scholarly journals Bright Light Sources

Nature ◽  
1945 ◽  
Vol 155 (3931) ◽  
pp. 265-265
Keyword(s):  
Bright Light ◽  
Light Sources

The Effect of Light on Sleep and Sleep-Related Physiological Factors Among Patients in Healthcare Facilities: A Systematic Review

2019 ◽  
Vol 12 (4) ◽  
pp. 116-141
Author(s):  
Khatereh Hadi ◽  
Jennifer R. Du Bose ◽  
Young-Seon Choi
Keyword(s):  
Light Exposure ◽  
Bright Light ◽  
Light Sources ◽  
Related Factors ◽  
Healthcare Facilities ◽  
New Findings ◽  
Healthcare Environments ◽  
The Impact ◽  
Improve Patient ◽  
Bright Light Exposure

Objectives: Lighting is one of the environmental factors which can improve patient sleep in healthcare environments. Due to the high degree of variation in study designs and results on this topic, the implications have been difficult to interpret. This review consolidates studies on the impact of bright light exposure on sleep to identify lighting conditions that can be applied and researched in future healthcare environments. Methods: We searched for peer-reviewed articles on the impact of light on sleep or sleep-related outcomes in healthcare settings. We provided detailed analysis of the direct links between light and sleep, and a more cursory analysis of links between light and sleep-related factors, from 34 articles which met our inclusion criteria. Results: The current state of the literature includes evidence on how various durations and intensities of morning, midday, and evening bright light exposure, as well as whole-day light exposure interventions can improve specific aspects of sleep. Lighting interventions differed in all attributes (illuminance levels, exposure time, exposure duration, and spectral qualities) but showed promising results in improving patients’ sleep. Conclusions: Short-term bright light exposure in the morning, up to 2 hr of moderate (3,000–10,000 lux) morning exposures, up to 4 hr of moderate evening exposure, and whole-day exposures to lower illuminance levels (<3,000 lux) can improve patient sleep outcomes. Based on new findings on the mechanism through which light impacts sleep, future studies should be more specific about the spectral qualities of light sources.

scholarly journals Refinements in Polarized Light Microscopy

1950 ◽  
Vol 27 (2) ◽  
pp. 226-237
Author(s):  
M. M. SWANN ◽  
J. M. MITCHISON
Keyword(s):  
Light Microscopy ◽  
Wave Length ◽  
Polarized Light ◽  
Bright Light ◽  
Visual Observation ◽  
Polarized Light Microscopy ◽  
Light Sources ◽  
Photographic Method ◽  
Biological Objects ◽  
Mica Plate

Various measures to increase the sensitivity of the polarizing microscope for visual observation are discussed. These include choice of polarizing apparatus, reducing condenser and objective aperture, reducing lamp iris, blooming lenses, use of mica plate compensators and use of bright light sources. By such means as these it is possible to detect retardations down to 0.28 A., or 1/20,000th of a wave-length. A photographic method for measuring retardations down to the same limit in small biological objects, is also described. We are deeply indebted to Mr E. W. Taylor of Messrs Cooke, Troughton and Simms Ltd., for his great help in fitting our microscope with double Polaroids and a graduated compensator mount, as well as for blooming our lenses and making special low retardation mica plate compensators. We are also indebted to Dr L. E. R. Picken and Dr A. F. Hallimond for helpful suggestions at various stages of the work.

A novel approach to the control of experimental environments: the ESCA microscopy data-acquisition system at ELETTRA

1998 ◽  
Vol 5 (3) ◽  
pp. 587-589 ◽  
Author(s):  
Roberto Pugliese ◽  
Luca Gregoratti ◽  
Renata Krempska ◽  
Fulvio Billè ◽  
Juray Krempasky ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Programming Languages ◽  
Bright Light ◽  
Data Acquisition System ◽  
Acquisition System ◽  
Light Sources ◽  
User Friendliness ◽  
Successful Operation ◽  
Novel Approach ◽  
Operating Environments

An efficient control system is today one of the key points for the successful operation of a beamline at third-generation synchrotron radiation sources. The high cost of these ultra-bright light sources and the limited beam time requires effective instrument handling in order to reduce any waste of measurement time. The basic requirements for such control software are reliability, user-friendliness, modularity, upgradability, as well as the capability of integrating a horde of different instruments, commercial tools and independent pre-existing systems in a possibly distributed environment. A novel approach has been adopted to implement the data-acquisition system of the ESCA microscopy beamline at ELETTRA. The system is based on YASB, a software bus, i.e. an underlying control model to coordinate information exchanges and networking software to implement that model. This `middleware' allows the developer to model applications as a set of interacting agents, i.e. independent software machines. Agents can be implemented using different programming languages and be executed on heterogeneous operating environments, which promotes an effective collaboration between software engineers and experimental physicists.

