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Case Reports in Dentistry 2022Recently, improvement of appearance and a quest for beauty have become a primary concern for patients. It is a challenging task for a clinician to achieve esthetic...
Recently, improvement of appearance and a quest for beauty have become a primary concern for patients. It is a challenging task for a clinician to achieve esthetic integration of prosthetic pieces for anterior teeth, particularly for highly demanding patients who give attention to particular details. The challenge is harder when only one tooth has to be restored. The objective is to achieve a fully and perfectly integrated rehabilitation with natural dentition. Poorly described, facial line angles are key to the success of achieving the desired tooth shape, especially for the maxillary central incisor. They influence both the shape and color of the tooth through optical illusion. Their misplacement could certainly spoil the esthetic outcome. Thus, it is mandatory to respect and recreate them. The objective of the present study was to define and then to highlight their importance. It also aimed to give some tips on how to perfect the shape of prosthetic teeth through a clinical case of central incisor esthetic rehabilitation.
PubMed: 36276236
DOI: 10.1155/2022/4917536 -
Optics Express Jul 2022Pepper's ghost optical illusion, used in amusement parks, theaters, movies, museums, and other venues since 1862, is produced by reflected light and is often wrongly...
Pepper's ghost optical illusion, used in amusement parks, theaters, movies, museums, and other venues since 1862, is produced by reflected light and is often wrongly described as holographic. This paper presents an alternative illusion technique based on the use of full-color analog Denisyuk holograms mixed with real elements with the help of special lighting. The result is a stunning applied-science experiment that arouses the curiosity of even the most discerning observer, first by combining the real-world and holography on a level never before achieved, and then by creating an unexpected final effect of disappearance.
PubMed: 36236922
DOI: 10.1364/OE.465247 -
International Journal of Retina and... Sep 2022Scanning laser ophthalmoscopes (SLOs) are used widely for reflectance, fluorescence or autofluorescence photography and less commonly for retroillumination imaging. SLOs... (Review)
Review
Scanning laser ophthalmoscopes (SLOs) are used widely for reflectance, fluorescence or autofluorescence photography and less commonly for retroillumination imaging. SLOs scan a visible light or near-infrared radiation laser beam across the retina, collecting light from each retinal spot as it's illuminated. An SLO's clinical applications, image contrast and axial resolution are largely determined by an aperture overlying its photodetector. High contrast, reflectance images are produced using small diameter, centered apertures (confocal apertures) that collect retroreflections and reject side-scattered veiling light returned from the fundus. Retroillumination images are acquired with annular on-axis or laterally-displaced off-axis apertures that capture scattered light and reject the retroreflected light used for reflectance imaging. SLO axial resolution is roughly 300 μm, comparable to macular thickness, so SLOs cannot provide the depth-resolved chorioretinal information obtainable with optical coherence tomography's (OCT's) 3 μm axial resolution. Retroillumination highlights and shades the boundaries of chorioretinal tissues and abnormalities, facilitating detection of small drusen, subretinal drusenoid deposits and subthreshold laser lesions. It also facilitates screening for large-area chorioretinal irregularities not readily identified with other en face retinal imaging modalities. Shaded boundaries create the perception of lesion elevation or depression, a characteristic of retroillumination but not reflectance SLO images. These illusions are not reliable representations of three-dimensional chorioretinal anatomy and they differ from objective OCT en face topography. SLO retroillumination has been a useful but not indispensable retinal imaging modality for over 30 years. Continuing investigation is needed to determine its most appropriate clinical roles in multimodal retinal imaging.
PubMed: 36180893
DOI: 10.1186/s40942-022-00421-0 -
Sexuality & Culture 2023Susan Sontag, in her classic 1967 essay, "The Pornographic Imagination," argued: "Tamed as it may be, sexuality remains one of the demonic forces in human consciousness...
