Mean Color Research Articles

Repeatability of different mobile phone applications for color measurement in dentistry.

To assess the repeatability of various color-measuring mobile phone applications (MPAs) on dental materials in clinically relevant shades in 1-mm thickness. A benchtop spectrophotometer was used as a reference instrument. Seven MPAs were used: Color Analysis, Color Analyzer-Iro Shirabe, Color Grab, and Colorimeter from Android, and Color Analyzer-Iro Shirabe, ColorMeter RGB, and Optishade from iOS. Color measurements were performed on 1-mm thickness slices of CAD-CAM materials, Vita Enamic shades 1M2, 2M2, 3M2, 4M2, and Vitablocs Mark II shades A1C, A2C, A3C, A4C (n=10, for a total 80 specimens). The specimens were measured at three time periods, Day 0, Day 1, and Day 7, and three measurements were made on each day, to mimic short-, medium-, and long-term repeatability. The color differences were analyzed using the CIEDE2000 formula, with the corresponding color difference (ΔE00), and mean color difference from the mean (MCDM00). One-way ANOVA, Repeated measures ANOVA, and Paired sample t-tests were used for statistical analysis. Optishade from iOS showed the lowest mean color difference among the MPAs (ΔE00=0.2 (SD 0.1), 0.3 (SD 0.2), and 0.2 (SD 0.1) at Day 0, 1, and 7, respectively, and ΔE00=0.5 (SD 0.3) for all three periods Days 0-1, 0-7, and 1-7). Material-dependent variations in the repeatability of color measurements were observed. There was a statistically significant difference among color measurements using MPAs and a spectrophotometer, among the MPAs, and materials. The spectrophotometer exhibited the highest repeatability across the tested time periods. The iOS Optishade showed the highest repeatability among the MPAs.

The PIPER survey. II. The globular cluster systems of low surface brightness galaxies in the Perseus cluster

ABSTRACT We present Hubble Space Telescope ACS/WFC and WFC3/UVIS imaging for a sample of 50 low-surface brightness (LSB) galaxies in the $\sim 10^{15}$ M$_{\odot }$ Perseus cluster, which were originally identified in ground-based imaging. We measure the structural properties of these galaxies and estimate the total number of globular clusters (GCs) they host. Around half of our sample galaxies meet the strict definition of an ultra-diffuse galaxy (UDG), while the others are UDG-like but are either somewhat more compact or slightly brighter. A small number of galaxies reveal systems with many tens of GCs, rivalling some of the richest GC systems known around UDGs in the Coma cluster. We find the sizes of rich GC systems, in terms of their half-number radii, extending to $\sim$1.2 times the half-light radii of their host galaxy on average. The mean colours of the GC systems are the same, within the uncertainties, as those of their host galaxy stars. This suggests that GCs and galaxy field stars may have formed at the same epoch from the same enriched gas. It may also indicate a significant contribution from disrupted GCs to the stellar component of the host galaxy as might be expected in the ‘failed galaxy’ formation scenario for UDGs.

Comparison of Various Surface Treatment Procedures on the Roughness and Susceptibility to Staining of Provisional Prosthodontic Materials.

