The Transcription Factor BcLTF1 Regulates Virulence and Light Responses in the Necrotrophic Plant Pathogen Botrytis cinerea

PubMed Central

Schumacher, Julia; Simon, Adeline; Cohrs, Kim Christopher; Viaud, Muriel; Tudzynski, Paul

2014-01-01

Botrytis cinerea is the causal agent of gray mold diseases in a range of dicotyledonous plant species. The fungus can reproduce asexually by forming macroconidia for dispersal and sclerotia for survival; the latter also participate in sexual reproduction by bearing the apothecia after fertilization by microconidia. Light induces the differentiation of conidia and apothecia, while sclerotia are exclusively formed in the absence of light. The relevance of light for virulence of the fungus is not obvious, but infections are observed under natural illumination as well as in constant darkness. By a random mutagenesis approach, we identified a novel virulence-related gene encoding a GATA transcription factor (BcLTF1 for light-responsive TF1) with characterized homologues in Aspergillus nidulans (NsdD) and Neurospora crassa (SUB-1). By deletion and over-expression of bcltf1, we confirmed the predicted role of the transcription factor in virulence, and discovered furthermore its functions in regulation of light-dependent differentiation, the equilibrium between production and scavenging of reactive oxygen species (ROS), and secondary metabolism. Microarray analyses revealed 293 light-responsive genes, and that the expression levels of the majority of these genes (66%) are modulated by BcLTF1. In addition, the deletion of bcltf1 affects the expression of 1,539 genes irrespective of the light conditions, including the overexpression of known and so far uncharacterized secondary metabolism-related genes. Increased expression of genes encoding alternative respiration enzymes, such as the alternative oxidase (AOX), suggest a mitochondrial dysfunction in the absence of bcltf1. The hypersensitivity of Δbctlf1 mutants to exogenously applied oxidative stress - even in the absence of light - and the restoration of virulence and growth rates in continuous light by antioxidants, indicate that BcLTF1 is required to cope with oxidative stress that is caused either by exposure to light

78 FR 61390 - Philips Lighting, Including Workers Whose Wages Were Paid Under Philips Lightolier, Genlyte Group...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-03

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-82,244] Philips Lighting, Including Workers Whose Wages Were Paid Under Philips Lightolier, Genlyte Group, and Genlyte Thomas Group LLC, and Including On-Site Leased Workers From Adecco, Wilmington, Massachusetts; Amended Certification Regarding Eligibility To Apply for Worker...

Members of the Dof transcription factor family in Triticum aestivum are associated with light-mediated gene regulation.

PubMed

Shaw, Lindsay M; McIntyre, C Lynne; Gresshoff, Peter M; Xue, Gang-Ping

2009-11-01

DNA binding with One Finger (Dof) protein is a plant-specific transcription factor implicated in the regulation of many important plant-specific processes, including photosynthesis and carbohydrate metabolism. This study has identified 31 Dof genes (TaDof) in bread wheat through extensive analysis of current nucleotide databases. Phylogenetic analysis suggests that the TaDof family can be divided into four clades. Expression analysis of the TaDof family across all major organs using quantitative RT-PCR and searches of the wheat genome array database revealed that the majority of TaDof members were predominately expressed in vegetative organs. A large number of TaDof members were down-regulated by drought and/or were responsive to the light and dark cycle. Further expression analysis revealed that light up-regulated TaDof members were highly correlated in expression with a number of genes that are involved in photosynthesis or sucrose transport. These data suggest that the TaDof family may have an important role in light-mediated gene regulation, including involvement in the photosynthetic process.

Effective light absorption and its enhancement factor for silicon nanowire-based solar cell.

PubMed

Duan, Zhiqiang; Li, Meicheng; Mwenya, Trevor; Fu, Pengfei; Li, Yingfeng; Song, Dandan

2016-01-01

Although nanowire (NW) antireflection coating can enhance light trapping capability, which is generally used in crystal silicon (CS) based solar cells, whether it can improve light absorption in the CS body depends on the NW geometrical shape and their geometrical parameters. In order to conveniently compare with the bare silicon, two enhancement factors E(T) and E(A) are defined and introduced to quantitatively evaluate the efficient light trapping capability of NW antireflective layer and the effective light absorption capability of CS body. Five different shapes (cylindrical, truncated conical, convex conical, conical, and concave conical) of silicon NW arrays arranged in a square are studied, and the theoretical results indicate that excellent light trapping does not mean more light can be absorbed in the CS body. The convex conical NW has the best light trapping, but the concave conical NW has the best effective light absorption. Furthermore, if the cross section of silicon NW is changed into a square, both light trapping and effective light absorption are enhanced, and the Eiffel Tower shaped NW arrays have optimal effective light absorption.

Productive Recognition of Factor IX by Factor XIa Exosites Requires Disulfide Linkage between Heavy and Light Chains of Factor XIa*

PubMed Central

Marcinkiewicz, Mariola M.; Sinha, Dipali; Walsh, Peter N.

2012-01-01

In the intrinsic pathway of blood coagulation factor XIa (FXIa) activates factor IX (FIX) by cleaving the zymogen at Arg145-Ala146 and Arg180-Val181 bonds releasing an 11-kDa activation peptide. FXIa and its isolated light chain (FXIa-LC) cleave S-2366 at comparable rates, but FXIa-LC is a very poor activator of FIX, possibly because FIX undergoes allosteric modification on binding to an exosite on the heavy chain of FXIa (FXIa-HC) required for optimal cleavage rates of the two scissile bonds of FIX. However preincubation of FIX with a saturating concentration of isolated FXIa-HC did not result in any potentiation in the rate of FIX cleavage by FXIa-LC. Furthermore, if FIX binding via the heavy chain exosite of FXIa determines the affinity of the enzyme-substrate interaction, then the isolated FXIa-HC should inhibit the rate of FIX activation by depleting the substrate. However, whereas FXIa/S557A inhibited FIX activation of by FXIa, FXIa-HC did not. Therefore, we examined FIX binding to FXIa/S557A, FXIa-HC, FXIa-LC, FXIa/C362S/C482S, and FXIa/S557A/C362S/C482S. The heavy and light chains are disulfide-linked in FXIa/S557A but not in FXIa/C362S/C482S and FXIa/S557A/C362S/C482S. In an ELISA assay only FXI/S557A ligated FIX with high affinity. Partial reduction of FXIa/S557A to produce heavy and light chains resulted in decreased FIX binding, and this function was regained upon reformation of the disulfide linkage between the heavy and the light chains. We therefore conclude that substrate recognition by the FXIa exosite(s) requires disulfide-linked heavy and light chains. PMID:22207756

Determination of eye safety filter protection factors associated with retinal thermal hazard and blue light photochemical hazard for intense pulsed light sources.

PubMed

Clarkson, D McG

2006-02-21

An assessment is provided of protection factors afforded for retinal thermal hazard and blue light photochemical hazard for a range of filters used with intense pulsed light sources (IPLs). A characteristic IPL spectrum based on black body radiation at 5000 K with a low cut filter at 515 nm was identified as suitable for such estimations. Specific filters assessed included types with idealized transmission properties and also a range of types whose transmission characteristics were measured by means of a Bentham DMc150 spectroradiometer. Predicted behaviour based on these spectra is outlined which describes both the effectiveness of protection and the level of luminous transmittance afforded. The analysis showed it was possible to describe a figure of merit for a particular filter material relating the degree of protection provided and corresponding value of luminous transmittance. This consideration is important for providing users of IPL equipment with safety eyewear with adequate level of visual transmittance.

Integration of light and circadian signals that regulate chloroplast transcription by a nuclear-encoded sigma factor.

PubMed

Belbin, Fiona E; Noordally, Zeenat B; Wetherill, Sarah J; Atkins, Kelly A; Franklin, Keara A; Dodd, Antony N

2017-01-01

We investigated the signalling pathways that regulate chloroplast transcription in response to environmental signals. One mechanism controlling plastid transcription involves nuclear-encoded sigma subunits of plastid-encoded plastid RNA polymerase. Transcripts encoding the sigma factor SIG5 are regulated by light and the circadian clock. However, the extent to which a chloroplast target of SIG5 is regulated by light-induced changes in SIG5 expression is unknown. Moreover, the photoreceptor signalling pathways underlying the circadian regulation of chloroplast transcription by SIG5 are unidentified. We monitored the regulation of chloroplast transcription in photoreceptor and sigma factor mutants under controlled light regimes in Arabidopsis thaliana. We established that a chloroplast transcriptional response to light intensity was mediated by SIG5; a chloroplast transcriptional response to the relative proportions of red and far red light was regulated by SIG5 through phytochrome and photosynthetic signals; and the circadian regulation of chloroplast transcription by SIG5 was predominantly dependent on blue light and cryptochrome. Our experiments reveal the extensive integration of signals concerning the light environment by a single sigma factor to regulate chloroplast transcription. This may originate from an evolutionarily ancient mechanism that protects photosynthetic bacteria from high light stress, which subsequently became integrated with higher plant phototransduction networks. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Budget-Minded Renovation Lights Up Students' Learning.

ERIC Educational Resources Information Center

McDaniel, Craig

1998-01-01

Provides considerations for educational facility lighting designs that support student learning while controlling costs. Lighting design decision factors include the types of classroom activities involved, the importance of properly using artificial and indirect lighting, the importance of color rendering, the positioning of windows and skylights,…

Light extraction block with curved surface

DOEpatents

Levermore, Peter; Krall, Emory; Silvernail, Jeffrey; Rajan, Kamala; Brown, Julia J.

2016-03-22

Light extraction blocks, and OLED lighting panels using light extraction blocks, are described, in which the light extraction blocks include various curved shapes that provide improved light extraction properties compared to parallel emissive surface, and a thinner form factor and better light extraction than a hemisphere. Lighting systems described herein may include a light source with an OLED panel. A light extraction block with a three-dimensional light emitting surface may be optically coupled to the light source. The three-dimensional light emitting surface of the block may includes a substantially curved surface, with further characteristics related to the curvature of the surface at given points. A first radius of curvature corresponding to a maximum principal curvature k.sub.1 at a point p on the substantially curved surface may be greater than a maximum height of the light extraction block. A maximum height of the light extraction block may be less than 50% of a maximum width of the light extraction block. Surfaces with cross sections made up of line segments and inflection points may also be fit to approximated curves for calculating the radius of curvature.

Uveal melanoma in relation to ultraviolet light exposure and host factors.

PubMed

Holly, E A; Aston, D A; Char, D H; Kristiansen, J J; Ahn, D K

1990-09-15

We conducted a case-control interview study among 1277 subjects (407 patients, 870 controls selected by using random digit dial) in 11 western United States to determine whether uveal melanoma and cutaneous melanoma shared common risk factors. After adjustment for other factors, the risk of uveal melanoma was increased for those with green, gray, or hazel eyes [relative risk (RR) = 2.5, P less than 0.001] or blue eyes (RR = 2.2, P less than 0.001) when compared to brown. A tendency to sunburn after 0.5 h midday summer sun exposure increased risk for uveal melanoma (burn with tanning RR = 1.5, P = 0.02; burn with little tanning RR = 1.8, P less than 0.001; burn with no tanning RR = 1.7, P = 0.002); as did exposure to UV or black lights (RR = 3.7, P = 0.003); and welding burn, sunburn of the eye, or snow blindness (RR = 7.2, P less than 0.001). An association with uveal melanoma was also noted with an increasing number of large nevi (P = 0.04 for trend), although the individual risk estimates were not remarkable. These data suggest that host factors and exposure to UV light are risk factors for uveal melanoma.

NOTE: Determination of eye safety filter protection factors associated with retinal thermal hazard and blue light photochemical hazard for intense pulsed light sources

NASA Astrophysics Data System (ADS)

McG Clarkson, D.

2006-02-01

An assessment is provided of protection factors afforded for retinal thermal hazard and blue light photochemical hazard for a range of filters used with intense pulsed light sources (IPLs). A characteristic IPL spectrum based on black body radiation at 5000 K with a low cut filter at 515 nm was identified as suitable for such estimations. Specific filters assessed included types with idealized transmission properties and also a range of types whose transmission characteristics were measured by means of a Bentham DMc150 spectroradiometer. Predicted behaviour based on these spectra is outlined which describes both the effectiveness of protection and the level of luminous transmittance afforded. The analysis showed it was possible to describe a figure of merit for a particular filter material relating the degree of protection provided and corresponding value of luminous transmittance. This consideration is important for providing users of IPL equipment with safety eyewear with adequate level of visual transmittance.

Renormalization group analysis of B →π form factors with B -meson light-cone sum rules

NASA Astrophysics Data System (ADS)

Shen, Yue-Long; Wei, Yan-Bing; Lü, Cai-Dian

2018-03-01

Within the framework of the B -meson light-cone sum rules, we review the calculation of radiative corrections to the three B →π transition form factors at leading power in Λ /mb. To resum large logarithmic terms, we perform the complete renormalization group evolution of the correlation function. We employ the integral transformation which diagonalizes evolution equations of the jet function and the B -meson light-cone distribution amplitude to solve these evolution equations and obtain renormalization group improved sum rules for the B →π form factors. Results of the form factors are extrapolated to the whole physical q2 region and are compared with that of other approaches. The effect of B -meson three-particle light-cone distribution amplitudes, which will contribute to the form factors at next-to-leading power in Λ /mb at tree level, is not considered in this paper.

Vehicle, driver and atmospheric factors in light-duty vehicle particle number emissions.

DOT National Transportation Integrated Search

2014-06-01

Made possible by the collection of on-board tailpipe emissions data, this research identifies road : and driver factors that are associated with a relatively understudied tailpipe pollutant from light-duty vehicles: ultrafine particle number emission...

Influence of the chopped frequency of light on optical transport characteristics of human skin including at acupuncture points

NASA Astrophysics Data System (ADS)

Yang, Hong-qin; Xie, Shu-sen; Liu, Song-hao; Li, Hui; Wang, Yu-hua; Guo, Zhou-yi

2007-11-01

An experimental protocol was established for noninvasively measuring the optical transport characteristics of skin tissue along human meridian direction over body surface including at acupuncture points. The diffuse remittance for 658 nm light radiation along the pericardium meridian and non-meridian directions were measured respectively. The influence of the chopped frequency of light on the detected light signal was investigated. It is shown that the optical transport characteristics of skin tissue accords with the Beer's exponential attenuation law along the meridian including at acupuncture points and non-median directions. However there is an obvious difference between the propagations along the meridian direction and non-meridian direction (P<0.05). Furthermore, the chopped frequency can affect the detected signal. The diffuse remittance signal decreased with the chopped frequency's increase and it was different between the meridian and non-meridian directions. These findings are important and meaningful for interpreting the human meridian phenomena by biomedical optics.

Redefining White Light Chromaticity Boundaries for Aviation

DOT National Transportation Integrated Search

2009-10-05

Several aspects are involved in the recognition of an aviation signal light's color, including its chromaticity, layout on the airfield, and the chromaticity of other light sources in view. The LRC conducted a human factors investigation of the bound...

Genome-wide regulation of light-controlled seedling morphogenesis by three families of transcription factors.

PubMed

Shi, Hui; Lyu, Mohan; Luo, Yiwen; Liu, Shoucheng; Li, Yue; He, Hang; Wei, Ning; Deng, Xing Wang; Zhong, Shangwei

2018-06-19

Three families of transcription factors have been reported to play key roles in light control of Arabidopsis seedling morphogenesis. Among them, bHLH protein PIFs and plant-specific protein EIN3/EIN3-LIKE 1 (EIN3/EIL1) accumulate in the dark to maintain skotomorphogenesis. On the other hand, HY5 and HY5 HOMOLOG (HYH), two related bZIP proteins, are stabilized in light and promote photomorphogenic development. To systemically investigate the transcriptional regulation of light-controlled seedling morphogenesis, we generated HY5 ox/ pifQein3eil1 , which contained mutations of EIN3/EIL1 and four PIF genes ( pifQein3eil1 ) and overexpression of HY5 Our results show that dark-grown HY5 ox/ pifQein3eil1 seedlings display a photomorphogenesis highly similar to that of wild-type seedlings grown in continuous light, with remarkably enhanced photomorphogenic phenotypes compared with the pifQ mutants. Consistent with the genetic evidence, transcriptome analysis indicated that PIFs, EIN3/EIL1, and HY5 are dominant transcription factors in collectively mediating a wide range of light-caused genome-wide transcriptional changes. Moreover, PIFs and EIN3/EIL1 independently control the expression of light-regulated genes such as HLS1 to cooperatively regulate apical hook formation, hypocotyl elongation, and cotyledon opening and expansion. This study illustrates a comprehensive regulatory network of transcription activities that correspond to specific morphological aspects in seedling skotomorphogenesis and photomorphogenesis.

A light- and calcium-gated transcription factor for imaging and manipulating activated neurons

PubMed Central

Wang, W.; Wildes, C. P.; Pattarabanjird, T.; Sanchez, M. I.; Glober, G.F.; Matthews, G. A.; Tye, K. M.; Ting, A. Y

2017-01-01

Activity remodels neurons, altering their molecular, structural, and electrical characteristics. To enable the selective characterization and manipulation of these neurons, we present FLARE, an engineered transcription factor that drives expression of fluorescent proteins, opsins, and other genetically-encoded tools only in the subset of neurons that experienced activity during a user-defined time window. FLARE senses the coincidence of elevated cytosolic calcium and externally-applied blue light, which together produce translocation of a membrane-anchored transcription factor to the nucleus to drive expression of any transgene. In cultured rat neurons, FLARE gives a light-to-dark signal ratio of 120 and a high-to-low calcium signal ratio of 10 after 10 minutes of stimulation. Channelrhodopsin expression permitted functional manipulation of FLARE-marked neurons. In adult mice, FLARE also gave light- and motor activity-dependent transcription in the cortex. Due to its modular design, minute-scale temporal resolution, and minimal dark-state leak, FLARE should be useful for the study of activity-dependent processes in neurons and other cells that signal with calcium. PMID:28650461

A light- and calcium-gated transcription factor for imaging and manipulating activated neurons.

PubMed

Wang, Wenjing; Wildes, Craig P; Pattarabanjird, Tanyaporn; Sanchez, Mateo I; Glober, Gordon F; Matthews, Gillian A; Tye, Kay M; Ting, Alice Y

2017-09-01

Activity remodels neurons, altering their molecular, structural, and electrical characteristics. To enable the selective characterization and manipulation of these neurons, we present FLARE, an engineered transcription factor that drives expression of fluorescent proteins, opsins, and other genetically encoded tools only in the subset of neurons that experienced activity during a user-defined time window. FLARE senses the coincidence of elevated cytosolic calcium and externally applied blue light, which together produce translocation of a membrane-anchored transcription factor to the nucleus to drive expression of any transgene. In cultured rat neurons, FLARE gives a light-to-dark signal ratio of 120 and a high- to low-calcium signal ratio of 10 after 10 min of stimulation. Opsin expression permitted functional manipulation of FLARE-marked neurons. In adult mice, FLARE also gave light- and motor-activity-dependent transcription in the cortex. Due to its modular design, minute-scale temporal resolution, and minimal dark-state leak, FLARE should be useful for the study of activity-dependent processes in neurons and other cells that signal with calcium.

Characterization of the interaction between the heavy and light chains of bovine factor Va.

PubMed

Walker, F J

1992-10-05

Bovine factor Va has been previously been shown to consist of heavy (M(r) = 94,000) and light chains (M(r) = 81,000), that interact in a manner dependent upon the presence of either calcium or manganese ions. In an attempt to understand the mechanism of subunit interaction we have studied the effects of temperature and ions on factor Va stability. The rates of formation of factor Va from isolated chains and dissociation were temperature-dependent with an energy of activation of 6.2 and 1.3 kcal mol-1, respectively. The yield of factor Va from isolated chains was inversely related to the amount of time the chains were incubated at 4 degrees C. Incubation of individual chains revealed that the heavy chain is cold-labile, an effect that is reversible. Manganese ion was observed to prevent the conversion to the inactive form. High salt tends to stabilize the two-chain structure of factor Va, but is inhibitory to its formation from isolated chains. High concentrations of either manganese or calcium ions also inhibited reconstitution of activity. The light chain, in particular, was sensitive to the presence of manganese or calcium ion. Heavy chain that had been cleaved by activated protein C had a weakened interaction with the light chain, and the resulting complex had no procoagulant activity. Cooling of the heavy chain to 4 degrees C enhanced its intrinsic fluorescence. Manganese ion prevented some of this enhancement. The heavy chain fluorescence returned to the room temperature value with a half-life of approximately 10 min. In the presence of manganese ion relaxation was accelerated. The intrinsic fluorescence of activated protein C-cleaved heavy chain was not increased when the temperature was decreased. These data suggest that the heavy chain can exist in two forms. Elevated temperature converts it to a form that can bind ions and have a productive interaction with the light chain. However, conditions that prevent the heavy chain from combining with the light

Simultaneous inactivation of sigma factors B and D interferes with light acclimation of the cyanobacterium Synechocystis sp. strain PCC 6803.

PubMed

Pollari, Maija; Ruotsalainen, Virpi; Rantamäki, Susanne; Tyystjärvi, Esa; Tyystjärvi, Taina

2009-06-01

In cyanobacteria, gene expression is regulated mainly at the level of transcription initiation, which is mediated by the RNA polymerase holoenzyme. The RNA polymerase core is catalytically active, while the sigma factor recognizes promoter sequences. Group 2 sigma factors are similar to the principal sigma factor but are nonessential. Group 2 sigma factors SigB and SigD are structurally the most similar sigma factors in Synechocystis sp. strain PCC 6803. Under standard growth conditions, simultaneous inactivation of sigB and sigD genes did not affect the growth, but the photosynthesis and growth of the DeltasigBD strain were slower than in the control strain at double light intensity. Light-saturated electron transfer rates and the fluorescence and thermoluminescence measurements showed that photosynthetic light reactions are fully functional in the DeltasigBD strain, but absorption and 77 K emission spectra measurements suggest that the light-harvesting system of the DeltasigBD strain does not acclimate normally to higher light intensity. Furthermore, the DeltasigBD strain is more sensitive to photoinhibition under bright light because impaired upregulation of psbA genes leads to insufficient PSII repair.

Risk Factors for Breast Cancer, Including Occupational Exposures

PubMed Central

Meo, Margrethe; Vainio, Harri

2011-01-01

The knowledge on the etiology of breast cancer has advanced substantially in recent years, and several etiological factors are now firmly established. However, very few new discoveries have been made in relation to occupational risk factors. The International Agency for Research on Cancer has evaluated over 900 different exposures or agents to-date to determine whether they are carcinogenic to humans. These evaluations are published as a series of Monographs (www.iarc.fr). For breast cancer the following substances have been classified as "carcinogenic to humans" (Group 1): alcoholic beverages, exposure to diethylstilbestrol, estrogen-progestogen contraceptives, estrogen-progestogen hormone replacement therapy and exposure to X-radiation and gamma-radiation (in special populations such as atomic bomb survivors, medical patients, and in-utero exposure). Ethylene oxide is also classified as a Group 1 carcinogen, although the evidence for carcinogenicity in epidemiologic studies, and specifically for the human breast, is limited. The classification "probably carcinogenic to humans" (Group 2A) includes estrogen hormone replacement therapy, tobacco smoking, and shift work involving circadian disruption, including work as a flight attendant. If the association between shift work and breast cancer, the most common female cancer, is confirmed, shift work could become the leading cause of occupational cancer in women. PMID:22953181

Improving poor fill factors for solar cells via light-induced plating

NASA Astrophysics Data System (ADS)

Zhao, Xing; Rui, Jia; Wuchang, Ding; Yanlong, Meng; Zhi, Jin; Xinyu, Liu

2012-09-01

Silicon solar cells are prepared following the conventional fabrication processes, except for the metallization firing process. The cells are divided into two groups with higher and lower fill factors, respectively. After light-induced plating (LIP), the fill factors of the solar cells in both groups with different initial values reach the same level. Scanning electron microscope (SEM) images are taken under the bulk silver electrodes, which prove that the improvement for cells with a poor factor after LIP should benefit from sufficient exploitation of the high density silver crystals formed during the firing process. Moreover, the application of LIP to cells with poor electrode contact performance, such as nanowire cells and radial junction solar cells, is proposed.

Form factors and generalized parton distributions in basis light-front quantization

NASA Astrophysics Data System (ADS)

Adhikari, Lekha; Li, Yang; Zhao, Xingbo; Maris, Pieter; Vary, James P.; El-Hady, Alaa Abd

2016-05-01

We calculate the elastic form factors and the generalized parton distributions (GPDs) for four low-lying bound states of a demonstration fermion-antifermion system, strong-coupling positronium (e e ¯ ), using basis light-front quantization (BLFQ). By using this approach, we also calculate the impact-parameter-dependent GPDs q (x ,b⃗⊥) to visualize the fermion density in the transverse plane (b⃗⊥). We compare selected results with corresponding quantities in the nonrelativistic limit to reveal relativistic effects. Our results establish the foundation within BLFQ for investigating the form factors and the GPDs for hadronic systems.

