keyword
MENU ▼
Read by QxMD icon Read
search

Light at night

keyword
https://www.readbyqxmd.com/read/28731695/how-rhodopsin-tunes-the-equilibrium-between-protonated-and-deprotonated-forms-of-the-retinal-chromophore
#1
Siri Camee van Keulen, Alicia Solano, Ursula Rothlisberger
Rhodopsin is a photoactive G-protein-coupled receptor (GPCR) that converts dim light into a signal for the brain, leading to eyesight. Full activation of this GPCR is achieved after passing through several steps of the protein's photoactivation pathway. Key events of rhodopsin activation are the initial cis-trans photoisomerisation of the covalently bound retinal moiety followed by conformational rearrangements and deprotonation of the chromophore's protonated Schiff base (PSB), which ultimately lead to full activation in the meta II state...
July 21, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28729868/the-c4-model-grass-setaria-is-a-short-day-plant-with-secondary-long-day-genetic-regulation
#2
Andrew N Doust, Margarita Mauro-Herrera, John G Hodge, Jessica Stromski
The effect of photoperiod (day:night ratio) on flowering time was investigated in the wild species, Setaria viridis, and in a set of recombinant inbred lines (RILs) derived from a cross between foxtail millet (S. italica) and its wild ancestor green foxtail (S. viridis). Photoperiods totaled 24 h, with three trials of 8:16, 12:12 and 16:8 light:dark hour regimes for the RIL population, and these plus 10:14 and 14:10 for the experiments with S. viridis alone. The response of S. viridis to light intensity as well as photoperiod was assessed by duplicating photoperiods at two light intensities (300 and 600 μmol...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28724450/variation-in-species-composition-and-infection-rates-of-anopheles-mosquitoes-at-different-altitudinal-transects-and-the-risk-of-malaria-in-the-highland-of-dirashe-woreda-south-ethiopia
#3
Taye Yohannes Daygena, Fekadu Massebo, Bernt Lindtjørn
BACKGROUND: The transmission of malaria is heterogeneous, and varies due to altitude. The information on whether the transmission of malaria is indigenous or imported to highland areas is scarce. Therefore, this study aimed to assess the species composition and infection rates of Anopheles at different altitudinal transects, and the risk of malaria if any in the highland of Dirashe Woreda, South Ethiopia. METHODS: This study was conducted in Gato (low altitude; average elevation of 1273 m), Onota (mid-altitude; average elevation of 1707 m) and Layignaw-Arguba (high altitude; average elevation of 2337 m) from August 2015 to April 2016...
July 19, 2017: Parasites & Vectors
https://www.readbyqxmd.com/read/28724246/health-consequences-of-electric-lighting-practices-in-the-modern-world-a-report-on-the-national-toxicology-program-s-workshop-on-shift-work-at-night-artificial-light-at-night-and-circadian-disruption
#4
REVIEW
Ruth M Lunn, David E Blask, Andrew N Coogan, Mariana G Figueiro, Michael R Gorman, Janet E Hall, Johnni Hansen, Randy J Nelson, Satchidananda Panda, Michael H Smolensky, Richard G Stevens, Fred W Turek, Roel Vermeulen, Tania Carreón, Claire C Caruso, Christina C Lawson, Kristina A Thayer, Michael J Twery, Andrew D Ewens, Sanford C Garner, Pamela J Schwingl, Windy A Boyd
The invention of electric light has facilitated a society in which people work, sleep, eat, and play at all hours of the 24-hour day. Although electric light clearly has benefited humankind, exposures to electric light, especially light at night (LAN), may disrupt sleep and biological processes controlled by endogenous circadian clocks, potentially resulting in adverse health outcomes. Many of the studies evaluating adverse health effects have been conducted among night- and rotating-shift workers, because this scenario gives rise to significant exposure to LAN...