Esthetically pleasing temporary prostheses are often necessary for extended periods in a variety of clinical scenarios. Adjustments to the occlusion or margins are commonly needed before cementing the temporary prosthesis. Therefore, it is clinically necessary to repolish the rough surface to avoid biological and esthetic issues associated with rough surfaces. The purpose of this in vitro study was to assess and compare the impact of various polishing protocols on the surface roughness and color stability of three resin materials used for provisional crowns. A total of 150 specimens were fabricated from auto-polymerizing polymethyl methacrylate, bis-acryl composite, and Methyl methacrylate-LC resin using a stainless steel mold. Each material group was divided into five groups (n = 10) based on the applied surface treatment: positive control group (G1): no roughening or surface treatment, Negative control group (G2): acrylic bur-roughened surface without any polishing, the different surface treatment groups of silicon carbide and aluminum oxide stone polishing (G3), diamond-coated rubber twist (G4), and Surface Glaze (G5). An optical profilometer was used to assess the surface roughness of all samples. After undergoing 6000 cycles of thermocycling followed by immersion in a coffee solution for 15 days at 37 °C, color parameters were measured using a spectrophotometer both before and after a storage period to evaluate color differences. A two-way ANOVA test with α = 0.05 significance level was carried out to determine the impacts of both the materials utilized and the polishing protocol. Among the three types of resin examined, the bisacryl group exhibited superior surface quality in positive control groups, while PMMA resin demonstrated higher polishability. The diamond-coated rubber twits resulted in lower Ra values of 0.36 (0.01) µm, 0.52 (0.11) µm, and 0.28 (0.05) µm for PMMA, BAMA, and MMLC resins, respectively. The application of photo-polymerized surface glaze led to a plaque accumulation threshold of 0.2 µm across all resin groups. The greatest mean color change occurred in the negative control group, indicating a propensity for more staining on rougher surfaces. The Bisacryl resin exhibited higher ΔE values, whereas PMMA showed better color stability. The lowest ΔE values were found when the surface glaze was applied to all of the provisional crown resins. Untreated Bisacryl resin exhibited the lowest Ra values, while PMMA resins demonstrated superior surface morphology after polishing. PMMA provisional crown resins showed increased resistance to staining. The use of surface glaze enhanced both smoothness and color stability on the surfaces.

The impact of various substrates, ceramic shades, and brands on the ultimate color and masking capacity of highly translucent monolithic zirconia: an in vitro study.

This study aimed to examine the impact of substrates, ceramic shades, and brands on the color and masking ability of highly translucent monolithic zirconia (HTMZ) using CIELab and CIEΔE2000 metrics. A total of 156 1-mm thick HTMZ disks in shades A1, A2, and A3 were produced using Dental Direkt and Kerox zirconia brands. Four 3-mm thick substrates (nickel-chromium alloy, non-precious gold alloy (NPG), zirconia shade A2, and resin composite shade A2) were prepared. HTMZ disks were overlaid on these substrates, and color measurements were taken with a spectrophotometer. Color differences (ΔE) were analyzed using CIELab and CIEΔE2000 formulas. The influence of brand, shade, substrate, and their interactions on ΔE values was assessed with a General Linear Model (GLM) and LSD pairwise comparison test. Spearman's correlation test examined the relationship between CIELab and CIEΔE2000 values. Results indicated that ΔEab was significantly influenced by substrate type and shade, while ΔE2000 was also affected by the ceramic brand. Mean color differences across ceramic-substrate groups were within clinically acceptable and perceptible ranges (clinically perceptible: ∆Eab ≥ 1.3 and ∆E2000 ≥ 0.8; clinically acceptable: 0.8 < ∆E2000 ≤ 1.8 and 1.3 < ∆Eab ≤ 2.7), except for NPG, which had ΔE values exceeding the perceptible range (ΔE2000: 1.1 ± 0.11 to 1.8 ± 0.31; ΔEab: 1.61 ± 0.15 to 2.16 ± 0.36). A significant correlation (r = 0.974, P < 0.001) was found between ΔEab and ΔE2000. Various ceramic brands and shades led to notable ΔE variations, yet average color differences within all ceramic-substrate groups remained clinically acceptable. Both ΔEab and ΔE2000 were reliable methods with a strong correlation for measuring color differences.

An In-Vitro Study on the Impact of Light-Emitting Diode (LED) and Laser-Activated Bleaching Techniques on the Color Change of Artificially Stained Teeth at Varying Time Intervals.