75 FR 11918 - General Electric Kentucky Glass Plant, Lighting, LLC, Including On-Site Leased Workers From the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-12

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-72,011] General Electric Kentucky Glass Plant, Lighting, LLC, Including On-Site Leased Workers From the Patty Tipton Company, Aetna Building Maintenance, and Concentra, Lexington, KY; Amended Certification Regarding Eligibility To Apply for Worker Adjustment Assistance In accordanc...

Arabidopsis CRY2 and ZTL mediate blue-light regulation of the transcription factor CIB1 by distinct mechanisms

PubMed Central

Liu, Hongtao; Wang, Qin; Liu, Yawen; Zhao, Xiaoying; Imaizumi, Takato; Somers, David E.; Tobin, Elaine M.; Lin, Chentao

2013-01-01

Plants possess multiple photoreceptors to mediate light regulation of growth and development, but it is not well understood how different photoreceptors coordinate their actions to jointly regulate developmental responses, such as flowering time. In Arabidopsis, the photoexcited cryptochrome 2 interacts with the transcription factor CRYPTOCHROME-INTERACTING basic helix–loop–helix 1 (CIB1) to activate transcription and floral initiation. We show that the CIB1 protein expression is regulated by blue light; CIB1 is highly expressed in plants exposed to blue light, but levels of the CIB1 protein decreases in the absence of blue light. We demonstrate that CIB1 is degraded by the 26S proteasome and that blue light suppresses CIB1 degradation. Surprisingly, although cryptochrome 2 physically interacts with CIB1 in response to blue light, it is not the photoreceptor mediating blue-light suppression of CIB1 degradation. Instead, two of the three light–oxygen–voltage (LOV)-domain photoreceptors, ZEITLUPE and LOV KELCH PROTEIN 2, but not FLAVIN-BINDING KELCH REPEAT 1, are required for the function and blue-light suppression of degradation of CIB1. These results support the hypothesis that the evolutionarily unrelated blue-light receptors, cryptochrome and LOV-domain F-box proteins, mediate blue-light regulation of the same transcription factor by distinct mechanisms. PMID:24101505

Temperature trumps light: Teasing apart interactive factors controlling non-indigenous Zostera japonica growth

EPA Science Inventory

In the Pacific Northwest Zostera marina and Z. japonica co-exist by occupying separate elevation niches. We conducted two mesocosm experiments to evaluate light and temperature as factors controlling the disjunct distribution of congeners. The first study tests the hypothesis t...

Subset of heat-shock transcription factors required for the early response of Arabidopsis to excess light

PubMed Central

Jung, Hou-Sung; Crisp, Peter A.; Estavillo, Gonzalo M.; Cole, Benjamin; Hong, Fangxin; Mockler, Todd C.; Pogson, Barry J.; Chory, Joanne

2013-01-01

Sunlight provides energy for photosynthesis and is essential for nearly all life on earth. However, too much or too little light or rapidly fluctuating light conditions cause stress to plants. Rapid changes in the amount of light are perceived as a change in the reduced/oxidized (redox) state of photosynthetic electron transport components in chloroplasts. However, how this generates a signal that is relayed to changes in nuclear gene expression is not well understood. We modified redox state in the reference plant, Arabidopsis thaliana, using either excess light or low light plus the herbicide DBMIB (2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone), a well-known inhibitor of photosynthetic electron transport. Modification of redox state caused a change in expression of a common set of about 750 genes, many of which are known stress-responsive genes. Among the most highly enriched promoter elements in the induced gene set were heat-shock elements (HSEs), known motifs that change gene expression in response to high temperature in many systems. We show that HSEs from the promoter of the ASCORBATE PEROXIDASE 2 (APX2) gene were necessary and sufficient for APX2 expression in conditions of excess light, or under low light plus the herbicide. We tested APX2 expression phenotypes in overexpression and loss-of-function mutants of 15 Arabidopsis A-type heat-shock transcription factors (HSFs), and identified HSFA1D, HSFA2, and HSFA3 as key factors regulating APX2 expression in diverse stress conditions. Excess light regulates both the subcellular location of HSFA1D and its biochemical properties, making it a key early component of the excess light stress network of plants. PMID:23918368

Surgical lights. Making a purchase decision.

PubMed

Gregory, M M

1987-11-01

Based on the preceding factors, a profile can be made for each light. The profile should include the following information: product literature with detailed information about the light, the average score from each of the six categories on the questionnaire, a summary of positive and negative comments from the questionnaire (recurring comments can identify significant factors), recommendations from other hospitals using the light, warranty and service information and any pertinent information about the vendor and manufacturer, information or comments from the clinical engineer, the purchasing agent, and the architect/engineer, and information about possible purchase agreements. Once the profiles of the lights are finished, present them to the OR committee or group charged with making the final decision. The information will enable the group to compare the lights and will serve as a basis for either the final purchase or a detailed bid specification. If cost is a major factor in the decision, the evaluation results can be used to justify purchasing lights that are more expensive but that the users believe are clearly superior. This constitutes the "professional justification" that some government institutions require to circumvent regulations that require buying the low-bid product. Although the result of this selection process is clearly a subjective decision, it is an informed subjective decision. Once the lights are installed, the staff members' satisfaction with the lights will not be based on objective criteria but on the same subjective opinions that were used to justify the selection.

Coordinated regulation of Arabidopsis microRNA biogenesis and red light signaling through Dicer-like 1 and phytochrome-interacting factor 4

PubMed Central

Sun, Zhenfei; Li, Min; Zhou, Ying; Guo, Tongtong; Liu, Yin; Zhang, Hui

2018-01-01

Light and microRNAs (miRNAs) are key external and internal signals for plant development, respectively. However, the relationship between the light signaling and miRNA biogenesis pathways remains unknown. Here we found that miRNA processer proteins DCL1 and HYL1 interact with a basic helix-loop-helix (bHLH) transcription factor, phytochrome-interacting factor 4 (PIF4), which mediates the destabilization of DCL1 during dark-to-red-light transition. PIF4 acts as a transcription factor for some miRNA genes and is necessary for the proper accumulation of miRNAs. DCL1, HYL1, and mature miRNAs play roles in the regulation of plant hypocotyl growth. These results uncovered a previously unknown crosstalk between miRNA biogenesis and red light signaling through the PIF4-dependent regulation of miRNA transcription and processing to affect red-light-directed plant photomorphogenesis. PMID:29522510

Enlightening Butterfly Conservation Efforts: The Importance of Natural Lighting for Butterfly Behavioral Ecology and Conservation

PubMed Central

2018-01-01

Light is arguably the most important abiotic factor for living organisms. Organisms evolved under specific lighting conditions and their behavior, physiology, and ecology are inexorably linked to light. Understanding light effects on biology could not be more important as present anthropogenic effects are greatly changing the light environments in which animals exist. The two biggest anthropogenic contributors changing light environments are: (1) anthropogenic lighting at night (i.e., light pollution); and (2) deforestation and the built environment. I highlight light importance for butterfly behavior, physiology, and ecology and stress the importance of including light as a conservation factor for conserving butterfly biodiversity. This review focuses on four parts: (1) Introducing the nature and extent of light. (2) Visual and non-visual light reception in butterflies. (3) Implications of unnatural lighting for butterflies across several different behavioral and ecological contexts. (4). Future directions for quantifying the threat of unnatural lighting on butterflies and simple approaches to mitigate unnatural light impacts on butterflies. I urge future research to include light as a factor and end with the hopeful thought that controlling many unnatural light conditions is simply done by flipping a switch. PMID:29439549

Blue light alters miR167 expression and microRNA-targeted auxin response factor genes in Arabidopsis thaliana plants.

PubMed

Pashkovskiy, Pavel P; Kartashov, Alexander V; Zlobin, Ilya E; Pogosyan, Sergei I; Kuznetsov, Vladimir V

2016-07-01

The effect of blue LED (450 nm) on the photomorphogenesis of Arabidopsis thaliana Col-0 plants and the transcript levels of several genes, including miRNAs, photoreceptors and auxin response factors (ARF) was investigated. It was observed that blue light accelerated the generative development, reduced the rosette leaf number, significantly reduced the leaf area, dry biomass and led to the disruption of conductive tissue formation. The blue LED differentially influenced the transcript levels of several phytochromes (PHY a, b, c, d, and e), cryptochromes (CRY 1 and 2) and phototropins (PHOT 1 and 2). At the same time, the blue LED significantly increased miR167 expression compared to a fluorescent lamp or white LEDs. This increase likely resulted in the enhanced transcription of the auxin response factor genes ARF4 and ARF8, which are regulated by this miRNA. These findings support the hypothesis that the effects of blue light on A. thaliana are mediated by auxin signalling pathway involving miRNA-dependent regulation of ARF gene expression. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Real-time emission factor measurements of isocyanic acid from light duty gasoline vehicles.

PubMed

Brady, James M; Crisp, Timia A; Collier, Sonya; Kuwayama, Toshihiro; Forestieri, Sara D; Perraud, Véronique; Zhang, Qi; Kleeman, Michael J; Cappa, Christopher D; Bertram, Timothy H

2014-10-07

Exposure to gas-phase isocyanic acid (HNCO) has been previously shown to be associated with the development of atherosclerosis, cataracts and rheumatoid arthritis. As such, accurate emission inventories for HNCO are critical for modeling the spatial and temporal distribution of HNCO on a regional and global scale. To date, HNCO emission rates from light duty gasoline vehicles, operated under driving conditions, have not been determined. Here, we present the first measurements of real-time emission factors of isocyanic acid from a fleet of eight light duty gasoline-powered vehicles (LDGVs) tested on a chassis dynamometer using the Unified Driving Cycle (UC) at the California Air Resources Board (CARB) Haagen-Smit test facility, all of which were equipped with three-way catalytic converters. HNCO emissions were observed from all vehicles, in contrast to the idealized laboratory measurements. We report the tested fleet averaged HNCO emission factors, which depend strongly on the phase of the drive cycle; ranging from 0.46 ± 0.13 mg kg fuel(-1) during engine start to 1.70 ± 1.77 mg kg fuel(-1) during hard acceleration after the engine and catalytic converter were warm. The tested eight-car fleet average fuel based HNCO emission factor was 0.91 ± 0.58 mg kg fuel(-1), within the range previously estimated for light duty diesel-powered vehicles (0.21-3.96 mg kg fuel(-1)). Our results suggest that HNCO emissions from LDGVs represent a significant emission source in urban areas that should be accounted for in global and regional models.

Antagonistic Basic Helix-Loop-Helix/bZIP Transcription Factors Form Transcriptional Modules That Integrate Light and Reactive Oxygen Species Signaling in Arabidopsis[W

PubMed Central

Chen, Dongqin; Xu, Gang; Tang, Weijiang; Jing, Yanjun; Ji, Qiang; Fei, Zhangjun; Lin, Rongcheng

2013-01-01

The critical developmental switch from heterotrophic to autotrophic growth of plants involves light signaling transduction and the production of reactive oxygen species (ROS). ROS function as signaling molecules that regulate multiple developmental processes, including cell death. However, the relationship between light and ROS signaling remains unclear. Here, we identify transcriptional modules composed of the basic helix-loop-helix and bZIP transcription factors PHYTOCHROME-INTERACTING FACTOR1 (PIF1), PIF3, ELONGATED HYPOCOTYL5 (HY5), and HY5 HOMOLOGY (HYH) that bridge light and ROS signaling to regulate cell death and photooxidative response. We show that pif mutants release more singlet oxygen and exhibit more extensive cell death than the wild type during Arabidopsis thaliana deetiolation. Genome-wide expression profiling indicates that PIF1 represses numerous ROS and stress-related genes. Molecular and biochemical analyses reveal that PIF1/PIF3 and HY5/HYH physically interact and coordinately regulate the expression of five ROS-responsive genes by directly binding to their promoters. Furthermore, PIF1/PIF3 and HY5/HYH function antagonistically during the seedling greening process. In addition, phytochromes, cryptochromes, and CONSTITUTIVE PHOTOMORPHOGENIC1 act upstream to regulate ROS signaling. Together, this study reveals that the PIF1/PIF3-HY5/HYH transcriptional modules mediate crosstalk between light and ROS signaling and sheds light on a new mechanism by which plants adapt to the light environments. PMID:23645630

Blue light treatment of Pseudomonas aeruginosa: Strong bactericidal activity, synergism with antibiotics and inactivation of virulence factors.

PubMed

Fila, Grzegorz; Kawiak, Anna; Grinholc, Mariusz Stanislaw

2017-08-18

Pseudomonas aeruginosa is among the most common pathogens responsible for both acute and chronic infections of high incidence and severity. Additionally, P. aeruginosa resistance to conventional antimicrobials has increased rapidly over the past decade. Therefore, it is crucial to explore new therapeutic options, particularly options that specifically target the pathogenic mechanisms of this microbe. The ability of a pathogenic bacterium to cause disease is dependent upon the production of agents termed 'virulence factors', and approaches to mitigate these agents have gained increasing attention as new antibacterial strategies. Although blue light irradiation is a promising alternative approach, only limited and preliminary studies have described its effect on virulence factors. The current study aimed to investigate the effects of lethal and sub-lethal doses of blue light treatment (BLT) on P. aeruginosa virulence factors. We analyzed the inhibitory effects of blue light irradiation on the production/activity of several virulence factors. Lethal BLT inhibited the activity of pyocyanin, staphylolysin, pseudolysin and other proteases, but sub-lethal BLT did not affect the production/expression of proteases, phospholipases, and flagella- or type IV pili-associated motility. Moreover, a eukaryotic cytotoxicity test confirmed the decreased toxicity of blue light-treated extracellular P. aeruginosa fractions. Finally, the increased antimicrobial susceptibility of P. aeruginosa treated with sequential doses of sub-lethal BLT was demonstrated with a checkerboard test. Thus, this work provides evidence-based proof of the susceptibility of drug-resistant P. aeruginosa to BLT-mediated killing, accompanied by virulence factor reduction, and describes the synergy between antibiotics and sub-lethal BLT.

FUNDAMENTAL AREAS OF PHENOMENOLOGY(INCLUDING APPLICATIONS): Experimental Investigation of Quality of Lensless Ghost Imaging with Pseudo-Thermal Light

NASA Astrophysics Data System (ADS)

Shen, Xia; Bai, Yan-Feng; Qin, Tao; Han, Shen-Sheng

2008-11-01

Factors influencing the quality of lensless ghost imaging are investigated. According to the experimental results, we find that the imaging quality is determined by the number of independent sub light sources on the imaging plane of the reference arm. A qualitative picture based on advanced wave optics is presented to explain the physics behind the experimental phenomena. The present results will be helpful to provide a basis for improving the quality of ghost imaging systems in future works.

77 FR 64827 - Certain Lighting Control Devices Including Dimmer Switches and Parts Thereof (IV); Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-23

...Notice is hereby given that the U.S. International Trade Commission has terminated the above-captioned investigation with a finding of violation of section 337, and has issued a general exclusion order directed against infringing lighting control devices including dimmer switches and parts thereof, and cease and desist orders directed against respondents American Top Electric Corp. (``American Top'') and Big Deal Electric Corp. (``Big Deal''), both of Santa Ana, California; Elemental LED, LLC d/b/a Diode LED (``Elemental'') of Emeryville, California; and Zhejiang Yuelong Mechanical and Electrical Co. (``Zhejiang Yuelong'') of Zhejiang, China.

Protein aggregation studied by forward light scattering and light transmission analysis

NASA Astrophysics Data System (ADS)

Penzkofer, A.; Shirdel, J.; Zirak, P.; Breitkreuz, H.; Wolf, E.

2007-12-01

The aggregation of the circadian blue-light photo-receptor cryptochrome from Drosophila melanogaster (dCry) is studied by transmission and forward light scattering measurement in the protein transparent wavelength region. The light scattering in forward direction is caused by Rayleigh scattering which is proportional to the degree of aggregation. The light transmission through the samples in the transparent region is reduced by Mie light scattering in all directions. It depends on the degree of aggregation and the monomer volume fill factor of the aggregates (less total scattering with decreasing monomer volume fill factor of protein globule) allowing a distinction between tightly packed protein aggregation (monomer volume fill factor 1) and loosely packed protein aggregation (monomer volume fill factor less than 1). An increase in aggregation with temperature, concentration, and blue-light exposure is observed. At a temperature of 4 °C and a protein concentration of less than 0.135 mM no dCry aggregation was observed, while at 24 °C and 0.327 mM gelation occurred (loosely packed aggregates occupying the whole solution volume).

The Effect of Incident Light Polarization on Vegetation Bidirectional Reflectance Factor

NASA Technical Reports Server (NTRS)

Georgiev, Georgi T.; Thome, Kurt; Ranson, Kurtis J.; King, Michael D.; Butler, James J.

2010-01-01

The Laboratory-based Bidirectional Reflectance Factor (BRF) polarization study of vegetation is presented in this paper. The BRF was measured using a short-arc Xenon lamp/monochromator assembly producing an incoherent, tunable light source with a well-defined spectral bandpass at visible and near-infrared wavelengths of interest at 470 nm and 870 nm and coherent light source at 1.656 microns. All vegetation samples were measured using P and S linearly polarized incident light over a range of incident and scatter angles. By comparing these results, we quantitatively examine how the BRF of the samples depends on the polarization of the incident light. The differences are significant, depend strongly on the incident and scatter angles, and can be as high as 120% at 67 deg incident and 470nm. The global nature of Earth's processes requires consistent long-term calibration of all instruments involved in data retrieval. The BRF defines the reflection characteristics of Earth surface. It provides the reflectance of a target in a specific direction as a function of illumination and viewing geometry. The BRF is a function of wavelength and reflects the structural and optical properties of the surface. Various space and airborne radiometric and imaging remote sensing instruments are used in the remote sensing characterization of vegetation canopies and soils, oceans, or especially large pollution sources. The satellite data is validated through comparison with airborne, ground-based and laboratory-based data in an effort to fully understand the vegetation canopy reflectance, The Sun's light is assumed to be unpolarized at the top of the atmosphere; however it becomes polarized to some degree due to atmospheric effects by the time it reaches the vegetation canopy. Although there are numerous atmospheric correction models, laboratory data is needed for model verification and improvement.

Platelet-Derived Growth Factor-BB Lessens Light-Induced Rod Photoreceptor Damage in Mice.

PubMed

Takahashi, Kei; Shimazawa, Masamitsu; Izawa, Hiroshi; Inoue, Yuki; Kuse, Yoshiki; Hara, Hideaki

2017-12-01

Platelet-derived growth factor (PDGF)-BB is known to have neuroprotective effects against various neurodegenerative disorders. The purpose of this study was to determine whether PDGF-BB can be neuroprotective against light-induced photoreceptor damage in mice. Mice were exposed to 8000-lux luminance for 3 hours to induce phototoxicity. Two hours before light exposure, the experimental mice were injected with PDGF-BB intravitreally, and the control mice were injected with phosphate-buffered saline. The light-exposed PDGF-BB-injected mice and saline-injected mice were evaluated electroretinographically and histologically. The site and expression levels of PDGFR-β and PDGF-BB were determined by immunostaining and Western blotting, respectively. The effect of PDGF-BB on light-induced cone and rod photoreceptor damage was also evaluated in vitro in 661W cells, a murine cone photoreceptor cell line, and in primary retinal cell cultures. An intravitreal injection of PDGF-BB significantly reduced the decrease in the amplitudes of the electroretinograms (ERGs) and the thinning of the outer nuclear layer (ONL) induced by the light exposure. It also reduced the number of TUNEL-positive cells in the ONL. PDGFR-β was expressed in the rod outer segments (OSs) but not the cone OSs. The levels of PDGF-BB and PDGFR-β were decreased after light irradiation. In addition, PDGF-BB had protective effects against light-induced damage to cells of rod photoreceptors but had no effect on the 661W cells in vitro. These findings indicate that PDGF-BB reduces the degree of light-induced retinal damage by activating PDGFR-β in rod photoreceptors. These findings suggest that PDGF-BB could play a role in the prevention of degeneration in eyes susceptible to phototoxicity.

Organic light emitting diode with light extracting electrode

DOEpatents

Bhandari, Abhinav; Buhay, Harry

2017-04-18

An organic light emitting diode (10) includes a substrate (20), a first electrode (12), an emissive active stack (14), and a second electrode (18). At least one of the first and second electrodes (12, 18) is a light extracting electrode (26) having a metallic layer (28). The metallic layer (28) includes light scattering features (29) on and/or in the metallic layer (28). The light extracting features (29) increase light extraction from the organic light emitting diode (10).

{lambda}{sub b}{yields}p, {lambda} transition form factors from QCD light-cone sum rules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Yuming; Lue Caidian; Shen Yuelong

2009-10-01

Light-cone sum rules for the {lambda}{sub b}{yields}p, {lambda} transition form factors are derived from the correlation functions expanded by the twist of the distribution amplitudes of the {lambda}{sub b} baryon. In terms of the {lambda}{sub b} three-quark distribution amplitude models constrained by the QCD theory, we calculate the form factors at small momentum transfers and compare the results with those estimated in the conventional light-cone sum rules (LCSR) and perturbative QCD approaches. Our results indicate that the two different versions of sum rules can lead to the consistent numbers of form factors responsible for {lambda}{sub b}{yields}p transition. The {lambda}{sub b}{yields}{lambda}more » transition form factors from LCSR with the asymptotic {lambda} baryon distribution amplitudes are found to be almost 1 order larger than those obtained in the {lambda}{sub b}-baryon LCSR, implying that the preasymptotic corrections to the baryonic distribution amplitudes are of great importance. Moreover, the SU(3) symmetry breaking effects between the form factors f{sub 1}{sup {lambda}{sub b}}{sup {yields}}{sup p} and f{sub 1}{sup {lambda}{sub b}}{sup {yields}}{sup {lambda}} are computed as 28{sub -8}{sup +14}% in the framework of {lambda}{sub b}-baryon LCSR.« less

The role of meson exchanges in light-by-light scattering

NASA Astrophysics Data System (ADS)

Lebiedowicz, Piotr; Szczurek, Antoni

2017-09-01

We discuss the role of meson exchange mechanisms in γγ → γγ scattering. Several pseudoscalar (π0, η, η‧ (958), ηc (1 S), ηc (2 S)), scalar (f0 (500), f0 (980), a0 (980), f0 (1370), χc0 (1 P)) and tensor (f2 (1270), a2 (1320), f2‧ (1525), f2 (1565), a2 (1700)) mesons are taken into account. We consider not only s-channel but also for the first time t- and u-channel meson exchange amplitudes corrected for off-shell effects including vertex form factors. We find that, depending on not well known vertex form factors, the meson exchange amplitudes interfere among themselves and could interfere with fermion-box amplitudes and modify the resulting cross sections. The meson contributions are shown as a function of collision energy as well as angular distributions are presented. Interesting interference effects separately for light pseudoscalar, scalar and tensor meson groups are discussed. The meson exchange contributions may be potentially important in the context of a measurement performed recently in ultraperipheral collisions of heavy ions by the ATLAS collaboration. The light-by-light interactions could be studied in future in electron-positron collisions by the Belle II at SuperKEKB accelerator.

Calculation of primordial abundances of light nuclei including a heavy sterile neutrino

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mosquera, M.E.; Civitarese, O., E-mail: mmosquera@fcaglp.unlp.edu.ar, E-mail: osvaldo.civitarese@fisica.unlp.edu.ar

2015-08-01

We include the coupling of a heavy sterile neutrino with active neutrinos in the calculation of primordial abundances of light-nuclei. We calculate neutrino distribution functions and primordial abundances, as functions depending on a renormalization of the sterile neutrino distribution function (a), the sterile neutrino mass (m{sub s}) and the mixing angle (φ). Using the observable data, we set constrains on these parameters, which have the values 0a < 0.4, sin{sup 2} φ ≈ 0.12−0.39 and 0m{sub s} < 7 keV at 1σ level, for a fixed value of the baryon to photon ratio. When the baryon to photon ratio is allowed to vary, its extracted value ismore » in agreement with the values constrained by Planck observations and by the Wilkinson Microwave Anisotropy Probe (WMAP). It is found that the anomaly in the abundance of {sup 7}Li persists, in spite of the inclusion of a heavy sterile neutrino.« less

Deriving depth-dependent light escape efficiency and optical Swank factor from measured pulse height spectra of scintillators.

