Evaluating colour preference of lighting with an empty light booth

In our recent work, the colour preference of several LED white lights with different correlated colour temperatures (CCT) was investigated with a wide selection of objects. The results highlighted the dominant effect of light itself on the colour preference of lighting. In this study, we similarly implemented two psychophysical experiments with the same lights but with nothing in the light booth. It was found that the subjective ratings for the lit environment of the empty booth were quite close to those of the previous studies that used various coloured objects. Such a finding corroborates our former conclusion that light dominates colour preference and we suspect that this finding can be attributed either to the colour memory of the observers or to the subconscious effect of human vision. Thus, it seems that for general multi-CCT conditions where the light sources do not have very different gamut shapes or object desaturation/oversaturation properties, the preferred white light could be determined by simply asking the observers to rate their preference for the lit environment of the empty light booth. To verify this wild and interesting conclusion and further clarify its applicability, follow-up studies are needed

Visual performance of the human eye with soft hydrophilic contact lenses

The recording of visual acuity using the Snellen letter chart is only a limited measure of the visual performance of an eye wearing a refractive aid. Qualitative in addition to quantitative information is required to establish such a parameter: spatial, temporal and photometric aspects must all be incorporated into the test procedure. The literature relating to the correction of ametropia by refractive aids was reviewed. Selected aspects of a comparison between the correction provided by spectacles and contact lenses were considered. Special attention was directed to soft hydrophilic contact lenses. Despite technological advances which have produced physiologically acceptable soft lenses, there still remain associated with this recent form of refractive aid unpredictable visual factors. Several techniques for vision assessment were described, and previous studies of visual performance were discussed. To facilitate the investigation of visual performance in a clinical environment, a new semi-automated system was described: this utilized the presentation of broken ring test stimuli on a television screen. The research project comprised two stages. Initial work was concerned with the validation of the television system, including the optimization of its several operational variables. The second phase involved the utilization of the system in an investigation of visual performance aspects of the first month of regular daily soft contact lens wear by experimentally-naive subjects. On the basis of the results of this work an ‘homoeostatic’ model has been proposed to represent the strategy which an observer adopts in order to optimize his visual performance with soft contact lenses

WNK1-OSR1 kinase-mediated phospho-activation of Na+-K+-2Cl- cotransporter facilitates glioma migration

Background: The bumetanide (BMT)-sensitive Na+-K+-2Cl- cotransporter isoform 1 (NKCC1) maintains cell volume homeostasis by increasing intracellular K+ and Cl- content via regulatory volume increase (RVI). Expression levels of NKCC1 positively correlate with the histological grade and severity of gliomas, the most common primary adult brain tumors, and up-regulated NKCC1 activity facilitates glioma cell migration and apoptotic resistance to the chemotherapeutic drug temozolomide (TMZ). However, the cellular mechanisms underlying NKCC1 functional up-regulation in glioma and in response to TMZ administration remain unknown. Methods: Expression of NKCC1 and its upstream kinases With-No-K (Lysine) kinase 1 (WNK1) and oxidative stress-responsive kinase-1 (OSR1) in different human glioma cell lines and glioma specimens were detected by western blotting and immunostaining. Live cell imaging and microchemotaxis assay were applied to record glioma cell movements under different treatment conditions. Fluorescence indicators were utilized to measure cell volume, intracellular K+ and Cl- content to reflect the activity of NKCC1 on ion transportation. Small interfering RNA (siRNA)-mediated knockdown of WNK1 or OSR1 was used to explore their roles in regulation of NKCC1 activity in glioma cells. Results of different treatment groups were compared by one-way ANOVA using the Bonferroni post-hoc test in the case of multiple comparisons. Results: We show that compared to human neural stem cells and astrocytes, human glioma cells exhibit robust increases in the activation and phosphorylation of NKCC1 and its two upstream regulatory kinases, WNK1 and OSR1. siRNA-mediated knockdown of WNK1 or OSR1 reduces intracellular K+ and Cl- content and RVI in glioma cells by abolishing NKCC1 regulatory phospho-activation. Unexpectedly, TMZ activates the WNK1/OSR1/NKCC1 signaling pathway and enhances glioma migration. Pharmacological inhibition of NKCC1 with its potent inhibitor BMT or siRNA knockdown of WNK1 or OSR1 significantly decreases glioma cell migration after TMZ treatment. Conclusion: Together, our data show a novel role for the WNK1/OSR1/NKCC1 pathway in basal and TMZ-induced glioma migration, and suggest that glioma treatment with TMZ might be improved by drugs that inhibit elements of the WNK1/OSR1/NKCC1 signaling pathway