Introduction Tooth color is a key factor in the perception of an attractive smile, making bleaching a widely sought-after cosmetic dental procedure. Valued for its minimally invasive approach, this technique effectively lightens teeth to achieve desired aesthetic outcomes. As the desire for immediate results grows among patients, various bleaching agents, and energy sources have been developed to expedite the bleaching process. The study aims to evaluate and compare the efficacy of 35% hydrogen peroxide activated by light-emitting diode (LED) and laser on artificially stained teeth, assessing color changes at different time intervals. Methodology Sixty maxillary central incisors with intact crowns were selected for the study. An artificial staining solution was prepared, and the samples were immersed in it for 15 days to simulate staining. After this period, the teeth were removed from the solution, rinsed with water, and dried. Baseline photographs of each tooth were taken for comparison. The teeth were then divided into two groups, one treated with LED activation and the other with laser activation of 35% hydrogen peroxide as the bleaching agent. The color changes were measured and recorded at different time intervals. Data were presented as mean and standard deviation, with statistical analysis conducted using independent sample t-test and repeated measures ANOVA to compare the efficacy of the two methods. Results Both LED and laser activation of 35% hydrogen peroxide demonstrated significant color changes in the stained teeth. The initial color improvement was noticeable in both groups, with LED and laser treatments producing comparable whitening effects. The mean color change values indicated that both activation sources were effective in enhancing the bleaching process, providing immediate and substantial results. Statistical analysis showed no significant difference between the two methods, suggesting their equivalency in clinical efficacy for tooth bleaching. Conclusion The study concludes that both LED and laser activation of 35% hydrogen peroxide are efficient methods for in-office tooth bleaching, providing immediate and enhanced whitening effects. The comparable results between the two energy sources indicate that can be effectively used to meet the increasing demand for rapid aesthetic improvements in a clinical setting. This finding supports the adoption of both LED and laser bleaching techniques as viable options for dental practitioners aiming to achieve optimal patient satisfaction with minimal invasiveness.

Evaluation of colour change, marginal adaptation, fracture strength, and failure type in maxillary and mandibular premolar zirconia endo-crowns

ObjectivesThe objective of this in vitro study was to evaluate the effects of different preparation designs on the mean colour change (ΔE*), marginal adaptation, fracture resistance, and fracture types of maxillary and mandibular premolar endocrowns (ECs).MethodologyA total of 40 extracted maxillary and mandibular premolars were treated endodontically, and each type was subdivided according to the remaining axial height (remaining walls on all surfaces; 2–4 mm) and 2 mm inside the pulp chamber. Specimens were immersed in coffee for 14 days, ΔE* was determined, marginal adaptation was observed, fracture forces test was conducted, and the samples were examined visually at 10× magnification to evaluate failure type and identify fracture origin. The data were entered and analyzed using Statistical Package for Social Sciences, and significance between and within groups was evaluated through ANOVA. The p-value ≤ 0.05 was considered statistically significant.ResultsThe ΔE* values of the maxillary premolar with 2 mm axial height were the highest (6.8 ± 0.89 units), whereas the lowest value was observed in the mandibular premolar with 4 mm axial height (2.9 ± 0.53 units). Significant differences (p < 0.05) in teeth and design were observed. The marginal adaptation of the mandibular premolar with 4 mm axial height was the highest (30.20 ± 1.53 μm), whereas the lowest marginal adaptation was observed in the maxillary premolar with 2 mm axial height (14.38 ± 0.99 μm), and the difference was statistically significant (p < 0.05). The maximum fracture force was observed in maxillary premolars with 2 mm axial height (2248.15 ± 134.74 N), and no statistically significant difference (p = 0.07) was observed between maxillary and mandibular premolars at 4 mm axial height.ConclusionThe recorded ΔE* values of the ECs were within clinically acceptable values or slightly higher, and the marginal adaption values were within acceptable and recommended clinical values in µm. EC preparation with 2 mm axial height in both arches recorded the highest fracture forces. Type III (split fracture) failure was recorded as the highest in the maxillary and mandibular premolar ECs with different axial wall heights.

Electrogeneration and Characterization of Poly(methylene blue) Thin Films on Stainless Steel 316 Electrodes-Effect of pH.

Methylene blue was electropolymerized on the surface of stainless steel 316. The addition of sodium oxalate and working at a pH near 11 allowed us to obtain steel electrodes coated with an electroactive polymer. This polymer shows electrochromic properties like those of the monomer, but also exhibits electroactivity at more positive potentials, which is associated with the active centers in the bridges between monomeric units. A digital video electrochemistry study allowed us to simultaneously quantify, on the one hand, the color changes on the entire surface of the stainless steel and on the other to separate the contribution of the active centers of the phenothiazine ring and of the inter-monomer bonds to the overall polymer response by means of assessing the mean color intensities. A reduction mechanism for the polymer, compatible with the pH variation of the observed electrochemical behavior, was proposed.

Comparison of color changes, fracture strengths, and failure modes of conventional endocrowns and endocrowns with different design modifications.

