Color constancy based on the Grey-edge hypothesis

International audienceA well-known color constancy method is based on the Grey-World assumption i.e. the average reflectance of surfaces in the world is achromatic. In this article we propose a new hypothesis for color constancy, namely the Grey-Edge hypothesis assuming that the average edge difference in a scene is achromatic. Based on this hypothesis, we propose an algorithm for color constancy. Recently, the Grey-World hypothesis and the max-RGB method were shown to be two instantiations of a Minkowski norm based color constancy method. Similarly we also propose a more general version of the Grey-Edge hypothesis which assumes that the Minkowsky norm of derivatives of the reflectance of surfaces is achromatic. The algorithms are tested on a large data set of images under different illuminants, and the results show that the new method outperforms the Grey-World assumption and the max-RGB method. Results are comparable to more elaborate algorithms, however at lower computational costs

The Mindful Attention Awareness Scale for Adolescents (MAAS-A): Psychometric Properties in a Dutch Sample

The factor structure and psychometric properties of the Dutch version of the Mindful Attention Awareness Scale for Adolescents (MAAS-A) was studied in a sample of adolescents (n = 717; age range, 11–17 years) of the general population. The MAAS-A and other questionnaires measuring other constructs were administered in high schools across the Netherlands. A one-factor structure was demonstrated using principal component analysis and was further confirmed using confirmatory factor analysis. The MAAS-A was shown to have high internal consistency. Expected negative correlations between mindfulness and self-reported stress and emotion regulation strategies such as rumination and catastrophizing were found. Further, mindfulness was positively correlated with happiness, healthy self-regulation, and with another recently developed measure of mindfulness in children and adolescents, the Child and Adolescent Mindfulness Measure. Mindfulness as measured by the MAAS-A correlated positively with quality of life, but an expected positive relationship with acceptance was not found. Interestingly, adolescents without meditation experience scored higher on the MAAS-A than adolescents without this experience. Further, adolescents with chronic disorders scored lower on the MAAS-A than adolescents without these disorders. Overall, this study has shown evidence of the first valid and reliable Dutch measure of mindfulness for adolescents. The factor structure, internal consistency, and convergent and divergent validity as well as their relationship to quality of life are comparable to the original MAAS-A

Continuity of Genetic Risk for Aggressive Behavior Across the Life-Course

We test whether genetic influences that explain individual differences in aggression in early life also explain individual differences across the life-course. In two cohorts from The Netherlands (N = 13,471) and Australia (N = 5628), polygenic scores (PGSs) were computed based on a genome-wide meta-analysis of childhood/adolescence aggression. In a novel analytic approach, we ran a mixed effects model for each age (Netherlands: 12–70 years, Australia: 16–73 years), with observations at the focus age weighted as 1, and decaying weights for ages further away. We call this approach a ‘rolling weights’ model. In The Netherlands, the estimated effect of the PGS was relatively similar from age 12 to age 41, and decreased from age 41–70. In Australia, there was a peak in the effect of the PGS around age 40 years. These results are a first indication from a molecular genetics perspective that genetic influences on aggressive behavior that are expressed in childhood continue to play a role later in life

Fast anisotropic Gauss filtering

Abstract. We derive the decomposition of the anisotropic Gaussian in a one dimensional Gauss filter in the x-direction followed by a one dimensional filter in a non-orthogonal direction ϕ. So also the anisotropic Gaussian can be decomposed by dimension. This appears to be extremely efficient from a computing perspective. An implementation scheme for normal convolution and for recursive filtering is proposed. Also directed derivative filters are demonstrated. For the recursive implementation, filtering an 512 × 512 image is performed within 65 msec, independent of the standard deviations and orientation of the filter. Accuracy of the filters is still reasonable when compared to truncation error or recursive approximation error. The anisotropic Gaussian filtering method allows fast calculation of edge and ridge maps, with high spatial and angular accuracy. For tracking applications, the normal anisotropic convolution scheme is more advantageous, with applications in the detection of dashed lines in engineering drawings. The recursive implementation is more attractive in feature detection applications, for instance in affine invariant edge and ridge detection in computer vision. The proposed computational filtering method enables the practical applicability of orientation scale-space analysis

Селекція in vitro м'якої пшениці на стійкість до Gaeumannomyces graminis var. tritici

Методом прямої клітинної селекції отримано стійкі до культурального фільтрату Gaeumannomyces graminis var. tritici калюсні лінії пшениці сорту Зимоярка та індуковано рослини-регенеранти. Вирощено насіннєве покоління R1, лабораторним способом оцінено його стійкість до метаболітів патогену. Виділено форми з підвищеною толерантністю.Методом прямой клеточной селекции получены резистентные к культуральному фильтрату G. graminis var. tritici каллюсные линии пшеницы сорта Зимоярка и индуцированы растениярегенеранты. Получено семенное поколение R1 и проведена его лабораторная оценка на устойчивость к метаболитам патогена. Выделены формы с повышенной толерантностью.By method of direct cellular selection resistant to culture filtrate of G. graminis var. tritici calli lines of bread wheat cultivar Zimoyarka were received, and plants-regenerants were induced. Seed generation R1 was received and its laboratory estimation for resistance to metabolites of pathogen was provided. Forms with the raised tolerance were allocated

Lower striatal dopamine D2/3 receptor availability in obese compared with non-obese subjects

Background: Obesity is a result of a relative excess in energy intake over energy expenditure. These processes are controlled by genetic, environmental, psychological and biological factors. One of the factors involved in the regulation of food intake and satiety is dopaminergic signalling. A small number of studies have reported that striatal dopamine D-2/D-3 receptor [D2/3R] availability is lower in morbidly obese subjects. Methods: To confirm the role of D2/3R in obesity, we measured striatal D2/3R availability, using [I-123]IBZM SPECT, in 15 obese women and 15 non-obese controls. Results: Striatal D2/3R availability was 23% (p = 0.028) lower in obese compared with non-obese women. Conclusion: This study is an independent replication of the finding that severely obese subjects have lower striatal D2/3R availability. Our findings invigorate the evidence for lower striatal D2/3R availability in obesity and confirm the role of the striatal dopaminergic reward system in obesit