Organic microcavity light-emitting diodes with metal mirrors: dependence of the emission wavelength on the viewing angle

Organic microcavity light-emitting diodes typically exhibit a blueshift of the emitting wavelength with increasing viewing angle. We have modeled the shift of the resonance wavelength for several metal mirrors. Eight metals (Al, Ag, Cr, Ti, Au, Ni, Pt, and Cu) have been considered as top or bottom mirrors, depending on their work functions. The model fully takes into account the dependence of the phase change that occurs on reflection on angle and wavelength for both s and p polarization, as well as on dispersion in the organic layers. Different contributions to the emission wavelength shift are discussed. The influence of the thickness of the bottom mirror and of the choice and thickness of the organic materials inside the cavity has been investigated. Based on the results obtained, guidelines for a choice of materials to reduce blueshift; are given. (C) 2002 Optical Society of America.

Modelling the activated sludge flocculation process combining laser light diffraction particle sizing and population balance modelling (PBM)

A technique based on laser light diffraction is shown to be successful in collecting on-line experimental data. Time series of floc size distributions (FSD) under different shear rates (G) and calcium additions were collected. The steady state mass mean diameter decreased with increasing shear rate G and increased when calcium additions exceeded 8 mg/l. A so-called population balance model (PBM) was used to describe the experimental data, This kind of model describes both aggregation and breakage through birth and death terms. A discretised PBM was used since analytical solutions of the integro-partial differential equations are non-existing. Despite the complexity of the model, only 2 parameters need to be estimated: the aggregation rate and the breakage rate. The model seems, however, to lack flexibility. Also, the description of the floc size distribution (FSD) in time is not accurate.

Light and electron microscopic analysis of aquaporin 1-like-immunoreactive amacrine cells in the rat retina

Aquaporin 1 (AQP1; also known as CHIP, a channel-forming integral membrane protein of 28 kDa) is the first protein to be shown to function as a water channel and has been recently shown to be present in the rat retina. We previously showed (Kim et al. [1998] Neurosci Lett 244:52-54) that AQP1-like immunoreactivity is present in a certain population of amacrine cells in the rat retina. This study was conducted to characterize these cells in more detail, With immunocytochemistry using specific antisera against AQP1, whole-mount preparations and 50-mum-thick vibratome sections were examined by light and electron microscopy. These cells were a class of amacrine cells, which had symmetric bistratified dendritic trees ramified in stratum 2 and in the border of strata 3 and 4 of the inner plexiform layer (IPL). Their dendritic field diameters ranged from 90 to 230 mum. Double labeling with antisera against AQP1 and gamma-aminobutyric acid or glycine demonstrated that these AQP1-like-immunoreactive amacrine cells were immunoreactive for glycine. Their most frequent synaptic input was from other amacrine cell processes in both sublaminae a and b of the IPL, followed by a few cone bipolar cells. Their primary targets were other amacrine cells and ganglion cells in both sublaminae a and b of the IPL. In addition, synaptic output Onto bipolar cells was rarely observed in sublamina b of the IPL. Thus, the AQP1 antibody labels a class of glycinergic amacrine cells with small to medium-sized dendritic fields in the rat retina. (C) 2002 Wiley-Liss, Inc.

Photosynthetic light and temperature responses of Eucalyptus cloeziana and Eucalyptus argophloia

Acclimation of gas exchange to temperature and light was determined in 18-month-old plants of humid coastal (Gympie) and dry inland ( Hungry Hills) provenances of Eucalyptus cloeziana F. Muell., and in those of a dry inland provenance of Eucalyptus argophloia Blakely. Plants were acclimated at day/night temperatures of 18/13, 23/18, 28/23 and 33/ 28 degreesC in controlled-temperature glasshouses for 4 months. Light and temperature response curves were measured at the beginning and end of the acclimation period. There were no significant differences in the shape and quantum-yield parameters among provenances at 23, 28 and 33 degreesC day temperatures. Quantum yield [mumol CO2 mumol(- 1) photosynthetic photon flux density (PPFD)] ranged from 0.04 to 0.06 and the light response shape parameter ranged from 0.53 to 0.78. Similarly, no consistent trends in the rate of dark respiration for plants of each provenance were identified at the four growth temperatures. Average values of dark respiration for the plants of the three provenances ranged from 0.61 to 1.86 mumol m(-2) s(-1). The optimum temperatures for net photosynthesis increased from 23 to 32 degreesC for the humid- and from 25 to 33 degreesC for the dry-provenance E. cloeziana and from 21 to 33 degreesC for E. argophloia as daytime temperature of the growth environment increased from 18 to 33 degreesC. These results have implications in predicting survival and productivity of E. cloeziana and E. argophloia in areas outside their natural distribution.