Endocrowns (ECs) are alternatives for rebuilding severely damaged teeth and show superior efficacy in molars over premolars. The objective of this in vitro study is to evaluate the effects of different preparation designs with short pulp chambers on the mean color change (Δ⁢E), fracture resistance, and failure types of mandibular molar ECs. A total of 40 extracted mandibular molars were treated endodontically and divided into four groups. Samples in groups 1, 2, 3, and 4 had occlusal preparation depths of 5 mm, 3 mm, 3 mm with ferrule, and 3 mm with boxes, respectively. The samples were immersed in coffee and their Δ⁢E values were measured by using the Commission Internationale de l'Eclairage color system. They were also subjected to a fracture test. Next, all specimens were examined visually under a stereomicroscope to evaluate their failure modes and identify their fracture origins. Data were entered and analyzed by using Statistical Package for Social Sciences. Among all groups, group 4 (3 mm + boxes) presented the highest Δ⁢E (4.15) after immersion in coffee. Moreover, ANOVA revealed that the Δ⁢E of group 4 (occlusal preparation depth of 3 mm with boxes) was significantly different (p< 0.05) from that of group 2 (3 mm + ferrule, 3.07). The EC with a 3 mm chamfer and ferrule showed the highest maximum load of 2847.68 ± 693.27 N, whereas that with a 5 mm chamfer finish line had a marginally reduced load at fracture of 2831.52 ± 881.83 N. The EC with a 3 mm chamber and boxes had a slightly increased maximum load of 2700.75 ± 436.40 N, whereas that with the 3 mm chamber had the lowest maximum load at fracture of 2385.97 ± 465.61 N. One-way ANOVA showed that different EC preparation designs had no effect on maximum fracture load (F [3,16] = 0.550, p= 0.6). The recorded Δ⁢E values of ECs in all groups were equal or marginally higher than the acceptable values. The EC with a 3 mm chamfer and ferrule displayed the highest mean maximum load. The EC with a 5 mm chamfer finish line had a marginally lower maximum load at fracture than other ECs. Failures, such as ceramic fracture, split fracture, and ceramic and tooth splitting above the cemento-enamel junction (CEJ) or vertically were predominant in samples with occlusal preparation depths of 3 mm with ferrule and 5 mm.

Comparative evaluation of the differential staining ability of carbol fuchsin, methylene blue, and turmeric GC-MI paste between enamel and adhesive composite remnant after orthodontic debonding using a spectrophotometer

Background: After debonding, the primary concern of the clinician is to ensure the complete removal of the orthodontic adhesive composite remnant and restore the tooth surface to as near its original state as possible. However, the color resemblance of composite adhesive and enamel can increase the risk of tooth damage during debonding. To delineate composite from enamel, using various hydrophobic stains can be helpful in clean debonding. Objective: The aim of the present research was to assess and compare the differential staining ability of three stains, i.e., carbol fuchsin, methylene blue, and turmeric GC-MI paste, using a spectrophotometer. Methodology: A total of 48 premolar samples were distributed among three groups, namely, Group A, Group B, and Group C. Each group of 16 samples was stained with carbol fuchsin, methylene blue, and turmeric GC-MI paste, respectively. The color value of enamel and composite was measured before and after staining by digital spectrophotometer using CIE L* a* b* scoring method. Results: The mean difference color value of composite and enamel before and after staining was found to be 38.473 ∆ E, 17.211 ∆ E, and 18.715 ∆ E and 1.647 ∆ E, 1.297 ∆ E, and 1.293 ∆ E in Groups A, B, and C, respectively. The mean color value of composite and enamel was compared before and after staining using a t-test for all three groups and was found to be statistically highly significant. Conclusion: Carbol fuchsin, methylene blue, and turmeric GC-MI paste have the potential to be used as composite disclosing agents. Turmeric GC-MI paste appears to be a better agent as it stains composite effectively without significant staining on enamel.

Colorimetric Evaluation of a Reintegration via Spectral Imaging-Case Study: Nasrid Tiling Panel from the Alhambra of Granada (Spain).