Changes in visual function after intraocular pressure reduction using antiglaucoma medications

Purpose To evaluate the change in visual function after starting glaucoma treatment and correlate this to a decrease in intraocular pressure (IOP) in primary open-angle glaucoma patients.Methods A prospective, randomized clinical trial was carried out involving 54 glaucoma patients (54 eyes). After inclusion, patients randomly received timolol maleate 0.5%, brimonidine tartrate 0.2%, or travoprost 0.004% in one randomly selected eye. Patients underwent Goldmann applanation tonometry, visual acuity test, standard automated perimetry (SAP), visual quality perception test (visual analogue scale), and contrast sensitivity (CS) test, in a random order before and after the 4-week glaucoma treatment.Results There were statistically significant changes in IOP (mean change [standard deviation], 7.8 [3.6] mmHg, P 0.001), SAP mean deviation index (0.84 [2.45] dB, P = 0.02), visual quality perception (0.56 [1.93], P = 0.045), and CS at frequencies of 12 cycles/degree (0.10 [0.37], P = 0.03) and 18 cycles/degree (0.18 [0.42], P = 0.02) after the 4-week treatment when compared with baseline. No statistically significant differences were found between the treatment groups in visual function changes after treatment (P > 0.40). No significant correlations between IOP reduction and changes in visual function were found (P > 0.30).Conclusions Visual quality perception, visual field mean deviation index, and CS at higher frequencies improve after starting glaucoma therapy. However, no correlation was found between IOP reduction and changes in visual function, and no differences were found in visual function when the three medications studied were compared. Eye (2009) 23, 1081-1085; doi:10.1038/eye.2008.226; published online 1 August 2008Universidade Federal de São Paulo, Glaucoma Serv, Dept Ophthalmol, BR-01404001 São Paulo, BrazilUniversidade Federal de São Paulo, Glaucoma Serv, Dept Ophthalmol, BR-01404001 São Paulo, BrazilWeb of Scienc

Symptoms of anxiety and depression are related to cardiovascular responses to active, but not passive, coping tasks

Objective: Anxiety and depression have been linked to blunted blood pressure (BP) and heart rate (HR) reactions to mental stress tests; however, most studies have not included indices of underlying hemodynamics nor multiple stress tasks. This study sought to examine the relationships of anxiety and depression with hemodynamic responses to acute active and passive coping tasks. Methods: A total of 104 participants completed the Hospital Anxiety and Depression Scales and mental arithmetic, speech, and cold pressor tasks while BP, HR, total peripheral resistance, and cardiac output (CO) were assessed. Results: After adjustment for traditional risk factors and baseline cardiovascular activity, depression scores were negatively associated with systolic BP, HR, and CO responses to the mental arithmetic task, while anxiety scores were inversely related to the systolic BP response to mental arithmetic. Conclusion: High anxiety or depression scores appear to be associated with blunted cardiac reactions to mental arithmetic (an active coping task), but not to the cold pressor test or speech tasks. Future research should further examine potential mechanisms and longitudinal pathways relating depression and anxiety to cardiovascular reactivity

Evolution of sex-specific pace-of-life syndromes: genetic architecture and physiological mechanisms

Sex differences in life history, physiology, and behavior are nearly ubiquitous across taxa, owing to sex-specific selection that arises from different reproductive strategies of the sexes. The pace-of-life syndrome (POLS) hypothesis predicts that most variation in such traits among individuals, populations, and species falls along a slow-fast pace-of-life continuum. As a result of their different reproductive roles and environment, the sexes also commonly differ in pace-of-life, with important consequences for the evolution of POLS. Here, we outline mechanisms for how males and females can evolve differences in POLS traits and in how such traits can covary differently despite constraints resulting from a shared genome. We review the current knowledge of the genetic basis of POLS traits and suggest candidate genes and pathways for future studies. Pleiotropic effects may govern many of the genetic correlations, but little is still known about the mechanisms involved in trade-offs between current and future reproduction and their integration with behavioral variation. We highlight the importance of metabolic and hormonal pathways in mediating sex differences in POLS traits; however, there is still a shortage of studies that test for sex specificity in molecular effects and their evolutionary causes. Considering whether and how sexual dimorphism evolves in POLS traits provides a more holistic framework to understand how behavioral variation is integrated with life histories and physiology, and we call for studies that focus on examining the sex-specific genetic architecture of this integration