July 15, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28721487/influence-of-light-intensity-and-spectral-composition-of-artificial-light-at-night-on-melatonin-rhythm-and-mrna-expression-of-gonadotropins-in-roach-rutilus-rutilus
#5
Anika Brüning, Franz Hölker, Steffen Franke, Wibke Kleiner, Werner Kloas
In this study we investigated the influence of artificial light at night (ALAN) of different intensities (0, 1, 10, 100 lx) and different colours (blue, green, red) on the daily melatonin rhythm and mRNA expression of gonadotropins in roach Rutilus rutilus, a ubiquitous cyprinid, which occur in standing and moderately flowing freshwater habitats of central Europe. Melatonin concentrations were significantly lowered under nocturnal white light already at 1 lx. Low intensity blue, green and red ALAN lowered the melatonin levels significantly in comparison to a dark control...
July 18, 2017: Fish Physiology and Biochemistry
https://www.readbyqxmd.com/read/28715957/the-transduction-cascade-in-retinal-on-bipolar-cells-signal-processing-and-disease
#6
Kirill A Martemyanov, Alapakkam P Sampath
Our robust visual experience is based on the reliable transfer of information from our photoreceptor cells, the rods and cones, to higher brain centers. At the very first synapse of the visual system, information is split into two separate pathways, ON and OFF, which encode increments and decrements in light intensity, respectively. The importance of this segregation is borne out in the fact that receptive fields in higher visual centers maintain a separation between ON and OFF regions. In the past decade, the molecular mechanisms underlying the generation of ON signals have been identified, which is unique in its use of a G-protein signaling cascade...
July 17, 2017: Annual Review of Vision Science
https://www.readbyqxmd.com/read/28709906/effects-of-feeding-time-on-daily-rhythms-of-neuropeptide-and-clock-gene-expression-in-the-rat-hypothalamus
#7
Dawei Wang, Anne-Loes Opperhuizen, Jane Reznick, Nigel Turner, Yan Su, Gregory J Cooney, Andries Kalsbeek
Shiftworkers are exposed to several adverse health conditions, one being eating at night. Food consumption at an unnatural time-of-day is thought to be one of the main factors responsible for the increased risk of developing metabolic diseases, such as obesity and diabetes mellitus. The underlying mechanism is considered to include disruption of the circadian organization of physiology, leading to disruption of metabolism. When food is consumed at night, the hypothalamus, a brain region central to homeostasis, receives contradicting input from the central clock and the systemic circulation...
July 11, 2017: Brain Research
https://www.readbyqxmd.com/read/28701782/haeme-oxygenase-protects-against-uv-light-dna-damages-in-the-retina-in-clock-dependent-manner
#8
Milena Damulewicz, Agnieszka Loboda, Alicja Jozkowicz, Jozef Dulak, Elzbieta Pyza
In the present study, we showed that in the retina of Drosophila, the expression of the ho gene, encoding haeme oxygenase (HO), is regulated by light but only at the beginning of the day. This timing must be set by the circadian clock as light pulses applied at other time points during the day do not increase the ho mRNA level. Moreover, light-induced activation of HO does not depend on the canonical phototransduction pathway but instead involves cryptochrome and is enhanced by ultraviolet (UV) light. Interestingly, the level of DNA damage in the retina after UV exposure was inversely related to the circadian oscillation of the ho mRNA level during the night, being the highest when the HO level was low and reversed during the day...
July 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28701566/chronotype-variation-drives-night-time-sentinel-like-behaviour-in-hunter-gatherers
#9
David R Samson, Alyssa N Crittenden, Ibrahim A Mabulla, Audax Z P Mabulla, Charles L Nunn
Sleep is essential for survival, yet it also represents a time of extreme vulnerability to predation, hostile conspecifics and environmental dangers. To reduce the risks of sleeping, the sentinel hypothesis proposes that group-living animals share the task of vigilance during sleep, with some individuals sleeping while others are awake. To investigate sentinel-like behaviour in sleeping humans, we investigated activity patterns at night among Hadza hunter-gatherers of Tanzania. Using actigraphy, we discovered that all subjects were simultaneously scored as asleep for only 18 min in total over 20 days of observation, with a median of eight individuals awake throughout the night-time period; thus, one or more individuals was awake (or in light stages of sleep) during 99...