PubMed

Howansky, Adrian; Peng, Boyu; Lubinsky, Anthony R; Zhao, Wei

2017-03-01

Pulse height spectroscopy has been used by investigators to deduce the imaging properties of scintillators. Pulse height spectra (PHS) are used to compute the Swank factor, which describes the variation in scintillator light output per x-ray interaction. The spread in PHS measured below the K-edge is related to the optical component of the Swank factor, i.e., variations in light escape efficiency from different depths of x-ray interaction in the scintillator, denoted ε¯(z). Optimizing scintillators for medical imaging applications requires understanding of these optical properties, as they determine tradeoffs between parameters such as x-ray absorption, light yield, and spatial resolution. This work develops a model for PHS acquisition such that the effect of measurement uncertainty can be removed. This method allows ε¯(z) to be quantified on an absolute scale and permits more accurate estimation of the optical Swank factor of scintillators. The pulse height spectroscopy acquisition chain was modeled as a linear system of stochastic gain stages. Analytical expressions were derived for signal and noise propagation through the PHS chain, accounting for deterministic and stochastic aspects of x-ray absorption, scintillation, and light detection with a photomultiplier tube. The derived expressions were used to calculate PHS of thallium-doped cesium iodide (CsI) scintillators using parameters that were measured, calculated, or known from literature. PHS were measured at 25 and 32 keV of CsI samples designed with an optically reflective or absorptive backing, with or without a fiber-optic faceplate (FOP), and with thicknesses ranging from 150-1000 μm. Measured PHS were compared with calculated PHS, then light escape model parameters were varied until measured and modeled results reached agreement. Resulting estimates of ε¯(z) were used to calculate each scintillator's optical Swank factor. For scintillators of the same optical design, only minor differences in

Deriving depth-dependent light escape efficiency and optical Swank factor from measured pulse height spectra of scintillators

PubMed Central

Howansky, Adrian; Peng, Boyu; Lubinsky, Anthony R.; Zhao, Wei

2017-01-01

Purpose Pulse height spectroscopy has been used by investigators to deduce the imaging properties of scintillators. Pulse height spectra (PHS) are used to compute the Swank factor, which describes the variation in scintillator light output per x-ray interaction. The spread in PHS measured below the K-edge is related to the optical component of the Swank factor, i.e. variations in light escape efficiency from different depths of x-ray interaction in the scintillator, denoted ε̄(z). Optimizing scintillators for medical imaging applications requires understanding of these optical properties, as they determine tradeoffs between parameters such as x-ray absorption, light yield, and spatial resolution. This work develops a model for PHS acquisition such that the effect of measurement uncertainty can be removed. This method allows ε̄(z) to be quantified on an absolute scale and permits more accurate estimation of the optical Swank factor of scintillators. Methods The pulse height spectroscopy acquisition chain was modeled as a linear system of stochastic gain stages. Analytical expressions were derived for signal and noise propagation through the PHS chain, accounting for deterministic and stochastic aspects of x-ray absorption, scintillation, and light detection with a photomultiplier tube. The derived expressions were used to calculate PHS of thallium-doped cesium iodide (CsI) scintillators using parameters that were measured, calculated, or known from literature. PHS were measured at 25 and 32 keV of CsI samples designed with an optically-reflective or absorptive backing, with or without a fiber-optic faceplate (FOP), and with thicknesses ranging from 150–1000 μm. Measured PHS were compared with calculated PHS, then light escape model parameters were varied until measured and modeled results reached agreement. Resulting estimates of ε̄(z) were used to calculate each scintillator’s optical Swank factor. Results For scintillators of the same optical design

Risk factors for venous thromboembolism in immunoglobulin light chain amyloidosis

PubMed Central

Bever, Katherine M.; Masha, Luke I.; Sun, Fangui; Stern, Lauren; Havasi, Andrea; Berk, John L.; Sanchorawala, Vaishali; Seldin, David C.; Sloan, J. Mark

2016-01-01

Patients with immunoglobulin light chain amyloidosis are at risk for both thrombotic and bleeding complications. While the hemostatic defects have been extensively studied, less is known about thrombotic complications in this disease. This retrospective study examined the frequency of venous thromboembolism in 929 patients with immunoglobulin light chain amyloidosis presenting to a single referral center, correlated risk of venous thromboembolism with clinical and laboratory factors, and examined complications of anticoagulation in this population. Sixty-five patients (7%) were documented as having at least one venous thromboembolic event. Eighty percent of these patients had events within one year prior to or following diagnosis. Lower serum albumin was associated with increased risk of VTE, with a hazard ratio of 4.30 (CI 1.60–11.55; P=0.0038) for serum albumin less than 3 g/dL compared to serum albumin greater than 4 g/dL. Severe bleeding complications were observed in 5 out of 57 patients with venous thromboembolism undergoing treatment with anticoagulation. Prospective investigation should be undertaken to better risk stratify these patients and to determine the optimal strategies for prophylaxis against and management of venous thromboembolism. PMID:26452981

Risk factors for venous thromboembolism in immunoglobulin light chain amyloidosis.

PubMed

Bever, Katherine M; Masha, Luke I; Sun, Fangui; Stern, Lauren; Havasi, Andrea; Berk, John L; Sanchorawala, Vaishali; Seldin, David C; Sloan, J Mark

2016-01-01

Patients with immunoglobulin light chain amyloidosis are at risk for both thrombotic and bleeding complications. While the hemostatic defects have been extensively studied, less is known about thrombotic complications in this disease. This retrospective study examined the frequency of venous thromboembolism in 929 patients with immunoglobulin light chain amyloidosis presenting to a single referral center, correlated risk of venous thromboembolism with clinical and laboratory factors, and examined complications of anticoagulation in this population. Sixty-five patients (7%) were documented as having at least one venous thromboembolic event. Eighty percent of these patients had events within one year prior to or following diagnosis. Lower serum albumin was associated with increased risk of VTE, with a hazard ratio of 4.30 (CI 1.60-11.55; P=0.0038) for serum albumin less than 3 g/dL compared to serum albumin greater than 4 g/dL. Severe bleeding complications were observed in 5 out of 57 patients with venous thromboembolism undergoing treatment with anticoagulation. Prospective investigation should be undertaken to better risk stratify these patients and to determine the optimal strategies for prophylaxis against and management of venous thromboembolism. Copyright© Ferrata Storti Foundation.

Light-front holographic QCD and emerging confinement

DOE PAGES

Brodsky, Stanley J.; de Téramond, Guy F.; Dosch, Hans Günter; ...

2015-05-21

In this study we explore the remarkable connections between light-front dynamics, its holographic mapping to gravity in a higher-dimensional anti-de Sitter (AdS) space, and conformal quantum mechanics. This approach provides new insights into the origin of a fundamental mass scale and the physics underlying confinement dynamics in QCD in the limit of massless quarks. The result is a relativistic light-front wave equation for arbitrary spin with an effective confinement potential derived from a conformal action and its embedding in AdS space. This equation allows for the computation of essential features of hadron spectra in terms of a single scale. Themore » light-front holographic methods described here give a precise interpretation of holographic variables and quantities in AdS space in terms of light-front variables and quantum numbers. This leads to a relation between the AdS wave functions and the boost-invariant light-front wave functions describing the internal structure of hadronic bound-states in physical spacetime. The pion is massless in the chiral limit and the excitation spectra of relativistic light-quark meson and baryon bound states lie on linear Regge trajectories with identical slopes in the radial and orbital quantum numbers. In the light-front holographic approach described here currents are expressed as an infinite sum of poles, and form factors as a product of poles. At large q 2 the form factor incorporates the correct power-law fall-off for hard scattering independent of the specific dynamics and is dictated by the twist. At low q 2 the form factor leads to vector dominance. The approach is also extended to include small quark masses. We briefly review in this report other holographic approaches to QCD, in particular top-down and bottom-up models based on chiral symmetry breaking. We also include a discussion of open problems and future applications.« less

Kinetic Modeling Sheds Light on the Mode of Action of Recombinant Factor VIIa on Thrombin Generation

DTIC Science & Technology

2011-01-01

Regular Article Kinetic modeling sheds light on the mode of action of recombinant factor VIIa on thrombin generation Alexander Y. Mitrophanov...its effects on the quantitative parameters of thrombin generation. For recombinant activated factor VII (rFVIIa) ― a promising hemostasis-inducing...modulate thrombin production , it is necessary to identify rFVIIa-induced effects that are compatible with the available biochemical knowledge about

Mechanisms of low level light therapy

NASA Astrophysics Data System (ADS)

Hamblin, Michael R.; Demidova, Tatiana N.

2006-02-01

The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing tissue damage has been known for almost forty years since the invention of lasers. Originally thought to be a peculiar property of laser light (soft or cold lasers), the subject has now broadened to include photobiomodulation and photobiostimulation using non-coherent light. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial. This likely is due to two main reasons; firstly the biochemical mechanisms underlying the positive effects are incompletely understood, and secondly the complexity of rationally choosing amongst a large number of illumination parameters such as wavelength, fluence, power density, pulse structure and treatment timing has led to the publication of a number of negative studies as well as many positive ones. In particular a biphasic dose response has been frequently observed where low levels of light have a much better effect than higher levels. This introductory review will cover some of the proposed cellular chromophores responsible for the effect of visible light on mammalian cells, including cytochrome c oxidase (with absorption peaks in the near infrared) and photoactive porphyrins. Mitochondria are thought to be a likely site for the initial effects of light, leading to increased ATP production, modulation of reactive oxygen species and induction of transcription factors. These effects in turn lead to increased cell proliferation and migration (particularly by fibroblasts), modulation in levels of cytokines, growth factors and inflammatory mediators, and increased tissue oxygenation. The results of these biochemical and cellular changes in animals and patients include such benefits as increased healing in chronic wounds, improvements in sports injuries and

Molecular mechanisms and ecological function of far-red light signalling.

PubMed

Sheerin, David J; Hiltbrunner, Andreas

2017-11-01

Land plants possess the ability to sense and respond to far-red light (700-760 nm), which serves as an important environmental cue. Due to the nature of far-red light, it is not absorbed by chlorophyll and thus is enriched in canopy shade and will also penetrate deeper into soil than other visible wavelengths. Far-red light responses include regulation of seed germination, suppression of hypocotyl growth, induction of flowering and accumulation of anthocyanins, which depend on one member of the phytochrome photoreceptor family, phytochrome A (phyA). Here, we review the current understanding of the underlying molecular mechanisms of how plants sense far-red light through phyA and the physiological responses to this light quality. Light-activated phytochromes act on two primary pathways within the nucleus; suppression of the E3 ubiquitin ligase complex CUL4/DDB1 COP1/SPA and inactivation of the PHYTOCHROME INTERACTING FACTOR (PIF) family of bHLH transcription factors. These pathways integrate with other signal transduction pathways, including phytohormones, for tissue and developmental stage specific responses. Unlike other phytochromes that mediate red-light responses, phyA is transported from the cytoplasm to the nucleus in far-red light by the shuttle proteins FAR-RED ELONGATED HYPOCOTYL 1 (FHY1) and FHY1-LIKE (FHL). However, additional mechanisms must exist that shift the action of phyA to far-red light; current hypotheses are discussed. © 2017 John Wiley & Sons Ltd.

Qualitative models of seat discomfort including static and dynamic factors.

PubMed

Ebe, K; Griffin, M J

2000-06-01

Judgements of overall seating comfort in dynamic conditions sometimes correlate better with the static characteristics of a seat than with measures of the dynamic environment. This study developed qualitative models of overall seat discomfort to include both static and dynamic seat characteristics. A dynamic factor that reflected how vibration discomfort increased as vibration magnitude increased was combined with a static seat factor which reflected seating comfort without vibration. The ability of the model to predict the relative and overall importance of dynamic and static seat characteristics on comfort was tested in two experiments. A paired comparison experiment, using four polyurethane foam cushions (50, 70, 100, 120 mm thick), provided different static and dynamic comfort when 12 subjects were exposed to one-third octave band random vertical vibration with centre frequencies of 2.5 and 5.5 Hz, at magnitudes of 0.00, 0.25 and 0.50 m x s(-2) rms measured beneath the foam samples. Subject judgements of the relative discomfort of the different conditions depended on both static and dynamic characteristics in a manner consistent with the model. The effect of static and dynamic seat factors on overall seat discomfort was investigated by magnitude estimation using three foam cushions (of different hardness) and a rigid wooden seat at six vibration magnitudes with 20 subjects. Static seat factors (i.e. cushion stiffness) affected the manner in which vibration influenced the overall discomfort: cushions with lower stiffness were more comfortable and more sensitive to changes in vibration magnitude than those with higher stiffness. The experiments confirm that judgements of overall seat discomfort can be affected by both the static and dynamic characteristics of a seat, with the effect depending on vibration magnitude: when vibration magnitude was low, discomfort was dominated by static seat factors; as the vibration magnitude increased, discomfort became dominated

NASA Lighting Research, Test, & Analysis

NASA Technical Reports Server (NTRS)

Clark, Toni

2015-01-01

The Habitability and Human Factors Branch, at Johnson Space Center, in Houston, TX, provides technical guidance for the development of spaceflight lighting requirements, verification of light system performance, analysis of integrated environmental lighting systems, and research of lighting-related human performance issues. The Habitability & Human Factors Lighting Team maintains two physical facilities that are integrated to provide support. The Lighting Environment Test Facility (LETF) provides a controlled darkroom environment for physical verification of lighting systems with photometric and spetrographic measurement systems. The Graphics Research & Analysis Facility (GRAF) maintains the capability for computer-based analysis of operational lighting environments. The combined capabilities of the Lighting Team at Johnson Space Center have been used for a wide range of lighting-related issues.

Riding through red lights: the rate, characteristics and risk factors of non-compliant urban commuter cyclists.

PubMed

Johnson, Marilyn; Newstead, Stuart; Charlton, Judith; Oxley, Jennifer

2011-01-01

This study determined the rate and associated factors of red light infringement among urban commuter cyclists. A cross-sectional observational study was conducted using a covert video camera to record cyclists at 10 sites across metropolitan Melbourne, Australia from October 2008 to April 2009. In total, 4225 cyclists faced a red light and 6.9% were non-compliant. The main predictive factor for infringement was direction of travel, cyclists turning left (traffic travels on the left-side in Australia) had 28.3 times the relative odds of infringement compared to cyclists who continued straight through the intersection. Presence of other road users had a deterrent effect with the odds of infringement lower when a vehicle travelling in the same direction was present (OR=0.39, 95% CI 0.28-0.53) or when other cyclists were present (OR=0.26, 95% CI 0.19-0.36). Findings suggest that some cyclists do not perceive turning left against a red signal to be unsafe and the opportunity to ride through the red light during low cross traffic times influences the likelihood of infringement. Copyright © 2010 Elsevier Ltd. All rights reserved.

Light beam shaping for collimated emission from white organic light-emitting diodes using customized lenticular microlens arrays structure

NASA Astrophysics Data System (ADS)

Zhou, Lei; Bai, Gui-Lin; Guo, Xin; Shen, Su; Ou, Qing-Dong; Fan, Yuan-Yuan

2018-05-01

We present a design approach to realizing a desired collimated planar incoherent light source (CPILS) by incorporating lenticular microlens arrays (LMLAs) onto the substrates of discrete white organic light-emitting diode (WOLED) light sources and demonstrate the effectiveness of this method in collimated light beam shaping and luminance enhancement simultaneously. The obtained collimated WOLED light source shows enhanced luminance by a factor of 2.7 compared with that of the flat conventional device at the normal polar angle and, more importantly, exhibits a narrowed angular emission with a full-width at half-maximum (FWHM) of ˜33.6°. We anticipate that the presented strategy could provide an alternative way for achieving the desired large scale CPILS, thereby opening the door to many potential applications, including LCD backlights, three-dimensional displays, car headlights, and so forth.

Hypoxic preconditioning protects photoreceptors against light damage independently of hypoxia inducible transcription factors in rods.

PubMed

Kast, Brigitte; Schori, Christian; Grimm, Christian

2016-05-01

Hypoxic preconditioning protects photoreceptors against light-induced degeneration preserving retinal morphology and function. Although hypoxia inducible transcription factors 1 and 2 (HIF1, HIF2) are the main regulators of the hypoxic response, photoreceptor protection does not depend on HIF1 in rods. Here we used rod-specific Hif2a single and Hif1a;Hif2a double knockout mice to investigate the potential involvement of HIF2 in rods for protection after hypoxic preconditioning. To identify potential HIF2 target genes in rods we determined the retinal transcriptome of hypoxic control and rod-specific Hif2a knockouts by RNA sequencing. We show that rods do not need HIF2 for hypoxia-induced increased survival after light exposure. The transcriptomic analysis revealed a number of genes that are potentially regulated by HIF2 in rods; among those were Htra1, Timp3 and Hmox1, candidates that are interesting due to their connection to human degenerative diseases of the retina. We conclude that neither HIF1 nor HIF2 are required in photoreceptors for protection by hypoxic preconditioning. We hypothesize that HIF transcription factors may be needed in other cells to produce protective factors acting in a paracrine fashion on photoreceptor cells. Alternatively, hypoxic preconditioning induces a rod-intrinsic response that is independent of HIF transcription factors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Robust Programming Problems Based on the Mean-Variance Model Including Uncertainty Factors

NASA Astrophysics Data System (ADS)

Hasuike, Takashi; Ishii, Hiroaki

2009-01-01

This paper considers robust programming problems based on the mean-variance model including uncertainty sets and fuzzy factors. Since these problems are not well-defined problems due to fuzzy factors, it is hard to solve them directly. Therefore, introducing chance constraints, fuzzy goals and possibility measures, the proposed models are transformed into the deterministic equivalent problems. Furthermore, in order to solve these equivalent problems efficiently, the solution method is constructed introducing the mean-absolute deviation and doing the equivalent transformations.

[Light and hens as attraction factors of Nyssomyia whitmani in a rural area, Southern Brazil].

PubMed

Teodoro, Ueslei; Lonardoni, Maria Valdrinez Campana; Silveira, Thaís Gomes Verzignassi; Dias, Alessandra de Cassia; Abbas, Milia; Alberton, Dayane; Santos, Demilson Rodrigues dos

2007-06-01

To verify the influence of traps with electric light and hens as factors that attract sandflies and compare results between capture methods. The study was conducted in the Palmital Farm, Southern Brazil. Sandfly collections were conducted with Falcão traps and an electric aspirator, fortnightly, between 8 p.m. and 11 p.m. in the presence or absence of light and hens in peridomiciliary areas, from September 1998 to June 1999. A total of 43,767 specimens from eight species of sandflies were collected: Nyssomyia whitmani, N. neivai and Migonemyia migonei constituting 99.9% of the total collected, with predominance of N. whitmani. The number of this species collected inside the hen's shed in the presence of hens (21,045) was greater than in their absence (10,434). In the presence of hens, with distinct intensities of light, a larger number of N. whitmani samples were collected with 3W light. In the presence of hens and light (3W), the number of N. whitmani collected with the electric aspirator (5,141) was superior to that collected with the Falcão trap (1,675). In the absence of light, with or without the presence hens, there was no difference between the numbers of N. whitmani collected with the electric aspirator or the Falcão trap. Hens and electric light together attract more N. whitmani to peridomicilary areas. The number of N. whitmani collected with an electric aspirator inside a hen's shed with the presence of hens and light is greater than those collected with a Falcão trap in the same conditions.

Red light for Anderson localization

NASA Astrophysics Data System (ADS)

Skipetrov, S. E.; Page, J. H.

2016-02-01

During the last 30 years, the search for Anderson localization of light in three-dimensional (3D) disordered samples yielded a number of experimental observations that were first considered successful, then disputed by opponents, and later refuted by their authors. This includes recent results for light in TiO2 powders that Sperling et al now show to be due to fluorescence and not to Anderson localization (2016 New J. Phys. 18 013039). The difficulty of observing Anderson localization of light in 3D may be due to a number of factors: insufficient optical contrast between the components of the disordered material, near-field effects, etc. The way to overcome these difficulties may consist in using partially ordered materials, complex structured scatterers, or clouds of cold atoms in magnetic fields.

A two-metric proposal to specify the color-rendering properties of light sources for retail lighting

NASA Astrophysics Data System (ADS)

Freyssinier, Jean Paul; Rea, Mark

2010-08-01

Lighting plays an important role in supporting retail operations, from attracting customers, to enabling the evaluation of merchandise, to facilitating the completion of the sale. Lighting also contributes to the identity, comfort, and visual quality of a retail store. With the increasing availability and quality of white LEDs, retail lighting specifiers are now considering LED lighting in stores. The color rendering of light sources is a key factor in supporting retail lighting goals and thus influences a light source's acceptance by users and specifiers. However, there is limited information on what consumers' color preferences are, and metrics used to describe the color properties of light sources often are equivocal and fail to predict preference. The color rendering of light sources is described in the industry solely by the color rendering index (CRI), which is only indirectly related to human perception. CRI is intended to characterize the appearance of objects illuminated by the source and is increasingly being challenged because new sources are being developed with increasingly exotic spectral power distributions. This paper discusses how CRI might be augmented to better use it in support of the design objectives for retail merchandising. The proposed guidelines include the use of gamut area index as a complementary metric to CRI for assuring good color rendering.

Citrullus colocynthis NAC transcription factors CcNAC1 and CcNAC2 are involved in light and auxin signaling.

PubMed

Wang, Zhuoyu; Rashotte, Aaron M; Dane, Fenny

2014-10-01

Two novel NAC transcription factors from C itrullus colocynthis implicated in light and auxin signaling pathway. NAC transcription factors (NAM, ATAF1, 2, CUC2) have multiple functions in plant growth and development. Two NACs, CcNAC1 and CcNAC2, were recently identified in the highly drought-tolerant cucurbit species, Citrullus colocynthis. This study examines the functional role of these genes under different qualities of light based on the in silico analysis of the CcNAC1 and CcNAC2 promoters that revealed the presence of several light-associated motifs. The impact of both light and auxin on CcNAC1 and CcNAC2 expression was examined in C. colocynthis leaves, and using reporter (pCcNAC1, 2::GUS) lines in Arabidopsis. Furthermore, the effects of constitutive overexpression (OE-CcNAC1, 2) in Arabidopsis were also examined under a range of conditions to confirm reporter line linkages. White, blue, red, and far-red light treatments resulted in similar patterns of quantitative changes in CcNAC1and CcNAC2 expression in both species, with the highest transcript increases following red light. Photomorphogenic changes in Arabidopsis hypocotyls were correlated with gene transcript levels. In the absence of light, hypocotyls of OE-CcNAC1/CcNAC2 lines were significantly longer as compared to WT. The addition of exogenous auxin (+IAA) to growth medium also resulted in changes to the hypocotyl lengths of overexpression lines and spatiotemporal reporter line changes in seedlings. Our data suggest that CcNAC1, 2 might be functionally important in the light signaling pathway, and appear connected to the hormone auxin. This is the first study to indicate that NAC genes might play a role in both light and auxin signaling pathways.

TH-CD-207B-06: Swank Factor of Segmented Scintillators in Multi-Slice CT Detectors: Pulse Height Spectra and Light Escape

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howansky, A; Peng, B; Lubinsky, A

Purpose: Pulse height spectra (PHS) have been used to determine the Swank factor of a scintillator by measuring fluctuations in its light output per x-ray interaction. The Swank factor and x-ray quantum efficiency of a scintillator define the upper limit to its imaging performance, i.e. DQE(0). The Swank factor below the K-edge is dominated by optical properties, i.e. variations in light escape efficiency from different depths of interaction, denoted e(z). These variations can be optimized to improve tradeoffs in x-ray absorption, light yield, and spatial resolution. This work develops a quantitative model for interpreting measured PHS, and estimating e(z) onmore » an absolute scale. The method is used to investigate segmented ceramic GOS scintillators used in multi-slice CT detectors. Methods: PHS of a ceramic GOS plate (1 mm thickness) and segmented GOS array (1.4 mm thick) were measured at 46 keV. Signal and noise propagation through x-ray conversion gain, light escape, detection by a photomultiplier tube and dynode amplification were modeled using a cascade of stochastic gain stages. PHS were calculated with these expressions and compared to measurements. Light escape parameters were varied until modeled PHS agreed with measurements. The resulting estimates of e(z) were used to calculate PHS without measurement noise to determine the inherent Swank factor. Results: The variation in e(z) was 67.2–89.7% in the plate and 40.2–70.8% in the segmented sample, corresponding to conversion gains of 28.6–38.1 keV{sup −1} and 17.1–30.1 keV{sup −1}, respectively. The inherent Swank factors of the plate and segmented sample were 0.99 and 0.95, respectively. Conclusion: The high light escape efficiency in the ceramic GOS samples yields high Swank factors and DQE(0) in CT applications. The PHS model allows the intrinsic optical properties of scintillators to be deduced from PHS measurements, thus it provides new insights for evaluating the imaging performance of

Evaluation of OLED and edge-lit LED lighting panels

NASA Astrophysics Data System (ADS)

Mou, Xi; Narendran, Nadarajah; Zhu, Yiting; Freyssinier, Jean Paul

2016-09-01

Solid-state lighting (SSL) offers a new technology platform for lighting designers and end-users to illuminate spaces with low energy demand. Two types of SSL sources include organic light-emitting diodes (OLEDs) and light-emitting diodes (LEDs). OLED is an area light source, and its primary competing technology is the edge-lit LED panel. Generally, both of these technologies are considered similar in shape and appearance, but there is little understanding of how people perceive discomfort glare from large area light sources. The objective of this study was to evaluate discomfort glare for the two lighting technologies under similar operating conditions by gathering observers' reactions. The human factors study results showed no statistically significant difference in human response to discomfort glare between OLED and edge-lit LED panels when the two light sources produced the same lighting stimulus. This means both technologies appeared equally glary beyond a certain luminance.

