scholarly journals Fabrication of Circadian Light Meter with Non-Periodic Optical Filters to Evaluate the Non-Visual Effects of Light on Humans

2021 ◽  
Vol 11 (18) ◽  
pp. 8283
Author(s):  
Yun Jae Eo ◽  
Seohyeon Kim ◽  
Keyong Nam Lee ◽  
Dae Hwan Kim ◽  
Changwook Kim ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Real World ◽  
Light Exposure ◽  
Action Spectrum ◽  
Optical Filters ◽  
Visual Effects ◽  
Human Circadian Rhythm ◽  
Exposure Levels ◽  
Exposure Measurements ◽  
Made In

Given that light is known to function as a zeitgeber, having the greatest influence on the human circadian rhythm, it is necessary to assess the effects of light on humans with the goal of maintaining the circadian rhythm. Herein, we fabricated a simple circadian light meter that directly measures the non-visual effects of light using optical filters that mimic the non-visual action spectrum. The fabricated light meter was calibrated and verified through the values obtained from a conventional illuminance spectrophotometer. Furthermore, during 24 h of everyday life, 11 participants wore hats equipped with the developed light meter so that we could investigate the effects of the light environment to which they were exposed to, both indoors and outdoors. For comparison, natural outdoor illumination was also measured with the same light meter. Based on the considerable difference between the light exposure levels during the daytime and nighttime, it is possible that the participant’s melatonin levels would be impacted by the light exposure measured by the light meter. Consequently, based on the light exposure measurements made in this study, the proposed circadian light meter would be a valuable tool for real world circadian lighting studies that require actual light dose to the eyes of the test subjects.

scholarly journals Systematic review of light exposure impact on human circadian rhythm

2018 ◽  
Vol 36 (2) ◽  
pp. 151-170 ◽  
Author(s):  
Leena Tähkämö ◽  
Timo Partonen ◽  
Anu-Katriina Pesonen
Keyword(s):  
Systematic Review ◽  
Circadian Rhythm ◽  
Light Exposure ◽  
Human Circadian Rhythm

Influence of the perceived size of a light source on non-visual effects in humans

2020 ◽  
Vol 9 (6) ◽  
pp. 385-393
Author(s):  
Arvid Niemeyer ◽  
Lucia Rottmair ◽  
Cornelius Neumann ◽  
Cornelius Möckel
Keyword(s):  
Working Memory ◽  
Light Exposure ◽  
Error Rates ◽  
Positive Contribution ◽  
Measurement Point ◽  
Visual Effects ◽  
Lighting Conditions ◽  
Light Measurement ◽  
And Performance ◽  
Main Effects

AbstractLight not only enables humans to perceive their surroundings, but also influences their sleep–wake cycle, mood, concentration and performance. Targeted use of these so called nonvisual effects could also have a positive contribution in automobiles by keeping passengers alert, minimizing error rates or bootsting attention in general. Since construction space in vehicle interios is scarce, this study compared the influence of differently-sized light panels and thus solid angles on nonvisual effects. In a counterbalanced order, 32 volunteers were exposed to three lighting conditions in the morning: baseline (12 lx, 2200 K), small (200 lx, 6500 K, 0.05 sr) and large (200 lx, 6500 K, 0.44 sr). During each session of 60 min, alertness, concentration and working memory were assessed before and during light exposure. After data analysis no significant main effects of light, measurement point or interaction between light and measurement point could be seen.

Application of melatonin for prevention and treatment of circadian rhythm disorders

2021 ◽  
Vol 19 (2) ◽  
pp. 34-38
Author(s):  
A. S. SAMOYLOV ◽  
◽  
N. V. RYLOVA ◽  
A. V. ZHOLINSKIY ◽  
I. V. BOLSHAKOV ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Side Effects ◽  
Light Exposure ◽  
The Body ◽  
Optimal Dosage ◽  
Vital Activity ◽  
Time Zone ◽  
Prevention And Treatment ◽  
Time Of Administration ◽  
Circadian Rhythm Disorders

The article presents data from the Russian and foreign literature of the properties of melatonin, its role in the vital activity of the body and the regulation of circadian rhythms. The features of using the drug in desynchronosis, the optimal dosage and time of administration, as well as the possibility of its use in combination with non-pharmacological treatment methods are discussed. These methods include dosed light exposure and exercise. Additionally, new studies are considered, indicating the beneficial effect of melatonin and its agonists on the immune, cardiovascular, endocrine and nervous systems. Based on the collected data, it is asserted that melatonin can significantly accelerate the process of adaptation to a new time zone without the development of side effects. Therefore, this drug is the most effective and safe treatment for desynchronosis. It is also important to note that the study of the multifaceted effects of melatonin on body functions opens up great prospects in the treatment of many diseases.

scholarly journals Evaluation of Exposure Assessment Tools under REACH: Part II—Higher Tier Tools