July 12, 2017: Proceedings. Biological Sciences
https://www.readbyqxmd.com/read/28698388/delayed-cryptochrome-degradation-asymmetrically-alters-the-daily-rhythm-in-suprachiasmatic-clock-neuron-excitability
#10
Sven Wegner, Mino D C Belle, Alun T L Hughes, Casey O Diekman, Hugh D Piggins
Suprachiasmatic nuclei (SCN) neurons contain an intracellular molecular circadian clock and the Cryptochromes (CRY1/2), key transcriptional repressors of this molecular apparatus, are subject to post-translational modification through ubiquitination and targeting for proteosomal degradation by the ubiquitin E3 ligase complex. Loss-of-function point mutations in a component of this ligase complex, Fbxl3, delay CRY1/2 degradation, reduce circadian rhythm strength, and lengthen the circadian period by ∼2.5h...
July 11, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28695706/seasonal-associations-with-urban-light-pollution-for-nocturnally-migrating-bird-populations
#11
Frank A La Sorte, Daniel Fink, Jeffrey J Buler, Andrew Farnsworth, Sergio A Cabrera-Cruz
The spatial extent and intensity of artificial light at night (ALAN) has increased worldwide through the growth of urban environments. There is evidence that nocturnally migrating birds are attracted to ALAN, and there is evidence that nocturnally migrating bird populations are more likely to occur in urban areas during migration, especially in the autumn. Here, we test if urban sources of ALAN are responsible, at least in part, for these observed urban associations. We use weekly estimates of diurnal occurrence and relative abundance for 40 nocturnally migrating bird species that breed in forested environments in North America to assess how associations with distance to urban areas and ALAN are defined across the annual cycle...
July 11, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28690558/blue-enriched-white-light-enhances-physiological-arousal-but-not-behavioral-performance-during-simulated-driving-at-early-night
#12
Beatriz Rodríguez-Morilla, Juan A Madrid, Enrique Molina, Angel Correa
Vigilance usually deteriorates over prolonged driving at non-optimal times of day. Exposure to blue-enriched light has shown to enhance arousal, leading to behavioral benefits in some cognitive tasks. However, the cognitive effects of long-wavelength light have been less studied and its effects on driving performance remained to be addressed. We tested the effects of a blue-enriched white light (BWL) and a long-wavelength orange light (OL) vs. a control condition of dim light on subjective, physiological and behavioral measures at 21:45 h...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/28682785/artificial-light-at-night-a-novel-lifestyle-risk-factor-for-metabolic-disorder-and-cancer-morbidity
#13
REVIEW
Abed E Zubidat, Abraham Haim
Both obesity and breast cancer are already recognized worldwide as the most common syndromes in our modern society. Currently, there is accumulating evidence from epidemiological and experimental studies suggesting that these syndromes are closely associated with circadian disruption. It has been suggested that melatonin (MLT) and the circadian clock genes both play an important role in the development of these syndromes. However, we still poorly understand the molecular mechanism underlying the association between circadian disruption and the modern health syndromes...
July 26, 2017: Journal of Basic and Clinical Physiology and Pharmacology
https://www.readbyqxmd.com/read/28676764/bed-rest-and-hypoxic-exposure-affect-sleep-architecture-and-breathing-stability
#14
Shawnda A Morrison, Dani Mirnik, Spela Korsic, Ola Eiken, Igor B Mekjavic, Leja Dolenc-Groselj
Objective: Despite over 50 years of research on the physiological effects of sustained bed rest, data characterizing its effects on sleep macrostructure and breathing stability in humans are scarce. This study was conducted to determine the effects of continuous exposure to hypoxia and sustained best rest, both individually and combined, on nocturnal sleep and breathing stability. Methods: Eleven participants completed three randomized, counter-balanced, 21-days trials of: (1) normoxic bed rest (NBR, PIO2 = 133...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28671403/refractive-eye-surgery-helping-patients-make-informed-decisions-about-lasik
#15
John M Wilkinson, Elizabeth W Cozine, Amir R Kahn
A variety of refractive surgery techniques, which reshape the corneal stroma using laser energy, have been marketed as simple and safe alternatives to glasses or contact lenses. Laser-assisted in-situ keratomileusis (LASIK) is the most common of these procedures. Although there are few high-quality prospective studies of long-term outcomes, complications, or stability for refractive surgery procedures, there is at least general agreement that more than 90% of appropriately selected patients achieve excellent uncorrected distance vision...