Color reintegration is a restoration treatment that involves applying paint or colored plaster to an object of cultural heritage to facilitate its perception and understanding. This study examines the impact of lighting on the visual appearance of one such restored piece: a tiled skirting panel from the Nasrid period (1238-1492), permanently on display at the Museum of the Alhambra (Spain). Spectral images in the range of 380-1080 nm were obtained using a hyperspectral image scanner. CIELAB and CIEDE2000 color coordinates at each pixel were computed assuming the CIE 1931 standard colorimetric observer and considering ten relevant illuminants proposed by the International Commission on Illumination (CIE): D65 plus nine white LEDs. Four main hues (blue, green, yellow, and black) can be distinguished in the original and reintegrated areas. For each hue, mean color difference from the mean (MCDM), CIEDE2000 average distances, volumes, and overlapping volumes were computed in the CIELAB space by comparing the original and the reintegrated zones. The study reveals noticeable average color differences between the original and reintegrated areas within tiles: 6.0 and 4.7 CIEDE2000 units for the yellow and blue tiles (with MCDM values of 3.7 and 4.5 and 5.8 and 7.2, respectively), and 16.6 and 17.8 CIEDE2000 units for the black and green tiles (with MCDM values of 13.2 and 12.2 and 10.9 and 11.3, respectively). The overlapping volume of CIELAB clouds of points corresponding to the original and reintegrated areas ranges from 35% to 50%, indicating that these areas would be perceived as different by observers with normal color vision for all four tiles. However, average color differences between the original and reintegrated areas changed with the tested illuminants by less than 2.6 CIEDE2000 units. Our current methodology provides useful quantitative results for evaluation of the color appearance of a reintegrated area under different light sources, helping curators and museum professionals to choose optimal lighting.

Effects of microabrasion and bleaching on color and shear bond strength of simulated stained-remineralized caries lesions

PurposeThis study investigated the effects of bleaching and microabrasion on the color and shear bond strength (SBS) of stained-remineralized caries-like lesions (s-RCLs). MethodsHuman enamel specimens were demineralized, stained (coffee/tea), then remineralized (2% NaF and artificial saliva [AS]) to create s-RCLs. Specimens were randomly divided into five groups (n = 18): G1, demineralized/AS; G2, s-RCLs/AS; G3, s-RCLs/at-home bleaching (15% carbamide peroxide [CP)], 6 h/d×7)/AS; G4, s-RCLs/microabrasion (6.6% hydrochloric acid, [1min/3cycles]/AS; and G5, s-RCLs/microabrasion and at-home bleaching/AS. Color was spectrophotometrically measured at baseline, after demineralization, after staining, and after treatment. After two weeks, the SBS was tested using a universal testing machine. Outcomes were analyzed using ANOVA models followed by Tukey’s test (α = 0.05). ResultsThe mean colors (ΔE) for demineralization and staining were significant (ΔE ≤ 5.9 and ≤14.4, respectively). G3 (ΔE 23.9) and G5 (ΔE 25.2) were significantly improved compared to G4 (ΔE 12.3). The SBS in G5 had the highest significant value (25.2 MPa), followed by G4 and G3 (21.5–20.6 MPa), which were significantly higher than G2 (16.8 MPa). G2, in turn, was more significant than G1 (10.9 MPa). ConclusionAt-home bleaching (15% CP) for seven days eliminated and improved organic stains on RCLs. Faster results were achieved when combined with microabrasion. All surface treatments resulted in high SBS.

Coral Health and Benthic Composition of Reefs in an MPA and Open-access Site in Western Calatagan, Batangas