2018 ◽  
Vol 63 (2) ◽  
pp. 230-241 ◽  
Author(s):  
Eun Gyung Lee ◽  
Judith Lamb ◽  
Nenad Savic ◽  
Ioannis Basinas ◽  
Bojan Gasic ◽  
...  
Keyword(s):  
Exposure Assessment ◽  
Assessment Tools ◽  
Worst Case ◽  
Local Exhaust Ventilation ◽  
Limit Value ◽  
Exposure Category ◽  
Input Parameters ◽  
Full Shift ◽  
Exposure Levels ◽  
Exposure Measurements

Abstract Stoffenmanager®v4.5 and Advanced REACH Tool (ART) v1.5, two higher tier exposure assessment tools for use under REACH, were evaluated by determining accuracy and robustness. A total of 282 exposure measurements from 51 exposure situations (ESs) were collected and categorized by exposure category. In this study, only the results of liquids with vapor pressure (VP) > 10 Pa category having a sufficient number of exposure measurements (n = 251 with 42 ESs) were utilized. In addition, the results were presented by handling/activity description and input parameters for the same exposure category. It should be noted that the performance results of Stoffenmanager and ART in this study cannot be directly compared for some ESs because ART allows a combination of up to four subtasks (and nonexposed periods) to be included, whereas the database for Stoffenmanager, separately developed under the permission of the legal owner of Stoffenmanager, permits the use of only one task to predict exposure estimates. Thus, it would be most appropriate to compare full-shift measurements against ART predictions (full shift including nonexposed periods) and task-based measurements against task-based Stoffenmanager predictions. For liquids with VP > 10 Pa category, Stoffenmanager®v4.5 appeared to be reasonably accurate and robust when predicting exposures [percentage of measurements exceeding the tool’s 90th percentile estimate (%M > T) was 15%]. Areas that could potentially be improved include ESs involving the task of handling of liquids on large surfaces or large work pieces, allocation of high and medium VP inputs, and absence of local exhaust ventilation input. Although the ART’s median predictions appeared to be reasonably accurate for liquids with VP > 10 Pa, the %M > T for the 90th percentile estimates was 41%, indicating that variance in exposure levels is underestimated by ART. The %M > T using the estimates of the upper value of 90% confidence interval (CI) of the 90th percentile estimate (UCI90) was considerably reduced to 18% for liquids with VP > 10 Pa. On the basis of this observation, users might be to consider using the upper limit value of 90% CI of the 90th percentile estimate for predicting reasonable worst case situations. Nevertheless, for some activities and input parameters, ART still shows areas to be improved. Hence, it is suggested that ART developers review the assumptions in relation to exposure variability within the tool, toward improving the tool performance in estimating percentile exposure levels. In addition, for both tools, only some handling/activity descriptions and input parameters were considered. Thus, further validation studies are still necessary.

scholarly journals Effect of Ceramic Interposition and Post-activation Times on Knoop Hardness of Different Shades of Resin Cement

2018 ◽  
Vol 29 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Marina Barrêto Pereira Moreno ◽  
Ana Rosa Costa ◽  
Frederick Allen Rueggeberg ◽  
Américo Bortolazzo Correr ◽  
Mário Alexandre Coelho Sinhoreti ◽  
...  
Keyword(s):  
Light Exposure ◽  
Knoop Hardness ◽  
Resin Cement ◽  
Cross Sectional ◽  
Commercial Resin ◽  
Cure Time ◽  
Different Depths ◽  
Activation Times ◽  
Post Hoc ◽  
Made In

Abstract The aim of this study was to evaluate Knoop hardness of different shades of a resin cement light-cured directly or through ceramic discs, measured 15 min or 24 h after light exposure, and at different depths. Specimens of a commercial resin cement (Variolink Veneer) in seven shades, were fabricated in an elastomeric mold, covered with a mylar strip, a 0.7 mm thick ceramic disc (IPS e.max Press) was placed and the cement was light-activated for 20 s using a blue LED (Radii-Cal). The cured resin cement specimens were transversely wet-flattened to their middle portion and microhardness (Knoop) values were recorded at 15 min after light exposure and after deionized water storage at 37 ºC for 24 h. Five indentations were made in the cross-sectional area at 100 and 700 μm depths from the top surface. Ten specimens were made for each test conditions. Data were submitted to ANOVA split-plot design (shade, post-cure time, mode of activation and depth), followed by Tukey post hoc test (α=0.05). Significant differences for shade (p<0.0001), mode of activation (p<0.001), post-cure time (p<0.0001) and depth (p<0.0001) were detected. No significant interactions (p>0.05) were found, except for shade x post-cure time (p<0.0045) and mode of activation x post-cure time (p<0.0003). Resin cement shade has a significant effect on Knoop hardness. Indirect activation through a ceramic material reduced significantly Knoop hardness. Hardness Knoop significantly increased after 24 h in all cements shades compared to values obtained after 15 min. Resin cement depth significantly reduced Knoop hardness.

