Análisis de la arquitectura de webs mediante tests de estrés de navegación, de usabilidad y eye tracking

Evaluar una arquitectura de la información en un sitio web ya desplegado no resulta una tarea sencilla. La mayoría de las técnicas se centran en examinar la usabilidad del sistema que, aunque afecta a la arquitectura de la información, no es el único factor que influye en ella. La principal técnica que se utiliza es el test de estrés de navegación. Se muestra un aporte metodológico para hacer dicha técnica más informativa, llevándola más allá de la simple anotación en papel por parte del usuario de respuestas a las preguntas de navegación planteadas. Se propone la combinación de ésta con otras técnicas de evaluación de la usabilidad: la técnica de pensar en voz alta o thinking aloud y un cuestionario de usabilidad. Se ha utilizado un sistema de seguimiento de la mirada o eye tracking para complementar la información obtenida mediante las técnicas aplicadas. El enfoque metodológico planteado se ha puesto a prueba analizando una serie de sitios web de bibliotecas de universidades públicas españolas. Se muestra en los resultados la validez del enfoque empleado, así como el valor que dicho enfoque y el uso del eye tracking aportan al análisis de la arquitectura de la información respecto al test de estrés de navegación tradicional.

Using the optical flow to implement a relative virtual mouse controlled by head movements

The following paper introduces the work conducted to create a relative virtual mouse based on the interpretation of head movements and face gesture through a low cost camera and the optical flow of the images. This virtual device is designed specifically as an alternative non-contact pointer for people with mobility impairments in the upper extremities and reduced head control. The proposed virtual device was compared with a conventional mouse, a touchpad and a digital joystick. Validation results show performances close to a digital joystick but far away from a conventional mouse.

An Analysis of Eye Scanpath Entropy in a Progressively Forming Virtual Environment

A sign of presence in virtual environments is that people respond to situations and events as if they were real, where response may be considered at many different levels, ranging from unconscious physiological responses through to overt behavior,emotions, and thoughts. In this paper we consider two responses that gave different indications of the onset of presence in a gradually forming environment. Two aspects of the response of people to an immersive virtual environment were recorded: their eye scanpath, and their skin conductance response (SCR). The scenario was formed over a period of 2 min, by introducing an increasing number of its polygons in random order in a head-tracked head-mounted display. For one group of experimental participants (n 8) the environment formed into one in which they found themselves standing on top of a 3 m high column. For a second group of participants (n 6) the environment was otherwise the same except that the column was only 1 cm high, so that they would be standing at normal ground level. For a third group of participants (n 14) the polygons never formed into a meaningful environment. The participants who stood on top of the tall column exhibited a significant decrease in entropy of the eye scanpath and an increase in the number of SCR by 99 s into the scenario, at a time when only 65% of the polygons had been displayed. The ground level participants exhibited a similar decrease in scanpath entropy, but not the increase in SCR. The random scenario grouping did not exhibit this decrease in eye scanpath entropy. A drop in scanpath entropy indicates that the environment had cohered into a meaningful perception. An increase in the rate of SCR indicates the perception of an aversive stimulus. These results suggest that on these two dimensions (scanpath entropy and rate of SCR) participants were responding realistically to the scenario shown in the virtual environment. In addition, the response occurred well before the entire scenario had been displayed, suggesting that once a set of minimal cues exists within a scenario,it is enough to form a meaningful perception. Moreover, at the level of the sympathetic nervous system, the participants who were standing on top of the column exhibited arousal as if their experience might be real. This is an important practical aspect of the concept of presence.

White eye phenotypes and their genetic analysis

An interesting case for undergraduate students of general Genetics is to consider that different genes can produce the same or similar phenotypes. We present here an experiment to discover that the same phenotype could be produced by different genes, and then, to carry out the genetic analysis of these genes. For this laboratory study we have used the following Drosophila melanogaster strains: white (white eyes) and scarlet-brown (white eyes).

White eye phenotypes and their genetic analysis

An interesting case for undergraduate students of general Genetics is to consider that different genes can produce the same or similar phenotypes. We present here an experiment to discover that the same phenotype could be produced by different genes, and then, to carry out the genetic analysis of these genes. For this laboratory study we have used the following Drosophila melanogaster strains: white (white eyes) and scarlet-brown (white eyes).

Common Quail (Coturnix coturnix) post-breeding movements and migration patterns: from knowledge to management.