Monitoring hard coral health and diversity is essential in assessing their resilience to disturbances such as coral bleaching. This study gathered baseline data on the health and benthic composition of coral reefs in western Calatagan, Batangas, the Philippines. Coral health in two sites – Buntong Gasang and the Quilitisan Marine Protected Area (MPA) – was assessed using the CoralWatch citizen science Coral Health Chart method. The average color score of more than 200 coral colonies was compared between sites and coral growth forms (i.e. branching, boulder, and plate). In addition, benthic composition in both sites was determined using photoquadrats. Buntong Gasang Point and Quilitisan MPA had mean coral scores that are 4.4 (± 1.0 SD) and 3.6 (± 1.0 SD), respectively, thus indicating normal symbiont densities. The analysis also showed little differences in mean color scores among coral growth forms ranging from 3.8–4.3. Both sites had relatively high coral cover (mean = 52.3% ± 4.3% SD in Buntong Gasang, mean = 49.7% ± 8.7% SD in Quilitisan MPA) despite having different benthic compositions [PERMANOVA, F(1,8) = 8.87, p = 0.006]. Branching coral cover was about six times higher in Buntong Gasang Point (17%), whereas encrusting corals dominated at Quilitisan MPA (~ 39%). In addition, algal cover was higher in Quilitisan (45.0%) than in Buntong Gasang (35.5%). Although other studies show that branching corals are less resistant than massive or encrusting forms to coral bleaching, examining coral color suggests that reefs in both Buntong Gasang and Quilitisan MPA appeared to have comparably recovered from the mass bleaching events in 2020–2021. However, regular monitoring is needed to assess the responses of these reefs to future thermal stress. This study shows the potential of monitoring coral color in assessing coral reef health in the Philippines.

Effect of phytopigments on discoloration of nanohybrid composite: An in vitro study

Objective: The purpose of this study is to comparatively evaluate the effect of discoloration of nanohybrid composite by four different phytopigments. Materials and Methods: Fifty disk-shaped samples of nanohybrid (3M Filtek Z350) resin composites were prepared using an acrylic template of dimension 5 mm × 3 mm. They were randomly divided into five groups and immersed in solutions of tomato powder, beetroot powder, java plum powder, and turmeric powder. Distilled water was used as the control group. The samples were placed in respective solutions for 3 h daily and stored in artificial saliva for the rest of the day for 28 days. Color values (L*, a*, b*) were measured by colorimeter using the CIE L*a*b* system at the end of the 7th and 28th days of immersion. Color differences ΔE*ab were statistically analyzed. Results: All the samples showed a change in color of nanohybrid composite resin to varying degrees. The mean ΔE*ab value obtained with beetroot solution was the highest among all the groups at the end of the 7th and 28th days, depicting that beetroot solution showed maximum mean color variation, followed by java plum solution, turmeric solution, and tomato solution. Conclusion: All the phytopigments used in this study have the potential to discolor the nanohybrid composite resin, with beetroot causing the most severe discoloration.

Tracing the green valley with entropic thresholding

ABSTRACT The green valley represents the population of galaxies that are transitioning from the actively star-forming blue cloud to the passively evolving red sequence. Studying the properties of the green valley galaxies is crucial for our understanding of the exact mechanisms and processes that drive this transition. The green valley does not have a universally accepted definition. The boundaries of the green valley are often determined by empirical lines that are subjective and vary across studies. We present an unambiguous definition of the green valley in the colour–stellar mass plane using the entropic thresholding. We first divide the galaxy population into the blue cloud and the red sequence based on a colour threshold that minimizes the intraclass variance and maximizes the interclass variance. Our method splits the region between the mean colours of the blue cloud and the red sequence into three parts by maximizing the total entropy of that region. We repeat our analysis in a number of independent stellar mass bins to define the boundaries of the green valley in the colour–mass diagram. Our method provides a robust and natural definition of the green valley.

Cosmic Dragons: A Two-Component Mixture Model of COSMOS Galaxies

Using the photometric population prediction method {}, we characterize the Red Sequence (RS) and Blue Cloud (BC) of DES galaxies in the COSMOS field. Red Dragon (RD) uses a redshift-evolving, error-corrected Gaussian mixture model to detail the distribution of photometric colors, smoothly parameterizing the two populations with relative weights, mean colors, intrinsic scatters, and inter-color correlations. This resulting fit of RS and BC yields RS membership probabilities for each galaxy. Even when training on only DES main bands griz, RD selects the quiescent population (defined here as galaxies with ) with ≳90% balanced accuracy out to z=2; augmenting with extended photometry from VIRCAM improves this accuracy to ∼95% out to z=3. We measure redshift evolution of sSFR and galactic age in several stellar mass bins, finding that the BC is consistently more star-forming (by ) and typically younger (by ) than the RS (up to z∼1.4). This characterization of both RS and BC as functions of redshift and stellar mass improves our understanding of both populations and opens the door to more precise galaxy population characterization in future deep optical and IR systems.