scholarly journals A bisazobenzene crosslinker that isomerizes with visible light

2012 ◽  
Vol 8 ◽  
pp. 2184-2190 ◽  
Author(s):  
Subhas Samanta ◽  
Harris I Qureshi ◽  
G Andrew Woolley
Keyword(s):  
Visible Light ◽  
Thermal Relaxation ◽  
Bright Light ◽  
Large Change ◽  
Light Sources ◽  
Functional Changes ◽  
End Distance ◽  
End To End ◽  
Azobenzene Derivatives

Background: Large conformational and functional changes of azobenzene-modified biomolecules require longer azobenzene derivatives that undergo large end-to-end distance changes upon photoisomerization. In addition, isomerization that occurs with visible rather than UV irradiation is preferred for biological applications. Results: We report the synthesis and characterization of a new crosslinker in which a central piperazine unit links two azobenzene chromophores. Molecular modeling indicates that this crosslinker can undergo a large change in end-to-end distance upon trans,trans to cis,cis isomerization. Photochemical characterization indicates that it does isomerize with visible light (violet to blue wavelengths). However, the thermal relaxation rate of this crosslinker is rather high (τ½ ~ 1 s in aqueous buffer at neutral pH) so that it is difficult to produce large fractions of the cis,cis-species without very bright light sources. Conclusion: While cis-lifetimes may be longer when the crosslinker is attached to a biomolecule, it appears the para-piperazine unit may be best suited for applications where rapid thermal relaxation is required.

scholarly journals Discomfort Glare Evaluation using DIALux Lighting Simulation software and using developed Python Program model

2018 ◽  
Vol 20 (2) ◽  
pp. 44-50
Author(s):  
Jayashri Aniket Bangali
Keyword(s):  
Bright Light ◽  
Simulation Software ◽  
Visual Sensation ◽  
Light Sources ◽  
Program Model ◽  
Conference Room ◽  
Discomfort Glare ◽  
Lighting Simulation ◽  
Disability Glare ◽  
Comparison Of The Results

Glare is a visual sensation caused by excessive brightness. It is subjective and person dependent. So, it is very difficult to measure glare factor accurately. Glare can be disabling or uncomfortable.  Disability glare is the reduction in vision caused by bright light sources and it can be increased with the age of a person. Discomfort glare is a sensation of irritation due to bright light sources. There are various methods to evaluate discomfort glare. These methods are discussed in this paper. This paper mainly focuses on two methods of discomfort glare evaluation; Unified Glare Rating (UGR) and Daylight Glare Probability (DGP). These glare factors are calculated by using DIALux lighting simulation software and by using developed program. The experimentation was carried out in two different spaces; Conference room and Optoelectronics laboratory. The values of UGR, daylight factor are calculated by using DIALux and developed program. The comparison of the results obtained is discussed at the end of this paper.

scholarly journals Gentle, fast and effective crystal soaking by acoustic dispensing

2016 ◽  
Author(s):  
Patrick M Collins ◽  
Jia Tsing Ng ◽  
Romain Talon ◽  
Karolina Nekrosiute ◽  
Tobias Krojer ◽  
...  
Keyword(s):  
High Throughput ◽  
Bright Light ◽  
Protein Crystals ◽  
Solvent Tolerance ◽  
Light Sources ◽  
X Ray Diffraction ◽  
Ligand Complex ◽  
Structure Based Drug Design ◽  
X Ray ◽  
Droplet Ejection

SynopsisA high-throughput method is described for crystal soaking using acoustic droplet ejection, and its effectiveness demonstrated. AbstractBright light sources, agile robotics, and fast detectors are continually reducing the time it takes to perform an X-ray diffraction experiment, making high throughput experiments more feasible than ever. But this is also pushing the upstream bottleneck towards sample preparation, even for robust and well characterised crystal systems. Crystal soaking is routinely used to generate protein-ligand complex structures, yet protein crystals are often sensitive to changes in solvent composition, and frequently require gentle or careful stepwise soaking techniques, limiting overall throughput. Here, we describe the use of acoustic droplet ejection for soaking of protein crystals with small molecules, and show that it is both gentle on crystals and allows very high throughput, with 1000 unique soaks easily performed in under 10 minutes. In addition to having very low compound consumption (tens of nanolitres per sample), the positional precision of acoustic droplet ejection enables targeted placement of the compound/solvent away from crystals and towards drop edges, allowing for gradual diffusion of solvent across the drop. This ensures both an improvement in reproducibility of X-ray diffraction and an increased solvent tolerance of the crystals, thus enabling higher effective compound soaking concentrations. We detail the technique here with examples from the protein target JMJD2D, a histone lysine demethylase, having roles in cancer and the focus of active structure based drug design efforts.

