Reproduetive biology aud conservation of Petrocoptis grandiflora in the NW of the Iberian Península

GulríÁN. J., SÁNCHEZ, 1. M. & GuITIÁN. P. 1993. Biología y Conservación de Prírocoptis grandilora cocí Noroeste Ibérico. flor. Ccmplutcnsis 18: 123-128 Se dan a conocer algunos datos básicos sobre la situación actual de las poblaciones de Petrocoptis g,-and,jlcra en el NW Ibérico y sobre su Biología (Fenología, Polinización, Fructificación y Dispersión). Finalmenle se señala la necesidad de profundizar en el conocimiento de la Biología Reproductiva de los endemismos ibéricos como paso previo al establecimiento de medidas de protección eficaces

Selective Pressure along a Latitudinal Gradient Affects Subindividual Variation in Plants

Individual plants produce repeated structures such as leaves, flowers or fruits, which, although belonging to the same genotype, are not phenotypically identical. Such subindividual variation reflects the potential of individual genotypes to vary with micro-environmental conditions. Furthermore, variation in organ traits imposes costs to foraging animals such as time, energy and increased predation risk. Therefore, animals that interact with plants may respond to this variation and affect plant fitness. Thus, phenotypic variation within an individual plant could be, in part, an adaptive trait. Here we investigated this idea and we found that subindividual variation of fruit size of Crataegus monogyna, in different populations throughout the latitudinal gradient in Europe, was explained at some extent by the selective pressures exerted by seed-dispersing birds. These findings support the hypothesis that within-individual variation in plants is an adaptive trait selected by interacting animals which may have important implications for plant evolution. © 2013 Sobral et al.This work was supported by the Spanish Ministry of Science and Education (project CGL2005-03826) and the European Commission (FEDER program). M.S. was the recipient of a María Barbeito fellowship (Galicia regional government, Spain) and a Fundación Pedro Barrié de la Maza grant. A.R.L. received financial support from the Spanish Research Council (JAEDoc program, partially funded by the European Social Fund) during the preparation of the manuscriptPeer Reviewe

Interfacce uomo-macchina nella realtà virtuale

Questo capitolo fornisce una descrizione dei principali elementi che influenzano l'interazione uomo-macchina in riferimento alla realtà virtuale, per come si configurano attualmente, e per come si prevede si svilupperanno in un prossimo futuro. Il capitolo è organizzato nel modo seguente: la sezione 1.1 presenta il concetto di realtà virtuale soprattutto in relazione alle possibilità offerte per quanto riguarda l’interazione tra uomo e macchina, ed alle applicazioni di nuova generazione. La sezione successiva descrive i principali requisiti ed i vincoli che un sistema di realtà virtuale deve soddisfare per riuscire a fornire all’utente un’impressione convincente e delle esperienze realmente immersive. La sezione 1.3 si concentra sul feedback sensoriale principale, descrivendo le principali tecnologie di nuova generazione per la realizzazione di dispositivi in grado di fornire delle sensazioni visive e tattili estremamente realistiche. Infine la sezione 1.4 descrive brevemente alcuni esempi di applicazioni di realtà virtuale realizzate dagli autori, nel campo della simulazione chirurgica, dei musei virtuali e dei sistemi di visualizzazione autostereoscopici multiutente, e la sezione 1.5 discute brevemente la situazione attuale ed il potenziale futuro della disciplina.289-33

Selective pressure along a latitudinal gradient affects subindividual variation in plants

Individual plants produce repeated structures such as leaves, flowers or fruits, which, although belonging to the same genotype, are not phenotypically identical. Such subindividual variation reflects the potential of individual genotypes to vary with micro-environmental conditions. Furthermore, variation in organ traits imposes costs to foraging animals such as time, energy and increased predation risk. Therefore, animals that interact with plants may respond to this variation and affect plant fitness. Thus, phenotypic variation within an individual plant could be, in part, an adaptive trait. Here we investigated this idea and we found that subindividual variation of fruit size of Crataegus monogyna, in different populations throughout the latitudinal gradient in Europe, was explained at some extent by the selective pressures exerted by seed-dispersing birds. These findings support the hypothesis that within-individual variation in plants is an adaptive trait selected by interacting animals which may have important implications for plant evolution.This work was supported by the Spanish Ministry of Science and Education (project CGL2005-03826) and the European Commission (FEDER program). M.S. was the recipient of a María Barbeito fellowship (Galicia regional government, Spain) and a Fundación Pedro Barrié de la Maza grant. A.R.L. received financial support from the Spanish Research Council (JAEDoc program, partially funded by the European Social Fund) during the preparation of the manuscriptS

Is there a hybridization barrier between Gentiana lutea color morphs?

