Chromatic Contrast Sensitivity

International audienc

Memory effects on color perception

International audienceDoes knowledge about an object’s typical color influence how we perceive the actual color of this object? For example, Germans know that a German mailbox is yellow. Does such knowledge influence how we see the actual color of a mailbox? Or can we perceive the color independently of our prior knowledge? These are the questions at the core of research on the so-called memory color effect

Red, yellow, green and blue are not particularly colorful

Colorfulness and saturation have been neglected in research on color appearance and color naming. Perceptual particularities, such as cross-cultural stability, “focality”, “uniqueness”, “salience” and “prominence” have been observed for red, yellow, green, and blue, when those colors were more saturated than other colors in the stimulus samples. The present study tests whether high saturation is a particular property of red, yellow, green and blue, which would explain those observations. First, we carefully determined the category prototypes and unique hues for red, yellow, green, and blue. Using different approaches in two experiments, we assessed discriminable saturation as the number of just-noticeable differences away from the adaptation point (i.e. neutral gray). Results show that some hues can reach much higher levels of maximal saturation than others. However, typical and unique red, yellow, green, and blue are not particularly colorful. Many other, intermediate colors have a larger range of discriminable saturation than these colors. These findings suggest that prior claims of perceptual salience of category prototypes and unique hues actually reflect biases in stimulus sets rather than perceptual properties. Additional analyses show that consistent prototype choices across fundamentally different languages are strongly related to the variation of discriminable saturation in the stimulus sets. Our findings also undermine the idea that every color can be produced by a mixture of unique hues. Finally, the measurements in this study provide a large amount of data on saturation across hues, which allows for reevaluating existing estimates of saturation in future studies

Saving energy through changing light: The impact of illumination on thermal comfort

The ‘Hue-Heat Hypothesis’ states that light with wavelengths predominantly at the red end of the spectrum (or of a low colour temperature) are felt as warmer, whilst light with wavelengths mainly in the blue end (or of a high colour temperature) are felt as cooler. If confirmed, the Hue-Heat-Hypothesis could be a powerful tool for energy savings: Temperatures could be lowered under a reddish light in the heating season. Conversely, less air-conditioning might be needed during the cooling season if higher temperatures were accepted under a bluish light. Even a transitory effect would be beneficial in managing power demand by allowing building temperatures to drift over a wider range of temperatures before heating or cooling was required. We used an experimental design to study the Hue-Heat-Hypothesis. Testing took place in a climate chamber, in which ambient temperature, relative humidity, and air speed can be controlled. We installed a LED-lighting system in the chamber covering the range of correlated colour temperatures from 2700K, a warm, reddish light, to 6500K which appears bluish-cold. Participants (age range 18 to 35 years) were exposed to combinations of colour temperature and ambient temperature and completed standard thermal comfort surveys at specific time-points. Prior to testing, participants filled in a survey that asked about other factors potentially impacting on thermal comfort. In Study 1, temperature in the climate chamber was cooled continuously from 24°C to 20°C over a 60-minute period. Comfort ratings were obtained every 10 minutes. Participants (N = 32) were either exposed to a colour temperature of 2700K or 6500K (between-subjects design). Thermal comfort was higher under the warm colour temperature (2700K) than under the cold one (6500K). This difference was particularly pronounced for temperatures around 21 and 22°C. For the same subjective thermal comfort rating, ambient temperatures differed by around half a degree under the different lighting conditions. The magnitude of the effect varied with temperature (greatest effects observed around 22-23˚C) and by comfort question asked. In Study 2, a within-subject design was used. Subjects were exposed to three different lights (2700K, 4440K,6500 K) with temperature decreasing from 23°C to 19°C. Preliminary results were similar to those of Study 1 with higher comfort under the warm-appearing light. Comfort ratings under the medium colour temperature of 4400K were positioned between the higher ratings obtained for 2700K and lower ratings for 6500K, again, only in a limited corridor of ambient temperature. In Study 3, light was changed gradually from a cold to a warm colour temperature whilst ambient temperature decreased from 23°C to 19°C. Testing is on-going, but initial results indicate that the changes in self-reported comfort under decreasing temperatures are slower in the condition of changing light dynamically than under a stable Our studies support the Hue-Heat-Hypothesis. Varying the ambient light has an effect on thermal comfort and hence may be a suitable tool for energy savings and reducing of peak power demand

