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Night vision

William N Grimes, Adree Songco-Aguas, Fred Rieke
We know a good deal about the operation of the retina when either rod or cone photoreceptors provide the dominant input (i.e., under very dim or very bright conditions). However, we know much less about how the retina operates when rods and cones are coactive (i.e., under intermediate lighting conditions, such as dusk). Such mesopic conditions span 20-30% of the light levels over which vision operates and encompass many situations in which vision is essential (e.g., driving at night). These lighting conditions are challenging because rod and cone signals differ substantially: Rod responses are nearing saturation, while cone responses are weak and noisy...
June 8, 2018: Annual Review of Vision Science
Qianping Zhang, Opeyemi J Olatunji, Hongxia Chen, Adesola J Tola, Omolara O Oluwaniyi
Cordyceps cicadae is a medicinal fungus used in treating night sweat, childhood convulsions, vision improvement and pain. This study was designed to evaluate the anti-diabetic activity of the crude polysaccharide (SHF) from the mycelium and body portion of C. cicadae. Diabetes mellitus was induced in the rat with a single intravenous injection of alloxan monohydrate (150 mg/kg). In other to evaluate the anti-diabetic effects of C. cicadae polysaccharide in alloxan-induced diabetic rats, the crude polysaccharide (SHF at 100, 200 and 400 mg/kg body weight) and glibenclamide were administered orally to diabetic rats for 30 days...
June 6, 2018: Chemistry & Biodiversity
Christina Zeitz, Cécile Méjécase, Mathilde Stévenard, Christelle Michiels, Isabelle Audo, Michael F Marmor
Autosomal dominant congenital stationary night blindness (adCSNB) is rare and results from altered phototransduction giving a Riggs type of electroretinogram (ERG) with loss of the rod a-wave and small b-waves. These patients usually have normal vision in light. Only few mutations in genes coding for proteins of the phototransduction cascade lead to this condition; most of these gene defects cause progressive rod-cone dystrophy. Mutation analysis of an adCSNB family with a Riggs-type ERG revealed a novel variant (c...
2018: BioMed Research International
Heather E Wright Beatty, Andrew J Law, J Russell Thomas, Viresh Wickramasinghe
INTRODUCTION: Rotary wing pilot neck strain is increasing in prevalence due to the combined effects of head supported mass (e.g., Night Vision Goggles, head mounted displays) and whole-body vibration. This study examined the physiological responses of pilots during exposure to whole-body vibration (WBV) representative of the National Research Council's Bell 412 helicopter in forward flight. WBV levels were measured and evaluated using the ISO-2631-1-1997 WBV standards. METHODS: Twelve pilots (aged 20-59 yr, 7 of the 12 with 20+ years flight experience) underwent six 15-min vibration trials on a human rated shaker platform...
June 1, 2018: Aerospace Medicine and Human Performance
Manoj Motwani
Purpose: The aim of this article was to demonstrate how WaveLight Contoura and wavefront optimization (WFO) can be used together to treat high myopia/myopic astigmatism corrections. Materials and methods: A retrospective analysis was conducted on 24 consecutive myopic/myopic astigmatism eyes that exceeded the Contoura labeling of -8.00 with -3.00 D of astigmatism. Residual correction after Contoura with Layer Yolked Reduction of Astigmatism protocol was treated with WFO Contoura LASIK correction...
2018: Clinical Ophthalmology
Xuan Cui, Ruben Jauregui, Karen Sophia Park, Stephen H Tsang
PURPOSE: Gyrate atrophy (GA) is a rare chorioretinal degeneration that results in the deterioration of night and peripheral vision, eventually leading to blindness. The disorder is caused by mutations in the gene encoding ornithine aminotransferase (OAT), causing increased levels of plasma ornithine. Treatment revolves around lowering plasma ornithine levels, with vitamin B6 supplementation being the preferred treatment. Nevertheless, most patients do not respond to this therapy. Here, we report a rare case of vitamin B6-responsive GA caused by a novel mutation in OAT and characterize the presentation with multimodal imaging...
May 14, 2018: Ophthalmic Genetics
Ali Hassoun, Neha Mehrotra
A 52-year-old white diabetic male with 4-weeks history of persistent cough followed by headache, drenching night sweats, low-grade fever, worsening photophobia, nausea and vomiting was presented. Examination was significant for photophobia and diminution of vision. His spinal fluid and blood cultures were positive for Cryptococcus neoformans Intravenous fluconazole were given for 2 weeks followed by oral fluconazole. There was significant improvement in systemic and ocular symptoms. HIV serology was negative, but his CD4 counts were low with inverted CD4:CD8 ratio...