In Gentiana lutea two varieties are described: G. lutea var. aurantiaca with orange corolla colors and G. lutea var. lutea with yellow corolla colors. Both color varieties co-occur in NW Spain, and pollinators select flower color in this species. It is not known whether a hybridization barrier exists between these G. lutea color varieties. We aim to test the compatibility between flower color varieties in G. lutea and its dependence on pollen vectors. Within a sympatric population containing both flower color morphs, we analyzed differences in reproductive success (number, weight, viability and germinability of seeds) depending on fertilization treatments (autogamy and xenogamy within variety and among varieties). We found a 93% reduction in number of seeds and a 37% reduction in seed weight respectively of autogamy treatments compared to xenogamy crossings. Additionally, reproductive success is higher within color varieties than among varieties, due to a 45% seed viability reduction on hybrids from different varieties. Our results show that G. lutea reproductive success is strongly dependent on pollinators and that a partial hybridization barrier exists between G. lutea varieties.This study is included in the project “Color polymorphism, geographic variation in the interactions and phenotypic selection. The case of Gentiana lutea L. in the Cantabrian Mountains” was financially supported by Secretary of State of I+D+I, Ministry of Science and Innovation, Government of Spain (2011–2013)S

Differences in pollination success between local and foreign flower color phenotypes: a translocation experiment with Gentiana lutea (Gentianaceae)

Background. The adaptive maintenance of flower color variation is frequently at-tributed to pollinators partly because they preferentially visit certain flower phenotypes.We tested whetherGentiana lutea—which shows a flower color variation (from orangeto yellow) in the Cantabrian Mountains range (north of Spain)—is locally adapted tothe pollinator community.Methods. We transplanted orange-flowering individuals to a population with yellow-flowering individuals and vice versa, in order to assess whether there is a pollinationadvantage in the local morph by comparing its visitation rate with the foreign morph.Results. Our reciprocal transplant experiment did not show clear local morphadvantage in overall visitation rate: local orange flowers received more visits thanforeign yellow flowers in the orange population, while both local and foreign flowersreceived the same visits in the yellow population; thus, there is no evidence of localadaptation inGentiana luteato the pollinator assemblage. However, some floral visitorgroups (such asBombus pratorum,B. soroensis ancaricusandB. lapidarius decipiens)consistently preferred the local morph to the foreign morph whereas others (such asBombus terrestris) consistently preferred the foreign morph.Discussion. We concluded that there is no evidence of local adaptation to the pollinatorcommunity in each of the twoG. luteapopulations studied. The consequences forlocal adaptation to pollinator onG. luteaflower color would depend on the variationalong the Cantabrian Mountains range in morph frequency and pollinator community composition.S

Selective pressures explain differences in flower color among Gentiana lutea Populations

Flower color variation among plant populations might reflect adaptation to local conditions such as the interacting animal community. In the northwest Iberian Peninsula, flower color of Gentiana lutea varies longitudinally among populations, ranging from orange to yellow. We explored whether flower color is locally adapted and the role of pollinators and seed predators as agents of selection by analyzing the influence of flower color on (i) pollinator visitation rate and (ii) escape from seed predation and (iii) by testing whether differences in pollinator communities correlate with flower color variation across populations. Finally, (iv) we investigated whether variation in selective pressures explains flower color variation among 12 G. lutea populations. Flower color influenced pollinator visits and differences in flower color among populations were related to variation in pollinator communities. Selective pressures on flower color vary among populations and explain part of flower color differences among populations of G. lutea. We conclude that flower color in G. lutea is locally adapted and that pollinators play a role in this adaptation.This work was financed by the Plan Nacional de I + D + I (2008-2011), CGL2009-08959 Ministerio de Ciencia. T.V. was supported by a PhD grant from the Plan Galego de Investigación e Crecemento 2011/2015 (Plan I2C), Consellería de Educación e Ordenación Universitaria e InnovaciónS

Flower color preferences of insects and livestock: effects on Gentiana lutea reproductive success

Angiosperms diversification was primarily driven by pollinator agents, but non-pollinator agents also promoted floral evolution. Gentiana lutea shows pollinator driven flower color variation in NW Spain. We test whether insect herbivores and livestock, which frequently feed in G.lutea, play a role in G. lutea flower color variation, by answering the following questions: (i) Do insect herbivores and grazing livestock show flower color preferences when feeding on G. lutea? (ii) Do mutualists (pollinators) and antagonists (seed predators, insect herbivores and livestock) jointly affect G. lutea reproductive 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 of G. lutea is not affected by insect herbivores or grazing livestockThis study is included in the project “Color polymorphism, geographic variation in the interactions and phenotypic selection. The case of Gentiana lutea L in the Cantabrian Mountains,” financially supported by Secretary of State of I+D+I, Ministry of Science and Innovation, Government of Spain (2011–2013). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptS

View-dependent Exploration of Massive Volumetric Models on Large Scale Light Field Displays

We report on a light-field display based virtual environment enabling multiple naked-eye users to perceive detailed multi-gigavoxel volumetric models as floating in space, responsive to their actions, and delivering different information in different areas of the workspace. Our contributions include a set of specialized interactive illustrative techniques able to provide different contextual information in different areas of the display, as well as an out-of-core CUDA based raycasting engine with a number of improvements over current GPU volume raycasters. The possibilities of the system are demonstrated by the multi-user interactive exploration of 64GVoxels datasets on a 35MPixel light field display driven by a cluster of PCs.1037-1047Pubblicat

An energy preserving upscaling technique for enhanced volume rendering of medical data

Proc. 3D Anatomical Human Summer School 2010, 23-24 May, Chania, Greece: EU Marie Curie Research Training Network. 2010.In this paper we describe an edge-directed optimization-based method for volumetric data supersampling. Our method faces the problem of partial volume effect by upscaling the volumetric data, subdividing voxels in smaller parts and performing an optimization step keeping constant the energy of each original subdivided voxel while enhancing edge continuity. Experimental tests show the good quality of the results obtained with our approach. Furthermore, we show how offline 3D upscaling of volumes can be coupled with recent techniques to perform high quality volume rendering of large datsets, obtaining a better inspection of medical volumetric data.In corso di stamp