929 research outputs found
Control by light and oxygen of B875 and B850 pigment-protein complexes in Rhodopseudomonas sphaeroides
AbstractControl by light and oxygen of the formation of B875 and B850 pigment-protein complexes in Rhodopseudomonas sphaeroides was evaluated by use of Hill plots. Kinetics of oxygen-dependent control exhibited Hill coefficients of n = 1.06 and n = 0.65 for B875 and B850 complexes, respectively. Half-maximum inhibition of B875 complexes was at 20.4% air saturation of the medium and of B850 complexes at 0.9%. Light controlled both complexes with an identical sigmoidal kinetics of n = 2.1
Fractal Dimensions in Perceptual Color Space: A Comparison Study Using Jackson Pollock's Art
The fractal dimensions of color-specific paint patterns in various Jackson
Pollock paintings are calculated using a filtering process which models
perceptual response to color differences (\Lab color space). The advantage of
the \Lab space filtering method over traditional RGB spaces is that the
former is a perceptually-uniform (metric) space, leading to a more consistent
definition of ``perceptually different'' colors. It is determined that the RGB
filtering method underestimates the perceived fractal dimension of lighter
colored patterns but not of darker ones, if the same selection criteria is
applied to each. Implications of the findings to Fechner's 'Principle of the
Aesthetic Middle' and Berlyne's work on perception of complexity are discussed.Comment: 21 pp LaTeX; two postscript figure
A complexity approach for identifying aesthetic composite landscapes
Third European Conference, EvoMUSART 2014, Granada, Spain, April 23-25, 2014, Revised Selected Papers[Abstract] The present paper describes a series of features related to complexity which may allow to estimate the complexity of an image as a whole, of all the elements integrating it and of those which are its focus of attention. Using a neural network to create a classifier based on those features an accuracy over 85% in an aesthetic composition binary classification task is achieved. The obtained network seems to be useful for the purpose of assessing the Aesthetic Composition of landscapes. It could be used as part of a media device for facilitating the creation of images or videos with a more professional aesthetic composition.Galicia. ConsellerĂa de InnovaciĂłn, Industria e Comercio; PGIDIT 10TIC105008PRPortugal. Fundação para a CiĂȘncia e a Tecnologia; PTDC/EIA-EIA/115667/200
View From Outside the Viewing Sphere
The âviewing sphereâ, as defined by Euclid and explored by Gibson as the âoptic arrayâ, is generally thought of as wrapped around the eye. Can an observer step out of it? With currently popular photographic techniques, the spectator is forced to, because the viewing sphere is presented as a pictorial object. Then the question is whether human observers are able to use such pictorial representations in an intuitive manner. Can the spectator âmentally step into the interiorâ of the pictorial viewing sphere? We explore this issue in a short experiment. Perhaps unsurprisingly, because the eye cannot see itself, the short answer is no
Phase transition in the genome evolution favours non-random distribution of genes on chromosomes
We have used the Monte Carlo based computer models to show that selection
pressure could affect the distribution of recombination hotspots along the
chromosome. Close to critical crossover rate, where genomes may switch between
the Darwinian purifying selection or complementation of haplotypes, the
distribution of recombination events and the force of selection exerted on
genes affect the structure of chromosomes. The order of expression of gene s
and their location on chromosome may decide about the extinction or survival of
competing populations.Comment: 13 pages, 7 figures, publicatio
Recommended from our members
Reactions to geovisualization: An experience from a European project
The paper is written jointly by two parties, computer scientists specializing in geovisualization and experts in forestry, who cooperated within a joint project. The authors tell a story about an attempt of the geovisualizers to introduce the foresters to the concept and principles of exploratory data analysis and to the use of visualization for systematic and comprehensive data exploration. This endeavor should be considered as an informal experiment rather than a rigorous scientific study. Unlike customary tests of the usability of specific tools and techniques, the geovisualizers did not give the forestry specialists a series of tasks to carry out by applying geovisualization tools and did not try to measure how well the foresters performed. The idea of the geovisualizers was to demonstrate the principles and power of exploratory data analysis to the foresters by example. For this purpose, the geovisualizers performed an exploration of a nonâtrivial data set by themselves and reported the procedure, the principles, the techniques, and the findings to the foresters. The reaction of the foresters uncovered a range of fundamental issues that are relevant to geovisualization and information visualization research. The authors analyze these issues from their perspectives and formulate a set of questions which researchers in geovisualization should be asking
A window on reality: perceiving edited moving images
Edited moving images entertain, inform, and coerce us throughout our daily lives, yet until recently, the way people perceive movies has received little psychological attention. We review the history of empirical investigations into movie perception and the recent explosion of new research on the subject using methods such as behavioral experiments, functional magnetic resonance imagery (fMRI) eye tracking, and statistical corpus analysis. The Hollywood style of moviemaking, which permeates a wide range of visual media, has evolved formal conventions that are compatible with the natural dynamics of attention and humansâ assumptions about continuity of space, time, and action. Identifying how people overcome the sensory differences between movies and reality provides an insight into how the same cognitive processes are used to perceive continuity in the real world
- âŠ