May 12, 2018: BMJ Case Reports
Anett Karl, Silke Agte, Astrid Zayas-Santiago, Felix N Makarov, Yomarie Rivera, Jan Benedikt, Mike Francke, Andreas Reichenbach, Serguei N Skatchkov, Andreas Bringmann
It has been shown that mammalian retinal glial (Müller) cells act as living optical fibers that guide the light through the retinal tissue to the photoreceptor cells (Agte et al., 2011; Franze et al., 2007). However, for nonmammalian species it is unclear whether Müller cells also improve the transretinal light transmission. Furthermore, for nonmammalian species there is a lack of ultrastructural data of the retinal cells, which, in general, delivers fundamental information of the retinal function, i.e. the vision of the species...
May 10, 2018: Experimental Eye Research
Matteo Santon, Pierre-Paul Bitton, Ulrike K Harant, Nico K Michiels
Ocular reflectors enhance eye sensitivity in dim light, but can produce reflected eyeshine when illuminated. Some fish can occlude their reflectors during the day. The opposite is observed in cryptic sit-and-wait predators such as scorpionfish and toadfish, where reflectors are occluded at night and exposed during the day. This results in daytime eyeshine, proposed to enhance pupil camouflage by reducing the contrast between the otherwise dark pupil and the surrounding tissue. In this study, we test this hypothesis in the scorpionfish Scorpaena porcus and show that eyeshine is the result of two mechanisms: the previously described Stratum Argenteum Reflected (SAR) eyeshine, and Pigment Epithelium Transmitted (PET) eyeshine, a newly described mechanism for this species...
May 9, 2018: Scientific Reports
Glenn P Lobo, Gayle Pauer, Joshua H Lipschutz, Stephanie A Hagstrom
Vitamin A/retinol (ROL) and its metabolites (retinoids) play critical roles in eye development and photoreception. Short-term dietary vitamin A deficiency (VAD) manifests clinically as night blindness, while prolonged VAD is known to cause retinal pigment epithelium (RPE) and photoreceptor degeneration. Therefore, sustained uptake of dietary vitamin A, for ocular retinoid production, is essential for photoreceptor health and visual function. The mechanisms influencing the uptake, storage, and supply of dietary vitamin A, for ocular retinoid production, however, are not fully understood...
2018: Advances in Experimental Medicine and Biology
Ayako Furukawa, Kayo Sugitani, Yoshiki Koriyama
Retinal degenerative diseases, such as retinitis pigmentosa, are characterized by night blindness and peripheral vision loss caused by the slowly progressive loss of photoreceptor cells. A comprehensive molecular mechanism of the photoreceptor cell death remains unclear. We previously reported that heat shock protein 70 (HSP70), which has a protective effect on neuronal cells, was cleaved by a calcium-dependent protease, calpain, in N-methyl-N-nitrosourea (MNU)-treated mice retina. Carbonylated HSP70 is much more vulnerable than noncarbonylated HSP70 to calpain cleavage...
2018: Advances in Experimental Medicine and Biology
Yuko Hayashi, Gen Miura, Akiyuki Uzawa, Takayuki Baba, Shuichi Yamamoto
BACKGROUND: To present our findings in a case of convulsive seizures and loss of consciousness that developed during recording electroretinograms (ERG). CASE PRESENTATION: A 34-year-old man had reduced vision in his left eye for about 15 years, and night blindness for about two years. His visual acuity was 20/15 in the right eye and 20/50 in the left eye. The fundus was normal but the sensitivity in the macular region of the left eye was decreased. Optical coherence tomography (OCT) showed partial loss of the interdigitation zone...
April 25, 2018: BMC Neurology
Kristina Teär Fahnehjelm, Monica Olsson, Enping Chen, Jürg Hengstler, Karin Naess, Jacek Winiarski
AIM: This prospective study assessed the long-term ocular and visual outcomes of children with mucopolysaccharidoses type I Hurler syndrome (MPS IH) who were treated with haematopoietic stem cell transplants (HSCT). METHODS: Clinical ophthalmological assessments were performed on eight patients at the St Erik Eye Hospital, Huddinge, Stockholm, Sweden, from 2001-2018: The median age at diagnosis and HSCT were 12.2 (range 5.0-16.4) and 16.7 (8.0-20.4) months. The last eye examination was at a median of 13...
