Gray Background Research Articles

Enhanced scanning electron microscopy images using muscovite mica, an example with Rhizaria.

Muscovite mica sheets were used as a support to capture scanning electron microscopy pictures of marine biological samples. The physical properties of the cleaved muscovite mica provide a clean background, which greatly reduces the postprocessing of images, thereby enhancing them and resulting in impressive images. We chose siliceous Rhizaria for this investigation due to their morphological diversity and elaborate skeletons. RESEARCH HIGHLIGHTS: Muscovite mica sheet was used as a SEM support for biological sample Physical properties of muscovite mica sheet can provide native dark, gray, and white background of SEM images Muscovite mica sheet should be considered for image production in the context of art and science intersection.

Colorimetric analysis of dental porcelains: effects of the background color

This study evaluated how the background (white or gray) affects the color parameter measurements and color difference calculations (∆Eab and ∆E00) of dental ceramics. Disc-shaped feldspathic ceramic specimens were prepared with two shades (enamel and dentin) and stained in red wine (7-day immersion). A spectrophotometer was used to perform color measurements (CIEL*a*b* coordinates) over gray and white backgrounds after the specimen preparation and after staining. The color difference was calculated with CIEDE2000 (ΔE00) and CIELAB (ΔEab) formulae. Initial L*a*b* coordinates, ΔE00, and ΔEab data were analyzed with t-tests separately for each ceramic shade. White background led to higher values of L* and b* coordinates from the enamel shade, and of L*, a*, and b* coordinates from the dentin shade. However, ΔE00 and ΔEab results from white and gray backgrounds were similar in both ceramic shades. Therefore, background color did not affect the color difference results of the slightly stained feldspathic ceramic samples.

Separating History and Fiction

Separating History and Fiction

Effect of background luminance of visual stimulus on elicited steady-state visual evoked potentials

Steady-state visual evoked potential (SSVEP)-based brain– computer interfaces (BCIs) have been widely studied. Considerable progress has been made in the aspects of stimulus coding, electroencephalogram processing, and recognition algorithms to enhance system performance. The properties of SSVEP have been demonstrated to be highly sensitive to stimulus luminance. However, thus far, there have been very few reports on the impact of background luminance on the system performance of SSVEP-based BCIs. This study investigated the impact of stimulus background luminance on SSVEPs. Specifically, this study compared two types of background luminance, i.e., (1) black luminance [red, green, blue (rgb): (0, 0, 0)] and (2) gray luminance [rgb: (128, 128, 128)], and determined their effect on the classification performance of SSVEPs at the stimulus frequencies of 9, 11, 13, and 15 Hz. The offline results from nine healthy subjects showed that compared with the gray background luminance, the black background luminance induced larger SSVEP amplitude and larger signal-to-noise ratio, resulting in a better classification accuracy. These results suggest that the background luminance of visual stimulus has a considerable effect on the SSVEP and therefore has a potential to improve the BCI performance.

Identification of Foliar Disease Regions on Corn Leaves Using SLIC Segmentation and Deep Learning Under Uniform Background and Field Conditions

Plant diseases lead to severe losses in crop yield worldwide. The conventional approach for diagnosing diseases relies on manual scouting. In recent years, advances in convolutional neural networks have motivated the use of deep learning-based computer vision for automatically identifying plant diseases. Although image classification techniques are commonly used for analyzing agricultural data, their use for accurately identifying diseased regions corresponding to different disease types on individual plant leaves is limited. In this study, Simple Linear Iterative Clustering (SLIC) segmentation was used on corn leaf images from the PlantVillage and CD&S datasets to create super-pixels, a cluster of pixels representing a region of interest on a corn leaf. The VGG16, ResNet50, DenseNet121, Xception, and InceptionV3, pre-trained deep learning models were utilized to identify diseased regions corresponding to five super-pixel classes (healthy, northern leaf blight (NLB), gray leaf spot (GLS), common rust, and background) for the PlantVillage dataset and four super-pixel classes (NLB, GLS, northern leaf spot, and background) for the CD&S dataset, on corn leaves. After setting the spatial proximity value (sigma) for SLIC segmentation to five, a total of 100 models were trained by using different numbers of segments per image (five and fifteen) in the SLIC algorithm for both datasets and choosing training: testing split ratios of 90:10, 80:20, 70:30, 60:40, and 50:50 for each of the five models. The highest overall testing accuracy of 97.77% was observed after training the DenseNet121 model to identify super-pixels created from the CD&S dataset, belonging to the four classes created using a sigma value of five, five segments per image, and an 80:20 training: testing split ratio. Web and mobile applications were developed to identify diseased regions on corn leaves using the best deep learning model as the classifier. The results suggest that SLIC segmentation on corn leaf images helps accurately identify diseased regions. This research demonstrates the potential of image-based scouting as an efficient alternative to manual scouting for disease monitoring.

