scholarly journals Relationship between pupillary size, brightness, and photoreceptor responses for unrelated self‐luminous stimuli at low photopic light levels

2020 ◽  
Vol 45 (6) ◽  
pp. 977-991
Author(s):  
Claudia Sandoval Salinas ◽  
Stijn Hermans ◽  
José Sandoval ◽  
Kevin A. G. Smet ◽  
Peter Hanselaer ◽  
...  
Keyword(s):  
Light Levels ◽  
Pupillary Size

Senior Living - Lighting, Circadian Rhythm and Dementia I

2019 ◽  
pp. 4-8
Author(s):  
Tadej Glažar ◽  
Marjeta Zupancic ◽  
Samo Kralj ◽  
Robert Peternelj
Keyword(s):  
The Elderly ◽  
Living Environment ◽  
Elderly Persons ◽  
Light Spectrum ◽  
Average Life Expectancy ◽  
The Real Estate ◽  
Lighting Conditions ◽  
Light Levels ◽  
Joint Fracture ◽  
Lease Contracts

The Real Estate Fund of Pension and Disability Insurance (Nepremicninski Sklad) in Slovenia, founded in1997 is the owner of 3255 properties in 116 locations throughout the country and is intended for solving housing issues of pensioners of 65 years or older and other elderly persons who are allowed independently to live. The lease contracts are concluded for an indefinite period of time. The aim and vision of the Fund is to improve the quality of life for the elderly tenants by adapting the living environment, the flats and surroundings according to the physical needs of aging tenants. Homes for seniors often have low light levels and poor light spectrum caused by fluorescent or incandescent lighting. Demographic changes in most European countries show rising average life expectancy which means that the number of people with weak visual capacity or visual impairment is increasing. Equally the risks of injuries due to poor lighting conditions are increasing, e.g. missing a step resulting in a hip joint fracture. Better lighting conditions are of critical importance for aging population, as stated also in the recently published CIE227:2017. To facilitate safe environment for the elderly, the Fund in 2013 initiated a lighting research study that should provide facts and evidence for a lighting standard for their own premises.

Change of color appearance due to extremely high light level: corresponding colors under 100 and 3000 cd/m2

2019 ◽  
Vol 2019 (1) ◽  
pp. 320-325 ◽  
Author(s):  
Wenyu Bao ◽  
Minchen Wei
Keyword(s):  
Light Level ◽  
Limited Range ◽  
High Light ◽  
Color Preference ◽  
Color Appearance ◽  
Appearance Model ◽  
Color Matching ◽  
Light Levels ◽  
Appearance Models ◽  
Psychophysical Study

Great efforts have been made to develop color appearance models to predict color appearance of stimuli under various viewing conditions. CIECAM02, the most widely used color appearance model, and many other color appearance models were all developed based on corresponding color datasets, including LUTCHI data. Though the effect of adapting light level on color appearance, which is known as "Hunt Effect", is well known, most of the corresponding color datasets were collected within a limited range of light levels (i.e., below 700 cd/m2), which was much lower than that under daylight. A recent study investigating color preference of an artwork under various light levels from 20 to 15000 lx suggested that the existing color appearance models may not accurately characterize the color appearance of stimuli under extremely high light levels, based on the assumption that the same preference judgements were due to the same color appearance. This article reports a psychophysical study, which was designed to directly collect corresponding colors under two light levels— 100 and 3000 cd/m2 (i.e., ≈ 314 and 9420 lx). Human observers completed haploscopic color matching for four color stimuli (i.e., red, green, blue, and yellow) under the two light levels at 2700 or 6500 K. Though the Hunt Effect was supported by the results, CIECAM02 was found to have large errors under the extremely high light levels, especially when the CCT was low.

