Deriving the cone fundamentals: a subspace intersection method.

Two ideas, proposed by Thomas Young and James Clerk Maxwell, form the foundations of colour science: (i) three types of retinal receptors encode light under daytime conditions, and (ii) colour matching experiments establish the critical spectral properties of this encoding. Experimental quantification of these ideas is used in international colour standards. However, for many years, the field did not reach consensus on the spectral properties of the biological substrate of colour matching: the spectral sensitivity of the cone fundamentals.

Theoretical impact of chromatic aberration correction on visual acuity.

It has been known for more than 220 years that the image quality of the human eye is significantly degraded by chromatic aberrations. Recently, it was shown experimentally that correcting chromatic aberrations results in a 0.2- to 0.

Orthogonal neural representations support perceptual judgements of natural stimuli.

In natural behavior, observers must separate relevant information from a barrage of irrelevant information. Many studies have investigated the neural underpinnings of this ability using artificial stimuli presented on simple backgrounds. Natural viewing, however, carries a set of challenges that are inaccessible using artificial stimuli, including neural responses to background objects that are task-irrelevant.

History constrains the evolution of efficient color naming, enabling historical inference.

Color naming in natural languages is not arbitrary: It reflects efficient partitions of perceptual color space [T. Regier, P. Kay, N.

Safety, pharmacodynamics, and antiviral activity of selgantolimod in viremic patients with chronic hepatitis B virus infection.

Background & Aims: Novel finite therapies for chronic hepatitis B (CHB) are needed, since lifelong treatment is usually required with current available oral antivirals. This phase II study (NCT03615066) evaluated the safety, pharmacodynamics, and antiviral activity of selgantolimod (a Toll-like receptor 8 agonist [TLR8]) with tenofovir alafenamide (TAF).

Methods: Viremic patients with CHB not receiving treatment were stratified by HBeAg status and randomized 2:2:1 to TAF 25 mg/day with selgantolimod 3 mg orally once weekly (QW), selgantolimod 1.

Repeatability and reciprocity of the cone optoretinogram.

Optoretinography has enabled noninvasive visualization of physiological changes in cone photoreceptors exposed to light. Understanding the cone optoretinogram in healthy subjects is essential for establishing it as a biomarker for cone function in disease. Here, we measure the population cone intensity optoretinogram in healthy adults, for multiple irradiance/duration combinations of visible stimuli with equal energy.

In vivo chromatic and spatial tuning of foveolar retinal ganglion cells in Macaca fascicularis.

The primate fovea is specialized for high acuity chromatic vision, with the highest density of cone photoreceptors and a disproportionately large representation in visual cortex. The unique visual properties conferred by the fovea are conveyed to the brain by retinal ganglion cells, the somas of which lie at the margin of the foveal pit. Microelectrode recordings of these centermost retinal ganglion cells have been challenging due to the fragility of the fovea in the excised retina.

Beneficial and Pest Arthropod Responses to Tillage and Cover Crop Residues in Organic Cucurbits.

Reduced tillage methods such as strip tillage are often combined with cover crop mixtures to provide agronomic benefits which can support crop and soil health. However, reduced tillage and cover crop species/arrangements effects on arthropods is less understood and results of previous studies have varied. In this study, we examined how agriculturally relevant pest and beneficial arthropod species were impacted by tillage and cover crop methods in USDA-certified organic Cucurbita (L.

Visual encoding: Principles and software.

For more than two centuries scientists and engineers have worked to understand and model how the eye encodes electromagnetic radiation (light). We now understand the principles of how light is transmitted through the optics of the eye and encoded by retinal photoreceptors and light-sensitive neurons. In recent years, new instrumentation has enabled scientists to measure the specific parameters of the optics and photoreceptor encoding.

Weed germinable seedbanks of rice-wheat systems in the Eastern Indo-Gangetic Plains: Do tillage and edaphic factors explain community variation?

Zero tillage (ZT) is widely promoted throughout India's Eastern Indo-Gangetic Plains (IGP) because of its potential to increase wheat productivity and resilience to abiotic stresses. Weeds remain a major barrier to ZT adoption, yet it remains unclear how ZT will influence weed communities in the Eastern-IGP. The primary objective of this study was to characterise the composition of the germinable weed seedbank sampled just prior to the wheat phase of rice-wheat farms in Bihar and Eastern Uttar Pradesh, and examine whether adoption of ZT wheat has shifted weed community composition compared to conventional tillage (CT).

Automated Assessment of Photoreceptor Visibility in Adaptive Optics Split-Detection Images Using Edge Detection.

Purpose: Adaptive optics scanning laser ophthalmoscopy (AOSLO) is a high-resolution imaging modality that allows measurements of cellular-level retinal changes in living patients. In retinal diseases, the visibility of photoreceptors in AOSLO images is affected by pathology, patient motion, and optics, which can lead to variability in analyses of the photoreceptor mosaic. Current best practice for AOSLO mosaic quantification requires manual assessment of photoreceptor visibility across overlapping images, a laborious and time-consuming task.

Capsid Inhibition with Lenacapavir in Multidrug-Resistant HIV-1 Infection.