Susan Sontag, in her classic 1967 essay, "The Pornographic Imagination," argued: "Tamed as it may be, sexuality remains one of the demonic forces in human consciousness …. "In the last half-century, Sontag's demonic force of sexuality has transformed pornography and the "pornographic imagination"-let along social relations between women and men. In this essay, I adopt Walter Benjamin's concept of phantasmagoria-a magic-lantern show of optical illusions, rapidly changing size and blending into one another-as the metaphoric commodity form of postmodern capitalist society, fetishism-on-display. I examine the evolution of technological forms of pornographic representation over the last two centuries, including the magiclantern, daguerreotype, photography, stereoscope and film as well as the internet, erotic toys, electronic devises, VR and sex robots. These developments are set against a background of equally profound legal and cultural developments that have recast the sexuality of postmodern America. I argue that these (and other) developments have recast patriarchy and, in some important ways, the sexual relations between "consenting" adults. I conclude reflecting on the current intellectual and political debate about pornography between "pro-sex" and "anti-sex" feminists. With the enormous increase in the production and availability of pornography, I ask, perhaps "quantity" can give way to improved "quality"? I ask whether today's sexual phantasmagoria can fashion a "new" feminist sexuality-and a more humane pornography?
PubMed: 36157715
DOI: 10.1007/s12119-022-10011-9 -
Scientific Reports Sep 2022Spatial planning and development use various visualisation methods. Technological advancements in visualisation techniques have allowed imaging to shift from 2 to 3D...
Spatial planning and development use various visualisation methods. Technological advancements in visualisation techniques have allowed imaging to shift from 2 to 3D dimensions. 3D optical illusion, which converts information recorded in the digital form into a three-dimensional presentation, can be a new tool for presenting spatial development solutions. Since a optical illusion is a direct spatial presentation, it requires neither specialist preparation nor spatial imagination. For this reason, it can become an effective means of visual communication with the public in the area of spatial planning and development. This article shows an example of the imaging of a model element of spatial development (a building) using the 3D illusion technique. Collected opinions of the test group of viewers confirm the usefulness of this tool. The presented 3D visualisation effect evoked positive reactions among the viewers. The use of the hologram technique in spatial planning and development appears to be justified and is an interesting research trend.
PubMed: 36130992
DOI: 10.1038/s41598-022-20173-z -
Frontiers in Psychology 2022Sensation (the reflection of past experience in the mind) is the reflection of the brain on the individual attributes of objective things that directly act on the sense...
Sensation (the reflection of past experience in the mind) is the reflection of the brain on the individual attributes of objective things that directly act on the sense organs. Feeling is the most elementary cognitive process and the simplest psychological phenomenon. Vision is a kind of sense, and sense is produced by objective things acting on the sense organs. But at present, it is rare to analyze interior design exhibition from the perspective of visual psychology, an emerging science, as an interdisciplinary attempt, only in interior design research. Therefore, the study of sensory process should start from its external stimuli, in order to first understand how it acts on the sensory organs to produce sensory phenomena. This paper mainly studies the visual performance of psychological factors in interior design under the background of artificial intelligence. This paper proposes a K-means clustering algorithm and a localization algorithm fused with visual and inertial navigation. The distance thresholds corresponding to the SIFT feature descriptors of threshold T1, 128D, 96D, 64D, and 32D are 170, 160, 150, and 90, respectively. This verifies that the candidate image with the highest number of matching points is considered the best matching image.
PubMed: 35967610
DOI: 10.3389/fpsyg.2022.941196 -
Vision Research Nov 2022The horizontal-vertical illusion (HVI) has been proposed as a method to increase the perceived height of steps, increase toe clearance and prevent falls. High contrast...
The horizontal-vertical illusion (HVI) has been proposed as a method to increase the perceived height of steps, increase toe clearance and prevent falls. High contrast vertical stripes are placed on the step riser abutting a horizontal edge-highlighter creating 'T' junctions which are thought to promote the illusion. Various configurations of the HVI were tested including luminance gratings (L) and second-order modulations of contrast (CM), spatial frequency (FM) and orientation (OM). Observers were asked to compare the apparent height of gratings with that of either filled, unmodulated rectangles or unfilled rectangles. Rectangles were presented alone or as part of a step with a highlighter. In some conditions highlighters matched the properties of the grating; in others or not. In one critical experiment, the HVI was compared for steps with highlighters that were separated from the riser by a thin line and those where the risers and highlighters were continuous. All gratings except FM appeared taller when presented in the step configuration with a continuous, matching highlighter. This effect was greatly reduced when a thin line separated the grating from the highlighter and abolished for mis-matched highlighters and risers. In the rectangle conditions, all cues appeared taller than blank rectangles and L and CM appeared taller than filled-unmodulated rectangles. In conclusion, second-order cues may be useful for inducing the HVI onto steps. However, the ability of vertical stripes and edge-highlighters to accentuate perceived step height may be due to aggregation of the highlighter into the grating rather than the normal horizontal-vertical illusion.
