Polarization- and Specular-Reflection-Based, Non-contact Latent Fingerprint Imaging and Lifting

In forensic science the finger marks left unintentionally by people at a crime scene are referred to as latent fingerprints . Most existing techniques to detect and lift latent fingerprints require application of certain material directly onto the exhibit. The chemical and physical processing applied onto the fingerprint potentially degrades or prevents further forensic testing on the same evidence sample. Many existing methods also come with deleterious side effects. We introduce a method to detect and extract latent fingerprint images without applying any powder or chemicals on the object. Our method is based on the optical phenomena of polarization and specular reflection together with the physiology of fingerprint formation. The recovered image quality is comparable to existing methods. In some cases like the sticky side of a tape our method shows unique advantages

Display of polarization information by coherently moving dots

It is known that human eyes are effectively polarization-blind. Therefore, in order to display the polarization information in an image, one may require exhibiting such information using other visual cues that are compatible with the human visual system and can be easily detectable by a human observer. Here, we present a technique for displaying polarization information in an image using coherently moving dots that are superimposed on the image. Our examples show that this technique would allow the image segments with polarization signals to pop out easily, which will lead to better target feature detection and visibility enhancement

Adaptive Algorithms for 2–Channel Polarization Sensing under Various Polarization Statistics with Non-Uniform Distributions

The polarization of light carries much useful information about the environment. Biological studies have shown that some animal species use polarization information for navigation and other purposes. It has been previously shown that a bio-inspired Polarization Difference Imaging technique can facilitate detection and feature extraction of targets in scattering media. It has also been established by S. Tyo1 that Polarization Sum and Polarization Difference are the optimum pair of linear combinations of images taken through two orthogonally oriented linear polarizers of a scene having a uniform distribution of polarization directions. However, in many real environments the scene has a non-uniform distribution of polarization directions. Using principal component analysis of the polarization statistics of the scene, here we develop a method to determine the two optimum information channels with unequal weighting coefficients that can be formed as linear combinations of the images of a scene taken through a pair of linear polarizers not constrained to the horizontal and vertical directions of the scene We determine the optimal orientations of linear polarization filters that enhance separation of a target from the background, where the target is defined as an area with distinct polarization characteristics as compared to the background. Experimental results confirm that in most situations adaptive polarization difference imaging outperforms conventional polarization difference imaging with fixed channels

Separation and contrast enhancement of overlapping cast shadow components using polarization

Shadow is an inseparable aspect of all natural scenes. When there are multiple light sources or multiple reflections several different shadows may overlap at the same location and create complicated patterns. Shadows are a potentially good source of information about a scene if the shadow regions can be properly identified and segmented. However, shadow region identification and segmentation is a difficult task and improperly identified shadows often interfere with machine vision tasks like object recognition and tracking. We propose here a new shadow separation and contrast enhancement method based on the polarization of light. Polarization information of the scene captured by our polarization-sensitive camera is shown to separate shadows from different light sources effectively. Such shadow separation is almost impossible to realize with conventional, polarization-insensitive imaging

Cone-like morphological, molecular, and electrophysiological features of the photoreceptors of the Nrl knockout mouse

PURPOSE. To test the hypothesis that Nrl Ϫ/Ϫ photoreceptors are cones, by comparing them with WT rods and cones using morphological, molecular, histochemical, and electrophysiological criteria. METHODS. The photoreceptor layer of fixed retinal tissue of 4-to 6-week-old mice was examined in plastic sections by electron microscopy, and by confocal microscopy in frozen sections immunolabeled for the mouse UV-cone pigment and colabeled with PNA. Quantitative immunoblot analysis was used to determine the levels of expression of key cone-specific proteins. Single-and paired-flash methods were used to extract the spectral sensitivity, kinetics, and amplification of the awave of the ERG. RESULTS. Outer segments of Nrl Ϫ/Ϫ photoreceptors (ϳ7 m) are shorter than those of wild-type (WT) rods (ϳ25 m) and cones (ϳ15 m); but, like WT cones, they have 25 or more basal discs open to the extracellular space, extracellular matrix sheaths stained by PNA, chromatin "clumping" in their nuclei, and mitochondria two times shorter than rods. Nrl Ϫ/Ϫ photoreceptors express the mouse UV cone pigment, cone transducin, and cone arrestin in amounts expected, given the relative size and density of cones in the two retinas. The ERG a-wave was used to assay the properties of the photocurrent response. The sensitivity of the Nrl -/-a-wave is at its maximum at 360 nm, with a secondary mode at 510 nm having approximately one-tenth the maximum sensitivity. These wavelengths are the max of the two mouse cone pigments. The time to peak of the dim-flash photocurrent response was ϳ50 ms, more than two times faster than that of rods. CONCLUSIONS. Many morphological, molecular, and electrophysiological features of the Nrl Ϫ/Ϫ photoreceptors are cone-like, and strongly distinguish these cells from rods. This retina provides a model for the investigation of cone function and cone-specific genetic disease. (Invest Ophthalmol Vis Sci