Evaluation of Shade Matching Accuracy of Smartphone Application compared to Conventional Visual Method: An Observational Pilot Study

Introduction: Shade selection has been always a challenging step for a dentist by using a shade guide in manual visual selection. “Colour Grab” application of the smartphone simplifies the procedure of shade selection by providing L a* b* values. Aim: To evaluate the accuracy of the Smartphone application in shade selection compared to the visual method of shade selection. Materials and Methods: This observational pilot study was conducted at Maratha Mandal Dental College, Belagavi, Karnataka, India, from January 2022 to March 2022. A total of 30 subjects were examined by five observers for shade selection using two methods - 1. Conventional visual method, 2. Smartphone application. A total of 300 samples were collected by the both methods. Colour grab application was used to determine L a* b* values of Vita Classic Shade tabs at a distance of 25 cm on neutral grey background and tabulated. Data was collected and subjected to statistical analysis. Cronbach’s alpha test for interobserver reliability analysis, intraclass correlation test and Spearman rho correlation tests were used to determine the inter-observer and intra-observer shade selection accuracy respectively. Results: A total of 30 subjects (Females-16, Males-14) of age between 18-40 years were observed and analysed. For observers 1, 2, 3, 4, and 5, the correlation coefficients were 0.962, 0.849, 0.824, 0.930 and 0.793 respectively at p-value <0.01 for all observers which was highly significant. This test showed that there was strong correlation between the two techniques for each observer which had excellent consistency. Conclusion: Colour Grab smartphone application can be used as an alternative method to conventional visual method in shade selection.

Recognising Nail Changes Induced by Chemotherapy with Taxane-based Regimens and their Dermoscopic Confirmation: A Prospective Observational Study from Northern India

Introduction: Taxanes are chemotherapeutic agents used in a variety of solid tumours. They are known to cause cutaneous as well as nail changes which are temporally associated with intake of drug. Nail involvement is reported in literature from some parts of the world. Aim: To study the pattern of nail changes occurring due to taxane-based chemotherapy regimens in patients suffering from malignancies. Materials and Methods: A prospective observational study was carried out in a tertiary care hospital in GMC, Patiala, Punjab, India from October 2020 to September 2021. A total of 160 adult patients undergoing cancer chemotherapy with taxanes were included in the study. After taking detailed history, nail changes were examined and confirmed by dermoscopy. The data was analysed using Epi Info 7 by CDC and Chi-square test was used to calculate the p-value. Results: A total of 144 patients (87 females and 57 males), with the mean age of 53.8 years, were screened for six chemotherapeutic cycles. Drug-induced Nail Pigmentation (DINP) was the most common nail abnormality seen in 43/144 (30%) patients after third cycle and in 105/144 (73%) patients after the sixth cycle. The most common pattern was diffuse nail pigmentation 40/105 (39%) followed by longitudinal melanonychia 22/105 (21%) after six cycles. Maximum pigmentation 52/60 (86%) was observed in patients who received taxane+adriamycin+ cyclophosphamide combination. On onychoscopy, DINP appeared as thin grey regularly arranged parallel longitudinal lines on homogenous grey background. Conclusion: Taxanes cause varied pattern of nail changes with DINP being the most common. It ranges from longitudinal bands after three cycles to diffuse pigmentation after six cycles. These nail changes show temporal relation with dose, duration, number of drugs, and colour of skin. Dermoscopy is a novel non invasive method with a good diagnostic accuracy.