Features of sanitary and hygienic characteristics of silvinite complexes

2020 ◽  
pp. 57-62
Author(s):  
E. Ryazanova ◽  
V. Barannikov ◽  
V. Khokhryakova ◽  
L. Kirichenko ◽  
S. Selivanova
Keyword(s):  
Video Camera ◽  
Treatment Center ◽  
Internal Environment ◽  
Radiation Background ◽  
Medical Environment ◽  
Light Levels ◽  
Salt Complex ◽  
Radio Equipment ◽  
Environment Noise ◽  
Medical University

Currently, medical technologies based on natural factors are widely used in practical health care, including the effect of the medicinal properties of the mineral silvinite (natural potassium salts of the Verkhnekamsk Deposit) on the patient’s body. However, there is no regulatory framework for sanitary control of such devices. The aim of the study was to develop methodological approaches to the hygienic assessment of silvinite complexes. The analysis of the current regulations used in carrying out hygienic supervision and preventive measures in the salt structures that are part of the silvinite complexes is carried out. Based on long-term hygienic studies of silvinite structures by the salt treatment Center of Perm medical University. academician E. A. Wagner together with LLC NPK «Medical climate» (Tchaikovsky) developed and implemented sanitary and hygienic requirements for the created salt complexes. It is a complex of structural divisions, including the place of stay and treatment of patients, as well as the salt device. All units must meet the requirements of current sanitary rules and regulations. It is necessary to conduct a thorough survey of the location of the future salt complex. Optimal conditions of the internal environment in silvinite structures are determined by a special air preparation system consisting of air conditioning and cleaning of the external air using a filter-saturator. The special hygienic requirements of the sylvinite furniture in the room, the decoration of walls, ceilings and floors. The room must be equipped with radio equipment and a video camera for monitoring patients. Full expanded hygienic control of the parameters of the medical environment of silvinite premises should be carried out at least once a year according to the following indicators: microclimate parameters, content of multicomponent fine salt aerosol, aeroionic composition of the air environment, radiation background, microbial contamination of the internal environment, noise and light levels. Thus, increasing the use of salt therapy requires further research to improve the sanitary and hygienic control of silvinite complexes.

Birds in the Dark: Complementary and Partial Information

2017 ◽  
Author(s):  
Graham R. Martin
Keyword(s):  
Annual Cycle ◽  
Colour Vision ◽  
Partial Information ◽  
Night Time ◽  
Light Levels ◽  
Night Feeding ◽  
Nocturnal Species ◽  
Length Changes

Night-time poses exacting problems for vision, resolution inevitably falls and colour vision is not possible as light levels decrease to those of natural night time. Furthermore, light levels are highly variable depending upon whether there is moonlight, and night length changes dramatically in the annual cycle according to latitude. Few birds exploit the resources available at night. Those that do rely upon information received from vision complemented by information from other senses (hearing, olfaction, and touch), and upon highly specialized and restricted behaviours. However, many birds occasionally exploit night-time, e.g. during migration, arriving and departing from nests, and occasional night feeding. Some seabirds dive to such depths that they experience night-time light levels when foraging. Truly nocturnal species such as owls, kiwi, and oilbirds are highly sedentary, and this is essential to allow them to interpret correctly the partial information that is available to them.

scholarly journals Thioredoxin-dependent control balances the metabolic activities of tetrapyrrole biosynthesis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Daniel Wittmann ◽  
Neha Sinha ◽  
Bernhard Grimm
Keyword(s):  
Environmental Changes ◽  
Nuclear Gene ◽  
Tetrapyrrole Biosynthesis ◽  
Nuclear Gene Expression ◽  
Light Levels ◽  
Organ Specific ◽  
Intracellular Compartments ◽  
The Face ◽  
Metabolic Activities ◽  
The Impact

AbstractPlastids are specialized organelles found in plants, which are endowed with their own genomes, and differ in many respects from the intracellular compartments of organisms belonging to other kingdoms of life. They differentiate into diverse, plant organ-specific variants, and are perhaps the most versatile organelles known. Chloroplasts are the green plastids in the leaves and stems of plants, whose primary function is photosynthesis. In response to environmental changes, chloroplasts use several mechanisms to coordinate their photosynthetic activities with nuclear gene expression and other metabolic pathways. Here, we focus on a redox-based regulatory network composed of thioredoxins (TRX) and TRX-like proteins. Among multiple redox-controlled metabolic activities in chloroplasts, tetrapyrrole biosynthesis is particularly rich in TRX-dependent enzymes. This review summarizes the effects of plastid-localized reductants on several enzymes of this pathway, which have been shown to undergo dithiol-disulfide transitions. We describe the impact of TRX-dependent control on the activity, stability and interactions of these enzymes, and assess its contribution to the provision of adequate supplies of metabolic intermediates in the face of diurnal and more rapid and transient changes in light levels and other environmental factors.

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