Different colour predictions of facial preference by Caucasian and Chinese observers

Facial colour characteristics convey vital personal information and influence social interactions and mate choices as contributing factors to perceived beauty, health, and age. How various colour characteristics affect facial preference and whether there are cultural differences are not fully understood. Here, we provide a useful and repeatable methodology for skin colour research based on a realistic skin model to investigate the effect of various facial colour characteristics on facial preference and compare the role of colour predictors in Caucasian (CA) and Chinese (CN) samples. Our results show that, although the average skin colour of facial areas plays a limited role, together with colour variation and contrast, there are stronger links between colour and facial preference than previously revealed. We also find large cultural differences in facial colour perceptions; Chinese observers tend to rely more heavily on colour and lightness cues to judge facial preference than Caucasian observers

NICE : A Computational solution to close the gap from colour perception to colour categorization

The segmentation of visible electromagnetic radiation into chromatic categories by the human visual system has been extensively studied from a perceptual point of view, resulting in several colour appearance models. However, there is currently a void when it comes to relate these results to the physiological mechanisms that are known to shape the pre-cortical and cortical visual pathway. This work intends to begin to fill this void by proposing a new physiologically plausible model of colour categorization based on Neural Isoresponsive Colour Ellipsoids (NICE) in the cone-contrast space defined by the main directions of the visual signals entering the visual cortex. The model was adjusted to fit psychophysical measures that concentrate on the categorical boundaries and are consistent with the ellipsoidal isoresponse surfaces of visual cortical neurons. By revealing the shape of such categorical colour regions, our measures allow for a more precise and parsimonious description, connecting well-known early visual processing mechanisms to the less understood phenomenon of colour categorization. To test the feasibility of our method we applied it to exemplary images and a popular ground-truth chart obtaining labelling results that are better than those of current state-of-the-art algorithms

Multi-objective design optimisation:Getting more for less

Multi-objective optimisation can help civil engineers achieve higher performance for lower costs in their designs. This is true whether ‘performance’ applies to structural strength or energy use, or whether ‘cost’ measures financial outlay or occupant satisfaction: if it can be quantified it can be optimised in some form. By exploring trade-offs between conflicting objectives and constraints, multi-objective optimisation enables informed decision-making. This paper outlines the principles and benefits of multi-objective optimisation and the means of implementation. The complementary aspects of parametric modelling and optimisation are discussed as an aid to the flexible design of buildings and structures. A range of real design problems are considered, including structural and environmental examples. </jats:p

Skin coloration is a culturally-specific cue for attractiveness, healthiness, and youthfulness in observers of Chinese and western European descent

Facial skin coloration signals information about an individual and plays an important role in social interactions and mate choice, due its putative association with health, attractiveness, and age. Whether skin coloration as an evolutionary significant cue is universal or specific to a particular culture is unclear and current evidence on the universality of skin color as a cue to health and attractiveness are equivocal. The current study used 80 calibrated, high-resolution, non-manipulated images of real human faces, either of Chinese or western European descent, which were rated in terms of attractiveness, healthiness, and perceived age by 44 observers, 22 western European (13 male; mean age ± SD = 24.27 ± 5.30) and 22 Chinese (7 male; mean age ± SD = 26.05 ± 3.96) observers. To elucidate the associations between skin coloration and these perceptual ratings and whether these associations are modulated by observer or image ethnicity, a linear mixed-effect model was setup with skin lightness (L*; CIELAB), redness (a*) and yellowness (b*), observer and image ethnicity as independent variables and perceived attractiveness, healthiness, and estimated age as dependent variables. We found robust positive associations between facial skin lightness (L*) and attractiveness, healthiness, and youthfulness, but only when Chinese observers judge facial images of their own ethnicity. Observers of European descent, on the other hand, associated an increase in yellowness(b*) with greater attractiveness and healthiness in Chinese facial images. We find no evidence that facial redness is positively associated with these attributes; instead, an increase in redness (a*) is associated with an increase in the estimated age of European facial images. We conclude that observers of both ethnicities make use of skin color and lightness to rate attractiveness, healthiness, and perceived age, but to a lesser degree than previously thought. Furthermore, these coloration cues are not universal and are utilized differently within the Chinese and western European ethnic groups. Our study adds to the growing body of work demonstrating the importance of skin color manipulations within an evolutionary meaningful parameter space, ideally using realistic skin models based on physical parameters