Implementation of Ant Colony Optimization and Principal Component Analysis for Early Prediction of Tomato Leaf Diseases: A Feature Reduction Approach

This paper details the implementation of a sophisticated algorithmic framework designed for the early prediction of various tomato leaf diseases, crucial for enhancing crop management and yield. The research deploys image processing techniques to extract pivotal features such as Red Mean, Green Mean, Blue Mean, Height, Width, and Defect Color channels from high-resolution images of tomato leaves. These features serve as indicators for diseases including Bacterial Spot, Early Blight, Late Blight, Leaf Mold, Septoria Leaf Spot, and infestations by Two-spotted Spider Mites. The core of the implementation lies in the integration of Ant Colony Optimization (ACO) with Principal Component Analysis (PCA) for feature reduction, which streamlines the dataset while retaining critical information. This combination not only reduces computational load but also improves the accuracy of the early prediction model. The paper demonstrates the application of this hybrid approach and compares its performance with existing models, emphasizing its efficiency and accuracy in early-stage disease prediction. The findings indicate that the proposed method outperforms traditional techniques, offering a reliable and scalable solution for agricultural disease management.

A comparative evaluation of the variations on the shades of pressable ceramic system with the layering technique after different number of firing cycles: An in vitro study.

The main aim of the present study was to compare and evaluate the effect of repetitive firings on different shades of a pressable all ceramic system layered with veneering porcelain. In-vitro comparative study. An in vitro comparative study was conducted, and a total of 60 disc shaped specimens (15 mm in diameter and 0.8 mm in thickness) were made of heat pressed ceramic of shades A2, A3, and B2 (20 discs of each shade) grouped as Group I, II, and III, respectively, using the lost wax technique. The discs were subsequently layered with veneering porcelain followed by glazing and overglazing and underwent a firing cycle at each step until six times combined. CIE L*a*b* measurements were noted on each sample after the third, fourth, fifth, and sixth firing using VITA Easyshade Advance 4.0 spectrophotometer. Statistical Analysis was done by SPSS 17.0 software. One way analysis of variance, multiple comparisons using the Tukey test, and descriptive statistical analysis were done for all the groups in the study. P <0.05 was statistically significant. The mean color differences for the repeated firings were imperceptible (ΔE <1.67) to the human eye for all ceramic samples tested except between the fourth and fifth firing of Group II (shade A3). The analysis revealed that although repeated firings lead to changes in L*, a*, and b* values, the mean color difference was below the clinically acceptable color change (ΔE <3.7).

Attentional cueing: Gaze is harder to override than arrows.

Gaze is an important and potent social cue to direct others' attention towards specific locations. However, in many situations, directional symbols, like arrows, fulfill a similar purpose. Motivated by the overarching question how artificial systems can effectively communicate directional information, we conducted two cueing experiments. In both experiments, participants were asked to identify peripheral targets appearing on the screen and respond to them as quickly as possible by a button press. Prior to the appearance of the target, a cue was presented in the center of the screen. In Experiment 1, cues were either faces or arrows that gazed or pointed in one direction, but were non-predictive of the target location. Consistent with earlier studies, we found a reaction time benefit for the side the arrow or the gaze was directed to. Extending beyond earlier research, we found that this effect was indistinguishable between the vertical and the horizontal axis and between faces and arrows. In Experiment 2, we used 100% "counter-predictive" cues; that is, the target always occurred on the side opposite to the direction of gaze or arrow. With cues without inherent directional meaning (color), we controlled for general learning effects. Despite the close quantitative match between non-predictive gaze and non-predictive arrow cues observed in Experiment 1, the reaction-time benefit for counter-predictive arrows over neutral cues is more robust than the corresponding benefit for counter-predictive gaze. This suggests that-if matched for efficacy towards their inherent direction-gaze cues are harder to override or reinterpret than arrows. This difference can be of practical relevance, for example, when designing cues in the context of human-machine interaction.

Current clinical evidence is insufficient to support HMME-PDT as the first choice of treatment for young children with port wine birthmarks.