May 15, 2017: American Family Physician
https://www.readbyqxmd.com/read/28668621/circadian-disruption-affects-initial-learning-but-not-cognitive-flexibility-in-an-automated-set-shifting-task-in-adult-long-evans-rats
#16
Audrey L Robertson, Rekha C Balachandran, Megan M Mahoney, Paul A Eubig
A sizeable percent of adults are subject to circadian disturbances such as shift work, which involves misalignment of time of light exposure, activity periods, sleep, and eating. Chronic adherence to disruptive circadian schedules can negatively impact cognitive functioning. Developing preclinical models of circadian disruption allow investigation of the relationship and underlying mechanisms between circadian disruption and cognitive functioning. We placed adult Long-Evans rats of both sexes on a 12:12h light:dark schedule in which rats performed an automated operant-behavior task for 3months, with daily testing occurring either 4h after lights-on or lights-off...
June 29, 2017: Physiology & Behavior
https://www.readbyqxmd.com/read/28656675/attenuation-of-short-wavelengths-alters-sleep-and-the-iprgc-pupil-response
#17
Lisa A Ostrin, Kaleb S Abbott, Hope M Queener
PURPOSE: Exposure to increasing amounts of artificial light during the night may contribute to the high prevalence of reported sleep dysfunction. Release of the sleep hormone melatonin is mediated by the intrinsically photosensitive retinal ganglion cells (ipRGCs). This study sought to investigate whether melatonin level and sleep quality can be modulated by decreasing night-time input to the ipRGCs. METHODS: Subjects (ages 17-42, n = 21) wore short wavelength-blocking glasses prior to bedtime for 2 weeks...
July 2017: Ophthalmic & Physiological Optics: the Journal of the British College of Ophthalmic Opticians (Optometrists)
https://www.readbyqxmd.com/read/28653429/paederus-dermatitis-outbreak-in-luanda-city-angola
#18
D A De Luca, Z Maianski, M Averbukh
Paederus dermatitis (PD), dermatitis linearis or "ferro em brasa" is an inflammatory skin reaction against pederin, a vesicant non-proteinaceous toxin present in the hemolymph of Paederus spp. The beetle distributes along tropical and subtropical climates; it inhabits crop fields (rice), marshes and riverbanks to avoid desiccation. Paederus is more active during the earliest hours after sunset and it is attracted by artificial lights, so humans are usually exposed at night in urban and suburban areas. This article is protected by copyright...
June 27, 2017: Journal of the European Academy of Dermatology and Venereology: JEADV
https://www.readbyqxmd.com/read/28644985/depressive-like-behavior-is-elevated-among-offspring-of-parents-exposed-to-dim-light-at-night-prior-to-mating
#19
Yasmine M Cissé, Kathryn L G Russart, Randy J Nelson
Rates of major depressive disorder (MDD) have steadily increased over the past 50 years. Many factors have been implicated in the etiology of depressive disorders and environmental influences are being increasingly recognized. The increase in depression rates has coincided with increased artificial nighttime lighting. Exposure to light at night (LAN) has been associated with increased depressive-like behavior in rodents and decreased mood in humans. However, relatively little is known on the multigenerational effects of dLAN on affect...
June 12, 2017: Psychoneuroendocrinology
https://www.readbyqxmd.com/read/28644828/a-mutant-of-chlamydomonas-without-lhcsr-maintains-high-rates-of-photosynthesis-but-has-reduced-cell-division-rates-in-sinusoidal-light-conditions
#20
Michael Cantrell, Graham Peers
The LHCSR protein belongs to the light harvesting complex family of pigment-binding proteins found in oxygenic photoautotrophs. Previous studies have shown that this complex is required for the rapid induction and relaxation of excess light energy dissipation in a wide range of eukaryotic algae and moss. The ability of cells to rapidly regulate light harvesting between this dissipation state and one favoring photochemistry is believed to be important for reducing oxidative stress and maintaining high photosynthetic efficiency in a rapidly changing light environment...
2017: PloS One
keyword
keyword
111098
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"