Pharmacognostic Studies of the Leaves and Fructus of Arctium lappa L. (Asteraceae Bercht. & J. Presl)

Introduction: The state quality assurance system ensures the confidence of consumers that the product meets its quality requirements. In this study, pharmacognostic standards of the leaves and fructus of burdock are specified for the first time. Methods: Microscopic analysis was carried out by using the microscope Carl Zeiss. The UV spectrum were measured on an SF-2000 spectrophotometer. Results: Macroscopically, the leaves are heart-shaped, broad-heart-ovate-shaped with a spaced emarginatedserrate or whole edge, with a wide, wedge-shaped, rounded, uneven base, acute apex, green on the outer surface, grayish slightly pubescent on the inner surface. The fructus are obovate or wedge-compressed, slightly curved, the color is brown/black with spots, or variegated with black spots on a gray background. The microscopic examination of the leaves revealed the presence of epidermis, large submerged and non-submerged stomata of the anomocytic type, 2 types of simple unbranched multi-cellular and glandular capitate trichomes; essential oil glands. Microscopic examination of the leaf petiole revealed the presence of 2 types of simple multi-cellular trichomes, epidermis, angular collenchyma, bicollateral bundles, parenchyma. The stomatal index value is 8.28±0.81 per 1cm2. The microscopy of the fructus revealed the presence of elongated cells of the pericarp epidermis; mesocarp; endocarp; endosperm with aleurone grains and drops of fatty oil. The qualitative phytochemical analysis of revealed the presence of polysaccharides, tannins, flavonoids, terpenoids, saponins, phenolic acids. Conclusion: Physical and chemical parameters (moisture, extractive value, ash content) were also specified. These specific data are important for establishing diagnostic indicators for standardization, identification, preparation of new quality standards.

Comparative Evaluation of the Effects of Lighting Conditions on the Shade Selection of Ceramics using Visual Method

Background: Tooth shade selection in prosthodontic restorations largely affects the patient satisfaction. Natural daylight is considered as the most recommended and standard source for shade selection. However, due to its inconsistency, shade matching lights have been introduced as an attempt to standardize the effect of light source.
 Objectives: Comparative evaluation of the effects of daylight, shade matching light and dental operating light against the grey background on visual shade matching of natural teeth with VITA Classic shade guide. Daylight will be taken as the control group.
 Methodology: Shade matching will be conducted in a well illuminated area with grey background. A group of 5 observers with superior color discrimination competence as determined by Pseudo Isochromatic colour test will be chosen for teeth shade matching. The matching will be carried out for 125 subjects under the three lighting conditions. The visual assessment will be done by matching the shade of maxillary central incisor of the subject with VITA Classic shade guide. Comparison will be done for two lighting conditions, each observer will perform this test three times that is for grey background in daylight, shade matching light and dental operatory light.
 Expected Results: This study will determine the lighting condition that could be used as a possible alternative of daylight.
 Conclusion: It will depict the lighting conditions that will best help the clinician to select the shade that will enhance the esthetics of the prosthesis and restorations.

Color Changes of Ceramic Materials Used for Inlay and Veneers Restorations after Staining with Different Time Intervals

Background: Stain color of CAD/CAM prosthetic materials is important for the long-term of these materials without affecting daily beverage consumption habits.
 Aims: To assess the influence of aging with Coca-Cola drinks on the color of the CAD/CAM materials used for inlay and veneer restoration over different time intervals.
 Methods: 48 specimens were fabricated from Vitablocs Mark II and zirconia CAD/CAM ceramic materials. Each group comprised 24 specimens with eight samples for every background (white [W], black [B], and gray). Baseline readings were taken by a spectrophotometer before staining (Baseline T0). After Coca-Cola staining and aging, the color measurement was repeated after 15 and 30 days (T1 and T2), while T3 was the difference between T2-T0. The data were analyzed with descriptive statistics, one-way ANOVA, and post hoc tests.
 Results: The ΔE00 color parameters of Mark II and zirconia materials were higher against the W background than other backgrounds. However, the zirconia materials recorded higher values than Mark II for the same parameters (L, a, and b) against the gray background during 15 and 30 days of immersion in Coca-Cola. Translucency parameters (TP) exhibited significant differences between ceramic types and immersion periods, with the TP values of zirconia being slightly higher than those of Mark II. The ΔE00 values for the three-time intervals were within clinically acceptable ranges. The ΔE00 values of both ceramic types at T3 were within 1.38–1.53 and 3.11–3.62 and lacked significant differences.
 Conclusions: Coca-Cola staining was obvious after 15 and 30 days of immersion and had a marked effect on the TP and ΔE00 of the tested CAD/CAM materials. Increasing the staining time resulted in a reduction in TP values at all time intervals. Zirconia samples had higher ΔE00 values than Mark II materials at different time periods. All of the colors of the tested materials had changed from B1 to different light colors in accordance with the Vita classical shade guide.