Topics: Humans; Optical Illusions; Visual Perception
PubMed: 35908371
DOI: 10.1016/j.visres.2022.108101 -
Frontiers in Bioengineering and... 2022Estimating kinematics from optical motion capture with skin-mounted markers, referred to as an inverse kinematic (IK) calculation, is the most common experimental...
Estimating kinematics from optical motion capture with skin-mounted markers, referred to as an inverse kinematic (IK) calculation, is the most common experimental technique in human motion analysis. Kinematics are often used to diagnose movement disorders and plan treatment strategies. In many such applications, small differences in joint angles can be clinically significant. Kinematics are also used to estimate joint powers, muscle forces, and other quantities of interest that cannot typically be measured directly. Thus, the accuracy and reproducibility of IK calculations are critical. In this work, we isolate and quantify the uncertainty in joint angles, moments, and powers due to two sources of error during IK analyses: errors in the placement of markers on the model (marker registration) and errors in the dimensions of the model's body segments (model scaling). We demonstrate that IK solutions are best presented as a distribution of equally probable trajectories when these sources of modeling uncertainty are considered. Notably, a substantial amount of uncertainty exists in the computed kinematics and kinetics even if low marker tracking errors are achieved. For example, considering only 2 cm of marker registration uncertainty, peak ankle plantarflexion angle varied by 15.9°, peak ankle plantarflexion moment varied by 26.6 N⋅m, and peak ankle power at push off varied by 75.9 W during healthy gait. This uncertainty can directly impact the classification of patient movements and the evaluation of training or device effectiveness, such as calculations of push-off power. We provide scripts in OpenSim so that others can reproduce our results and quantify the effect of modeling uncertainty in their own studies.
PubMed: 35694232
DOI: 10.3389/fbioe.2022.874725 -
Frontiers in Human Neuroscience 2022It is known that the human brain has a strong preference for rectangularity in interpreting pictures as 3D shapes. Symmetry is also considered to be a factor that the...
It is known that the human brain has a strong preference for rectangularity in interpreting pictures as 3D shapes. Symmetry is also considered to be a factor that the human vision system places high priority on when perceiving 3D objects. Thus, a question is raised: which is more basic, the rectangularity preference or the symmetry preference? To answer this question, we carried out experiments using pictures that have at least two interpretations as 3D objects, one of which was rectangular but not symmetric, and the other of which was symmetric but not rectangular. We found that the preference for rectangularity is stronger than that for symmetry. This observation will help us to understand various 3D optical illusions, including the room-size illusion and the ambiguous object illusion.
PubMed: 35547197
DOI: 10.3389/fnhum.2022.849159 -
Healthcare (Basel, Switzerland) Mar 2022This work surveyed how the Mach band effect was mentioned in the dental literature and provided a qualitative assessment of diagnostic relevance and interfaces covered....
This work surveyed how the Mach band effect was mentioned in the dental literature and provided a qualitative assessment of diagnostic relevance and interfaces covered. PubMed, Scopus, and Google Scholar were queried in mid-Jan 2022. The search string was ("mach band effect" OR "mach effect") AND (dental OR oral OR tooth OR teeth OR maxillofacial OR orofacial). All publications returned by the searches were screened. Exclusion criteria included irrelevance (e.g., dealing with "Mach effect" that was non-radiographic or non-dental) and not written in English. Reference lists of returned publications were manually searched to identify potentially missed papers. For each included publication, the following parameters were recorded: any presentation of radiographic images showing a Mach band effect, direct investigation of the effect, relevance to which structural interfaces, diagnostic relevance, and in which parts of the publication Mach band effect was mentioned. Seventy-seven publications were included and analyzed. The majority of the publications mentioned the Mach band effect in the Discussion section about its diagnostic relevance to caries detection at the enamel-dentinal junction and the interface between restorative material and tooth structure. Eight of them presented radiographic images showing a Mach band effect. Three of them investigated the Mach band effect. Dental publications seldom covered the Mach band effect. When they covered it, most of them only mentioned it in the Discussion section without actually investigating it.
PubMed: 35455810
DOI: 10.3390/healthcare10040632