Occlusable corneas in toadfishes: light transmission, movement and ultrastruture of pigment during light- and dark-adaptation

The toadfishes Tetractenos hamiltoni and Torquigener pleurogramma (Tetraodontidae) possess occlusable yellow corneas. We examine the light transmission and location of the yellow/orange pigment throughout the cornea, the temporal properties of pigment migration and the ultrastructure of the pigmented processes during light- and dark-adaptation. Each species was dark-adapted during the day and light-adapted during the night and then exposed to either sun illumination or darkness for different lengths of time (0-70 min). Movement of corneal pigment could be induced in both species regardless of time of day or night. The pigment was able to migrate in a dorsal or ventral direction and changed from minimal to maximal pigmentation within 60 min. Three types of transmission curves were found with varying degrees of transmission in the 400-500 nm waveband, indicating that the pigment distribution is not uniform across the cornea; some areas of the cornea transmit near UV light, while others absorb blue light. The gradual change of the transmission characteristics in different areas of the cornea indicates the presence of different concentrations of a single type of pigment. Ultrastructural examination of the corneas showed that the layer containing the pigment is situated within the scleral cornea either surrounding (T. pleurogramma) or abutting (T. hamiltoni) an iridescent layer. Long sheet-like processes or chromatophores extending centrally from dorsal and ventral reservoirs are filled with pigment during the light-adapted state but empty in the dark-adapted state.

Retinal specializations in the blue marlin: eyes designed for sensitivity to low light levels

The large eyes and well-developed visual system of billfishes suggest that vision is an important sense for the detection and interception of prey and lures. Investigations of visual abilities in these large pelagic fishes are difficult, however anatomical studies of billfish eyes and retinas allow prediction of a number of visual capabilities. From the density of ganglion cells in the blue marlin (Makaira nigricans) retina, visual acuities of less than 10 cycles per degree were derived, a surprisingly low visual resolution given the absolute size of the marlin eye. Cone photoreceptors, on the other hand, were present in high densities, resulting in a presumed summation of cones to ganglion cells at a ratio of 40:1, even in the area of best vision. The optical sensitivity of the marlin eye was high owing to the large dimensions of the cone photoreceptors. These results indicate that the marlin eye is specifically adapted to cope with the low light levels encountered during diving. Since the marlin is likely to use its vision at depth, it is suggested that this line of research could help estimate the limits of vertical distribution based on light level.

Visual Biology of Hawaiian Coral Reef Fishes. III. Environmental Light and an Integrated Approach to the Ecology of Reef Fish Vision

In the previous two papers in this three-part series, we have examined visual pigments, ocular media transmission, and colors of the coral reef fish of Hawaii. This paper first details aspects of the light field and background colors at the microhabitat level on Hawaiian reefs and does so from the perspective and scale of fish living on the reef. Second, information from all three papers is combined in an attempt to examine trends in the visual ecology of reef inhabitants. Our goal is to begin to see fish the way they appear to other fish. Observations resulting from the combination of results in all three papers include the following. Yellow and blue colors on their own are strikingly well matched to backgrounds on the reef such as coral and bodies of horizontally viewed water. These colors, therefore, depending on context, may be important in camouflage as well as conspicuousness. The spectral characteristics of fish colors are correlated to the known spectral sensitivities in reef fish single cones and are tuned for maximum signal reliability when viewed against known backgrounds. The optimal positions of spectral sensitivity in a modeled dichromatic visual system are generally close to the sensitivities known for reef fish. Models also predict that both UV-sensitive and red-sensitive cone types are advantageous for a variety of tasks. UV-sensitive cones are known in some reef fish, red-sensitive cones have yet to be found. Labroid colors, which appear green or blue to us, may he matched to the far-red component of chlorophyll reflectance for camouflage. Red cave/hole dwelling reef fish are relatively poorly matched to the background they are often viewed against but this may be visually irrelevant. The model predicts that the task of distinguishing green algae from coral is optimized with a relatively long wavelength visual pigment pair. Herbivorous grazers whose visual pigments are known possess the longest sensitivities so far found. Labroid complex colors are highly contrasting complementary colors close up but combine, because of the spatial addition, which results from low visual resolution, at distance, to match background water colors remarkably well. Therefore, they are effective for simultaneous communication and camouflage.