Port wine birthmark (PWB) is a congenital vascular malformation of the skin. Pulsed dye laser (PDL) is the "gold standard" for the treatment of PWB globally. Hematoporphyrin monomethyl ether (HMME or hemoporfin)-mediated photodynamic therapy (HMME-PDT) has emerged as the first choice for PWB treatment, particularly for young children, in many major hospitals in China during the past several decades. To evaluate whether HMME-PDT is superior to PDL by comparing the clinical efficacies of both modalities. PubMed records were searched for all relevant studies of PWB treatment using PDL (1988-2023) or HMME-PDT (2007-2023). Patient characteristics and clinical efficacies were extracted. Studies with a quartile percentage clearance or similar scale were included. A mean color clearance index (CI) per study was calculated and compared among groups. An overall CI (C0), with data weighted by cohort size, was used to evaluate the final efficacy for each modality. A total of 18 HMME-PDT studies with 3910 patients in China were eligible for inclusion in this analysis. Similarly, 40 PDL studies with 5094 patients from nine different countries were eligible for inclusion in this analysis. Over 58% of patients in the HMME-PDT studies were minors (<18 years old). A significant portion (21.3%) were young children (<3 years old). Similarly, 33.2% of patients in the PDL studies were minors. A small proportion (9.3%) was young children. The overall clearance rates for PDL were slightly, but not significantly, higher than those for HMME-PDT in cohorts with patients of all ages (C0, 0.54 vs. 0.48, p = 0.733), subpopulations with only minors (C0, 0.54 vs. 0.46, p = 0.714), and young children (C0, 0.67 vs. 0.50, p = 0.081). Regrettably, there was a lack of long-term data on follow-up evaluations for efficacy and impact of HMME-PDT on young children in general, and central nervous system development in particular, because their blood-brain barriers have a greater permeability as compared to adults. PDL shows overall albeit insignificantly higher clearance rates than HMME-PDT in patients of all ages; particularly statistical significance is nearly achieved in young children. Collectively, current evidence is insufficient to support HMME-PDT as the first choice of treatment of PWBs in young children given: (1) overall inferior efficacy as compared to PDL; (2) risk of off-target exposure to meningeal vasculature during the procedure; (3) administration of steriods for mitigation of side effects; -and (4) lack of long-term data on the potential impact of HMME on central nervous system development in young children.

Biomass estimations of cultivated kelp using underwater RGB images from a mini-ROV and computer vision approaches

Seaweed farming is the fastest-growing aquaculture sector worldwide. As farms continue to expand, automated methods for monitoring growth and biomass become increasingly important. Imaging techniques, such as Computer Vision (CV), which allow automatic object detection and segmentation can be used for rapid estimation of underwater kelp size. Here, we segmented in situ underwater RGB images of cultivated Saccharina latissima using CV techniques and explored pixel area as a tool for biomass estimations. Sampling consisted of underwater imaging of S. latissima hanging vertically from a cultivation line using a mini-ROV. In situ chlorophyll a concentrations and turbidity (proxies for phytoplankton and particle concentrations) were monitored for water visibility. We first compared manual length estimations of kelp individuals obtained from the images (through manual annotation using ImageJ software). Then, we applied CV methods to segment and calculate kelp area and investigated these measurements as a robust proxy for wet weight biomass. A strong positive linear correlation (r2 = 0.959) between length estimates from underwater image frames and manual measurements from the harvested kelp was observed. Using unsupervised learning algorithms, such as mean shift clustering, colour segmentation and adaptive thresholding from the OpenCV package in Python, kelp area was segmented and the number of individual pixels in the contour area was counted. A positive power relationship was found between length from manual measurements with CV-derived area (r2 = 0.808) estimated from underwater images. Likewise, CV-derived area had a positive power relationship with wet weight biomass (r² = 0.887). When removing data where visibility was poor due to high turbidity levels (mid-June), the power relationship was stronger between CV-derived area estimates and the field measurements (r² = 0.976 for wet weight biomass and r² = 0.979 for length). These results show that robust estimates of cultivated kelp biomass in situ are possible through kelp colour segmentation. However, we demonstrate that the quality of CV post-processing and accuracy of the model are highly dependent of environmental conditions (e.g. turbidity and chlorophyll a concentrations). The establishment of these technologies has the potential to offer scalability of production, efficient real-time monitoring of sea cultivation and improved yield predictions.