Interactive effects of genotype and N/S-supply on glucosinolates and glucosinolate breakdown products in Chinese cabbage (<i>Brassica rapa</i> L. ssp. <i>pekinensis</i>)

Chinese cabbage is rich in glucosinolates (GLS) and their breakdown products, mainly isothiocyanates (ITC), which are assumed to be human health-promoting compounds. Sulphur and nitrogen have been shown to influence concentrations and patterns of both. Little is known as to whether the effect of varying sulphur and nitrogen nutrition on glucosinolate and isothiocyanate content is influenced by the genotype. Therefore, two cultivars of Brassica rapa L. ssp. pekinensis were grown with increasing S (0.0, 0.3, and 0.6 g pot-1) and N (1 and 2 g pot-1) supply. Results show that total GLS concentration increased with higher N and S application, but ratios between individual GLS compounds remained unchanged. High N supply reduced the concentration of GLS, especially of the aliphatic ones, while the indole and aromatic GLS exhibited statistically insignificant responses to increasing N and S application. The profile of breakdown products was dominated by epithionitriles, followed by ITCs and nitriles. The ITCs were substantially reduced in response to increasing N and decreasing S supply. This was not observed for nitriles. Overall, GLS pattern were primarily influenced by the genetic background of the cultivar and less influenced by differential nutrition. Results show that selection of the cultivar is of utmost importance when glucosinolates and their breakdown products shall be increased by fertilization.   The online version of this article (doi: 10.5073/JABFQ.2016.089.036) contains supplementary files

ERBB2‐amplified lobular breast carcinoma exhibits concomitant CDK12 co‐amplification associated with poor prognostic features

Most invasive lobular breast carcinomas (ILBCs) are luminal‐type carcinomas with an HER2‐negative phenotype (ERBB2 or HER2 un‐amplified) and CDH1 mutations. Rare variants include ERBB2‐amplified subtypes associated with an unfavorable prognosis and less response to anti‐HER2 targeted therapies. We analyzed the clinicopathological and molecular features of ERBB2‐amplified ILBC and compared these characteristics with ERBB2‐unamplified ILBC. A total of 253 patients with ILBC were analyzed. Paraffin‐embedded formalin‐fixed tumor samples from 250 of these patients were added to a tissue microarray. Protein expression of prognostic, stem cell and breast‐specific markers was tested by immunohistochemistry (IHC). Hybrid capture‐based comprehensive genomic profiling (CGP) was performed for 10 ILBCs that were either fluorescent in situ hybridization (FISH) or IHC positive for HER2 amplification/overexpression and 10 ILBCs that were either FISH or IHC negative. Results were compared with a CGP database of 44,293 invasive breast carcinomas. The CGP definition of ERBB2 amplification was five copies or greater. A total of 17 of 255 ILBC (5%) were ERBB2 amplified. ERBB2‐amplified ILBC had higher tumor stage (p < 0.0001), more frequent positive nodal status (p = 0.00022), more distant metastases (p = 0.012), and higher histological grade (p < 0.0001), and were more often hormone receptor negative (p < 0.001) and more often SOX10 positive (p = 0.005). ERBB2 short variant sequence mutations were more often detected in ERBB2‐unamplified tumors (6/10, p = 0.027), whereas CDH1 mutations/copy loss were frequently present in both subgroups (9/10 and 7/10, respectively). Amplification of pathogenic genes were more common in HER2‐positive ILBC (p = 0.0009). CDK12 gene amplification (≥6 copies) was detected in 7 of 10 ERBB2‐amplified ILBC (p = 0.018). There were no CDK12 gene amplifications reported in 44,293 invasive breast carcinomas in the FMI Insights CGP database. ERBB2‐amplified ILBC is a distinct molecular subgroup with frequent coamplification of CDK12, whereas ERBB2 sequence mutations occur only in ERBB2‐unamplified ILBC. CDK12/ERBB2 co‐amplification may explain the poor prognosis and therapy resistance of ERBB2‐amplified ILBC