April 23, 2018: Acta Paediatrica
Xuechao Yu, Peng Yu, Di Wu, Bahadur Singh, Qingsheng Zeng, Hsin Lin, Wu Zhou, Junhao Lin, Kazu Suenaga, Zheng Liu, Qi Jie Wang
The interest in mid-infrared technologies surrounds plenty of important optoelectronic applications ranging from optical communications, biomedical imaging to night vision cameras, and so on. Although narrow bandgap semiconductors, such as Mercury Cadmium Telluride and Indium Antimonide, and quantum superlattices based on inter-subband transitions in wide bandgap semiconductors, have been employed for mid-infrared applications, it remains a daunting challenge to search for other materials that possess suitable bandgaps in this wavelength range...
April 18, 2018: Nature Communications
Li Zhang, Jun Ding, Hanyu Zheng, Sensong An, Hongtao Lin, Bowen Zheng, Qingyang Du, Gufan Yin, Jerome Michon, Yifei Zhang, Zhuoran Fang, Mikhail Y Shalaginov, Longjiang Deng, Tian Gu, Hualiang Zhang, Juejun Hu
The mid-infrared (mid-IR) is a strategically important band for numerous applications ranging from night vision to biochemical sensing. Here we theoretically analyzed and experimentally realized a Huygens metasurface platform capable of fulfilling a diverse cross-section of optical functions in the mid-IR. The meta-optical elements were constructed using high-index chalcogenide films deposited on fluoride substrates: the choices of wide-band transparent materials allow the design to be scaled across a broad infrared spectrum...
April 16, 2018: Nature Communications
Attila Aydin, S Bilge, M Eryilmaz
INTRODUCTION: Cannulation for the administration of intravenous fluids is integral to the prehospital management of injured military patients. However, this may be technically challenging to undertake during night-time conditions where the use of light to aid cannulation may give the tactical situation away to opponents. The aim of this study was to investigate the success and tactical safety of venepuncture under battlefield conditions with different colour light sources. METHOD: The procedure was carried out with naked eye in a bright room in the absence of a separate light source, with a naked eye in a dark room under red, white, blue and green light sources and under an infrared light source while wearing night vision goggles (NVGs)...
April 6, 2018: Journal of the Royal Army Medical Corps
Yan-Jun Liu, Shuo Yan, Zhong-Jian Shen, Zhen Li, Xin-Fang Zhang, Xiao-Ming Liu, Qing-Wen Zhang, Xiao-Xia Liu
Phototaxis in nocturnal moths is widely utilized to control pest populations in practical production. However, as an elusive behavior, phototactic behavior is still not well understood. Determination of whether the opsin gene plays a key role in phototaxis is an interesting topic. This study was conducted to analyze expression levels and biological importance of three opsin genes (Se-uv, Se-bl, and Se-lw) and phototactic behavior of Spodoptera exigua. The three opsin genes exhibited higher expression levels during daytime, excluding Se-bl in females, whose expression tended to increase at night...
May 2018: Insect Biochemistry and Molecular Biology
Sasha M Woods, Edward Mountjoy, Duncan Muir, Sarah E Ross, Denize Atan
In the mammalian retina, rods and a specialised rod-driven signalling pathway mediate visual responses under scotopic (dim light) conditions. As rods primarily signal to rod bipolar cells (RBCs) under scoptic conditions, disorders that affect rod or RBC function are often associated with impaired night vision. To identify novel genes expressed by RBCs and, therefore, likely to be involved in night vision, we took advantage of the adult Bhlhe23-/- mouse retina (that lacks RBCs) to derive the RBC transcriptome...
April 3, 2018: Scientific Reports
Airam Rodríguez, Ross Holmberg, Peter Dann, André Chiaradia
Wildlife watching is an emerging ecotourism activity around the world. In Australia and New Zealand, night viewing of little penguins attracts hundreds of thousands of visitors per year. As penguins start coming ashore after sunset, artificial lighting is essential to allow visitors to view them in the dark. This alteration of the nightscape warrants investigation for any potential effects of artificial lighting on penguin behavior. We experimentally tested how penguins respond to different light wavelengths (colors) and intensities to examine effects on the colony attendance behavior at two sites on Phillip Island, Australia...
March 30, 2018: Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology
Renee M Borges
The night is a special niche characterized by dim light, lower temperatures, and higher humidity compared to the day. Several animals have made the transition from the day into the night and have acquired unique adaptations to cope with the challenges of performing nocturnal activities. Several plant species have opted to bloom at night, possibly as a response to aridity to prevent excessive water loss through evapotranspiration since flowering is often a water-demanding process, or to protect pollen from heat stress...
March 2018: Yale Journal of Biology and Medicine
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