Alternatively spliced products of the human kinesin light chain 1 (KNS2) gene

Conventional kinesin is a microtubule-based molecular motor involved in the transport of membranous and non-membranous cargoes. The kinesin holoenzyme exists as a heterotetramer, consisting of two heavy chain and two light chain subunits. It is thought that one function of the light chains is to interact with the cargo. Alternative splicing of kinesin light chain pre-mRNA has been observed in lower organisms, although evidence for alternative splicing of the human gene has not been reported. We have identified 19 variants of the human KNS2 gene (KLC1) that are generated by alternative splicing of downstream exons, but calculate that KNS2 has the potential to produce 285919 spliceforms. Corresponding spliceforms of the mouse KLC1 gene were also identified. The alternative exons are all located 3' of exon 12 and the novel spliceforms produce both alternative carboxy termini and alternative 3' untranslated regions. The observation of multiple light chain isoforms is consistent with their proposed role in specific cargo attachment.

Ocular scanning and perceptual size distortion in hemispatial neglect: effects of prism adaptation and sequential stimulus presentation

When asked to compare two lateralized shapes for horizontal size, neglect patients often indicate the left stimulus to be smaller. Gainotti and Tiacci (1971) hypothesized that this phenomenon might be related to a rightward bias in the patients' gaze. This study aimed to assess the relation between this size underestimation and oculomotor asymmetries. Eye movements were recorded while three neglect patients judged the horizontal extent of two rectangles. Two experimental manipulations were performed to increase the likelihood of symmetrical scanning of the stimulus display. The first manipulation entailed a sequential, rather than simultaneous presentation of the two rectangles. The second required adaptation to rightward displacing prisms, which is known to reduce many manifestations of neglect. All patients consistently underestimated the left rectangle, but the pattern of verbal responses and eye movements suggested different underlying causes. These include a distortion of space perception without ocular asymmetry, a failure to view the full leftward extent of the left stimulus, and a high-level response bias. Sequential presentation of the rectangles and prism adaptation reduced ocular asymmetries without affecting size underestimation. Overall, the results suggest that leftward size underestimation in neglect can arise for a number of different reasons. Incomplete leftward scanning may perhaps be sufficient to induce perceptual size distortion, but it is not a necessary prerequisite.

The influence of light spectra, UV-A, and growth regulators on the in vitro seed germination of Senecio cineraria DC.

This study was carried out to investigate the effects of light spectra, additional UV-A, and different growth regulators on the in vitro germination of Senecio cineraria DC. Seeds were surface-sterilized and inoculated in MS medium to evaluate the following light spectra: white, white plus UV-A, blue, green, red or darkness. The maximum germinability was obtained using MS0 medium under white light (30%) and MS + 0.3 mg L-1 GA3 in the absence of light (30.5%). S. cineraria seeds were indifferent to light. Blue and green lights inhibited germination. Different concentrations of gibberellic acid (GA3) (0.1; 0.4; 0.6; 0.8; 1.0 and 2.0 mg L-1) and indole-3-acetic acid IAA (0.1; 0.3 and 1.0 mg L-1) were evaluated under white light and darkness. No concentration of GA3 enhanced seed germination percentage under white light. However, when the seeds were maintained in darkness, GA3 improved germination responses in all tested concentrations, except at 1.0 mg L-1. Under white light, these concentrations also increased the germination time and reduced germination rate. Germination rate, under light or darkness, was lower using IAA compared with GA3.

Radial Distortion Self-Calibration

In cameras with radial distortion, straight lines in space are in general mapped to curves in the image. Although epipolar geometry also gets distorted, there is a set of special epipolar lines that remain straight, namely those that go through the distortion center. By finding these straight epipolar lines in camera pairs we can obtain constraints on the distortion center(s) without any calibration object or plumbline assumptions in the scene. Although this holds for all radial distortion models we conceptually prove this idea using the division distortion model and the radial fundamental matrix which allow for a very simple closed form solution of the distortion center from two views (same distortion) or three views (different distortions). The non-iterative nature of our approach makes it immune to local minima and allows finding the distortion center also for cropped images or those where no good prior exists. Besides this, we give comprehensive relations between different undistortion models and discuss advantages and drawbacks.