Hemos investigado los patrones de los movimientos postcría de la codorniz común (Coturnix coturnix) en la península ibérica con el fin de describir su fenología de paso migratorio y algunas características fisiológicas de los individuos. Esta información es necesaria para un ajuste óptimo de los períodos de caza. Hemos trabajado a partir de dos conjuntos de datos: a) capturas efectuadas en una zona que no es de cría (Garraf) de agosto a octubre en 2009 y 2010; b) recuperaciones, posteriores a la presunta época de cría, de individuos anillados en Europa y recapturados en España durante el período 1933-2005. Los resultados obtenidos muestran que los movimientos postcría en Garraf están formados por dos oleadas: una primera, que se produce sobre el 10 VIII, formada principalmente por jóvenes del año inactivos sexualmente que no son fisiológicamente migrantes; y una segunda, mucho más intensa, que se produce sobre el 17 IX, formada principalmente por migrantes jóvenes del año inactivos sexualmente. La época de caza en España tiene lugar principalmente durante la primera oleada, preservando el paso de los migrantes provenientes de España y de otros países europeos. La información de los movimientos postcría en otras regiones españolas y en otros países europeos en los que la codorniz común es una especie cinegética popular, permitiría mejorar el ajuste entre el período de caza y la migración, proporcionando recomendaciones de gestión cinegética más precisas para esta especie.

Apartar y girar los ojos en los textos latinos

This article presents some of the conclusions drawn from our research on eye gestures in Latin texts. This investigation is part of a broader study on gestures in Ancient Rome. We have established a classification of eye gestures that comprises two major categories based on the nature of the gestures: gestures that involve eyelid movements and those that consist of iris movements. This paper focuses on two gestures which belong to this second category: staring and rolling the eyes. We analyse the way these gestures were made, how they were referred to by Roman writers and the meanings that may be inferred from their use in literary texts.

Ocean surface winds drive dynamics of transoceanic aerial movements

Global wind patterns influence dispersal and migration processes of aerial organisms, propagules and particles, which ultimately could determine the dynamics of colonizations, invasions or spread of pathogens. However, studying how wind-mediated movements actually happen has been hampered so far by the lack of high resolution global wind data as well as the impossibility to track aerial movements. Using concurrent data on winds and actual pathways of a tracked seabird, here we show that oceanic winds define spatiotemporal pathways and barriers for large-scale aerial movements. We obtained wind data from NASA SeaWinds scatterometer to calculate wind cost (impedance) models reflecting the resistance to the aerial movement near the ocean surface. We also tracked the movements of a model organism, the Cory's shearwater (Calonectris diomedea), a pelagic bird known to perform long distance migrations. Cost models revealed that distant areas can be connected through"wind highways" that do not match the shortest great circle routes. Bird routes closely followed the low-cost"wind-highways" linking breeding and wintering areas. In addition, we found that a potential barrier, the near surface westerlies in the Atlantic sector of the Intertropical Convergence Zone (ITCZ), temporally hindered meridional trans-equatorial movements. Once the westerlies vanished, birds crossed the ITCZ to their winter quarters. This study provides a novel approach to investigate wind-mediated movements in oceanic environments and shows that large-scale migration and dispersal processes over the oceans can be largely driven by spatiotemporal wind patterns.

Feeding ecology and movements of the Barolo shearwater Puffinus baroli baroli in the Azores, NE Atlantic

Trophic ecology and movements are critical issues for understanding the role of marine predators in food webs and for facing the challenges of their conservation. Seabird foraging ecology has been increasingly studied, but small elusive species, such as those forming the"little shearwater" complex, remain poorly known. We present the first study on the movements and feeding ecology of the Barolo shearwater Puffinus baroli baroli in a colony from the Azores archipelago (NE Atlantic), combining global location-sensing units, stable isotope analyses of feathers (δ13C and δ15N), stomach flushings and data from maximum depth gauges. During the chick-rearing period, parents visited their nests most nights, foraged mainly south of the colony and fed at lower trophic levels than during the non-breeding period. Squid was the most diverse prey (6 families and at least 10 different taxa), but species composition varied considerably between years. Two squid families, Onychoteuthidae and Argonautidae, and the fish family Phycidae accounted for 82.3% of ingested prey by number. On average, maximum dive depths per foraging trip reached 14.8 m (range: 7.9 to 23.1 m). After the breeding period, birds dispersed offshore in all directions and up to 2500 km from the breeding colony, and fed at higher trophic levels. Overall, our results indicate that the Barolo shearwater is a non-migratory shearwater feeding at the lowest trophic level among Macaronesian seabirds, showing both diurnal and nocturnal activity and feeding deeper in the water column, principally on small schooling squid and fish. These traits contrast with those of 3 other Azorean Procellariiformes (Cory"s shearwater Calonectris diomedea, the Madeiran storm-petrel Oceanodroma castro and Monteiro"s storm-petrel O. monteiroi), indicating ecological segregation within the Azorean seabird community.