Visualization and Analysis of Light Pollution: a Case Study in Hong Kong

NASA Astrophysics Data System (ADS)

Wu, B.; Wong, H.

2012-07-01

The effects of light pollution problems in metropolitan areas are investigated in this study. Areas of Hong Kong are used as the source of three typical study cases. One case represents the regional scale, a second represents the district scale, and a third represents the street scale. Two light pollution parameters, Night Sky Brightness (NSB) and Street Light Level (SLL), are the focus of the analyses. Light pollution visualization approaches in relation to the different scales include various light pollution maps. They provide straightforward presentations of the light pollution situations in the study areas. The relationship between light pollution and several social-economic factors such as land use, household income, and types of outdoor lighting in the scale areas given, are examined. Results show that: (1) Land use may be one factor affecting light pollution in the regional scale; (2) A relatively strong correlation exists between light pollution and household income in the district scale; (3) The heaviest light pollution in the street scale is created by spotlights and also the different types of lighting from shops. The impact of the latter is in relation to the shop profile and size.

Light-Front Holography, Light-Front Wavefunctions, and Novel QCD Phenomena

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; de Teramond, Guy F.

2012-02-16

transverse momentum distributions. The effective confining potential also creates quark-antiquark pairs from the amplitude q {yields} q{bar q}q. Thus in holographic QCD higher Fock states can have any number of extra q{bar q} pairs. We discuss the relevance of higher Fock-states for describing the detailed structure of space and time-like form factors. The AdS/QCD model can be systematically improved by using its complete orthonormal solutions to diagonalize the full QCD light-front Hamiltonian or by applying the Lippmann-Schwinger method in order to systematically include the QCD interaction terms. A new perspective on quark and gluon condensates is also obtained.« less

Factors other than light affecting the pineal gland: hypophysectomy, testosterone, dihydrotestosterone, estradiol, cryptorchidism, and stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Urry, R.L.; Dougherty, K.A.; Frehn, J.L.

The article reviews those factors other than light that affect the activity of the pineal gland. Both testosterone and dihydroterosterone were shown to have tissue-specific inhibitory effects on pineal MAO activity concomitant with an increased activity of the gland. The effect also was tissue-specific. Bilateral and unilateral experimental cryptorchidism also decreased pineal MAO activity 3 to 4 weeks after surgery. Acute stresses appear to increase adrenal catecholamine output (epinephrine and norepinephrine) as well as to stimulate local adrenergic pathways, while chronic stress, such as starvation, appears to act through the adrenal corticosteroids by decreasing pineal MAO activity thereby indirectly increasingmore » melatonin synthesis. Thus, both components of the adrenal gland appear to act in concert to increase effectively melatonin synthesis by the pineal function----the latter specifically inhibits HIOMT activity. These observations indicate that many factors other than light affect pineal morphology and melatonin synthesis. The pineal appears to be a true neuroendocrine organ that is affected by hypophysectomy and is responsive to feedback and control from other organs within the mammalian organism. (auth)« less

Light and Libraries.

ERIC Educational Resources Information Center

Scherer, Jeffrey

1999-01-01

Addresses how to integrate various types of light within the context of library design. Discusses light basics; the light spectrum; light measurement; reflectance; glare and brightness ratio; daylighting; electric lighting; and computer screens and lighting. Includes a checklist for plan review. (Author/LRW)

Real-time black carbon emission factors of light-duty vehicles tested on a chassis dynamometer

NASA Astrophysics Data System (ADS)

Forestieri, S. D.; Cappa, C. D.; Kuwayama, T.; Collier, S.; Zhang, Q.; Kleeman, M. J.

2012-12-01

Eight light-duty gasoline vehicles were tested on a Chassis dynamometer using the California Unified Driving Cycle (UDC) at the Haagen-Smit vehicle test facility at the California Air Resources Board (CARB) in El Monte, CA during September 2011. In addition, one light-duty gasoline vehicle, one ultra low-emission vehicle, one diesel passenger vehicle, and one gasoline direct injection vehicle were tested on a constant velocity driving cycle. Vehicle exhaust was diluted through CARB's CVS tunnel and a secondary dilution system in order to examine particulate matter (PM) emissions at atmospherically relevant concentrations (5-30 μg-m3). A variety of real-time instrumentation was used to characterize how the major PM components vary during a typical driving cycle, which includes a cold start phase followed by a hot stabilized running phase. Aerosol absorption coefficients were obtained at 532 nm and 405 nm with a time resolution of 2 seconds from a photo-acoustic spectrometer. These absorption coefficients were then converted to black carbon (BC) concentrations via a mass absorption coefficient. Non-refractory organic and inorganic PM and CO2 concentrations were quantified with a time resolution of 10 seconds using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). Real-time BC and CO2 concentrations allowed for the determination of BC emission factors (EFs), providing insights into the variability of BC EFs during different phases of a typical driving cycle and aiding in the modeling BC emissions.

PIF4 and PIF5 transcription factors link blue light and auxin to regulate the phototropic response in Arabidopsis.

PubMed

Sun, Jiaqiang; Qi, Linlin; Li, Yanan; Zhai, Qingzhe; Li, Chuanyou

2013-06-01

Both blue light (BL) and auxin are essential for phototropism in Arabidopsis thaliana. However, the mechanisms by which light is molecularly linked to auxin during phototropism remain elusive. Here, we report that phytochrome interacting factoR4 (PIF4) and PIF5 act downstream of the BL sensor phototropin1 (PHOT1) to negatively modulate phototropism in Arabidopsis. We also reveal that PIF4 and PIF5 negatively regulate auxin signaling. Furthermore, we demonstrate that PIF4 directly activates the expression of the auxin/indole-3-acetic acid (IAA) genes IAA19 and IAA29 by binding to the G-box (CACGTG) motifs in their promoters. Our genetic assays demonstrate that IAA19 and IAA29, which physically interact with auxin response factor7 (ARF7), are sufficient for PIF4 to negatively regulate auxin signaling and phototropism. This study identifies a key step of phototropic signaling in Arabidopsis by showing that PIF4 and PIF5 link light and auxin.

Organic light emitting diode with light extracting layer

DOEpatents

Lu, Songwei

2016-06-14

A light extraction substrate includes a glass substrate having a first surface and a second surface. A light extraction layer is formed on at least one of the surfaces. The light extraction layer is a coating, such as a silicon-containing coating, incorporating nanoparticles.

Plant Light Measurement & Calculations.

ERIC Educational Resources Information Center

Hershey, David R.

1991-01-01

The differences between measuring light intensity for the human eye and for plant photosynthesis are discussed. Conversion factors needed to convert various units of light are provided. Photosynthetic efficiency and the electricity costs for plants to undergo photosynthesis using interior lighting are described. (KR)

Light meson form factors at high Q2 from lattice QCD

NASA Astrophysics Data System (ADS)

Koponen, Jonna; Zimermmane-Santos, André; Davies, Christine; Lepage, G. Peter; Lytle, Andrew

2018-03-01

Measurements and theoretical calculations of meson form factors are essential for our understanding of internal hadron structure and QCD, the dynamics that bind the quarks in hadrons. The pion electromagnetic form factor has been measured at small space-like momentum transfer |q2| < 0.3 GeV2 by pion scattering from atomic electrons and at values up to 2.5 GeV2 by scattering electrons from the pion cloud around a proton. On the other hand, in the limit of very large (or infinite) Q2 = -q2, perturbation theory is applicable. This leaves a gap in the intermediate Q2 where the form factors are not known. As a part of their 12 GeV upgrade Jefferson Lab will measure pion and kaon form factors in this intermediate region, up to Q2 of 6 GeV2. This is then an ideal opportunity for lattice QCD to make an accurate prediction ahead of the experimental results. Lattice QCD provides a from-first-principles approach to calculate form factors, and the challenge here is to control the statistical and systematic uncertainties as errors grow when going to higher Q2 values. Here we report on a calculation that tests the method using an ηs meson, a 'heavy pion' made of strange quarks, and also present preliminary results for kaon and pion form factors. We use the nf = 2 + 1 + 1 ensembles made by the MILC collaboration and Highly Improved Staggered Quarks, which allows us to obtain high statistics. The HISQ action is also designed to have small dicretisation errors. Using several light quark masses and lattice spacings allows us to control the chiral and continuum extrapolation and keep systematic errors in check. Warning, no authors found for 2018EPJWC.17506016.

Lighted display devices for producing static or animated visual displays, including animated facial features

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heilbron, Valerie J; Clem, Paul G; Cook, Adam Wade

An illuminated display device with a base member with a plurality of cavities therein. Illumination devices illuminate the cavities and emit light through an opening of the cavities in a pattern, and a speaker can emit sounds in synchronization with the pattern. A panel with translucent portions can overly the base member and the cavities. An animated talking character can have an animated mouth cavity complex with multiple predetermined mouth lighting configurations simulative of human utterances. The cavities can be open, or optical waveguide material or positive members can be disposed therein. Reflective material can enhance internal reflectance and lightmore » emission.« less

A chemical light meter for forest research

Treesearch

David A. Marquis; George Yelenosky

1961-01-01

Light is one of the most important factors that influence the growth and development of forest trees. Not only is light necessary for the basic process of photosynthesis; light also regulates and modifies other factors of the environment such as temperature and moisture. Yet despite the importance of light, few investigators have succeeded in measuring it adequately in...

Factors controlling charge recombination under dark and light conditions in dye sensitised solar cells.

PubMed

Barnes, Piers R F; Anderson, Assaf Y; Juozapavicius, Mindaugas; Liu, Lingxuan; Li, Xiaoe; Palomares, Emilio; Forneli, Amparo; O'Regan, Brian C

2011-02-28

A simple and powerful approach for assessing the recombination losses in dye sensitised solar cells (DSSCs) across the current voltage curve (j-V) as a function of TiO(2) electron concentration (n) is demonstrated. The total flux of electrons recombining with iodine species in the electrolyte and oxidised dye molecules can be thought of as a recombination current density, defined as j(rec) = j(inj)-j where j(inj) is the current of electrons injected from optically excited dye states and j is the current density collected at cell voltage (V). The electron concentration at any given operating conditions is determined by charge extraction. This allows comparison of factors influencing electron recombination rates at matched n. We show that j(rec) is typically 2-3 times higher under 1 sun equivalent illumination (j(inj) > 0) relative to dark (j(inj) = 0) conditions. This difference was increased by increasing light intensity, electrolyte iodine concentration and electrolyte solvent viscosity. The difference was reduced by increasing the electrolyte iodide concentration and increasing the temperature. These results allowed us to verify a numerical model of complete operational cells (Barnes et al., Phys. Chem. Chem. Phys., DOI: 10.1039/c0cp01554g) and to relate the differences in j(rec) to physical processes in the devices. The difference between j(rec) in the light and dark can be explained by two factors: (1) an increase in the concentration of electron acceptor species (I(3)(-) and/or I(2)) when current is flowing under illumination relative to dark conditions where the current is flowing in the opposite direction, and (2) a non-trivial contribution from electron recombination to oxidised dye molecules under light conditions. More generally, the technique helps to assign the observed relationship between the components, processing and performance of DSSCs to more fundamental physical processes.

Continuous light exposure causes cumulative stress that affects the localization oscillation dynamics of the transcription factor Msn2p.

PubMed

Bodvard, Kristofer; Wrangborg, David; Tapani, Sofia; Logg, Katarina; Sliwa, Piotr; Blomberg, Anders; Kvarnström, Mats; Käll, Mikael

2011-02-01

Light exposure is a potentially powerful stress factor during in vivo optical microscopy studies. In yeast, the general transcription factor Msn2p translocates from the cytoplasm to the nucleus in response to illumination. However, previous time-lapse fluorescence microscopy studies of Msn2p have utilized a variety of discrete exposure settings, which makes it difficult to correlate stress levels and illumination parameters. We here investigate how continuous illumination with blue light, corresponding to GFP excitation wavelengths, affects the localization pattern of Msn2p-GFP in budding yeast. The localization pattern was analyzed using a novel approach that combines wavelet decomposition and change point analysis. It was found that the Msn2p nucleocytoplasmic localization trajectories for individual cells exhibit up to three distinct and successive states; i) Msn2p localizes to the cytoplasm; ii) Msn2p rapidly shuttles between the cytoplasm and the nucleus; iii) Msn2p localizes to the nucleus. Many cells pass through all states consecutively at high light intensities, while at lower light intensities most cells only reach states i) or ii). This behaviour strongly indicates that continuous light exposure gradually increases the stress level over time, presumably through continuous accumulation of toxic photoproducts, thereby forcing the cell through a bistable region corresponding to nucleocytoplasmic oscillations. We also show that the localization patterns are dependent on protein kinase A (PKA) activity, i.e. yeast cells with constantly low PKA activity showed a stronger stress response. In particular, the nucleocytoplasmic oscillation frequency was found to be significantly higher for cells with low PKA activity for all light intensities. 2010 Elsevier B.V. All rights reserved.

Effect of light dispersion of LED curing lights on resin composite polymerization.

PubMed

Vandewalle, Kraig S; Roberts, Howard W; Andrus, Jeffrey L; Dunn, William J

2005-01-01

This study evaluated the effect of light dispersion of halogen and LED curing lights on resin composite polymerization. One halogen (Optilux 501, SDS/Kerr, Orange, CA, USA) and five light-emitting diode (LED) curing lights (SmartLite iQ, Dentsply Caulk, Milford, DE, USA; LEDemetron 1, SDS/Kerr; FLASHlite 1001, Discus Dental, Culver City, CA, USA; UltraLume LED 5, Ultradent Products, South Jordan, UT, USA; Allegro, Den-Mat, Santa Maria, CA, USA) were used in this study. Specimens (8 mm diameter by 2 mm thick) were made in polytetrafluoroethylene molds using hybrid (Z100, 3M ESPE, St. Paul, MN, USA) and microfill (A110, 3M ESPE) composite resins. The top surface was polymerized for 5 seconds with the curing light guide tip positioned at a distance of 1 and 5 mm. Degree of conversion (DC) of the composite specimens was analyzed on the bottom surface using micro-Fourier Transform Infrared (FTIR) spectroscopy (Perkin-Elmer FTIR Spectrometer, Wellesley, PA, USA) 10 minutes after light activation. DC at the bottom of the 2 mm specimen was expressed as a percentage of the mean maximum DC. Five specimens were created per curing light and composite type (n=5). Percent mean DC ratios and SDs were calculated for each light under each testing condition. Data were analyzed by analysis of variance (ANOVA)/Tukey's test (alpha = .05). A beam analyzer (LBA-700, Spiricon, Logan, UT, USA) was used to record the emitted light from the curing lights at 0 and 5 mm distances (n=5). A Top Hat factor was used to compare the quality of the emitted beam profile (LBA/PC, Spiricon). The divergence angle from vertical was also determined in the x- and y-axes (LBA/PC). Mean values and SDs were calculated for each light under each testing condition (0 and 5 mm, x- and y-axes) and analyzed by a two-way ANOVA/Tukey's test (alpha = .05). For DC ratios, significant differences were found based on curing light and curing distance (p < .05). At 1 mm, Optilux 501 and FLASHlite 1001 produced significantly

Energy efficient lighting and communications

NASA Astrophysics Data System (ADS)

Zhou, Z.; Kavehrad, M.; Deng, P.

2012-01-01

As Light-Emitting Diode (LED)'s increasingly displace incandescent lighting over the next few years, general applications of Visible Light Communication (VLC) technology are expected to include wireless internet access, vehicle-to-vehicle communications, broadcast from LED signage, and machine-to-machine communications. An objective in this paper is to reveal the influence of system parameters on the power distribution and communication quality, in a general plural sources VLC system. It is demonstrated that sources' Half-Power Angles (HPA), receivers' Field-Of Views (FOV), sources layout and the power distribution among sources are significant impact factors. Based on our findings, we developed a method to adaptively change working status of each LED respectively according to users' locations. The program minimizes total power emitted while simultaneously ensuring sufficient light intensity and communication quality for each user. The paper also compares Orthogonal Frequency-Division Multiplexing (OFDM) and On-Off Keying (OOK) signals performance in indoor optical wireless communications. The simulation is carried out for different locations where different impulse response distortions are experienced. OFDM seems a better choice than prevalent OOK for indoor VLC due to its high resistance to multi-path effect and delay spread. However, the peak-to-average power limitations of the method must be investigated for lighting LEDs.

Light, plants, and power for life support on Mars

NASA Technical Reports Server (NTRS)

Salisbury, F. B.; Dempster, W. F.; Allen, J. P.; Alling, A.; Bubenheim, D.; Nelson, M.; Silverstone, S.

2002-01-01

Regardless of how well other growing conditions are optimized, crop yields will be limited by the available light up to saturation irradiances. Considering the various factors of clouds on Earth, dust storms on Mars, thickness of atmosphere, and relative orbits, there is roughly 2/3 as much light averaged annually on Mars as on Earth. On Mars, however, crops must be grown under controlled conditions (greenhouse or growth rooms). Because there presently exists no material that can safely be pressurized, insulated, and resist hazards of puncture and deterioration to create life support systems on Mars while allowing for sufficient natural light penetration as well, artificial light will have to be supplied. If high irradiance is provided for long daily photoperiods, the growing area can be reduced by a factor of 3-4 relative to the most efficient irradiance for cereal crops such as wheat and rice, and perhaps for some other crops. Only a small penalty in required energy will be incurred by such optimization. To obtain maximum yields, crops must be chosen that can utilize high irradiances. Factors that increase ability to convert high light into increased productivity include canopy architecture, high-yield index (harvest index), and long-day or day-neutral flowering and tuberization responses. Prototype life support systems such as Bios-3 in Siberia or the Mars on Earth Project need to be undertaken to test and further refine systems and parameters.

Light, plants, and power for life support on Mars.

PubMed

Salisbury, F B; Dempster, W F; Allen, J P; Alling, A; Bubenheim, D; Nelson, M; Silverstone, S

2002-01-01

Regardless of how well other growing conditions are optimized, crop yields will be limited by the available light up to saturation irradiances. Considering the various factors of clouds on Earth, dust storms on Mars, thickness of atmosphere, and relative orbits, there is roughly 2/3 as much light averaged annually on Mars as on Earth. On Mars, however, crops must be grown under controlled conditions (greenhouse or growth rooms). Because there presently exists no material that can safely be pressurized, insulated, and resist hazards of puncture and deterioration to create life support systems on Mars while allowing for sufficient natural light penetration as well, artificial light will have to be supplied. If high irradiance is provided for long daily photoperiods, the growing area can be reduced by a factor of 3-4 relative to the most efficient irradiance for cereal crops such as wheat and rice, and perhaps for some other crops. Only a small penalty in required energy will be incurred by such optimization. To obtain maximum yields, crops must be chosen that can utilize high irradiances. Factors that increase ability to convert high light into increased productivity include canopy architecture, high-yield index (harvest index), and long-day or day-neutral flowering and tuberization responses. Prototype life support systems such as Bios-3 in Siberia or the Mars on Earth Project need to be undertaken to test and further refine systems and parameters.

Trade-off between light availability and soil fertility determine refugial conditions for the relict light-demanding species in lowland forests

NASA Astrophysics Data System (ADS)

Kiedrzyński, Marcin; Kurowski, Józef Krzysztof; Kiedrzyńska, Edyta

2017-11-01

Identifying potential refugial habitats in the face of rapid environmental change is a challenge faced by scientists and nature conservation managers. Relict populations and refugial habitats are the model objects in those studies. Based on the example of Actaea europaea from Central Poland, we analyse the habitat factors influencing relict populations of continental, light-demanding species in lowland forests and examine which habitats of studied species corresponding most closely to ancient vegetation. Our results indicate that the current refugial habitats of Actaea europaea include not only communities which are very similar to ancient open forest but also forests with a closed canopy. Although the populations are influenced by nitrogen and light availability, the co-occurrence of these two factors in forest communities is limited by dense canopy formation by hornbeam and beech trees on fertile soils and in more humid conditions. Our findings indicate that the future survival of relict, light-demanding communities in lowland forests requires low-intensity disturbances to be performed in tree-stands, according to techniques, which imitate traditional forests management.

SUMOylation of phytochrome-B negatively regulates light-induced signaling in Arabidopsis thaliana

PubMed Central

Sadanandom, Ari; Ádám, Éva; Orosa, Beatriz; Viczián, András; Klose, Cornelia; Zhang, Cunjin; Josse, Eve-Marie; Kozma-Bognár, László; Nagy, Ferenc

2015-01-01

The red/far red light absorbing photoreceptor phytochrome-B (phyB) cycles between the biologically inactive (Pr, λmax, 660 nm) and active (Pfr; λmax, 730 nm) forms and functions as a light quality and quantity controlled switch to regulate photomorphogenesis in Arabidopsis. At the molecular level, phyB interacts in a conformation-dependent fashion with a battery of downstream regulatory proteins, including PHYTOCHROME INTERACTING FACTOR transcription factors, and by modulating their activity/abundance, it alters expression patterns of genes underlying photomorphogenesis. Here we report that the small ubiquitin-like modifier (SUMO) is conjugated (SUMOylation) to the C terminus of phyB; the accumulation of SUMOylated phyB is enhanced by red light and displays a diurnal pattern in plants grown under light/dark cycles. Our data demonstrate that (i) transgenic plants expressing the mutant phyBLys996Arg-YFP photoreceptor are hypersensitive to red light, (ii) light-induced SUMOylation of the mutant phyB is drastically decreased compared with phyB-YFP, and (iii) SUMOylation of phyB inhibits binding of PHYTOCHROME INTERACTING FACTOR 5 to phyB Pfr. In addition, we show that OVERLY TOLERANT TO SALT 1 (OTS1) de-SUMOylates phyB in vitro, it interacts with phyB in vivo, and the ots1/ots2 mutant is hyposensitive to red light. Taken together, we conclude that SUMOylation of phyB negatively regulates light signaling and it is mediated, at least partly, by the action of OTS SUMO proteases. PMID:26283376

Can the season of birth risk factor for schizophrenia be prevented by bright light treatment for the second trimester mother around the winter solstice?

PubMed

Schwartz, Paul J

2014-12-01

The season of birth risk factor for schizophrenia exerts a pervasive effect on the global population, particularly at northerly latitudes. The winter infection hypothesis and the low vitamin D hypothesis are both compelling but lack conclusive clinical data. The present work develops a maternal-fetal chronobiological hypothesis for this season of birth risk factor and its prevention by maternal bright light treatment. Around the winter solstice, due to decreased sunlight, the chronobiological apparatus of the at-risk second trimester mother is characterized by a reduced amplitude circadian pacemaker, and a reduced maximum of her nocturnal plasma melatonin concentrations (MTmax) and an increased minimum of her nocturnal core body temperatures (Tmin)--both of which exert adverse effects on the fetal hippocampus and dorsal striatum. The consequences for the fetus include reduced volume and increased excitability of the hippocampus, ventral striatal dysfunction, increased presynaptic nigrostriatal dopamine transmission, and increased propensity for pathological nigrostriatal neuronal phasic firing. Thus, the maternal-fetal chronobiological hypothesis fully accounts for the fetal precursors of the major pathognomonic abnormalities in adults with schizophrenia. Bright light treatment for the second trimester mother around the winter solstice, by increasing maternal circadian amplitude, could possibly prevent the fetal hippocampal and striatal abnormalities and eliminate the season of birth risk factor for schizophrenia. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acceleration of small, light projectiles (including hydrogen isotopes) to high speeds using a two-stage light gas gun

DOE Office of Scientific and Technical Information (OSTI.GOV)

Combs, S.K.; Foust, C.R.; Gouge, M.J.