Angular dependence of polarisation contrast sensitivity in octopus

Cephalopod photoreceptors are polarisation-sensitive, giving them an ability to discriminate between lights of different angle and degree of polarisation. While colour vision is achieved by comparison of signals of photoreceptors tuned to different parts of light spectra, polarisation vision is achieved by comparison of signals of photoreceptors tuned to different orientations of e-vector. Therefore, from a theoretical point of view, polarisation vision is similar to colour vision. In particular, detection of polarised light against an unpolarised background is analogous to detection of chromatic light against grey. The dependence of polarisation contrast sensitivity on the angle of polarisation can be theoretically predicted using a receptor noise limited model in much the same way as it has been done for predicting the shape of the increment threshold spectral sensitivity in animals with colour vision. Here we report angular dependence of polarisation contrast sensitivity in octopus (O. tetricus, Gould 1852) and compare the theoretical predictions of polarisation contrast with the experimental results. Polarisation gratings were generated using LCD screens with removed polarisers and the orientation of polarisation was changed by rotating the screen. Reaction to the stimulus was recorded using a fixation reflex. We show that, in agreement with the theoretical predictions, the maximum contrast sensitivity is achieved at horizontal and vertical orientations of polarisation. Our results demonstrate that the dependence of polarisation contrast sensitivity on the angle of polarisation can be analysed in the same way as the dependence of colour thresholds on wavelength of monochromatic light added to a grey background.

Effects of nature virtual backgrounds on creativity during videoconferencing

Previous research has demonstrated that exposure to nature environments versus urban environments can help restore cognitive processing and improve overall well-being. The current study examined the restorative effects of nature on creativity using virtual backgrounds during videoconferencing on Zoom. Eighty participants completed the Alternative Uses Test (AUT) of creative divergent thinking when viewing one of three different virtual background images: nature setting, urban setting, plain grey background (control). Results showed that the nature background facilitated higher creativity performance compared to either the urban or control backgrounds (which did not significantly differ from each other). The results are discussed in terms of practical implications for workplace and educational environments that involve videoconferencing sessions between users.

Effects of Display and Ambient Illuminance on Visual Comfort for Reading on a Mobile Device

A psychophysical experiment was carried out to investigate visual comfort when reading on three OPPO Find X3s displays at three luminance levels (100, 250 and 500 cd/m2) at five illuminance levels (0, 10, 100, 500 and 1000 lx). Twenty young observers evaluated visual comfort using a 6-category points method. The results showed that observers felt most comfortable at the illuminance of 500 lx or display luminance of 500 cd/m2. There was an interaction between ambient illuminance and display luminance. High ambient light and display brightness levels provide a more pleasant visual experience. In low ambient light, however, the lower the brightness level, the more comfortable it is to see. Regarding the influence of background colour on visual comfort, the observers felt more comfortable having a grey background than white or black colour. When at dim illuminance, the background colour would have a great influence on visual comfort for negative contrast conditions, but when at higher illuminance, different background lightness levels had a great impact on visual comfort for positive contrast conditions. The above findings are very similar to the display luminance levels of 100 and 250 cd/m2.