Unknown Radial Distortion Centers in Multiple View Geometry Problems

The radial undistortion model proposed by Fitzgibbon and the radial fundamental matrix were early steps to extend classical epipolar geometry to distorted cameras. Later minimal solvers have been proposed to find relative pose and radial distortion, given point correspondences between images. However, a big drawback of all these approaches is that they require the distortion center to be exactly known. In this paper we show how the distortion center can be absorbed into a new radial fundamental matrix. This new formulation is much more practical in reality as it allows also digital zoom, cropped images and camera-lens systems where the distortion center does not exactly coincide with the image center. In particular we start from the setting where only one of the two images contains radial distortion, analyze the structure of the particular radial fundamental matrix and show that the technique also generalizes to other linear multi-view relationships like trifocal tensor and homography. For the new radial fundamental matrix we propose different estimation algorithms from 9,10 and 11 points. We show how to extract the epipoles and prove the practical applicability on several epipolar geometry image pairs with strong distortion that - to the best of our knowledge - no other existing algorithm can handle properly.

Anotação, numa perspectiva de Direito Penal e de Criminologia, ao Acórdão do Supremo Tribunal de Justiça (português), de 13 de Abril de 2009 [Juiz Conselheiro Rodrigues da COSTA (Relator), Juiz Conselheiro Arménio SOTTOMAYOR (vencido nos termos da declaração junta) e Juiz Conselheiro Mota MIRANDA] - são o «lenocínio» e a prostituição, entre adultos livres, crimes? «Roxanne, you don't have to put on the red light»

Resumo: 1 – Sumário do Acórdão do Supremo Tribunal de Justiça, de 13 de Abril de 2011; 2 – Texto completo do Acórdão do Supremo Tribunal de Justiça, de 13 de Abril de 2009, Juiz Conselheiro Rodrigues da COSTA (Relator), Juiz Conselheiro Arménio SOTTOMAYOR (vencido nos termos da declaração junta) e Juiz Conselheiro Mota MIRANDA: cfr. http://www.dgsi.pt , 26 de Abril de 2011; 3 – Anotação; 3.1 – Introdução à anotação; 3.2 – A questão do suposto «bem jurídico» que seria tutelado pelo crime de «lenocínio» p.p.p.p.p. 169.º do código penal português; 3.2.1 – Ainda a questão do suposto «bem jurídico» que seria tutelado pelo crime de «lenocínio» p.p.p.p.p. 169.º do código penal português: uma maior procura e concretização jurídica e científica; 4 – Conclusões; § Abstract: 1 - Summary of the Sentence of the Supreme Court of Justice, 13 of April of 2011; 2 - Complete text of the Sentence of the Supreme Court of Justice, 13 of April of 2009, Advising Judge Rodrigues da COSTA (Reporter), Advising Judge Arménio SOTTOMAYOR (looser in the terms of the together declaration) and Advising Judge Mota MIRANDA: cfr. http://www.dgsi.pt , 26 of April of 2011; 3 - Notation; 3.1 - Introduction to the notation; 3.2 - The question of the presumption «legally protected interest» that would be tutored person for the crime of «pimpery (“pimping”)» p.p.p.p.p. 169.º of the Portuguese criminal code; 3.2.1 - Still the question of the presumption «legally protected interest» that would be tutored person for the crime of «pimpery» («pimping») p.p.p.p.p. 169.º of the Portuguese criminal code: a bigger search and legal and scientific concretion; 4 - Conclusions;

Selection of full-sib families of Panicum maximum Jacq under low light conditions

The silvopastoral system is a viable technological alternative to extensive cattle grazing, however, for it to be successful, forage grass genotypes adapted to reduced light need to be identified. The objective of this study was to select progenies of Panicum maximum tolerant to low light conditions for use in breeding programs and to study the genetic control and performance of some traits associated with shade tolerance. Six full-sib progenies were evaluated in full sun, 50% and 70% of light reduction in pots and subjected to cuttings. Progeny genotypic values ​​(GV) increased with light reduction in relation to plant height (H) and specific leaf area (SLA). The traits total dry mass accumulation (DM) and leaf dry mass accumulation (LDM) had GV higher in 50% shade and intermediate in 70% shade. The GV of tiller number (TIL) and root dry mass accumulation (RDM) decreased with light reduction. The highest positive correlations were obtained for the traits H and RDM with SLA and DM; the highest negative correlations were between TIL and SLA and RDM, and H and LDM. The progenies showed higher tolerance to 50% light reduction and, among them, two stood out and will be used in breeding programs. It was also found that it is not necessary to evaluate some traits under all light conditions. All traits had high broad sense heritability and high genotypic correlation between progenies in all light intensities. There is genetic difference among the progenies regarding the response to different light intensities, which will allow selection for shade tolerance