Background: Patients with multidrug-resistant human immunodeficiency virus type 1 (HIV-1) infection have limited treatment options. Lenacapavir is a first-in-class capsid inhibitor that showed substantial antiviral activity in a phase 1b study.

Methods: In this phase 3 trial, we enrolled patients with multidrug-resistant HIV-1 infection in two cohorts, according to the change in the plasma HIV-1 RNA level between the screening and cohort-selection visits.

Equivalent noise characterization of human lightness constancy.

A goal of visual perception is to provide stable representations of task-relevant scene properties (e.g. object reflectance) despite variation in task-irrelevant scene properties (e.

An image reconstruction framework for characterizing initial visual encoding.

We developed an image-computable observer model of the initial visual encoding that operates on natural image input, based on the framework of Bayesian image reconstruction from the excitations of the retinal cone mosaic. Our model extends previous work on ideal observer analysis and evaluation of performance beyond psychophysical discrimination, takes into account the statistical regularities of the visual environment, and provides a unifying framework for answering a wide range of questions regarding the visual front end. Using the error in the reconstructions as a metric, we analyzed variations of the number of different photoreceptor types on human retina as an optimal design problem.

Melanopic stimulation does not alter psychophysical threshold sensitivity for luminance flicker.

In addition to the rod and cone photoreceptors the retina contains intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells express the photopigment melanopsin and are known to be involved in reflexive visual functions such as pupil response and photo-entrainment of the circadian rhythm. It is possible that the ipRGCs contribute to conscious visual perception, either by providing an independent signal to the geniculo-striate pathway, or by interacting with and thus modifying signals arising from "classical" retinal ganglion cells that combine and contrast cone input.

Tocilizumab and remdesivir in hospitalized patients with severe COVID-19 pneumonia: a randomized clinical trial.

Purpose: Trials of tocilizumab in patients with severe COVID-19 pneumonia have demonstrated mixed results, and the role of tocilizumab in combination with other treatments is uncertain. Here we evaluated whether tocilizumab plus remdesivir provides greater benefit than remdesivir alone in patients with severe COVID-19 pneumonia.

Methods: This randomized, double-blind, placebo-controlled, multicenter trial included patients hospitalized with severe COVID-19 pneumonia requiring > 6 L/min supplemental oxygen.

What we talk about when we talk about colors.

Names for colors vary widely across languages, but color categories are remarkably consistent. Shared mechanisms of color perception help explain consistent partitions of visible light into discrete color vocabularies. But the mappings from colors to words are not identical across languages, which may reflect communicative needs-how often speakers must refer to objects of different color.

Brief Report: Efficacy and Safety of Bictegravir/Emtricitabine/Tenofovir Alafenamide in Females Living With HIV: An Integrated Analysis of 5 Trials.

Background: We characterized the efficacy and safety of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in a broad population of pediatric/adolescent/adult/elderly females living with HIV (FWH).

Setting: Integrated analysis.

Methods: Available data from 5 trials were integrated.

Reflexive Eye Closure in Response to Cone and Melanopsin Stimulation: A Study of Implicit Measures of Light Sensitivity in Migraine.

Background And Objectives: To quantify interictal photophobia in migraine with and without aura using reflexive eye closure as an implicit measure of light sensitivity and to assess the contribution of melanopsin and cone signals to these responses.

Methods: Participants were screened to meet criteria for 1 of 3 groups: headache-free (HF) controls, migraine without aura (MO), and migraine with visual aura (MA). MO and MA participants were included if they endorsed ictal and interictal photophobia.

Switching to Bictegravir/Emtricitabine/Tenofovir Alafenamide in Black Americans With HIV-1: A Randomized Phase 3b, Multicenter, Open-Label Study.

Background: With the highest rates of HIV/AIDS in the United States, Black Americans are still underrepresented in HIV medical research.

Setting: BRAAVE (NCT03631732) is a randomized, phase 3b, multicenter, open-label US study.

Methods: Adults identifying as Black or African American and virologically suppressed on 2 nucleoside reverse transcriptase inhibitors (NRTIs) plus third agent were randomized (2:1) to switch to open-label bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) once daily or stay on baseline regimen (SBR) for 24 weeks, after which SBR had delayed switch to B/F/TAF.

A quadratic model captures the human V1 response to variations in chromatic direction and contrast.

An important goal for vision science is to develop quantitative models of the representation of visual signals at post-receptoral sites. To this end, we develop the quadratic color model (QCM) and examine its ability to account for the BOLD fMRI response in human V1 to spatially uniform, temporal chromatic modulations that systematically vary in chromatic direction and contrast. We find that the QCM explains the same, cross-validated variance as a conventional general linear model, with far fewer free parameters.

Fixed-dose combination bictegravir, emtricitabine, and tenofovir alafenamide in adolescents and children with HIV: week 48 results of a single-arm, open-label, multicentre, phase 2/3 trial.

Background: Bictegravir is a potent integrase strand-transfer inhibitor (INSTI) with a high genetic barrier to resistance. Bictegravir, coformulated with emtricitabine and tenofovir alafenamide, is recommended by key European and US HIV treatment guidelines as the preferred single-tablet regimen for adults and adolescents. The aim of this study was to assess the pharmacokinetics, safety, and efficacy of switching to this regimen in virologically suppressed children and adolescents with HIV.