Abstract P160: Non-invasive Method to Assess Human Circadian Rhythms

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Daian Chen ◽  
S Justin Thomas ◽  
David A Calhoun ◽  
David M Pollock ◽  
Jennifer S Pollock
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Salivary Cortisol ◽  
Metabolic Diseases ◽  
Clock Genes ◽  
Light Exposure ◽  
Rna Isolation ◽  
Buccal Cells ◽  
Non Invasive ◽  
Salivary Melatonin

Circadian rhythms are controlled by an endogenous time-keeping system oscillating approximately on a 24-h cycle under constant conditions. These rhythms depend on a network of interacting genes and proteins, including transcriptional activators such as CLOCK, NPAS2, and ARNTL (BMAL1), which induce transcription of the clock genes Period ( Per1 , Per2 , and Per3 ) and Cryptochrome ( Cry1 and Cry2 ). Human salivary cortisol and melatonin follow a clear circadian rhythm as well. Disruption of the circadian rhythm and sleep-wake cycles are considered risk factors for a variety of health problems, especially hypertension and other cardiovascular and metabolic diseases. Here we put together practical methods for assessing circadian rhythms in adult subjects conducted by each individual. This method is non-invasive, inexpensive and provides a predictive profile of an individual’s circadian rhythm related to clock-controlled gene expression in buccal cells, salivary cortisol, salivary melatonin, and subject’s activity or sleep. Subjects are instructed on how to obtain buccal cells using swabs (Whatman OmniSwab) from the inside of their cheeks and collect saliva using salivettes (Sarstedt) every 4 hours starting at 6am, for 2 consecutive days. Subjects also wear actigraphy watches (Phillips Respironics) during the 2 days, to record their activity, light exposure and estimates of sleep times. To monitor adherence to correct time point collections, each subject is given an electronic vial called eCAP (Information Mediary Corp) that records the exact time the container is opened to place samples once collected. We demonstrate feasibility to extract up to 150ng/μl of RNA (Ambion RNAqueous-Micro Total RNA Isolation Kit) from buccal cells swabs. Salivary melatonin and cortisol are measured by radioimmunoassay (Buhlmann Lab) with melatonin peak levels ranging from 14 to 23 pg/ml and cortisol peak levels ranging from 10 to 24 ng/ml. We suggest that buccal cell expression of clock-controlled genes, salivary melatonin, salivary cortisol, and actigraphy data are valuable in providing reliable assessment of human circadian rhythm profiles under a variety of conditions.

Challenges in Sharing Computer and Network Logs

2010 ◽  
pp. 2310-2325
Author(s):  
Adam Slagell ◽  
Kiran Lakkaraju
Keyword(s):  
Real World ◽  
Future Research ◽  
The Past ◽  
Trade Offs ◽  
Reduce Risk ◽  
Share Information ◽  
Made In

It is desirable for many reasons to share information, particularly computer and network logs. Researchers need it for experiments, incident responders need it for collaborative security, and educators need this data for real world examples. However, the sensitive nature of this information often prevents its sharing. Anonymization techniques have been developed in recent years that help reduce risk and navigate the trade-offs between privacy, security and the need to openly share information. This chapter looks at the progress made in this area of research over the past several years, identifies the major problems left to solve and sets a roadmap for future research.

Molecular Cloning, Characterisation, Tissue Distribution, and mRNA Expression Changes under Different Light Regimes of Brain and Muscle Arnt-Like Protein-1 (BMAL1) in Columba Livia

2017 ◽  
Vol 10 (3) ◽  
pp. 156-163 ◽  
Author(s):  
Y. Wang ◽  
H.M. Yang ◽  
Y.B. Li ◽  
W. Cao
Keyword(s):  
Circadian Rhythm ◽  
Light Exposure ◽  
Columba Livia ◽  
Full Length ◽  
Day Length ◽  
Mrna Levels ◽  
Tyto Alba ◽  
Full Length Cdna ◽  
Light Regimes ◽  
Significant Difference

Brain and muscle Arnt-like protein-1 (BMAL1) plays an important role in circadian rhythm, which is involved in daily behaviours and physiological activities. However, little is known about the molecular function of BMAL1 in the Pigeon ( Columba livia). In our study, the full-length cDNA of Bmal1 was cloned and sequenced from the Pigeon for the first time, and submitted to the GenBank to obtain the accession number (KF906247). The full-length cDNA of Bmal1 consists of 2,488 nucleotides, and encodes 634 amino acids. Phylogenetic analysis showed that it bore the greatest similarity to Bmal1 from the Chicken ( Gallus gallus) and Barn Owl ( Tyto alba). The amino acid sequence of the Pigeon BMAL1 contained a HLH domain and two PAS domains, which are involved in forming hetero-homodimers with the CLOCK as the positive element of the circadian rhythm. The results of real-time quantitative PCR of Bmal1 under different light regimes showed that the amplitude and expression pattern of Bmal1 were strongly affected by day length. Bmal1 was most highly expressed in the pancreas. Relative to Bmal1 expression level under 12 h of light exposure, it was increased significantly in the pituitary gland, ovary and uterus under 15 h of light exposure ( P < 0.05). However, other tissues, including the hypothalamus, heart, liver, spleen, kidney, intestines, crureus, and pectorals exhibited no significant difference ( P < 0.05) under the two light regimes. This is the first study to investigate Bmal1 mRNA levels in various tissues under different light cycles, and thereby provide data for further study of the molecular and regulatory mechanisms of Bmal1 and circadian clock genes of the Pigeon.

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