White Appearance for Optimal Text-Background Lightness Combination Document Layout on a Tablet Display under Normal Light Levels

In the study, two psychophysical experiments are carried out to understand the visual comfort and white appearance of a tablet display. Twenty-four observers assess the visual comfort of document layouts, and eleven observers rate the whiteness percentage of the stimulus under normal light levels with a CCT of 6500 K. The result of the experiment for visual comfort indicates that a combination of black text with a light grey background presents the better visual comfort. On the other hand, the finding of the white appearance experiment shows that the observers rate the stimulus with CCT of 6515 K and a Duv of 0 as the whitest.

3x3x6 – 9 Sq.m. and 6 Surveillance Cameras

The title of Shu Lea Cheang’s 3x3x6 which represented Taiwan at Venice Biennale 2019 derives from the 21st century high-security prison cell measured in 9 square meter and equipped with 6 surveillance cameras. As an immersive installation, 3x3x6 is comprised of multiple interfaces to reflect on the construction of sexual subjectivity by technologies of confinement and control, from physical incarceration to the omnipresent surveillance systems of contemporary society, from Jeremy Bentham’s panopticon conceptualized in 1791 to China’s Sharp Eyes that boasts 200 million surveillance cameras with facial recognition capacity for its 1.4 billion population. By employing strategic and technical interventions, 3x3x6 investigates 10 criminal cases in which the prisoners across time and space are incarcerated for sexual provocation and gender affirmation. The exhibition constructs collective counter-accounts of sexuality where trans punk fiction, queer, and anti-colonial imaginations hacks the operating system of the history of sexual subjection. This Image and Text piece intersperses images from the exhibition with handout texts written by curator Paul B. Preciado (against a grey background), as well as an interview between special section co-editor Paula Gardner and the artist that brings the extraordinary exhibition into further conversation with feminist technoscience scholarship. The project website is available at https://3x3x6-v2.webflow.io/.

Context-dependent coloration of prey and predator decision making in contrasting light environments.

A big question in behavioral ecology is what drives diversity of color signals. One possible explanation is that environmental conditions, such as light environment, may alter visual signaling of prey, which could affect predator decision-making. Here, we tested the context-dependent predator selection on prey coloration. In the first experiment, we tested detectability of artificial visual stimuli to blue tits (Cyanistes caeruleus) by manipulating stimulus luminance and chromatic context of the background. We expected the presence of the chromatic context to facilitate faster target detection. As expected, blue tits found targets on chromatic yellow background faster than on achromatic grey background whereas in the latter, targets were found with smaller contrast differences to the background. In the second experiment, we tested the effect of two light environments on the survival of aposematic, color polymorphic wood tiger moth (Arctia plantaginis). As luminance contrast should be more detectable than chromatic contrast in low light intensities, we expected birds, if they find the moths aversive, to avoid the white morph which is more conspicuous than the yellow morph in low light (and vice versa in bright light). Alternatively, birds may attack first moths that are more detectable. We found birds to attack yellow moths first in low light conditions, whereas white moths were attacked first more frequently in bright light conditions. Our results show that light environments affect predator foraging decisions, which may facilitate context-dependent selection on visual signals and diversity of prey phenotypes in the wild.

Nonsymbolic numerosity in sets with illusory-contours exploits a context-sensitive, but contrast-insensitive, visual boundary formation process

The visual mechanisms underlying approximate numerical representation are still intensely debated because numerosity information is often confounded with continuous sensory cues (e.g., texture density, area, convex hull). However, numerosity is underestimated when a few items are connected by illusory contours (ICs) lines without changing other physical cues, suggesting in turn that numerosity processing may rely on discrete visual input. Yet, in these previous works, ICs were generated by black-on-gray inducers producing an illusory brightness enhancement, which could represent a further continuous sensory confound. To rule out this possibility, we tested participants in a numerical discrimination task in which we manipulated the alignment of 0, 2, or 4 pairs of open/closed inducers and their contrast polarity. In Experiment 1, aligned open inducers had only one polarity (all black or all white) generating ICs lines brighter or darker than the gray background. In Experiment 2, open inducers had always opposite contrast polarity (one black and one white inducer) generating ICs without strong brightness enhancement. In Experiment 3, reverse-contrast inducers were aligned but closed with a line preventing ICs completion. Results showed that underestimation triggered by ICs lines was independent of inducer contrast polarity in both Experiment 1 and Experiment 2, whereas no underestimation was found in Experiment 3. Taken together, these results suggest that mere brightness enhancement is not the primary cause of the numerosity underestimation induced by ICs lines. Rather, a boundary formation mechanism insensitive to contrast polarity may drive the effect, providing further support to the idea that numerosity processing exploits discrete inputs.