1990-05-01

Small, light projectiles have been accelerated to high speeds using a two-stage light gas gun at Oak Ridge National Laboratory. With 35-mg plastic projectiles (4 mm in diameter), speeds of up to 4.5 km/s have been recorded. The pipe gun'' technique for freezing hydrogen isotopes {ital in} {ital situ} in the gun barrel has been used to accelerate deuterium pellets (nominal diameter of 4 mm) to velocities of up to 2.85 km/s. The primary application of this technology is for plasma fueling of fusion devices via pellet injection of hydrogen isotopes. Conventional pellet injectors are limited to pellet speeds inmore » the range 1--2 km/s. Higher velocities are desirable for plasma fueling applications, and the two-stage pneumatic technique offers performance in a higher velocity regime. However, experimental results indicate that the use of sabots to encase the cryogenic pellets and protect them from the high peak pressures will be required to reliably attain intact pellets at speeds of {approx}3 km/s or greater. In some limited tests, lithium hydride pellets were accelerated to speeds up to 4.2 km/s. Also, repetitive operation of the two-stage gun (four plastic pellets fired at {approx}0.5 Hz) was demonstrated for the first time in preliminary tests. The equipment and operation are described, and experimental results and some comparisons with a theoretical model are presented.« less

Acceleration of small, light projectiles (including hydrogen isotopes) to high speeds using a two-stage light gas gun

DOE Office of Scientific and Technical Information (OSTI.GOV)

Combs, S.K.; Foust, C.R.; Gouge, M.J.

1989-01-01

Small, light projectiles have been accelerated to high speeds using a two-stage light gas gun at Oak Ridge National Laboratory. With 35-mg plastic projectiles (4 mm in diameter), speeds of up to 4.5 km/s have been recorded. The pipe gun'' technique for freezing hydrogen isotopes in situ in the gun barrel has been used to accelerate deuterium pellets (nominal diameter of 4 mm) to velocities of up to 2.85 km/s. The primary application of this technology is for plasma fueling of fusion devices via pellet injection of hydrogen isotopes. Conventional pellet injectors are limited to pellet speeds in the rangemore » 1-2 km/s. Higher velocities are desirable for plasma fueling applications, and the two-stage pneumatic technique offers performance in a higher velocity regime. However, experimental results indicate that the use of sabots to encase the cryogenic pellets and protect them for the high peak pressures will be required to reliably attain intact pellets at speeds of {approx}3 km/s or greater. In some limited tests, lithium hydride pellets were accelerated to speeds of up to 4.2 km/s. Also, repetitive operation of the two-stage gun (four plastic pellets fired at {approx}0.5 Hz) was demonstrated for the first time in preliminary tests. The equipment and operation are described, and experimental results and some comparisons with a theoretical model are presented. 17 refs., 6 figs., 2 tabs.« less

New rules of thumb maximizing energy efficiency in street lighting with discharge lamps: The general equations for lighting design

NASA Astrophysics Data System (ADS)

Peña-García, A.; Gómez-Lorente, D.; Espín, A.; Rabaza, O.

2016-06-01

New relationships between energy efficiency, illuminance uniformity, spacing and mounting height in public lighting installations were derived from the analysis of a large sample of outputs generated with a widely used software application for lighting design. These new relationships greatly facilitate the calculation of basic lighting installation parameters. The results obtained are also based on maximal energy efficiency and illuminance uniformity as a premise, which are not included in more conventional methods. However, these factors are crucial since they ensure the sustainability of the installations. This research formulated, applied and analysed these new equations. The results of this study highlight their usefulness in rapid planning and urban planning in developing countries or areas affected by natural disasters where engineering facilities and computer applications for this purpose are often unavailable.

Degradation of photovoltaic backsheet materials under multi-factor accelerated UV light exposures

NASA Astrophysics Data System (ADS)

Klinke, Addison G.; Gok, Abdulkerim; Ifeanyi, Silas I.; French, Roger H.; Bruckman, Laura S.

2017-08-01

Long term outdoor durability of photovoltaic (PV) module backsheets is critical to a module's power output over its lifetime. The use of uoropolymer-based backsheets or the addition of stabilizers to polyethylene-terephthalate (PET) and polyamide (PA) type backsheets can help extend their lifetime. This study presents the performance of 21 backsheets made of 8 different material combinations under ASTM G154 Cycle 4 accelerated light exposures. The backsheets were subjected to 4000 hours of high irradiance UVA light at a peak intensity of 1.55 W=m2 at 340 nm at 70°C with and without a condensing humidity cycle at 50°C. Backsheets were evaluated, with repeated measurements, using various evaluation techniques to identify and assess potential signs of degradation. These evaluations included the yellowness index (YI), CIE color space coordinates, and gloss at 20, 60, and 85°. The temporal evolution of the relative color change ΔE was statistically analyzed to develop a stress-response model which used the UVA light dose to predict color change. It was found that the PVF/PET/E backsheet performed the best while PET/PET/E and THV/PET/EVA backsheets performed the worst. Additionally, substantial variation in color change response, attributable to key manufacturing differences, was observed within a given material type.

[Reconstructed ambient light extinction coefficient and its contribution factors in Beijing in January, 2010].

PubMed

Zhu, Li-Hua; Tao, Jun; Chen, Zhong-Ming; Zhao, Yue; Zhang, Ren-Jian; Cao, Jun-Ji

2012-01-01

Aerosol samples for PM2.5 were collected from 1st January to 31st January 2010, in Beijing. The concentrations of organic carbon, elemental carbon, water-solubile ions and soil elements of all particle samples were determined by thermal/optical carbon analyzer, ion chromatography and X-ray fluorescence spectrometer, respectively. The scattering coefficients (b(sp)), absorbing coefficients (b(ap)) and meteorological parameters for this period were also measured. Ambient light extinction coefficients were reconstructed by IMPROVE formula and were compared with measured light extinction coefficients. The results showed that the average mass concentration of PM2.5 was (144.3 +/- 89.1) microg x m(-3) during campaigning period. The average values of measured b(ap), b(sp) and extinction coefficient (b(ext)) were (67.4 +/- 54.3), (328.5 +/- 353.8) and (395.9 +/- 405.2) Mm(-1), respectively. IMPROVE formula is suitable for source apportionment of light extinction coefficient in campaign period. The average value of calculated b'(ext) was (611 +/- 503) Mm(-1) in January, 2010. The major contributors to ambient light extinction coefficients included (NH4) 2SO4 (24.6%), NH4NO3 (11.6%), OM (45.5%), EC (11.9%) and FS (6.4%), respectively.

Mobile lighting apparatus

DOEpatents

Roe, George Michael; Klebanoff, Leonard Elliott; Rea, Gerald W; Drake, Robert A; Johnson, Terry A; Wingert, Steven John; Damberger, Thomas A; Skradski, Thomas J; Radley, Christopher James; Oros, James M; Schuttinger, Paul G; Grupp, David J; Prey, Stephen Carl

2013-05-14

A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.

Multiple coherent light scattering in ultracold rubidium

NASA Astrophysics Data System (ADS)

Kulatunga, P.; Sukenik, C. I.; Havey, M. D.; Kupriyanov, D. V.; Sokolov, I. M.

2001-11-01

We report investigation of multiple coherent light scattering from ^85Rb atoms confined in a magneto-optic trap. In a theoretical study of intensity enhancement of near-resonant backscattered light from cold ^85,87Rb atoms, we consider the dominant mode of double scattering only. Enhancement factors are calculated for all D1 and D2 hyperfine components and for both isotopes. In experimental studies, measurements are made of coherent backscattering of a low-intensity probe beam tuned near the F = 3 - F' = 4 transition in ^85Rb atoms. Polarization of backscattered light is determined by a backscattering polarimeter; the spatial distribution of light intensity is measured by a liquid-nitrogen cooled CCD camera set in the focal plane of the analyzing optics. The instrument has angular resolution of about 100 micro-radians, and a polarization analyzing power of roughly 1000. In this paper we describe the instrument details, including calibration procedures, and progress towards observation of atomic coherent backscattering.

Multiple coherent light scattering in ultracold rubidium

NASA Astrophysics Data System (ADS)

Havey, M. D.; Sukenik, C. I.; Kulatunga, P.; Kupriyanov, D. V.; Sokolov, I. M.

2001-05-01

We report investigation of multiple coherent light scattering from ^85Rb atoms confined in a magneto-optic trap. In a theoretical study of intensity enhancement of near-resonant backscattered light from cold ^85,87Rb atoms, we consider the dominant mode of double scattering only. Enhancement factors are calculated for all D1 and D2 hyperfine components and for both isotopes. In experimental studies, measurements are made of coherent backscattering of a low-intensity probe beam tuned near the F = 3 - F' = 4 transition in ^85Rb atoms. Polarization of backscattered light is determined by a backscattering polarimeter; the spatial distribution of light intensity is measured by a liquid-nitrogen cooled CCD camera set in the focal plane of the analyzing optics. The instrument has angular resolution of about 100 micro-radians, and a polarization analyzing power of roughly 1000. In this paper we describe the instrument details, including calibration procedures, and progress towards observation of atomic coherent backscattering.

Fly-by-light technology development plan

NASA Technical Reports Server (NTRS)

Todd, J. R.; Williams, T.; Goldthorpe, S.; Hay, J.; Brennan, M.; Sherman, B.; Chen, J.; Yount, Larry J.; Hess, Richard F.; Kravetz, J.

1990-01-01

The driving factors and developments which make a fly-by-light (FBL) viable are discussed. Documentation, analyses, and recommendations are provided on the major issues pertinent to facilitating the U.S. implementation of commercial FBL aircraft before the turn of the century. Areas of particular concern include ultra-reliable computing (hardware/software); electromagnetic environment (EME); verification and validation; optical techniques; life-cycle maintenance; and basis and procedures for certification.

Coronary heart disease risk factors in men with light and dark skin in Puerto Rico.

PubMed Central

Costas, R; Garcia-Palmieri, M R; Sorlie, P; Hertzmark, E

1981-01-01

The association of skin color with coronary heart disease risk factors was studied in 4,000 urban Puerto Rican men. Skin color on the inner upper arm was classified according to the von Luschan color tiles. Using this grading, men were separated into two groups of light or dark skin color. The dark group had a lower socioeconomic status (SES) based on income, education, and occupation. Dark men had slightly higher mean systolic blood pressures (SBP) and lower mean serum cholesterol levels than the light, but the relative weights and cigarette smoking habits of both groups were similar. After controlling for the differences in SES, skin color showed a small but statistically significant association with SBP. Whether this association with skin color represents genetic or environmental influences on SBP could not be determined from this study. PMID:7235099

High performance incandescent lighting using a selective emitter and nanophotonic filters

NASA Astrophysics Data System (ADS)

Leroy, Arny; Bhatia, Bikram; Wilke, Kyle; Ilic, Ognjen; Soljačić, Marin; Wang, Evelyn N.

2017-09-01

Previous approaches for improving the efficiency of incandescent light bulbs (ILBs) have relied on tailoring the emitted spectrum using cold-side interference filters that reflect the infrared energy back to the emitter while transmitting the visible light. While this approach has, in theory, potential to surpass light-emitting diodes (LEDs) in terms of luminous efficiency while conserving the excellent color rendering index (CRI) inherent to ILBs, challenges such as low view factor between the emitter and filter, high emitter (>2800 K) and filter temperatures and emitter evaporation have significantly limited the maximum efficiency. In this work, we first analyze the effect of non-idealities in the cold-side filter, the emitter and the view factor on the luminous efficiency. Second, we theoretically and experimentally demonstrate that the loss in efficiency associated with low view factors can be minimized by using a selective emitter (e.g., high emissivity in the visible and low emissivity in the infrared) with a filter. Finally, we discuss the challenges in achieving a high performance and long-lasting incandescent light source including the emitter and filter thermal stability as well as emitter evaporation.

OLED lighting devices having multi element light extraction and luminescence conversion layer

DOEpatents

Krummacher, Benjamin Claus; Antoniadis, Homer

2010-11-16

An apparatus such as a light source has a multi element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

Light Signaling in Bud Outgrowth and Branching in Plants

PubMed Central

Leduc, Nathalie; Roman, Hanaé; Barbier, François; Péron, Thomas; Huché-Thélier, Lydie; Lothier, Jérémy; Demotes-Mainard, Sabine; Sakr, Soulaiman

2014-01-01

Branching determines the final shape of plants, which influences adaptation, survival and the visual quality of many species. It is an intricate process that includes bud outgrowth and shoot extension, and these in turn respond to environmental cues and light conditions. Light is a powerful environmental factor that impacts multiple processes throughout plant life. The molecular basis of the perception and transduction of the light signal within buds is poorly understood and undoubtedly requires to be further unravelled. This review is based on current knowledge on bud outgrowth-related mechanisms and light-mediated regulation of many physiological processes. It provides an extensive, though not exhaustive, overview of the findings related to this field. In parallel, it points to issues to be addressed in the near future. PMID:27135502

SCHOOL LIGHTING

ERIC Educational Resources Information Center

1965

SEVERAL ARTICLES ON SCHOOL LIGHTING ARE CONTAINED IN THIS JOURNAL. THE TITLES AND AUTHORS INCLUDED ARE AS FOLLOWS--(1) "TODAY'S CONCEPTS IN SCHOOL LIGHTING" BY CHARLES D. GIBSON, (2) "CHALLENGE OF TOMMORROW'S LIGHTING" BY S.K. GUTH AND E.H. WITTE, (3) "PEEK PREVIEW OF THE WINDOWLESS SCHOOL" BY JAMES J. MORISSEAU, (4) "MAINTENANCE BEGINS BEFORE…

Light Sources and Lighting Circuits

NASA Astrophysics Data System (ADS)

Honda, Hisashi; Suwa, Takumi; Yasuda, Takeo; Ohtani, Yoshihiko; Maehara, Akiyoshi; Okada, Atsunori; Komatsu, Naoki; Mannami, Tomoaki

means of using filler gas with a higher atomic weight. Regarding fluorescent lamps, studies and developments for longer operating life and improvement in the lumen maintenance factor for the straight-type and circular-type fluorescent lamps were actively pursued. Regarding self-ballasted fluorescent lamps, the main stream of development was aimed at reducing lamp size and increasing energy conservation, and the development of new products that took advantage of these features proceeded. In regard to LED light sources, basic research and product development, including new application development, were vigorously implemented. In basic research, studies were reported, not only on efficacy improvements through optimization of the LED chips, phosphor layers, and packaging technology, but also on photometry, colorimetry, and visual psychology. In the field of application, applications were studied for general lighting sources and also for a wide range of fields, such as automotive headlights and visible light communication. Also, many academic conferences and exhibitions were held domestically and overseas, and the high level of interest suggests high expectations for this next-generation light source. Regarding HID lamps, there was much activity in research and development and in the commercialization of the ceramic metal halide lamp product, and products were commercialized with features such as higher efficiency (130 lm/W) and higher color rendering properties (R9 ≥ 90). In the high-pressure sodium lamps, there were many study reports concerning plant growth and insect pest control using its low insect-attracting characteristics. With high-pressure mercury lamps, there were many reports on reducing lamp size and increasing intensity for use as a light source for projectors.

Stray light characteristics of the diffractive telescope system

NASA Astrophysics Data System (ADS)

Liu, Dun; Wang, Lihua; Yang, Wei; Wu, Shibin; Fan, Bin; Wu, Fan

2018-02-01

Diffractive telescope technology is an innovation solution in construction of large light-weight space telescope. However, the nondesign orders of diffractive optical elements (DOEs) may affect the imaging performance as stray light. To study the stray light characteristics of a diffractive telescope, a prototype was developed and its stray light analysis model was established. The stray light characteristics including ghost, point source transmittance, and veiling glare index (VGI) were analyzed. During the star imaging test of the prototype, the ghost images appeared around the star image as the exposure time of the charge-coupled device improving, consistent with the simulation results. The test result of VGI was 67.11%, slightly higher than the calculated value 57.88%. The study shows that the same order diffraction of the diffractive primary lens and correcting DOE is the main factor that causes ghost images. The stray light sources outside the field of view can illuminate the image plane through nondesign orders diffraction of the primary lens and contributes to more than 90% of the stray light flux on the image plane. In summary, it is expected that these works will provide some guidance for optimizing the imaging performance of diffractive telescopes.

Flexible, liquid core light guide with focusing and light shaping attachments

DOEpatents

Wojcik, Randolph Frank; Majewski, Stanislaw; Zorn, Carl John; Kross, Brian

1999-01-01

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. The end closures include a metal crimping arrangement that utilizes two layers of deformable materials to prevent cracking of endplugs.

Flexible, liquid core light guide with focusing and light shaping attachments

DOEpatents

Wojcik, R.F.; Majewski, S.; Zorn, C.J.; Kross, B.

1999-04-20

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. The end closures include a metal crimping arrangement that utilizes two layers of deformable materials to prevent cracking of endplugs. 19 figs.

Fatal Attraction of Short-Tailed Shearwaters to Artificial Lights

PubMed Central

Rodríguez, Airam; Burgan, Graeme; Dann, Peter; Jessop, Roz; Negro, Juan J.; Chiaradia, Andre

2014-01-01

Light pollution is increasing around the world and altering natural nightscapes with potential ecological and evolutionary consequences. A severe ecological perturbation caused by artificial lights is mass mortalities of organisms, including seabird fledglings that are attracted to lights at night on their first flights to the sea. Here, we report on the number of fledging short-tailed shearwaters Ardenna tenuirostris found grounded in evening and morning rescue patrols conducted at Phillip Island, Australia, during a 15-year period (1999–2013). We assessed factors affecting numbers of grounded birds and mortality including date, moon phase, wind direction and speed, number of visitors and holiday periods. We also tested experimentally if birds were attracted to lights by turning the lights off on a section of the road. Of 8871 fledglings found, 39% were dead or dying. This mortality rate was 4–8 times higher than reported elsewhere for other shearwater species, probably because searching for fledglings was part of our systematic rescue effort rather than the opportunistic rescue used elsewhere. Thus, it suggests that light-induced mortality of seabirds is usually underestimated. We rescued more birds (dead and alive) in peak fledging, moonless and windy nights. Mortality increased through the fledging period, in the mornings and with increased traffic on holiday periods. Turning the road lights off decreased the number of grounded birds (dead and alive). While moon, wind and time are uncontrolled natural constraints, we demonstrated that reduction of light pollution and better traffic management can mitigate artificial light-induced mortality. PMID:25334014

Two-loop matching factors for light quark masses and three-loop mass anomalous dimensions in the RI/SMOM schemes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sturm, C.; Almeida, L.

2010-04-26

Light quark masses can be determined through lattice simulations in regularization invariant momentum-subtraction (RI/MOM) schemes. Subsequently, matching factors, computed in continuum perturbation theory, are used in order to convert these quark masses from a RI/MOM scheme to the {ovr MS} scheme. We calculate the two-loop corrections in QCD to these matching factors as well as the three-loop mass anomalous dimensions for the RI/SMOM and RI/SMOM{sub {gamma}{mu}} schemes. These two schemes are characterized by a symmetric subtraction point. Providing the conversion factors in the two different schemes allows for a better understanding of the systematic uncertainties. The two-loop expansion coefficients ofmore » the matching factors for both schemes turn out to be small compared to the traditional RI/MOM schemes. For n{sub f} = 3 quark flavors they are about 0.6%-0.7% and 2%, respectively, of the leading order result at scales of about 2 GeV. Therefore, they will allow for a significant reduction of the systematic uncertainty of light quark mass determinations obtained through this approach. The determination of these matching factors requires the computation of amputated Green's functions with the insertions of quark bilinear operators. As a by-product of our calculation we also provide the corresponding results for the tensor operator.« less

Corticotropin-Releasing Factor Critical for Zebrafish Camouflage Behavior Is Regulated by Light and Sensitive to Ethanol

PubMed Central

Wagle, Mahendra; Mathur, Priya; Guo, Su

2011-01-01

The zebrafish camouflage response is an innate “hard-wired” behavior that offers an excellent opportunity to explore neural circuit assembly and function. Moreover, the camouflage response is sensitive to ethanol, making it a tractable system for understanding how ethanol influences neural circuit development and function. Here we report the identification of corticotropin releasing factor (CRF) as a critical component of the camouflage response pathway. We further show that ethanol, having no direct effect on the visual sensory system or the melanocytes, acts downstream of retinal ganglion cells and requires the CRF-proopiomelanocortin (POMC) pathway to exert its effect on camouflage. Treatment with ethanol, as well as alteration of light exposure that changes sensory input into the camouflage circuit, robustly modifies CRF expression in subsets of neurons. Activity of both Adenylyl Cyclase 5 and Extracellular signal Regulated Kinase (ERK) is required for such ethanol- or light- induced plasticity of crf expression. These results reveal an essential role of a peptidergic pathway in camouflage that is regulated by light and influenced by ethanol at concentrations relevant to abuse and anxiolysis, in a cAMP- and ERK- dependent manner. We conclude that this ethanol-modulated camouflage response represents a novel and relevant system for molecular genetic dissection of a neural circuit that is regulated by light and sensitive to ethanol. PMID:21209207

Corticotropin-releasing factor critical for zebrafish camouflage behavior is regulated by light and sensitive to ethanol.

PubMed

Wagle, Mahendra; Mathur, Priya; Guo, Su

2011-01-05

The zebrafish camouflage response is an innate "hard-wired" behavior that offers an excellent opportunity to explore neural circuit assembly and function. Moreover, the camouflage response is sensitive to ethanol, making it a tractable system for understanding how ethanol influences neural circuit development and function. Here we report the identification of corticotropin-releasing factor (CRF) as a critical component of the camouflage response pathway. We further show that ethanol, having no direct effect on the visual sensory system or the melanocytes, acts downstream of retinal ganglion cells and requires the CRF-proopiomelanocortin pathway to exert its effect on camouflage. Treatment with ethanol, as well as alteration of light exposure that changes sensory input into the camouflage circuit, robustly modifies CRF expression in subsets of neurons. Activity of both adenylyl cyclase 5 and extracellular signal-regulated kinase (ERK) is required for such ethanol-induced or light-induced plasticity of crf expression. These results reveal an essential role of a peptidergic pathway in camouflage that is regulated by light and influenced by ethanol at concentrations relevant to abuse and anxiolysis, in a cAMP-dependent and ERK-dependent manner. We conclude that this ethanol-modulated camouflage response represents a novel and relevant system for molecular genetic dissection of a neural circuit that is regulated by light and sensitive to ethanol.

Develop a PWL System for Dense Graded Hot Mix Asphalt Construction, Including Pay Factors

DOT National Transportation Integrated Search

2015-01-01

This research project developed a PWL system that the Nevada DOT can effectively implement on the construction of dense graded HMA mixtures. The PWL system includes pay factors that are based on pavement performance indicators such as rutting and cra...

Factors Influencing Injury Severity of Bicyclists Involved in Crashes with Motor Vehicles: Bike Lanes, Alcohol, Lighting, Speed, and Helmet Use.

PubMed

Helak, Kelsey; Jehle, Dietrich; McNabb, Daniel; Battisti, Amanda; Sanford, Steward; Lark, Mary Claire

2017-07-01

In 2014, 726 bicyclists were killed and an additional 50,000 were injured in crashes with motor vehicles. The number of cyclists in the United States is increasing, and as a result there has been a call for more bike lanes. We examined the difference in the severity of injury of bicyclists involved in motor vehicle crashes when riding in the traffic lane compared with riding in a bike lane or on a paved shoulder. We also controlled for other safety factors, including alcohol use, travel speed, posted speed, helmet usage, and lighting conditions to determine their impact on bicyclist safety. Single-year National Automotive Sampling System-General Estimates System files were used to analyze data regarding the bike lanes, and multiyear data were used to analyze the additional factors. Univariate and multiple regression analyses controlling for confounders were performed on the data. When adjusting for speed limit, alcohol use by driver, weather conditions, time of day, and helmet use, the cyclist's position had no significant effect on the severity of injury ( P = 0.57). The severity of injury was significantly greater when the driver or bicyclist had been drinking alcohol ( P < 0.0001 and P < 0.003, respectively). Bicyclists were more severely injured when vehicles moved at greater speeds and the posted speed limit was higher ( P < 0.0001 for both). Also, injury severity was found to be significantly higher when lighting conditions were "dark" ( P < 0.0001). Our findings suggest that simply having a dedicated space for bicyclists, such as a bike lane or a paved shoulder, does not reduce the severity of injuries sustained when a crash with a motor vehicle takes place. Cyclist safety could be improved by implementing changes that affect vehicle speed, alcohol use by drivers, and lighting conditions. Moreover, emergency physicians should be aware that when they receive a report of a cyclist being struck by a car in a bike lane, they should prepare to treat injuries of

Red-light running violation prediction using observational and simulator data.