scholarly journals High-NOON States with High Flux of Photons Using Coherent Beam Stimulated Noncollinear Parametric Down Conversion

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Aziz Kolkiran
Keyword(s):  
Count Rate ◽  
Amplitude Ratio ◽  
Bright Light ◽  
Super Resolution ◽  
Coherent Beam ◽  
Light Sources ◽  
Coherent Light ◽  
High Count ◽  
Parametric Down Conversion ◽  
Down Conversion

We show how to reach high fidelity NOON states with a high count rate inside optical interferometers. Previously, it has been shown that by mixing squeezed and coherent light at a beam splitter, it is possible to generate NOON states of arbitrary N with a fidelity as high as 94%. The scheme is based on higher-order interference between “quantum” down-converted light and “classical” coherent light. However, this requires optimizing the amplitude ratio of classical to quantum light, thereby limiting the overall count rate for the interferometric super-resolution signal. We propose using coherent beam stimulated noncollinear two-mode down-converted light as input to the interferometer. Our scheme is based on the stimulation of noncollinear parametric down conversion by coherent light sources. We get a better flexibility of choosing the amplitude ratio in generating NOON states. This enables super-resolution intensity exceeding the previous scheme by many orders of magnitude. Therefore, we hope to improve the magnitude of N-fold super-resolution in quantum interferometry for arbitrary N using bright light sources. We give improved results for N = 4 and 5.

scholarly journals Evaluation of Postmortem Inspection Procedures to Diagnose Bovine Tuberculosis at Debre Birhan Municipal Abattoir

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2620
Author(s):  
Fanos Tadesse Woldemariyam ◽  
Tibebeu Markos ◽  
Dereje Shegu ◽  
Kassa Demissie Abdi ◽  
Jan Paeshuyse
Keyword(s):  
Lymph Nodes ◽  
Bovine Tuberculosis ◽  
Body Condition Score ◽  
Bright Light ◽  
Cross Sectional Study ◽  
Meat Inspection ◽  
Light Sources ◽  
Efficacy Evaluation ◽  
Cross Sectional ◽  
Debre Birhan

Routine meat inspection in the abattoir was used to examine carcass for subsequent approval for consumption. However, the chance of missing lesions results in approval of carcass and/or the offal with lesions of tuberculosis. A cross-sectional study was conducted at Debre Birhan Municipal abattoir from October 2016 to May 2017. Lesion prevalence estimation and two meat inspection procedures’ efficacy evaluation was attempted. The breeds of the animals inspected were zebu breeds. Routine abattoir meat inspection involves visual inspection, palpation and incision of intact organs such as the liver and kidneys, as well as inspection, palpation and incision of tracheobronchial, mediastinal and prescapular lymph nodes. The detailed meat inspection involves inspection of each of the carcass. In this case, the seven lobes of the two lungs, lymph nodes and organs were also thoroughly examined. The cut surfaces were examined under bright light sources for the presence of an abscess, cheesy mass, and tubercles in detail. The study involved and compared both routine and detailed meat inspections at the abattoir. Chi-square test of independence and odds ratio were used to see the association of lesion and different risk factors. Based on detailed meat inspection, the overall lesion prevalence of bovine tuberculosis in the carcass of cattle slaughtered at Debre Birhan municipality abattoir was found to be 4.7% but only 0.5% of the carcass examined had detectable bovine tuberculosis lesions when routine abattoir meat inspection alone was used. The majority of the lesions were distributed to the lungs and associated lymph nodes. There was a significant association (p < 0.05) in TB infection rate and body condition score. In conclusion, this study has clearly indicated the prevalence of bovine tuberculosis lesions in the abattoir that are missed by routine abattoir meat inspection. In addition, it showed low sensitivity of the routine meat inspection procedure used. Hence, our study warrants immediate attention to strengthen the current meat inspection practices at Debre Birhan public abattoir.

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