The Effects of Munsell Neutral Grey Backgrounds on the Colour of Chrysoprase and the Application of AP Clustering to Chrysoprase Colour Grading

Chrysoprase is a popular gemstone with consumers because of its charming apple green colour but a scientific classification of its colour has not yet been achieved. In this research, we determined the most effective background of the Munsell Chart for chrysoprase colour grading under a 6504K fluorescent lamp and applied an affinity propagation (AP) clustering algorithm to the colour grading of coloured gems for the first time. Forty gem-quality chrysoprase samples from Australia were studied using a UV-VIS spectrophotometer and Munsell neutral grey backgrounds. The results determined the effects of a Munsell neutral grey background on the observed colour. It was found that the Munsell N9.5 background was the most effective for colour grading in this case. The observed chrysoprase colours were classified into five groups: Fancy Light, Fancy, Fancy Intense, Fancy Deep and Fancy Dark. The feasibility of the colour grading scheme was verified using the colour difference formula DE2000.

A large-scale standardized survey of neural receptive fields in an entire column in mouse V1

The organization and properties of the neural receptive fields in the visual cortex is a prominent factor in understanding the mechanism of neural coding. Here, we perform a systematic and standardized analysis of the structure, organization and properties of the receptive fields in the pan-excitatory neuronal population in the mouse primary visual cortex (area V1). We collected and analyzed a large-scale 2-photon volumetric imaging dataset from an 800x800x600 μm^3 volume in V1 of two mice. The visual responses from were recorded during presentation of a locally sparse noise stimulus to efficiently reconstruct the neural receptive fields. The locally sparse noise stimulus consisted of 9 degree black or white spots on a mean luminance gray background presented at ~3Hz. We designed and implemented a computational pipeline to identify responsive trials, ON and OFF subfields and their geometric properties. Using these experimental and computational pipelines, we found that OFF subfields tended to have larger areas than ON subfields, particularly in layer 2/3. On average, OFF subfields were 15.6 degree^2 larger than the ON subfields across all imaging depths. We also found that the average receptive field area decreased as a function of cortical depth. ON and OFF subfields in layer 5 were on average 22% (ON subfields) and 31.5% (OFF subfields) smaller than those in layer 2/3. Additionally, we found that the responsiveness rate to the sparse noise decreased in deeper layers of cortex. Neurons in layer 2/3 were about 4 times more likely to respond to our visual stimulus compared to neurons in layer 5. Our results provide a systematic and standardized survey of the receptive field properties in V1. The dataset and computational pipeline could serve as a valuable resource to the community to further study the visual responses of neurons in V1.

A novel method for carbon emission forecasting based on Gompertz's law and fractional grey model: Evidence from American industrial sector

With the manufacturing reshoring to the US, increasing attention are focus on its energy consumption and environmental effects and accurate prediction of carbon emissions is vital to controlling growth from the source. Considering the slowing growth in carbon emissions with the Gompertz's law, this paper establishes a Gompertz differential equation. According to the differential information principle and fractional accumulation operator, this differential equation is transformed into a fractional accumulation grey Gompertz model. Furthermore, the chaotic whale optimization algorithm is used to optimize the order of accumulation generation and the grey background value in the proposed model. Then the Gompertz's datasets and six validation cases about carbon emissions are used to show that the proposed model demonstrates better accuracy in all cases and efficiency in the carbon emissions forecasting with several existing models. Three case studies indicate that the proposed model can fit the trend of American industrial carbon emissions better. The model results also reveal the recent policy changes have promoted the uptrend of the industrial and the total carbon emissions in the U.S. The future forecasting suggests that U.S. carbon emission is estimated to be 17.01% (in total emissions) or 17.89% (in industrial emission) percent below 2005 levels by 2025 under current policies, falling short of its commitment submitted to the United Nations Framework Convention on Climate Change.