PubMed

Jahangiri, Arash; Rakha, Hesham; Dingus, Thomas A

2016-11-01

In the United States, 683 people were killed and an estimated 133,000 were injured in crashes due to running red lights in 2012. To help prevent/mitigate crashes caused by running red lights, these violations need to be identified before they occur, so both the road users (i.e., drivers, pedestrians, etc.) in potential danger and the infrastructure can be notified and actions can be taken accordingly. Two different data sets were used to assess the feasibility of developing red-light running (RLR) violation prediction models: (1) observational data and (2) driver simulator data. Both data sets included common factors, such as time to intersection (TTI), distance to intersection (DTI), and velocity at the onset of the yellow indication. However, the observational data set provided additional factors that the simulator data set did not, and vice versa. The observational data included vehicle information (e.g., speed, acceleration, etc.) for several different time frames. For each vehicle approaching an intersection in the observational data set, required data were extracted from several time frames as the vehicle drew closer to the intersection. However, since the observational data were inherently anonymous, driver factors such as age and gender were unavailable in the observational data set. Conversely, the simulator data set contained age and gender. In addition, the simulator data included a secondary (non-driving) task factor and a treatment factor (i.e., incoming/outgoing calls while driving). The simulator data only included vehicle information for certain time frames (e.g., yellow onset); the data did not provide vehicle information for several different time frames while vehicles were approaching an intersection. In this study, the random forest (RF) machine-learning technique was adopted to develop RLR violation prediction models. Factor importance was obtained for different models and different data sets to show how differently the factors influence the

Light Redirective Display Panel And A Method Of Making A Light Redirective Display Panel

DOEpatents

Veligdan, James T.

2005-07-26

An optical display panel which provides improved light intensity at a viewing angle by redirecting light emitting from the viewing screen, and a method of making a light redirective display panel, are disclosed. The panel includes an inlet face at one end for receiving light, and an outlet screen at an opposite end for displaying the light. The inlet face is defined at one end of a transparent body, which body may be formed by a plurality of waveguides, and the outlet screen is defined at an opposite end of the body. The screen includes light redirective elements at the outlet screen for re-directing light emitting from the outlet screen. The method includes stacking a plurality of glass sheets, with a layer of adhesive or epoxy between each sheet, curing the adhesive to form a stack, placing the stack against a saw and cutting the stack at two opposite ends to form a wedge-shaped panel having an inlet face and an outlet face, and forming at the outlet face a plurality of light redirective elements which direct light incident on the outlet face into a controlled light cone.

Light redirective display panel and a method of making a light redirective display panel

DOEpatents

Veligdan, James T.

2002-01-01

An optical display panel which provides improved light intensity at a viewing angle by redirecting light emitting from the viewing screen, and a method of making a light redirective display panel, are disclosed. The panel includes an inlet face at one end for receiving light, and an outlet screen at an opposite end for displaying the light. The inlet face is defined at one end of a transparent body, which body may be formed by a plurality of waveguides, and the outlet screen is defined at an opposite end of the body. The screen includes light redirective elements at the outlet screen for re-directing light emitting from the outlet screen. The method includes stacking a plurality of glass sheets, with a layer of adhesive or epoxy between each sheet, curing the adhesive to form a stack, placing the stack against a saw and cutting the stack at two opposite ends to form a wedge-shaped panel having an inlet face and an outlet face, and forming at the outlet face a plurality of light redirective elements which direct light incident on the outlet face into a controlled light cone.

Light as stress factor to plant roots – case of root halotropism

PubMed Central

Yokawa, Ken; Fasano, Rossella; Kagenishi, Tomoko; Baluška, František

2014-01-01

Despite growing underground, largely in darkness, roots emerge to be very sensitive to light. Recently, several important papers have been published which reveal that plant roots not only express all known light receptors but also that their growth, physiology and adaptive stress responses are light-sensitive. In Arabidopsis, illumination of roots speeds-up root growth via reactive oxygen species-mediated and F-actin dependent process. On the other hand, keeping Arabidopsis roots in darkness alters F-actin distribution, polar localization of PIN proteins as well as polar transport of auxin. Several signaling components activated by phytohormones are overlapping with light-related signaling cascade. We demonstrated that the sensitivity of roots to salinity is altered in the light-grown Arabidopsis roots. Particularly, light-exposed roots are less effective in their salt-avoidance behavior known as root halotropism. Here we discuss these new aspects of light-mediated root behavior from cellular, physiological and evolutionary perspectives. PMID:25566292

Four structural risk factors identify most fibril-forming kappa light chains.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevens, F. J.; Biosciences Division

2000-09-01

Antibody light chains (LCs) comprise the most structurally diverse family of proteins involved in amyloidosis. Many antibody LCs incorporate structural features that impair their stability and solubility, leading to their assembly into fibrils and to their subsequent pathological deposition when produced in excess during multiple myeloma and primary amyloidosis. The particular amino acid variations in antibody LCs that account for fibril formation and amyloidogenesis have not been identified. This study focuses on amyloidogenesis within the Kl family of human LCs. Reanalysis of the current database of primary structures of proteins from more than 100 patients who produced Kl LCS, 37more » of which were amyloidogenic, reveals apparent structural features that may contribute to amyloidosis. These features include loss of conserved residues or the gain of particular residues through mutation at sites involving a repertoire of approximately 20% of the amino acid positions in the light chain variable domain (V{sub L}). Moreover, 80% of all K1 amyloidogenic V{sub L}s are identifiable by the presence of at least one of three single-site substitutions or the acquisition of an N-linked glycosylation site through mutations. These findings suggest that it is feasible to predict fibril propensity by analysis of primary structure.« less

On-road measurements of NMVOCs and NOx: Determination of light-duty vehicles emission factors from tunnel studies in Brussels city center

NASA Astrophysics Data System (ADS)

Ait-Helal, W.; Beeldens, A.; Boonen, E.; Borbon, A.; Boréave, A.; Cazaunau, M.; Chen, H.; Daële, V.; Dupart, Y.; Gaimoz, C.; Gallus, M.; George, C.; Grand, N.; Grosselin, B.; Herrmann, H.; Ifang, S.; Kurtenbach, R.; Maille, M.; Marjanovic, I.; Mellouki, A.; Miet, K.; Mothes, F.; Poulain, L.; Rabe, R.; Zapf, P.; Kleffmann, J.; Doussin, J.-F.

2015-12-01

Emission factors (EFs) of pollutants emitted by light-duty vehicles (LDV) were investigated in the Leopold II tunnel in Brussels city center (Belgium), in September 2011 and in January 2013, respectively. Two sampling sites were housing the instruments for the measurements of a large range of air pollutants, including non-methane volatile organic compounds (NMVOCs), nitrogen oxides (NOx) and carbon dioxide (CO2). The NMVOCs and NOx traffic EFs for LDV were determined from their correlation with CO2 using a single point analysis method. The emission factor of NOx is (544 ± 199) mg vehicle-1 km-1; NMVOCs emission factors vary from (0.26 ± 0.09) mg vehicle-1 km-1 for cis-but-2-ene to (8.11 ± 2.71) mg vehicle-1 km-1 for toluene. Good agreement is observed between the EFs determined in the Leopold II tunnel and the most recent EFs determined in another European roadway tunnel in 2004, with only a slight decrease of the EFs during the last decade. An historical perspective is provided and the observed trend in the NMVOCs emission factors reflect changes in the car fleet composition, the fuels and/or the engine technology that have occurred within the last three decades in Europe.

Photosynthetic light capture and processing from cell to canopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stenberg, P.; DeLucia, E.H.; Schoettle, A.W.

1995-07-01

We have addressed the unique structural features of conifers, as they relate to photosynthetic production, at different levels of organization (from needle to canopy). Many concepts and measures must be defined for conifers so that they are consistent with the structural properties of needles and shoots. Consistency is needed in comparing the photosynthetic performance of conifers and broad leaves, wherein it is important to distinguish the effect of structural factors on light capture from differences in the photosynthetic response at a fixed interception. Needles differ from broad leaves both with respect to inner structure and external shape, which includes amore » continuum from nearly flat to cylindrical. For nonflat three-dimensional objects such as for conifer needles, total surface area is the natural measure. The meaning of the one-sided area of needles is not clear, but consistency requires that it be defined as half the total needle surface area, as concluded. Characteristic structural factors of conifers that affect their ability to harvest light are a deep canopy combined with a small needle size, which create an important penumbra effect, and the clustering of needles on shoots, which creates a discontinuous distribution of needle area. These factors imply that, at a fixed leaf area index, the intercepted PAR would be smaller in coniferous than in broad-leafed canopies, but the vertical gradient of light in conifers is less steep and light reaching the lower canopy is all penumbral (diffuse). Conifers can maintain a higher leaf area index, and this may be accomplished by a more even distribution of light between shoots at different locations in the canopy and also because shade shoots have a structure that effectively intercepts light. Broad leaves in general have higher maximum photosynthetic rates than do needles, and yet conifers are at least equally productive on a stand basis. Possible reasons are discussed.« less

Solid State Light Evaluation in the U.S. Lab Mockup

NASA Technical Reports Server (NTRS)

Maida, James c.; Bowen, Charles K.; Wheelwright, Chuck

2009-01-01

This document constitutes the publication of work performed by the Space Human Factors Laboratory (mail code SF5 at the time) at the Johnson Space Center (JSC) in the months of June and July of 2000. At that time, the Space Human Factors Laboratory was part of the Space Human Factors Branch in the Flight Projects Division of the Space and Life Directorate. This report was originally to be a document for internal consumption only at JSC as it was seen to be only preliminary work for the further development of solid state illumination for general lighting on future space vehicles and the International Space Station (ISS). Due to funding constraints, immediate follow-on efforts were delayed and the need for publication of this document was overcome by other events. However, in recent years and with the development and deployment of a solid state light luminaire prototype on ISS, the time was overdue for publishing this information for general distribution and reference. Solid state lights (SSLs) are being developed to potentially replace the general luminaire assemblies (GLAs) currently in service in the International Space Station (ISS) and included in designs of modules for the ISS. The SSLs consist of arrays of light emitting diodes (LEDs), small solid state electronic devices that produce visible light in proportion to the electrical current flowing through them. Recent progressive advances in electrical power-to-light conversion efficiency in LED technology have allowed the consideration of LEDs as replacements for incandescent and fluorescent light sources in many circumstances, and their inherent advantages in ruggedness, reliability, and life expectancy make them attractive for applications in spacecraft. One potential area of application for the SSLs in the U.S. Laboratory Module of the ISS. This study addresses the suitability of the SSLs as replacements for the GLAs in this application.

Pattern Inspection of EUV Masks Using DUV Light

NASA Astrophysics Data System (ADS)

Liang, Ted; Tejnil, Edita; Stivers, Alan R.

2002-12-01

Inspection of extreme ultraviolet (EUV) lithography masks requires reflected light and this poses special challenges for inspection tool suppliers as well as for mask makers. Inspection must detect all the printable defects in the absorber pattern as well as printable process-related defects. Progress has been made under the NIST ATP project on "Intelligent Mask Inspection Systems for Next Generation Lithography" in assessing the factors that impact the inspection tool sensitivity. We report in this paper the inspection of EUV masks with programmed absorber defects using 257nm light. All the materials of interests for masks are highly absorptive to EUV light as compared to deep ultraviolet (DUV) light. Residues and contamination from mask fabrication process and handling are prone to be printable. Therefore, it is critical to understand their EUV printability and optical inspectability. Process related defects may include residual buffer layer such as oxide, organic contaminants and possible over-etch to the multilayer surface. Both simulation and experimental results will be presented in this paper.

Optical probe with light fluctuation protection

DOEpatents

Da Silva, Luiz B.; Chase, Charles L.

2003-11-11

An optical probe for tissue identification includes an elongated body. Optical fibers are located within the elongated body for transmitting light to and from the tissue. Light fluctuation protection is associated with the optical fibers. In one embodiment the light fluctuation protection includes a reflective coating on the optical fibers to reduce stray light. In another embodiment the light fluctuation protection includes a filler with very high absorption located within the elongated body between the optical fibers.

Odontological light-emitting diode light-curing unit beam quality.

PubMed

de Magalhães Filho, Thales Ribeiro; Weig, Karin de Mello; Werneck, Marcelo Martins; da Costa Neto, Célio Albano; da Costa, Marysilvia Ferreira

2015-05-01

The distribution of light intensity of three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] was calculated. The index is based on the M2 index, which is used for laser beams. An optical spectrum analyzer was used with an optical fiber to produce an x-y power profile of each LCU light guide. The FTF-calculated values were 0.51 for LCU1 and 0.55 for LCU2, which was the best FTF, although it still differed greatly from the perfect FTF = 1, and 0.27 for LCU3, which was the poorest value and even lower than the Gaussian FTF = 0.5. All LCUs presented notably heterogeneous light distribution, which can lead professionals and researchers to produce samples with irregular polymerization and poor mechanical properties.

Odontological light-emitting diode light-curing unit beam quality

NASA Astrophysics Data System (ADS)

de Magalhães Filho, Thales Ribeiro; Weig, Karin de Mello; Werneck, Marcelo Martins; da Costa Neto, Célio Albano; da Costa, Marysilvia Ferreira

2015-05-01

The distribution of light intensity of three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] was calculated. The index is based on the M2 index, which is used for laser beams. An optical spectrum analyzer was used with an optical fiber to produce an x-y power profile of each LCU light guide. The FTF-calculated values were 0.51 for LCU1 and 0.55 for LCU2, which was the best FTF, although it still differed greatly from the perfect FTF=1, and 0.27 for LCU3, which was the poorest value and even lower than the Gaussian FTF=0.5. All LCUs presented notably heterogeneous light distribution, which can lead professionals and researchers to produce samples with irregular polymerization and poor mechanical properties.

DNA Damage Response Factors from Diverse Pathways, Including DNA Crosslink Repair, Mediate Alternative End Joining

PubMed Central

Howard, Sean M.; Yanez, Diana A.; Stark, Jeremy M.

2015-01-01

Alternative end joining (Alt-EJ) chromosomal break repair involves bypassing classical non-homologous end joining (c-NHEJ), and such repair causes mutations often with microhomology at the repair junction. Since the mediators of Alt-EJ are not well understood, we have sought to identify DNA damage response (DDR) factors important for this repair event. Using chromosomal break reporter assays, we surveyed an RNAi library targeting known DDR factors for siRNAs that cause a specific decrease in Alt-EJ, relative to an EJ event that is a composite of Alt-EJ and c-NHEJ (Distal-EJ between two tandem breaks). From this analysis, we identified several DDR factors that are specifically important for Alt-EJ relative to Distal-EJ. While these factors are from diverse pathways, we also found that most of them also promote homologous recombination (HR), including factors important for DNA crosslink repair, such as the Fanconi Anemia factor, FANCA. Since bypass of c-NHEJ is likely important for both Alt-EJ and HR, we disrupted the c-NHEJ factor Ku70 in Fanca-deficient mouse cells and found that Ku70 loss significantly diminishes the influence of Fanca on Alt-EJ. In contrast, an inhibitor of poly ADP-ribose polymerase (PARP) causes a decrease in Alt-EJ that is enhanced by Ku70 loss. Additionally, the helicase/nuclease DNA2 appears to have distinct effects from FANCA and PARP on both Alt-EJ, as well as end resection. Finally, we found that the proteasome inhibitor Bortezomib, a cancer therapeutic that has been shown to disrupt FANC signaling, causes a significant reduction in both Alt-EJ and HR, relative to Distal-EJ, as well as a substantial loss of end resection. We suggest that several distinct DDR functions are important for Alt-EJ, which include promoting bypass of c-NHEJ and end resection. PMID:25629353

No-Light Light Bulbs

ERIC Educational Resources Information Center

Modern Schools, 1976

1976-01-01

A thumbnail sketch of some of the light bulbs manufactured for a purpose other than seeing. These "dark" lamps perform varied tasks including keeping food fresh, detecting and preventing disease, spurring plant growth, heating, and copying printed material. (Author/MLF)

Light intensity as major factor to maximize biomass and lipid productivity of Ettlia sp. in CO2-controlled photoautotrophic chemostat.

PubMed

Seo, Seong-Hyun; Ha, Ji-San; Yoo, Chan; Srivastava, Ankita; Ahn, Chi-Yong; Cho, Dae-Hyun; La, Hyun-Joon; Han, Myung-Soo; Oh, Hee-Mock

2017-11-01

The optimal culture conditions are critical factors for high microalgal biomass and lipid productivity. To optimize the photoautotrophic culture conditions, combination of the pH (regulated by CO 2 supply), dilution rate, and light intensity was systematically investigated for Ettlia sp. YC001 cultivation in a chemostat during 143days. The biomass productivity increased with the increase in dilution rate and light intensity, but decreased with increasing pH. The average lipid content was 19.8% and statistically non-variable among the tested conditions. The highest biomass and lipid productivities were 1.48gL -1 d -1 and 291.4mgL -1 d -1 with a pH of 6.5, dilution rate of 0.78d -1 , and light intensity of 1500μmolphotonsm -2 s -1 . With a sufficient supply of CO 2 and nutrients, the light intensity was the main determinant of the photosynthetic rate. Therefore, the surface-to-volume ratio of a photobioreactor should enable efficient light distribution to enhance microalgal growth. Copyright © 2017 Elsevier Ltd. All rights reserved.

PIF4 and PIF5 Transcription Factors Link Blue Light and Auxin to Regulate the Phototropic Response in Arabidopsis[C][W][OPEN

PubMed Central

Sun, Jiaqiang; Qi, Linlin; Li, Yanan; Zhai, Qingzhe; Li, Chuanyou

2013-01-01

Both blue light (BL) and auxin are essential for phototropism in Arabidopsis thaliana. However, the mechanisms by which light is molecularly linked to auxin during phototropism remain elusive. Here, we report that PHYTOCHROME INTERACTING FACTOR4 (PIF4) and PIF5 act downstream of the BL sensor PHOTOTROPIN1 (PHOT1) to negatively modulate phototropism in Arabidopsis. We also reveal that PIF4 and PIF5 negatively regulate auxin signaling. Furthermore, we demonstrate that PIF4 directly activates the expression of the AUXIN/INDOLE-3-ACETIC ACID (IAA) genes IAA19 and IAA29 by binding to the G-box (CACGTG) motifs in their promoters. Our genetic assays demonstrate that IAA19 and IAA29, which physically interact with AUXIN RESPONSE FACTOR7 (ARF7), are sufficient for PIF4 to negatively regulate auxin signaling and phototropism. This study identifies a key step of phototropic signaling in Arabidopsis by showing that PIF4 and PIF5 link light and auxin. PMID:23757399

Influences of motorcycle rider and driver characteristics and road environment on red light running behavior at signalized intersections.

PubMed

Jensupakarn, Auearree; Kanitpong, Kunnawee

2018-04-01

In Thailand, red light running is considered as one of the most dangerous behaviors at intersection. Red light running (RLR) behavior is the failure to obey the traffic control signal. However, motorcycle riders and car drivers who are running through red lights could be influenced by human factors or road environment at intersection. RLR could be advertent or inadvertent behavior influenced by many factors. Little research study has been done to evaluate the contributing factors influencing the red-light violation behavior. This study aims to determine the factors influencing the red light running behavior including human characteristics, physical condition of intersection, traffic signal operation, and traffic condition. A total of 92 intersections were observed in Chiang Mai, Nakhon Ratchasima, and Chonburi, the major provinces in each region of Thailand. In addition, the socio-economic characteristics of red light runners were obtained from self-reported questionnaire survey. The Binary Logistic Regression and the Multiple Linear Regression models were used to determine the characteristics of red light runners and the factors influencing rates of red light running respectively. The results from this study can help to understand the characteristics of red light runners and factors affecting them to run red lights. For motorcycle riders and car drivers, age, gender, occupation, driving license, helmet/seatbelt use, and the probability to be penalized when running the red light significantly affect RLR behavior. In addition, the results indicated that vehicle travelling direction, time of day, existence of turning lane, number of lanes, lane width, intersection sight distance, type of traffic signal pole, type of traffic signal operation, length of yellow time interval, approaching speed, distance from intersection warning sign to stop line, and pavement roughness significantly affect RLR rates. Copyright © 2018 Elsevier Ltd. All rights reserved.

Driver circuit for solid state light sources

DOEpatents

Palmer, Fred; Denvir, Kerry; Allen, Steven

2016-02-16

A driver circuit for a light source including one or more solid state light sources, a luminaire including the same, and a method of so driving the solid state light sources are provided. The driver circuit includes a rectifier circuit that receives an alternating current (AC) input voltage and provides a rectified AC voltage. The driver circuit also includes a switching converter circuit coupled to the light source. The switching converter circuit provides a direct current (DC) output to the light source in response to the rectified AC voltage. The driver circuit also includes a mixing circuit, coupled to the light source, to switch current through at least one solid state light source of the light source in response to each of a plurality of consecutive half-waves of the rectified AC voltage.

Quantum dot light emitting devices for photomedical applications.

PubMed

Chen, Hao; He, Juan; Lanzafame, Raymond; Stadler, Istvan; Hamidi, Hamid El; Liu, Hui; Celli, Jonathan; Hamblin, Michael R; Huang, Yingying; Oakley, Emily; Shafirstein, Gal; Chung, Ho-Kyoon; Wu, Shin-Tson; Dong, Yajie

2017-03-01

While OLEDs have struggled to find a niche lighting application that can fully take advantage of their unique form factors as thin, flexible, lightweight and uniformly large-area luminaire, photomedical researchers have been in search of low-cost, effective illumination devices with such form factors that could facilitate widespread clinical applications of photodynamic therapy (PDT) or photobiomodulation (PBM). Although existing OLEDs with either fluorescent or phosphorescent emitters cannot achieve the required high power density at the right wavelength windows for photomedicine, the recently developed ultrabright and efficient deep red quantum dot light emitting devices (QLEDs) can nicely fit into this niche. Here, we report for the first time the in-vitro study to demonstrate that this QLED-based photomedical approach could increase cell metabolism over control systems for PBM and kill cancerous cells efficiently for PDT. The perspective of developing wavelength-specific, flexible QLEDs for two critical photomedical fields (wound repair and cancer treatment) will be presented with their potential impacts summarized. The work promises to generate flexible QLED-based light sources that could enable the widespread use and clinical acceptance of photomedical strategies including PDT and PBM.

Quantum dot light emitting devices for photomedical applications

PubMed Central

Chen, Hao; He, Juan; Lanzafame, Raymond; Stadler, Istvan; Hamidi, Hamid El; Liu, Hui; Celli, Jonathan; Hamblin, Michael R.; Huang, Yingying; Oakley, Emily; Shafirstein, Gal; Chung, Ho-Kyoon; Wu, Shin-Tson; Dong, Yajie

2017-01-01

While OLEDs have struggled to find a niche lighting application that can fully take advantage of their unique form factors as thin, flexible, lightweight and uniformly large-area luminaire, photomedical researchers have been in search of low-cost, effective illumination devices with such form factors that could facilitate widespread clinical applications of photodynamic therapy (PDT) or photobiomodulation (PBM). Although existing OLEDs with either fluorescent or phosphorescent emitters cannot achieve the required high power density at the right wavelength windows for photomedicine, the recently developed ultrabright and efficient deep red quantum dot light emitting devices (QLEDs) can nicely fit into this niche. Here, we report for the first time the in-vitro study to demonstrate that this QLED-based photomedical approach could increase cell metabolism over control systems for PBM and kill cancerous cells efficiently for PDT. The perspective of developing wavelength-specific, flexible QLEDs for two critical photomedical fields (wound repair and cancer treatment) will be presented with their potential impacts summarized. The work promises to generate flexible QLED-based light sources that could enable the widespread use and clinical acceptance of photomedical strategies including PDT and PBM. PMID:28867926

Leveraging brightness from transportation lighting systems through light source color.

DOT National Transportation Integrated Search

2013-11-01

Roadway transportation lighting is installed for multiple reasons including traffic safety and pedestrian : security. Judgments of pedestrian safety and security along roadways are not strictly correlated to : specified light levels, but the color of...

International lighting in controlled environments workshop: Proceedings

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1994-12-31

Lighting is a central and critical aspect of control in environmental research for plant research and is gaining recognition as a significant factor to control carefully for animal and human research. Thus this workshop was convened to reevaluate the technology that is available today and to work toward developing guidelines for the most effective use of lighting in controlled environments with emphasis on lighting for plants but also to initiate interest in the development of improved guidelines for human and animal research. There are a number of established guidelines for lighting in human and animal environments. Development of new lightingmore » guidelines is necessary for three reasons: (1) recent scientific discoveries show that in addition to supporting the sensation of vision, light has profound nonvisual biological and behavioral effects in both animals and humans; (2) federal regulations (EPACT 1992) are requiring all indoor environments to become more energy efficient with a specific emphasis on energy conservation in lighting; (3) lighting engineers and manufacturers have developed a wealth of new light sources and lighting products that can be applied in animal and human environments. The workshop was aimed at bringing together plant scientists and physical scientists to interact in the discussions. It involved participation of biological scientists involved in studying mechanisms of light reactions and those involved in utilizing lighting for production of plants and maintenance of animals in controlled environments. It included participation of physical scientists from universities and government involved in research as well as those from industry involved in producing lamps and in construction of controlled growth facilities. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.« less

White LEDs and modules in chip-on-board technology for general lighting

NASA Astrophysics Data System (ADS)

Hartmann, Paul; Wenzl, Franz P.; Sommer, Christian; Pachler, Peter; Hoschopf, Hans; Schweighart, Marko; Hartmann, Martin; Kuna, Ladislav; Jakopic, Georg; Leising, Guenther; Tasch, Stefan

2006-08-01

At present, light-emitting diode (LED) modules in various shapes are developed and designed for the general lighting, advertisement, emergency lighting, design and architectural markets. To compete with and to surpass the performance of traditional lighting systems, enhancement of Lumen output and the white light quality as well as the thermal management and the luminary integration are key factors for success. Regarding these issues, white LEDs based on the chip-on-board (COB) technology show pronounced advantages. State-of-the-art LEDs exploiting this technology are now ready to enter the general lighting segments. We introduce and discuss the specific properties of the Tridonic COB technology dedicated for general lighting. This technology, in combination with a comprehensive set of tools to improve and to enhance the Lumen output and the white light quality, including optical simulation, is the scaffolding for the application of white LEDs in emerging areas, for which an outlook will be given.

