Annette E. Allen, Joshua W. Mouland, Jessica Rodgers, Beatriz Bano-Otalora, Ronald H. Douglas, Glen Jeffery, Anthony A. Vugler, Timothy M. Brown, and Robert J. Lucas

An animal's temporal niche – the time of day at which it is active – is known to drive a variety of adaptations in the visual system. This includes variations in the topography, spectral sensitivity and density of retinal photoreceptors, and changes in the eye's gross anatomy and spectral transmission characteristics. We have characterised visual spectral sensitivity in the murid rodent Rhabdomys pumilio (‘the four-striped grass mouse’), which is the same family as (nocturnal) mice and rats, but exhibits a strong diurnal niche. As is common in diurnal species, the Rhabdomys lens acts as a long-pass spectral filter, providing limited transmission of light <400nm. Conversely, we found strong sequence homologies with the Rhabdomys SWS and MWS opsins and those of related nocturnal species (mice and rats) whose SWS opsins are maximally sensitive in the near UV. We continued to assess in vivo spectral sensitivity of cone vision using electroretinography and multi-channel recordings from the visual thalamus. These revealed that responses across the human visible range could be adequately described by those of a single pigment (assumed to be MWS opsin) maximally sensitive ~500nm, but that sensitivity in the near UV required inclusion of a second pigment whose peak sensitivity lay well into the UV range (_max <400nm, likely ~360nm). We therefore conclude that, despite the UV-filtering effects of the lens, the Rhabdomys retains an SWS pigment with a UV-A _max. In effect, this somewhat paradoxical combination of long-pass lens and UV-A _max results in narrow-band sensitivity for SWS cone pathways in the UV-A range.

Cone photoreceptors in the retina enable vision over a wide range of light intensities. However, the processes enabling cone vision in bright light (i.e. photopic vision) are not adequately understood. Chromophore regeneration of cone photopigments may require the retinal pigment epithelium (RPE) and/or retinal Müller glia. In the RPE, isomerization of all-trans-retinyl esters to 11-cis-retinol is mediated by the retinoid isomerohydrolase Rpe65. A putative alternative retinoid isomerase, dihydroceramide desaturase-1 (DES1), is expressed in RPE and Müller cells. The retinol-isomerase activities of Rpe65 and Des1 are inhibited by emixustat and fenretinide, respectively. Here, we tested the effects of these visual cycle inhibitors on immediate, early, and late phases of cone photopic vision. In zebrafish larvae raised under cyclic light conditions, fenretinide impaired late cone photopic vision, while the emixustat-treated zebrafish unexpectedly had normal vision. In contrast, emixustat-treated larvae raised under extensive dark-adaptation displayed significantly attenuated immediate photopic vision concomitant with significantly reduced 11-cis-retinaldehyde (11cRAL). Following 30 min of light, early photopic vision was recovered, despite 11cRAL levels remaining significantly reduced. Defects in immediate cone photopic vision were rescued in emixustat- or fenretinide-treated larvae following exogenous 9-cis-retinaldehyde supplementation. Genetic knockout of Des1 (degs1) or retinaldehyde-binding protein 1b (rlbp1b) did not eliminate photopic vision in zebrafish. Our findings define molecular and temporal requirements of the nonphotopic or photopic visual cycles for mediating vision in bright light.

A primary school girl, who discovered a passion for baking during the coronavirus lockdown, has made hundreds of scones to cheer up the elderly and vulnerable.

The department today announced a comprehensive settlement agreement under the Americans with Disabilities Act (ADA) with the Beth Israel Deaconess Medical Center (BIDMC) in Brookline, Mass., to ensure access to medical facilities and services for individuals with disabilities.

San Diego mayor Kevin Faulconer joins "Squawk Alley" to discuss the process of reopening cities and keeping infections down.

I have been in love with the idea of giving a Schultüte (or German school cone) since I came across them online. Traditionally they are a big cardboard cone, prettily decorated and filled with toys, chocolate, candies, school supplies, and various other goodies. It is given to children to make … Continue reading →

Imports of Silicones in Japan increased to 1477.14 JPY Million in March from 954.56 JPY Million in February of 2020. Imports of Silicones in Japan averaged 1069.65 JPY Million from 1988 until 2020, reaching an all time high of 2251.93 JPY Million in October of 2018 and a record low of 269.68 JPY Million in February of 1991. This page includes a chart with historical data for Japan Imports of Silicones.

The supermodel, 46, looked sensational in a skin-tight pink dress and sparkling heels as she attended the Paul Gaultier Haute Couture Spring/Summer 2020 show on Wednesday.

The mystery of whether Serena Williams will mix with Andy Murray in the doubles has finally been solved, but the question of her competitiveness as an individual entity remains unanswered.

British gardening expert Mont Don shares his advice for growing coneflowers. He says the plants are great for biodiversity as they are extremely attractive to insects and butterflies.

Celebrate VE Day at home with classic teatime treats, from crunchy macaroons to succulent sausage rolls and delicate little sponges.

Cham, Switzerland : Springer, c2019.

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Dewey Library - HF5718.T43 2019

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The panelists talk to Sam Saccone about Marionette.js 2.0.

On today's episode, Charles Max Wood, Joe Eames, and Aimee Knight discuss Loading and Optimizing Web Applications with Sam Saccone and Jeff Cross. Tune in to their interesting talk, and learn how you can improve user experience and performance with better loading!

Rotch Library - DT96.M36 2019