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Method of Using Polarization Differencing to Improve Vision

PatentThe present invention is directed to a system, which uses polarized light difference to improve vision. The system obtains an image at a first polarization direction. The system then obtains an image at a second orthogonal polarization direction. The second orthogonal polarization value is subtracted from the first value. The difference value is then amplified in order to provide an enhanced image

The Origin of the Vertebrate Eye

Abstract In his considerations of "organs of extreme perfection," Charles Darwin described the evidence that would be necessary to support the evolutionary origin of the eye, namely, demonstration of the existence of "numerous gradations" from the most primitive eye to the most perfect one, where each such tiny change had provided a survival advantage (however slight) to the organism possessing the subtly altered form. In this paper, we discuss evidence indicating that the vertebrate eye did indeed evolve through numerous subtle changes. The great majority of the gradual transitions that did occur have not been preserved to the present time, either in the fossil record or in extant species; yet clear evidence of their occurrence remains. We discuss the remarkable "eye" of the hagfish, which has features intermediate between a simple light detector and an image-forming camera-like eye and which may represent a step in the evolution of our eye that can now be studied by modern methods. We also describe the important clues to the evolutionary origin of the vertebrate eye that can be found by studying the embryological development of our own eye, by examining the molecular genetic record preserved in our own genes and in the genes of other vertebrates, and through consideration of the imperfections (or evolutionary "scars") in the construction of our eye. Taking these findings together, it is possible to discuss in some detail how the vertebrate eye evolved

cGMP in mouse rods: the spatiotemporal dynamics underlying single photon responses

Vertebrate vision begins when retinal photoreceptors transduce photons into electrical signals that are then relayed to other neurons in the eye, and ultimately to the brain. In rod photoreceptors, transduction of single photons is achieved by a well-understood G-protein cascade that modulates cGMP levels, and in turn, cGMP-sensitive inward current. The spatial extent and depth of the decline in cGMP during the single photon response (SPR) have been major issues in phototransduction research since the discovery that single photons elicit substantial and reproducible changes in membrane current. The spatial profile of cGMP decline during the SPR affects signal gain, and thus may contribute to reduction of trial-to-trial fluctuations in the SPR. Here we summarize the general principles of rod phototransduction, emphasizing recent advances in resolving the spatiotemporal dynamics of cGMP during the SPR

Schematic diagram of light-regulated disk assembly.

<p>A. Rods housed in an alternating light-dark cycle (<i>top panel</i>) will vary the rate of disk assembly and displacement (<i>second panel</i>) in response to the phase of the cycle <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080059#pone.0080059-Young1" target="_blank">[6]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080059#pone.0080059-Besharse1" target="_blank">[7]</a>. Since endogenous rhodopsin density in OS membranes is constant, the rate of rhodopsin incorporation (<i>third panel</i>) must change in phase with the lighting cycle and disk assembly. By contrast, Rho-eGFP appears to have a relatively constant rate of incorporation into the OS (<i>bottom panel</i>). This would then lead to a periodic variation in Rho-eGFP content, with higher densities assembled at night. B. Schematic diagram illustrating the density variation of Rho-eGFP (<i>green</i>) throughout a light cycle and the absence of variation in endogenous rhodopsin (red). The length of the lighting cycle and the size of the cell are not to scale.</p