Effects of light wavelength and coherence in structured light sensors

NASA Astrophysics Data System (ADS)

Harding, Kevin; Ramamurthy, Rajesh; Zhai, Zirong; Han, Jie; Yang, Dongmin

2016-05-01

Structured light methods are used by many commercial products on the market today. Many such systems using white light projectors while many line gages use standard red laser diodes. However, in recent years there has been much claimed about using blue light, polarized light and partially coherent systems to obtain better performance. Unlike interferometers, moving from red to blue light for a system using only geometric shape information does not gain an automatic advantage from the shorter wavelength. The sensitivity metric does not have a wavelength component to it. But there are other factors that can improve gage performance. The ability to measure some feature is also a function of other parameters such as signal to noise ratio, reflectivity variations, and depth-of-field over which a clear pattern can be seen. This paper will explore the theoretical and experimental data relating to what works and what can be expected from variations on the old methods.

Myb transcription factors and light regulate sporulation in the oomycete Phytophthora infestans.

PubMed

Xiang, Qijun; Judelson, Howard S

2014-01-01

Life cycle progression in eukaryotic microbes is often influenced by environment. In the oomycete Phytophthora infestans, which causes late blight on potato and tomato, sporangia have been reported to form mostly at night. By growing P. infestans under different light regimes at constant temperature and humidity, we show that light contributes to the natural pattern of sporulation by delaying sporulation until the following dark period. However, illumination does not permanently block sporulation or strongly affect the total number of sporangia that ultimately form. Based on measurements of sporulation-induced genes such as those encoding protein kinase Pks1 and Myb transcription factors Myb2R1 and Myb2R3, it appears that most spore-associated transcripts start to rise four to eight hours before sporangia appear. Their mRNA levels oscillate with the light/dark cycle and increase with the amount of sporangia. An exception to this pattern of expression is Myb2R4, which is induced several hours before the other genes and declines after cultures start to sporulate. Transformants over-expressing Myb2R4 produce twice the number of sporangia and ten-fold higher levels of Myb2R1 mRNA than wild-type, and chromatin immunoprecipitation showed that Myb2R4 binds the Myb2R1 promoter in vivo. Myb2R4 thus appears to be an early regulator of sporulation. We attempted to silence eight Myb genes by DNA-directed RNAi, but succeeded only with Myb2R3, which resulted in suppressed sporulation. Ectopic expression studies of seven Myb genes revealed that over-expression frequently impaired vegetative growth, and in the case of Myb3R6 interfered with sporangia dormancy. We observed that the degree of silencing induced by a hairpin construct was correlated with its copy number, and ectopic expression was often unstable due to epigenetic silencing and transgene excision.

Myb Transcription Factors and Light Regulate Sporulation in the Oomycete Phytophthora infestans

PubMed Central

Xiang, Qijun; Judelson, Howard S.

2014-01-01

Life cycle progression in eukaryotic microbes is often influenced by environment. In the oomycete Phytophthora infestans, which causes late blight on potato and tomato, sporangia have been reported to form mostly at night. By growing P. infestans under different light regimes at constant temperature and humidity, we show that light contributes to the natural pattern of sporulation by delaying sporulation until the following dark period. However, illumination does not permanently block sporulation or strongly affect the total number of sporangia that ultimately form. Based on measurements of sporulation-induced genes such as those encoding protein kinase Pks1 and Myb transcription factors Myb2R1 and Myb2R3, it appears that most spore-associated transcripts start to rise four to eight hours before sporangia appear. Their mRNA levels oscillate with the light/dark cycle and increase with the amount of sporangia. An exception to this pattern of expression is Myb2R4, which is induced several hours before the other genes and declines after cultures start to sporulate. Transformants over-expressing Myb2R4 produce twice the number of sporangia and ten-fold higher levels of Myb2R1 mRNA than wild-type, and chromatin immunoprecipitation showed that Myb2R4 binds the Myb2R1 promoter in vivo. Myb2R4 thus appears to be an early regulator of sporulation. We attempted to silence eight Myb genes by DNA-directed RNAi, but succeeded only with Myb2R3, which resulted in suppressed sporulation. Ectopic expression studies of seven Myb genes revealed that over-expression frequently impaired vegetative growth, and in the case of Myb3R6 interfered with sporangia dormancy. We observed that the degree of silencing induced by a hairpin construct was correlated with its copy number, and ectopic expression was often unstable due to epigenetic silencing and transgene excision. PMID:24704821

The promoter structure differentiation of a MYB transcription factor RLC1 causes red leaf coloration in Empire Red Leaf Cotton under light.

PubMed

Gao, Zhenrui; Liu, Chuanliang; Zhang, Yanzhao; Li, Ying; Yi, Keke; Zhao, Xinhua; Cui, Min-Long

2013-01-01

The red leaf coloration of Empire Red Leaf Cotton (ERLC) (Gossypium hirsutum L.), resulted from anthocyanin accumulation in light, is a well known dominant agricultural trait. However, the underpin molecular mechanism remains elusive. To explore this, we compared the molecular biological basis of anthocyanin accumulation in both ERLC and the green leaf cotton variety CCRI 24 (Gossypium hirsutum L.). Introduction of R2R3-MYB transcription factor Rosea1, the master regulator anthocyanin biosynthesis in Antirrhinum majus, into CCRI 24 induced anthocyanin accumulation, indicating structural genes for anthocyanin biosynthesis are not defected and the leaf coloration might be caused by variation of regulatory genes expression. Expression analysis found that a transcription factor RLC1 (Red Leaf Cotton 1) which encodes the ortholog of PAP1/Rosea1 was highly expressed in leaves of ERLC but barely expressed in CCRI 24 in light. Ectopic expression of RLC1 from ERLC and CCRI 24 in hairy roots of Antirrhinum majus and CCRI 24 significantly enhanced anthocyanin accumulation. Comparison of RLC1 promoter sequences between ERLC and CCRI 24 revealed two 228-bp tandem repeats presented in ERLC with only one repeat in CCRI 24. Transient assays in cotton leave tissue evidenced that the tandem repeats in ERLC is responsible for light-induced RLC1 expression and therefore anthocyanin accumulation. Taken together, our results in this article strongly support an important step toward understanding the role of R2R3-MYB transcription factors in the regulatory menchanisms of anthocyanin accumulation in red leaf cotton under light.

Lighting: Traffic Safety Tips

DOT National Transportation Integrated Search

1996-01-01

This fact sheet, NHTSA Facts: Summer 1996, discusses traffic safety tips on motor vehicle lighting, including headlights, tail lights, and signal lights. It details the cleaning of headlamps, proper aiming of headlamps, and replacement of burned out ...

Patterns of Daily Outdoor Light Exposure in Australian and Singaporean Children.

PubMed

Read, Scott A; Vincent, Stephen J; Tan, Chuen-Seng; Ngo, Cheryl; Collins, Michael J; Saw, Seang-Mei

2018-05-01

Myopia is rising in prevalence in many locations, and there is evidence that outdoor light exposure is a major environmental factor playing a role in myopia development. This study examined the patterns of daily light exposure in similarly aged children from two geographic locations (Australia and Singapore) known to exhibit differences in myopia prevalence. Wearable light sensors were used to assess daily light exposure in 69 Singaporean children aged 8 to 12 years (mean, 9.2 ± 1.1) and 43 Australian children aged 10 to 12 years (mean, 11.3 ± 0.6). The mean daily time exposed to bright outdoor light (>1000 lux) and the number and duration of daily episodes of outdoor exposure were examined. Patterns of daily outdoor light exposure differed substantially between Australia and Singapore. Australian children (105 ± 42 min/d) experienced significantly longer daily outdoor light exposure than Singaporean children (61 ± 40 min/d; P = 0.005), with the largest differences found on weekdays during school hours. Australian children (6.9 ± 1.5 episodes per day) had more frequent daily episodes of outdoor light exposure compared with Singaporean children (4.6 ± 1.5; P = 0.02); however, there was no significant difference in the mean duration of these episodes between countries ( P = 0.54). Children living in Singapore were exposed to significantly less daily outdoor light than Australian children, and these differences may be one of several factors contributing to the differences in myopia prevalence typically found between these populations. Knowledge of these light exposure patterns may assist in the design of outdoor interventions, including school programs, to increase outdoor time in urban Asian populations.

Illuminating system and method for specialized and decorative lighting using liquid light guides

DOEpatents

Zorn, Carl J.; Kross, Brian J.; Majewski, Stanislaw; Wojcik, Randolph F.

1998-01-01

The present invention comprises an illumination system for specialized decorative lighting including a light source, a flexible plastic tube sheath for distributing the light to a remote location, a transparent liquid core filling the tube that has an index of refraction greater than that of the plastic tube and an arrangement where light coupled from the light source is caused to leak from the liquid light guide at desired locations for the purposes of specialized lighting, such as underwater illumination in swimming pools.

Analysis of vehicle classification data, including monthly and seasonal ADT factors, hourly distribution factors, and lane distribution factors

DOT National Transportation Integrated Search

1998-11-01

This report documents the development of monthly and seasonal average daily traffic (ADT) factors for performing estimating AADTs. It appears that seasonal factors can estimate AADT as well as monthly factors, and it is recommended that seasonal fact...

Dependency between light intensity and refractive development under light-dark cycles.

PubMed

Cohen, Yuval; Belkin, Michael; Yehezkel, Oren; Solomon, Arieh S; Polat, Uri

2011-01-01

The emmetropization process involves fine-tuning the refractive state by altering the refractive components toward zero refraction. In this study, we provided light-dark cycle conditions at several intensities and examined the effect of light intensity on the progression of chicks' emmetropization. Chicks under high-, medium-, and low-light intensities (10,000, 500, and 50 lux, respectively) were followed for 90 days by retinoscopy, keratometry, as well as ultrasound measurements. Emmetropization was reached from days 30-50 and from days 50-60 for the low- and medium-intensity groups, respectively. On day 90, most chicks in the low-intensity group were myopic, with a mean refraction of -2.41D (95% confidence interval (CI) -2.9 to -1.8D), whereas no chicks in the high-intensity group developed myopia, but they exhibited a stable mean hyperopia of +1.1D. The medium-intensity group had a mean refraction of +0.03D. The low-intensity group had a deeper vitreous chamber depth and a longer axial length compared with the high-intensity group, and shifted refraction to the myopic side. The low-intensity group had a flatter corneal curvature, a deeper anterior chamber, and a thinner lens compared with the high-intensity group, and shifted refraction to the hyperopic side. In all groups the corneal power was correlated with the three examined levels of log light intensity for all examined times (e.g., day 20 r = 0.6 P < 0.0001, day 90 r = 0.56 P < 0.0001). Thus, under light-dark cycles, light intensity is an environmental factor that modulates the process of emmetropization, and the low intensity of ambient light is a risk factor for developing myopia. Copyright © 2010 Elsevier Ltd. All rights reserved.

Seeing the Light: The Roles of Red- and Blue-Light Sensing in Plant Microbes.

PubMed

Beattie, Gwyn A; Hatfield, Bridget M; Dong, Haili; McGrane, Regina S

2018-05-16

Plants collect, concentrate, and conduct light throughout their tissues, thus enhancing light availability to their resident microbes. This review explores the role of photosensing in the biology of plant-associated bacteria and fungi, including the molecular mechanisms of red-light sensing by phytochromes and blue-light sensing by LOV (light-oxygen-voltage)-domain proteins in these microbes. Bacteriophytochromes function as major drivers of the bacterial transcriptome and mediate light-regulated suppression of virulence, motility, and conjugation in some phytopathogens and light-regulated induction of the photosynthetic apparatus in a stem-nodulating symbiont. Bacterial LOV proteins also influence light-mediated changes in both symbiotic and pathogenic phenotypes. Although red-light sensing by fungal phytopathogens is poorly understood, fungal LOV proteins contribute to blue-light regulation of traits, including asexual development and virulence. Collectively, these studies highlight that plant microbes have evolved to exploit light cues and that light sensing is often coupled with sensing other environmental signals. Expected final online publication date for the Annual Review of Phytopathology Volume 56 is August 25, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Illuminating system and method for specialized and decorative lighting using liquid light guides

DOEpatents

Zorn, C.J.; Kross, B.J.; Majewski, S.; Wojcik, R.F.

1998-08-25

The present invention comprises an illumination system for specialized decorative lighting including a light source, a flexible plastic tube sheath for distributing the light to a remote location, a transparent liquid core filling the tube that has an index of refraction greater than that of the plastic tube and an arrangement where light coupled from the light source is caused to leak from the liquid light guide at desired locations for the purposes of specialized lighting, such as underwater illumination in swimming pools. 5 figs.

The effects of deterioration and technological levels on pollutant emission factors for gasoline light-duty trucks.

PubMed

Zhang, Qingyu; Fan, Juwang; Yang, Weidong; Chen, Bixin; Zhang, Lijuan; Liu, Jiaoyu; Wang, Jingling; Zhou, Chunyao; Chen, Xuan

2017-07-01

Vehicle deterioration and technological change influence emission factors (EFs). In this study, the impacts of vehicle deterioration and emission standards on EFs of regulated pollutants (carbon monoxide [CO], hydrocarbon [HC], and nitrogen oxides [NO x ]) for gasoline light-duty trucks (LDTs) were investigated according to the inspection and maintenance (I/M) data using a chassis dynamometer method. Pollutant EFs for LDTs markedly varied with accumulated mileages and emission standards, and the trends of EFs are associated with accumulated mileages. In addition, the study also found that in most cases, the median EFs of CO, HC, and NO x are higher than those of basic EFs in the International Vehicle Emissions (IVE) model; therefore, the present study provides correction factors for the IVE model relative to the corresponding emission standards and mileages. Currently, vehicle emissions are great contributors to air pollution in cities, especially in developing countries. Emission factors play a key role in creating emission inventory and estimating emissions. Deterioration represented by vehicle age and accumulated mileage and changes of emission standards markedly influence emission factors. In addition, the results provide collection factors for implication in the IVE model in the region levels.

[Influence of light and temperature factors on biomass accumulation of winter wheat in field].

PubMed

Ma, Peng-li; Pu, Jin-yong; Zhao, Chun-yu; Wang, Wei-tai

2010-05-01

To explore the influence of light and temperature factors on the biomass accumulation of winter wheat at its development stages and in different organs, this paper analyzed the variation patterns of the biomass accumulation and the influence of TEP (thermal effectiveness photosynthetically active radiation) on the accumulation at each development stage, based on the observation data from the Xifen Agrometeorological Experiment Station in Gansu Province, including winter wheat phenophase and yield factors in 1981-2008, biomass at three-leaf, over-wintering, jointing, heading, milky maturity, and maturity stages in 1995-2008, and meteorological data in 1995-2008. The biomass accumulation of winter wheat in its whole growth period presented "S" curve, with the maximum value at heading-milky maturity stage. Since 1981, the TEP at heading-milky maturity stage increased with a rate of 3. 314 MJ x m(-2) x a(-1), and the TEP at other stages varied as parable curves. The TEP at turning green-jointing and milky maturity-maturity stages had a higher value in the 1990s and a lower value in the 1980s and early 21st century, while that at jointing-heading stage had a lower value in the 1990s but a higher value in the 1980s and early 21st century. There was a significant correlation between the TEP at each development stage and the actual yield. The LAI (leaf area index) at each development stage also had a significant correlation with the utilization rate of TEP at corresponding stage. When the LAI at jointing and heading stages was increased by 1, the utilization rate of TEP was correspondingly increased by 0.049 and 0.259 g x MJ(-1), respectively.

Luminance requirements for lighted signage

NASA Astrophysics Data System (ADS)

Freyssinier, Jean Paul; Narendran, Nadarajah; Bullough, John D.

2006-08-01

Light-emitting diode (LED) technology is presently targeted to displace traditional light sources in backlighted signage. The literature shows that brightness and contrast are perhaps the two most important elements of a sign that determine its attention-getting capabilities and its legibility. Presently, there are no luminance standards for signage, and the practice of developing brighter signs to compete with signs in adjacent businesses is becoming more commonplace. Sign luminances in such cases may far exceed what people usually need for identifying and reading a sign. Furthermore, the practice of higher sign luminance than needed has many negative consequences, including higher energy use and light pollution. To move toward development of a recommendation for lighted signage, several laboratory human factors evaluations were conducted. A scale model of a storefront was used to present human subjects with a typical red channel-letter sign at luminances ranging from 8 cd/m2 to 1512 cd/m2 under four background luminances typical of nighttime outdoor and daytime inside-mall conditions (1, 100, 300, 1000 cd/m2), from three scaled viewing distances (30, 60, 340 ft), and either in isolation or adjacent to two similar signs. Subjects rated the brightness, acceptability, and ease of reading of the test sign for each combination of sign and background luminances and scaled viewing distances.

Nrf2 protects photoreceptor cells from photo-oxidative stress induced by blue light.

PubMed

Chen, Wan-Ju; Wu, Caiying; Xu, Zhenhua; Kuse, Yoshiki; Hara, Hideaki; Duh, Elia J

2017-01-01

Oxidative stress plays a key role in age-related macular degeneration and hereditary retinal degenerations. Light damage in rodents has been used extensively to model oxidative stress-induced photoreceptor degeneration, and photo-oxidative injury from blue light is particularly damaging to photoreceptors. The endogenous factors protecting photoreceptors from oxidative stress, including photo-oxidative stress, are continuing to be elucidated. In this study, we evaluated the effect of blue light exposure on photoreceptors and its relationship to Nrf2 using cultured murine photoreceptor (661W) cells. 661W cells were exposed to blue light at 2500 lux. Exposure to blue light for 6-24 h resulted in a significant increase in intracellular reactive oxygen species (ROS) and death of 661W cells in a time-dependent fashion. Blue light exposure resulted in activation of Nrf2, as indicated by an increase in nuclear translocation of Nrf2. This was associated with a significant induction of expression of Nrf2 as well as an array of Nrf2 target genes, including antioxidant genes, as indicated by quantitative reverse transcription PCR (qRT-PCR). In order to determine the functional role of Nrf2, siRNA-mediated knockdown studies were performed. Nrf2-knockdown in 661W cells resulted in significant exacerbation of blue light-induced reactive oxygen species levels as well as cell death. Taken together, these findings indicate that Nrf2 is an important endogenous protective factor against oxidative stress in photoreceptor cells. This suggests that drugs targeting Nrf2 could be considered as a neuroprotective strategy for photoreceptors in AMD and other retinal conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of coloured lighting on the perception of interior spaces.

PubMed

Odabaşioğlu, Seden; Olguntürk, Nіlgün

2015-02-01

Use of coloured lighting in interior spaces has become prevalent in recent years. Considerable importance is ascribed to coloured lighting in interior and lighting design. The effects of colour on the perception of interior spaces have been studied as surface colour; but here, the effects of three different types of chromatic light were investigated. The lighting differed in colour (red, green and white) and perceptions of interior space were assessed. 97 participants (59 women, 38 men; M age = 21.4 yr.) evaluated the experiment room on a questionnaire assessing eight evaluative factors: Pleasantness, Arousal, Aesthetics, Usefulness, Comfort, Spaciousness, Colour, and Lighting quality. Perceptions of the room differed by colour of lighting for some of the evaluative factors, but there was no sex difference in perceptions. Interior spaces may be perceived as equally pleasant under white, green and red lighting. Under white lighting a space is perceived as more useful, spacious, clear, and luminous. Green lighting would make the same effect. Green and white lighting were perceived equally comfortable in an interior space. Chromatic coloured lighting was perceived to be more aesthetic than white lighting. The results support previous findings for some evaluative factors, but differed for others.

Influence of light on the biosynthesis of ophiobolin A by Bipolaris maydis.

PubMed

Fanelli, Francesca; Reveglia, Pierluigi; Masi, Marco; Mulè, Giuseppina; Zonno, Maria Chiara; Cimmino, Alessio; Vurro, Maurizio; Evidente, Antonio

2017-04-01

Ophiobolin A (O-A) is a sesterpenoid with numerous biological activities, including potential anticancer effects. Its production at an industrial level is hampered due to inability of fungus Bipolaris maydis to biosynthesise it in vitro in large amount. Among the environmental factors regulating fungal metabolism, light plays a crucial role. In this study, the use of different light wavelength (light emitting diodes (LEDs)) was evaluated to increase the O-A production. The white light allowed the highest production of the metabolite. The blue and green lights showed an inhibitory effect, reducing the production to 50%, as well as red and yellow but at a lower level. No correlation between fungal growth and metabolite production was found in relation to the light type. A novel application of LED technologies, which can be optimised to foster specific pathways and promote the production of metabolites having scientific and industrial interest was proposed.

Optimization of Light-Harvesting Pigment Improves Photosynthetic Efficiency.

PubMed

Jin, Honglei; Li, Mengshu; Duan, Sujuan; Fu, Mei; Dong, Xiaoxiao; Liu, Bing; Feng, Dongru; Wang, Jinfa; Wang, Hong-Bin

2016-11-01

Maximizing light capture by light-harvesting pigment optimization represents an attractive but challenging strategy to improve photosynthetic efficiency. Here, we report that loss of a previously uncharacterized gene, HIGH PHOTOSYNTHETIC EFFICIENCY1 (HPE1), optimizes light-harvesting pigments, leading to improved photosynthetic efficiency and biomass production. Arabidopsis (Arabidopsis thaliana) hpe1 mutants show faster electron transport and increased contents of carbohydrates. HPE1 encodes a chloroplast protein containing an RNA recognition motif that directly associates with and regulates the splicing of target RNAs of plastid genes. HPE1 also interacts with other plastid RNA-splicing factors, including CAF1 and OTP51, which share common targets with HPE1. Deficiency of HPE1 alters the expression of nucleus-encoded chlorophyll-related genes, probably through plastid-to-nucleus signaling, causing decreased total content of chlorophyll (a+b) in a limited range but increased chlorophyll a/b ratio. Interestingly, this adjustment of light-harvesting pigment reduces antenna size, improves light capture, decreases energy loss, mitigates photodamage, and enhances photosynthetic quantum yield during photosynthesis. Our findings suggest a novel strategy to optimize light-harvesting pigments that improves photosynthetic efficiency and biomass production in higher plants. © 2016 American Society of Plant Biologists. All Rights Reserved.

Outdoor Lighting Ordinances

NASA Astrophysics Data System (ADS)

Davis, S.

2004-05-01

A principal means to prevent poor exterior lighting practices is a lighting control ordinance. It is an enforceable legal restriction on specific lighting practices that are deemed unacceptable by the government body having jurisdiction. Outdoor lighting codes have proven to be effective at reducing polluting and trespassing light. A well written exterior lighting code will permit all forms of necessary illumination at reasonable intensities, but will demand shielding and other measures to prevent trespass and light pollution. A good code will also apply to all forms of outdoor lighting, including streets, highways, and exterior signs, as well as the lighting on dwellings, commercial and industrial buildings and building sites. A good code can make exceptions for special uses, provided it complies with an effective standard. The IDA Model Lighting Ordinance is a response to these requests. It is intended as an aid to communities that are seeking to take control of their outdoor lighting, to "take back the night" that is being lost to careless and excessive use of night lighting.

Chromatic aberration of light focusing in hyperbolic anisotropic metamaterial made of metallic slit array.

PubMed

Guo, Kai; Liu, Jianlong; Zhang, Yan; Liu, Shutian

2012-12-17

The dispersion of a hyperbolic anisotropic metamaterial (HAM) and the chromatic aberration of light focusing in this kind of HAM are studied. The HAM is formed by alternately stacking metal and dielectric layers. The rules of materials and filling factors affecting the optical property of HAM are given. The chromatic aberration of light focusing is demonstrated both theoretically and numerically. By comparing the theory with the simulation results, the factors influencing the focal length, including the heat loss of material and low spatial frequency modes, are discussed. The investigation emphasizes the anomalous properties, such as chromatic aberration and low spatial frequency modes influencing focus position, of HAM compared with that in conventional lens. Based on the analysis, the possibility of using HAM to focus light with two different wavelengths at the same point is studied.

