimate the PSF. Two reconstruction methods were used, depending on the relative contribution of diffraction and aberrations. When aberrations are dominant (large pupils), the PSF can be obtained directly by combining the modulus and phase. When aberrations are small (small to medium pupils), however, a partial phase-retrieval algorithm has to be applied. In agreement with previous findings, the PSFs show substantial intersubject variability and for large pupils, they display the characteristic ray-pattern of star images.
The adaptive maintenance of flower color variation is frequently attributed to pollinators partly... more The adaptive maintenance of flower color variation is frequently attributed to pollinators partly because they preferentially visit certain flower phenotypes. We tested whether Gentiana lutea-which shows a flower color variation (from orange to yellow) in the Cantabrian Mountains range (north of Spain)-is locally adapted to the pollinator community. We transplanted orange-flowering individuals to a population with yellow-flowering individuals and vice versa, in order to assess whether there is a pollination advantage in the local morph by comparing its visitation rate with the foreign morph. Our reciprocal transplant experiment did not show clear local morph advantage in overall visitation rate: local orange flowers received more visits than foreign yellow flowers in the orange population, while both local and foreign flowers received the same visits in the yellow population; thus, there is no evidence of local adaptation in Gentiana lutea to the pollinator assemblage. However, some...
Objetivo: Revisar las indicaciones de las histerectomias postparto en el Hospital Universitario J... more Objetivo: Revisar las indicaciones de las histerectomias postparto en el Hospital Universitario Joan XXIII de Tarragona. Material y metodos: Estudio retrospectivo de las 18 histerectomias postparto realizadas en el Hospital Universitario Joan XXIII de Tarragona, en el periodo comprendido entre enero de 1999 a diciembre de 2005. Resultados: La frecuencia de histerectomias postparto en el periodo de 7 anos, es de 1,5%. La causa mas frecuente fue atonia uterina en 13 pacientes, placenta acreta en 3 pacientes, placenta previa oclusiva en 1 paciente y desgarro uterino en 1 paciente. La edad media es de 30,2 anos. Las complicaciones fueron 5 pacientes coagulacion intravascular diseminadas, 2 shock hipovolemicos, 2 lesiones de cupula vesical, 2 reintervenciones, 2 muertes maternas (un caso por embolia de liquido amniotico y otro por traumatismo craneoencefalico y sospecha de embolismo pultmonar), 1 hematoma de cupula vaginal, 1 absceso pelvico y 1 hipotension intraoperativa.
Angiosperms diversification was primarily driven by pollinator agents, but non-pollinator agents ... more Angiosperms diversification was primarily driven by pollinator agents, but non-pollinator agents also promoted floral evolution.Gentiana luteashows pollinator driven flower color variation in NW Spain. We test whether insect herbivores and livestock, which frequently feed inG.lutea, play a role inG. luteaflower color variation, by answering the following questions: (i) Do insect herbivores and grazing livestock show flower color preferences when feeding onG. lutea? (ii) Do mutualists (pollinators) and antagonists (seed predators, insect herbivores and livestock) jointly affectG. luteareproductive success? Insect herbivores fed more often on yellow flowering individuals but they did not affect seed production, whereas livestock affected seed production but did not show clear color preferences. Our data indicate that flower color variation ofG. luteais not affected by insect herbivores or grazing livestock.
Here, we propose a method to estimate misalignment losses that is based on the calculation of the... more Here, we propose a method to estimate misalignment losses that is based on the calculation of the radiated angular power distribution as light propagates through space using the fiber far field pattern (FFP) and simplifying and speeding calculations with the Hankel transform. This method gives good estimates for combined transversal and longitudinal losses at short, intermediate and long offset distances. In addition, the same methodology can be adapted to describe not only scalar loss but also its angular dependence caused by misalignments. We show that this approach can be applied to upgrade a connector matrix included in a propagation model that is integrated into simulation software. This way, we assess the effects of misalignments at different points in the link and are able to predict the performance of different layouts at system level.
2013 15th International Conference on Transparent Optical Networks (ICTON), 2013
ABSTRACT Structural health monitoring (SHM) is a cost-effective approach to meet operational requ... more ABSTRACT Structural health monitoring (SHM) is a cost-effective approach to meet operational requirements, and to reduce maintenance costs in aircrafts. Besides, fiber optic sensor technology is a mature technology which can be used to monitor physical parameters of wing leading-edge surfaces and fuselage sections made of composites carbon fiber-reinforced plastic (CFRP) materials. This paper deals with some applications of plastic and glass optical fiber based sensors for SHM. Among other, we will describe the results we have obtained for damage detection, impact location, strain and deformation measurements. We will also show some results of the blade tip timing and tip clearance in aircraft turbines. These are two of the main parameters governing the efficiency of turbine engine.
In this chapter the deployment of plastic optical fibers in short-range (in-building) networks is... more In this chapter the deployment of plastic optical fibers in short-range (in-building) networks is examined. The application is evaluated in the context of the problem of modeling optical power propagation through the fiber when it is deployed in peculiar environments such as those inside a house. A fast and versatile matrix method is developed to model optical power transmission throughout the fiber. This method is flexible in incorporating the effects of localized disturbances over transmission and compact in facilitating integration in commercial software packages.
The aim of the present paper is to provide a comprehensive analysis of the coupling losses in mul... more The aim of the present paper is to provide a comprehensive analysis of the coupling losses in multi-step index (MSI) fibres. Their light power acceptance properties are investigated to obtain the corresponding analytical expressions taking into account longitudinal, transverse, and angular misalignments. For this purpose, a uniform power distribution is assumed. In addition, we perform several experimental measurements and computer simulations in order to calculate the coupling losses for two different MSI polymer optical fibres (MSI-POFs). These results serve us to validate the theoretical expressions we have obtained.
ABSTRACT The time-dependent power flow equation is employed to calculate frequency response and b... more ABSTRACT The time-dependent power flow equation is employed to calculate frequency response and bandwidth in addition to mode coupling and mode-dependent attenuation in step-index plastic optical fibers. Frequency response is specified in the paper as a function of fiber length. Results are found to match reported measurements better than the existing analytical solution does. Mode-dependent attenuation and mode dispersion and coupling are known to be strong in plastic optical fibers, leading to major implications for their frequency response.
Pure and Applied Optics: Journal of the European Optical Society Part A, 1998
We present an experimental method to obtain the point spread function (PSF) of human eyes, based ... more We present an experimental method to obtain the point spread function (PSF) of human eyes, based on two techniques: the conventional symmetric double-pass method and the recently introduced asymmetric one-and-a-half-pass method. The symmetric double-pass method provides the autocorrelation of the retinal PSF and thus, the modulation transfer function (MTF). Here, we show that the double-pass MTF can be combined with partial phase information provided by the one-and-a-half-pass method to estimate the PSF. Two reconstruction methods were used, depending on the relative contribution of diffraction and aberrations. When aberrations are dominant (large pupils), the PSF can be obtained directly by combining the modulus and phase. When aberrations are small (small to medium pupils), however, a partial phase-retrieval algorithm has to be applied. In agreement with previous findings, the PSFs show substantial intersubject variability and for large pupils, they display the characteristic ray-pattern of star images.
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