PRECYCLE: multicenter, randomized phase IV intergroup trial to evaluate the impact of eHealth-based patient-reported outcome (PRO) assessment on quality of life in patients with hormone receptor positive, HER2 negative locally advanced or metastatic breast cancer treated with palbociclib and an aromatase inhibitor or palbociclib and fulvestrant

Background Efficacy and quality of life (QoL) are key criteria for therapy selection in metastatic breast cancer (MBC). In hormone receptor positive (HR +) human epidermal growth factor receptor 2 negative (HER2 −) MBC, addition of targeted oral agents such as everolimus or a cycline-dependent kinase 4/6 (CDK 4/6) inhibitor (e.g., palbociclib, ribociclib, abemaciclib) to endocrine therapy substantially prolongs progression-free survival and in the case of a CDK 4/6i also overall survival. However, the prerequisite is adherence to therapy over the entire course of treatment. However, particularly with new oral drugs, adherence presents a challenge to disease management. In this context, factors influencing adherence include maintaining patients’ satisfaction and early detection/management of side effects. New strategies for continuous support of oncological patients are needed. An eHealth-based platform can help to support therapy management and physician–patient interaction. Methods PreCycle is a multicenter, randomized, phase IV trial in HR + HER2 − MBC. All patients (n = 960) receive the CDK 4/6 inhibitor palbociclib either in first (62.5%) or later line (37.5%) together with endocrine therapy (AI, fulvestrant) according to national guidelines. PreCycle evaluates and compares the time to deterioration (TTD) of QoL in patients supported by eHealth systems with substantially different functionality: CANKADO active vs. inform. CANKADO active is the fully functional CANKADO-based eHealth treatment support system. CANKADO inform is a CANKADO-based eHealth service with a personal login, documentation of daily drug intake, but no further functions. To evaluate QoL, the FACT-B questionnaire is completed at every visit. As little is known about relationships between behavior (e.g., adherence), genetic background, and drug efficacy, the trial includes both patient-reported outcome and biomarker screening for discovery of forecast models for adherence, symptoms, QoL, progression free survival (PFS), and overall survival (OS). Discussion The primary objective of PreCycle is to test the hypothesis of superiority for time to deterioration (TTD) in terms of DQoL = “Deterioration of quality of life” (FACT-G scale) in patients supported by an eHealth therapy management system (CANKADO active) versus in patients merely receiving eHealth-based information (CANKADO inform). EudraCT Number: 2016–004191-2

Role of microsurgical tumor burden reduction in patients with breast cancer brain metastases considering molecular subtypes: a two-center volumetric survival analysis

Background Advancements in metastatic breast cancer (BC) treatment have enhanced overall survival (OS), leading to increased rates of brain metastases (BM). This study analyzes the association between microsurgical tumor reduction and OS in patients with BCBM, considering tumor molecular subtypes and perioperative treatment approaches. Methods Retrospective analysis of surgically treated patients with BCBM from two tertiary brain tumor Swiss centers. The association of extent of resection (EOR), gross-total resection (GTR) achievement, and postoperative residual tumor volume (RV) with OS and intracranial progression-free survival (IC-PFS) was evaluated using Cox proportional hazard model. Results 101 patients were included in the final analysis, most patients (38%) exhibited HER2-/HR + BC molecular subtype, followed by HER2 + /HR + (25%), HER2-/HR- (21%), and HER2 + /HR- subtypes (13%). The majority received postoperative systemic treatment (75%) and radiotherapy (84%). Median OS and intracranial PFS were 22 and 8 months, respectively. The mean pre-surgery intracranial tumor volume was 26 cm$^{3}$, reduced to 3 cm$^{3}$ post-surgery. EOR, GTR achievement and RV were not significantly associated with OS or IC-PFS, but higher EOR and lower RV correlated with extended OS in patients without extracranial metastases. HER2-positive tumor status was associated with longer OS, extracranial metastases at BM diagnosis and symptomatic lesions with shorter OS and IC-PFS. Conclusions Our study found that BC molecular subtypes, extracranial disease status, and BM-related symptoms were associated with OS in surgically treated patients with BCBM. Additionally, while extensive resection to minimize residual tumor volume did not significantly affect OS across the entire cohort, it appeared beneficial for patients without extracranial metastases