Device structure for OLED light device having multi element light extraction and luminescence conversion layer

DOEpatents

Antoniadis,; Homer, Krummacher [Mountain View, CA; Claus, Benjamin [Regensburg, DE

2008-01-22

An apparatus such as a light source has a multi-element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

Multisite Light-Induced Phosphorylation of the Transcription Factor PIF3 Is Necessary for Both Its Rapid Degradation and Concomitant Negative Feedback Modulation of Photoreceptor phyB Levels in Arabidopsis[C][W

PubMed Central

Ni, Weimin; Xu, Shou-Ling; Chalkley, Robert J.; Pham, Thao Nguyen D.; Guan, Shenheng; Maltby, Dave A.; Burlingame, Alma L.; Wang, Zhi-Yong; Quail, Peter H.

2013-01-01

Plants constantly monitor informational light signals using sensory photoreceptors, which include the phytochrome (phy) family (phyA to phyE), and adjust their growth and development accordingly. Following light-induced nuclear translocation, photoactivated phy molecules bind to and induce rapid phosphorylation and degradation of phy-interacting basic Helix Loop Helix (bHLH) transcription factors (PIFs), such as PIF3, thereby regulating the expression of target genes. However, the mechanisms underlying the signal-relay process are still not fully understood. Here, using mass spectrometry, we identify multiple, in vivo, light-induced Ser/Thr phosphorylation sites in PIF3. Using transgenic expression of site-directed mutants of PIF3, we provide evidence that a set of these phosphorylation events acts collectively to trigger rapid degradation of the PIF3 protein in response to initial exposure of dark-grown seedlings to light. In addition, we show that phyB-induced PIF3 phosphorylation is also required for the known negative feedback modulation of phyB levels in prolonged light, potentially through codegradation of phyB and PIF3. This mutually regulatory intermolecular transaction thus provides a mechanism with the dual capacity to promote early, graded, or threshold regulation of the primary, PIF3-controlled transcriptional network in response to initial light exposure, and later, to attenuate global sensitivity to the light signal through reductions in photoreceptor levels upon prolonged exposure. PMID:23903316

Photodetector with enhanced light absorption

DOEpatents

Kane, James

1985-01-01

A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

Analysis of the injury severity of crashes by considering different lighting conditions on two-lane rural roads.

PubMed

Jafari Anarkooli, A; Hadji Hosseinlou, M

2016-02-01

Many studies have examined different factors contributing to the injury severity of crashes; however, relatively few studies have focused on the crashes by considering the specific effects of lighting conditions. This research investigates lighting condition differences in the injury severity of crashes using 3-year (2009-2011) crash data of two-lane rural roads of the state of Washington. Separate ordered-probit models were developed to predict the effects of a set of factors expected to influence injury severity in three lighting conditions; daylight, dark, and dark with street lights. A series of likelihood ratio tests were conducted to determine if these lighting condition models were justified. The modeling results suggest that injury severity in specific lighting conditions are associated with contributing factors in different ways, and that such differences cannot be uncovered by focusing merely on one aggregate model. Key differences include crash location, speed limit, shoulder width, driver action, and three collision types (head-on, rear-end, and right-side impact collisions). This paper highlights the importance of deploying street lights at and near intersections (or access points) on two-lane rural roads because injury severity highly increases when crashes occur at these points in dark conditions. Copyright © 2016 Elsevier Ltd and National Safety Council. All rights reserved.

Large-area high-efficiency flexible PHOLED lighting panels

NASA Astrophysics Data System (ADS)

Pang, Huiqing; Mandlik, Prashant; Levermore, Peter A.; Silvernail, Jeff; Ma, Ruiqing; Brown, Julie J.

2012-09-01

Organic Light Emitting Diodes (OLEDs) provide various attractive features for next generation illumination systems, including high efficiency, low power, thin and flexible form factor. In this work, we incorporated phosphorescent emitters and demonstrated highly efficient white phosphorescent OLED (PHOLED) devices on flexible plastic substrates. The 0.94 cm2 small-area device has total thickness of approximately 0.25 mm and achieved 63 lm/W at 1,000 cd/m2 with CRI = 85 and CCT = 2920 K. We further designed and fabricated a 15 cm x 15 cm large-area flexible white OLED lighting panels, finished with a hybrid single-layer ultra-low permeability single layer barrier (SLB) encapsulation film. The flexible panel has an active area of 116.4 cm2, and achieved a power efficacy of 47 lm/W at 1,000 cd/m2 with CRI = 83 and CCT = 3470 K. The efficacy of the panel at 3,000 cd/m2 is 43 lm/W. The large-area flexible PHOLED lighting panel is to bring out enormous possibilities to the future general lighting applications.

Macroenvironmental factors including GDP per capita and physical activity in Europe.

PubMed

Cameron, Adrian J; Van Stralen, Maartje M; Kunst, Anton E; Te Velde, Saskia J; Van Lenthe, Frank J; Salmon, Jo; Brug, Johannes

2013-02-01

Socioeconomic inequalities in physical activity at the individual level are well reported. Whether inequalities in economic development and other macroenvironmental variables between countries are also related to physical activity at the country level is comparatively unstudied. We examined the relationship between country-level data on macroenvironmental factors (gross domestic product (GDP) per capita, public sector expenditure on health, percentage living in urban areas, and cars per 1000 population) with country-level physical activity prevalence obtained from previous pan-European studies. Studies that assessed leisuretime physical activity (n = 3 studies including 27 countries in adults, n = 2 studies including 28 countries in children) and total physical activity (n = 3 studies in adults including 16 countries) were analyzed separately as were studies among adults and children. Strong and consistent positive correlations were observed between country prevalence of leisure-time physical activity and country GDP per capita in adults (average r = 0.70; all studies, P G 0.05). In multivariate analysis, country prevalence of leisure-time physical activity among adults remained associated with country GDP per capita (two of three studies) but not urbanization or educational attainment. Among school-age populations, no association was found between country GDP per capita and country prevalence of leisure-time physical activity. In those studies that assessed total physical activity (which also includes occupational and transport physical activity), no association with country GDP per capita was observed. Clear differences in national leisure-time physical activity levels throughout Europe may be a consequence of economic development. Lack of economic development of some countries in Europe may make increasing leisure-time physical activity more difficult. Further examination of the link between country GDP per capita and national physical activity levels (across

Towards a data-driven analysis of hadronic light-by-light scattering

NASA Astrophysics Data System (ADS)

Colangelo, Gilberto; Hoferichter, Martin; Kubis, Bastian; Procura, Massimiliano; Stoffer, Peter

2014-11-01

The hadronic light-by-light contribution to the anomalous magnetic moment of the muon was recently analyzed in the framework of dispersion theory, providing a systematic formalism where all input quantities are expressed in terms of on-shell form factors and scattering amplitudes that are in principle accessible in experiment. We briefly review the main ideas behind this framework and discuss the various experimental ingredients needed for the evaluation of one- and two-pion intermediate states. In particular, we identify processes that in the absence of data for doubly-virtual pion-photon interactions can help constrain parameters in the dispersive reconstruction of the relevant input quantities, the pion transition form factor and the helicity partial waves for γ*γ* → ππ.

Color-tunable lighting devices and methods of use

DOEpatents

Davis, James Lynn

2017-02-07

A lighting device (100) includes a housing (104) enclosing a housing interior (108), a light source (132), a light converter (136), and a color tuning device. The light source is configured for emitting a primary light beam of a primary wavelength (140) through the housing interior. The light converter includes a luminescent material (144) facing the housing interior and configured for emitting secondary light (156, 158) of one or more wavelengths different from the primary wavelength, in response to excitation by the primary light beam. The housing includes a light exit (124) for outputting a combination of primary light and secondary light. The color tuning device is configured for adjusting a position of the primary light beam relative to the luminescent material.

Lens epithelium-derived growth factor promotes photoreceptor survival in light-damaged and RCS rats.

PubMed

Machida, S; Chaudhry, P; Shinohara, T; Singh, D P; Reddy, V N; Chylack, L T; Sieving, P A; Bush, R A

2001-04-01

To investigate possible protective effects of lens epithelium-derived growth factor (LEDGF) against photoreceptor death in light-damaged, Royal College of Surgeons (RCS) and P23H rhodopsin transgenic rats. Twelve-week-old Sprague-Dawley (SD), 6-week-old RCS, and 10-day-old P23H (line 1, heterozygote) rats received an intravitreal injection of LEDGF fused with glutathione-S-transferase (GST-LEDGF). Fellow eyes received vehicle and served as control specimens. Two days after the injections, the SD rats were exposed to light of 2000 lux for 48 hours. Corneal Ganzfeld ERGs were recorded 10 days after light damage, at 10 weeks of age in RCS rats, and at 4 weeks of age in P23H rats. The eyes were then processed for histologic analysis. Heat shock protein (hsp) content in the sensory retina was analyzed quantitatively by protein immunoblot. In light-damaged rats, the ERG indicated retinal protection in GST-LEDGF-injected eyes, with b-wave and STR thresholds being 1.14 +/- 0.50 (mean +/- SD) and 0.60 +/- 0.26 log candela (cd)/m2 lower, respectively, than in vehicle-injected eyes (P < 0.01). The GST-LEDGF-treated eyes had maximum b-wave amplitudes that were significantly larger (P < 0.0005), had more than twice as many remaining photoreceptors, and had better organized outer segments than the control eyes. In RCS rats, the treated eyes had 2.76 +/- 0.73 and 0.83 +/- 0.09 log cd/m(2) lower thresholds for the b-wave and STR, respectively (P < 0.005), and had significantly larger maximum b-wave amplitude (P < 0.0005). GST-LEDGF-treated eyes of RCS rats also had more photoreceptors remaining (P < 0.005) and a thinner debris layer than control eyes. In P23H rats, GST-LEDGF treatment did not protect either retinal function or structure. The retinas from GST-LEDGF-treated eyes of SD and RCS rats had higher levels of hsp25 and alphaB-crystallin than vehicle-injected eyes. GST-LEDGF protects photoreceptor structure and function in both light-damaged and RCS rats. The increased

Pollution-free road lighting

NASA Astrophysics Data System (ADS)

Schreuder, Duco A.

They relate to reducing road accidents and some forms of crime but also enhance the social safety of residents and pedestrians and the amenity for residents. Road traffic in developing countries is much more hazardous than in industrialized countries. Accident rates in 'low' income countries may be as much as 35 times higher than in 'high' income countries. Thus, it might be much more cost-effective to light roads in the developing world than in the industrialized world. Fighting light pollution is more pressing in developing countries as most of the major high-class astronomical observatories are there. Astronomical observations are disturbed by light from outdoor lighting installations, part of which is scattered in the atmosphere to form 'sky glow'. The International Lighting Commission CIE has published a Technical Report giving general guidance for lighting designers and policy makers on the reduction of the sky glow. Lighting improves visibility, essential for almost all human activity. However, light that hits the road contributes to visibility only if it is reflected. In poorly designed lighting equipment much of the lumen output of the lamps is sent directly upwards. This can be avoided by properly defined light fittings. The light output of fittings is determined by their optical quality and by the installation maintenance factor. Open fittings are to be preferred. If mounted horizontally, they make street lighting with the least light pollution.

Lighting in Commercial Buildings

EIA Publications

2009-01-01

Lighting is a major consumer of electricity in commercial buildings and a target for energy savings through use of energy-efficient light sources along with other advanced lighting technologies. The Commercial Buildings Energy Consumption Survey (CBECS) collects information on types of lighting equipment, the amount of floorspace that is lit, and the percentage of floorspace lit by each type. In addition, CBECS data are used to model end-use consumption, including energy consumed for lighting in commercial buildings.

Representing and organizing information to describe the lived experience of health from a personal factors perspective in the light of the International Classification of Functioning, Disability and Health (ICF): a discussion paper.

PubMed

Geyh, Szilvia; Schwegler, Urban; Peter, Claudio; Müller, Rachel

2018-03-06

To discuss the representation and organization of information describing persons' lived experience of health from a personal factors perspective in the light of the International Classification of Functioning, Disability and Health, using spinal cord injury as a case in point for disability. The scientific literature was reviewed, discussion rounds conducted, and qualitative secondary analyses of data carried out using an iterative inductive-deductive approach. Conceptual considerations are explicated that distinguish the personal factors perspective from other components of the International Classification of Functioning, Disability and Health. A representation structure is developed that organizes health-related concepts describing the internal context of functioning. Concepts are organized as individual facts, subjective experiences, and recurrent patterns of experience and behavior specifying 7 areas and 211 concept groups. The article calls for further scientific debate on the perspective of personal factors in the light of the International Classification of Functioning, Disability and Health. A structure that organizes concepts in relation to a personal factors perspective can enhance the comprehensiveness, transparency and standardization of health information, and contribute to the empowerment of persons with disabilities. Implications for rehabilitation The present study collected data from scientific literature reviews, discussion rounds and qualitative secondary analyses in order to develop a representation and organization of information describing persons' lived experience of health from a personal factors perspective in the light of the International Classification of Functioning, Disability and Health. The following representation structure for health-related information from a personal factors perspective was developed: (i) Individuals facts (i.e., socio-demographical factors, position in the immediate social and physical context, personal history

Nanoscale determination of the mass enhancement factor in the lightly doped bulk insulator lead selenide.

PubMed

Zeljkovic, Ilija; Scipioni, Kane L; Walkup, Daniel; Okada, Yoshinori; Zhou, Wenwen; Sankar, R; Chang, Guoqing; Wang, Yung Jui; Lin, Hsin; Bansil, Arun; Chou, Fangcheng; Wang, Ziqiang; Madhavan, Vidya

2015-03-27

Bismuth chalcogenides and lead telluride/selenide alloys exhibit exceptional thermoelectric properties that could be harnessed for power generation and device applications. Since phonons play a significant role in achieving these desired properties, quantifying the interaction between phonons and electrons, which is encoded in the Eliashberg function of a material, is of immense importance. However, its precise extraction has in part been limited due to the lack of local experimental probes. Here we construct a method to directly extract the Eliashberg function using Landau level spectroscopy, and demonstrate its applicability to lightly doped thermoelectric bulk insulator PbSe. In addition to its high energy resolution only limited by thermal broadening, this novel experimental method could be used to detect variations in mass enhancement factor at the nanoscale level. This opens up a new pathway for investigating the local effects of doping and strain on the mass enhancement factor.

The Benefits of Including Clinical Factors in Rectal Normal Tissue Complication Probability Modeling After Radiotherapy for Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Defraene, Gilles, E-mail: gilles.defraene@uzleuven.be; Van den Bergh, Laura; Al-Mamgani, Abrahim

2012-03-01

Purpose: To study the impact of clinical predisposing factors on rectal normal tissue complication probability modeling using the updated results of the Dutch prostate dose-escalation trial. Methods and Materials: Toxicity data of 512 patients (conformally treated to 68 Gy [n = 284] and 78 Gy [n = 228]) with complete follow-up at 3 years after radiotherapy were studied. Scored end points were rectal bleeding, high stool frequency, and fecal incontinence. Two traditional dose-based models (Lyman-Kutcher-Burman (LKB) and Relative Seriality (RS) and a logistic model were fitted using a maximum likelihood approach. Furthermore, these model fits were improved by including themore » most significant clinical factors. The area under the receiver operating characteristic curve (AUC) was used to compare the discriminating ability of all fits. Results: Including clinical factors significantly increased the predictive power of the models for all end points. In the optimal LKB, RS, and logistic models for rectal bleeding and fecal incontinence, the first significant (p = 0.011-0.013) clinical factor was 'previous abdominal surgery.' As second significant (p = 0.012-0.016) factor, 'cardiac history' was included in all three rectal bleeding fits, whereas including 'diabetes' was significant (p = 0.039-0.048) in fecal incontinence modeling but only in the LKB and logistic models. High stool frequency fits only benefitted significantly (p = 0.003-0.006) from the inclusion of the baseline toxicity score. For all models rectal bleeding fits had the highest AUC (0.77) where it was 0.63 and 0.68 for high stool frequency and fecal incontinence, respectively. LKB and logistic model fits resulted in similar values for the volume parameter. The steepness parameter was somewhat higher in the logistic model, also resulting in a slightly lower D{sub 50}. Anal wall DVHs were used for fecal incontinence, whereas anorectal wall dose best described the other two endpoints. Conclusions

AdS/QCD and Applications of Light-Front Holography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; Cao, Fu-Guang

2012-02-16

Light-Front Holography leads to a rigorous connection between hadronic amplitudes in a higher dimensional anti-de Sitter (AdS) space and frame-independent light-front wavefunctions of hadrons in 3 + 1 physical space-time, thus providing a compelling physical interpretation of the AdS/CFT correspondence principle and AdS/QCD, a useful framework which describes the correspondence between theories in a modified AdS5 background and confining field theories in physical space-time. To a first semiclassical approximation, where quantum loops and quark masses are not included, this approach leads to a single-variable light-front Schroedinger equation which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spinmore » and orbital angular momentum. The coordinate z in AdS space is uniquely identified with a Lorentz-invariant coordinate {zeta} which measures the separation of the constituents within a hadron at equal light-front time. The internal structure of hadrons is explicitly introduced and the angular momentum of the constituents plays a key role. We give an overview of the light-front holographic approach to strongly coupled QCD. In particular, we study the photon-to-meson transition form factors (TFFs) F{sub M{gamma}}(Q{sup 2}) for {gamma}{gamma}* {yields} M using light-front holographic methods. The results for the TFFs for the {eta} and {eta}' mesons are also presented. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates. A method for computing the hadronization of quark and gluon jets at the amplitude level is outlined.« less

Getting Pool Light Right.

ERIC Educational Resources Information Center

Hunsaker, Scot

1998-01-01

Examines the use of lighting, both artificial and natural, that can enhance the aesthetic quality and functionality of areas with indoor swimming pools. Discusses glare and shadow-reduction measures that aid competitive events, including lighting above and below water levels, and highlights lighting issues during televised events. Descriptions of…

Simulation and measurement of complete dye sensitised solar cells: including the influence of trapping, electrolyte, oxidised dyes and light intensity on steady state and transient device behaviour.

PubMed

Barnes, Piers R F; Anderson, Assaf Y; Durrant, James R; O'Regan, Brian C

2011-04-07

A numerical model of the dye sensitised solar cell (DSSC) is used to assess the importance of different loss pathways under various operational conditions. Based on our current understanding, the simulation describes the processes of injection, regeneration, recombination and transport of electrons, oxidised dye molecules and electrolyte within complete devices to give both time dependent and independent descriptions of performance. The results indicate that the flux of electrons lost from the nanocrystalline TiO(2) film is typically at least twice as large under conditions equivalent to 1 sun relative to dark conditions at matched TiO(2) charge concentration. This is in agreement with experimental observations (Barnes et al. Phys. Chem. Chem. Phys. [DOI: 10.1039/c0cp01855d]). The simulated difference in recombination flux is shown to be due to variation in the concentration profile of electron accepting species in the TiO(2) pores between light and dark conditions and to recombination to oxidised dyes in the light. The model is able to easily incorporate non-ideal behaviour of a cell such as the variation of open circuit potential with light intensity and non-first order recombination of conduction band electrons. The time dependent simulations, described by the multiple trapping model of electron transport and recombination, show good agreement with both small and large transient photocurrent and photovoltage measurements at open circuit, including photovoltage rise measurements. The simulation of photovoltage rise also suggests the possibility of assessing the interfacial resistance between the TiO(2) and substrate. When cells with a short diffusion length relative to film thickness were modelled, the simulated small perturbation photocurrent transients at short circuit (but not open circuit) yielded significantly higher effective diffusion coefficients than expected from the mean concentration of electrons and the electrolyte in the cell. This implies that

Short Course in Highway Lighting.

ERIC Educational Resources Information Center

Federal Highway Administration (DOT), Washington, DC.

This course guide in highway lighting includes an overview of trends in highway lighting, illustrated information on three light sources for today's luminaires, a reference guide to lamp classification, specifications for highway lighting equipment, and instructions for calculating appropriate use. Maintenance notes on highway illumination and…

Estimation of light source colours for light pollution assessment.

PubMed

Ziou, D; Kerouh, F

2018-05-01

The concept of the smart city raised several technological and scientific issues including light pollution. There are various negative impacts of light pollution on economy, ecology, and heath. This paper deals with the census of the colour of light emitted by lamps used in a city environment. To this end, we derive a light bulb colour estimator based on Bayesian reasoning, directional data, and image formation model in which the usual concept of reflectance is not used. All choices we made are devoted to designing an algorithm which can be run almost in real-time. Experimental results show the effectiveness of the proposed approach. Copyright © 2018 Elsevier Ltd. All rights reserved.

Light directs zebrafish period2 expression via conserved D and E boxes.

PubMed

Vatine, Gad; Vallone, Daniela; Appelbaum, Lior; Mracek, Philipp; Ben-Moshe, Zohar; Lahiri, Kajori; Gothilf, Yoav; Foulkes, Nicholas S

2009-10-01

For most species, light represents the principal environmental signal for entraining the endogenous circadian clock. The zebrafish is a fascinating vertebrate model for studying this process since unlike mammals, direct exposure of most of its tissues to light leads to local clock entrainment. Importantly, light induces the expression of a set of genes including certain clock genes in most zebrafish cell types in vivo and in vitro. However, the mechanism linking light to gene expression remains poorly understood. To elucidate this key mechanism, here we focus on how light regulates transcription of the zebrafish period2 (per2) gene. Using transgenic fish and stably transfected cell line-based assays, we define a Light Responsive Module (LRM) within the per2 promoter. The LRM lies proximal to the transcription start site and is both necessary and sufficient for light-driven gene expression and also for a light-dependent circadian clock regulation. Curiously, the LRM sequence is strongly conserved in other vertebrate per2 genes, even in species lacking directly light-sensitive peripheral clocks. Furthermore, we reveal that the human LRM can substitute for the zebrafish LRM to confer light-regulated transcription in zebrafish cells. The LRM contains E- and D-box elements that are critical for its function. While the E-box directs circadian clock regulation by mediating BMAL/CLOCK activity, the D-box confers light-driven expression. The zebrafish homolog of the thyrotroph embryonic factor binds efficiently to the LRM D-box and transactivates expression. We demonstrate that tef mRNA levels are light inducible and that knock-down of tef expression attenuates light-driven transcription from the per2 promoter in vivo. Together, our results support a model where a light-dependent crosstalk between E- and D-box binding factors is a central determinant of per2 expression. These findings extend the general understanding of the mechanism whereby the clock is entrained by light

Heavy-to-light scalar form factors from Muskhelishvili-Omnès dispersion relations

NASA Astrophysics Data System (ADS)

Yao, D.-L.; Fernandez-Soler, P.; Albaladejo, M.; Guo, F.-K.; Nieves, J.

2018-04-01

By solving the Muskhelishvili-Omnès integral equations, the scalar form factors of the semileptonic heavy meson decays D→ π \\bar{ℓ }ν _ℓ , D→ {\\bar{K}} \\bar{ℓ }ν _ℓ , {\\bar{B}}→ π ℓ \\bar{ν }_ℓ and {\\bar{B}}_s→ K ℓ \\bar{ν }_ℓ are simultaneously studied. As input, we employ unitarized heavy meson-Goldstone boson chiral coupled-channel amplitudes for the energy regions not far from thresholds, while, at high energies, adequate asymptotic conditions are imposed. The scalar form factors are expressed in terms of Omnès matrices multiplied by vector polynomials, which contain some undetermined dispersive subtraction constants. We make use of heavy quark and chiral symmetries to constrain these constants, which are fitted to lattice QCD results both in the charm and the bottom sectors, and in this latter sector to the light-cone sum rule predictions close to q^2=0 as well. We find a good simultaneous description of the scalar form factors for the four semileptonic decay reactions. From this combined fit, and taking advantage that scalar and vector form factors are equal at q^2=0, we obtain |V_{cd}|=0.244± 0.022, |V_{cs}|=0.945± 0.041 and |V_{ub}|=(4.3± 0.7)× 10^{-3} for the involved Cabibbo-Kobayashi-Maskawa (CKM) matrix elements. In addition, we predict the following vector form factors at q^2=0: |f_+^{D→ η }(0)|=0.01± 0.05, |f_+^{D_s→ K}(0)|=0.50 ± 0.08, |f_+^{D_s→ η }(0)|=0.73± 0.03 and |f_+^{{\\bar{B}}→ η }(0)|=0.82 ± 0.08, which might serve as alternatives to determine the CKM elements when experimental measurements of the corresponding differential decay rates become available. Finally, we predict the different form factors above the q^2-regions accessible in the semileptonic decays, up to moderate energies amenable to be described using the unitarized coupled-channel chiral approach.

Light shielding apparatus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Richard Dean; Thom, Robert Anthony

A light shielding apparatus for blocking light from reaching an electronic device, the light shielding apparatus including left and right support assemblies, a cross member, and an opaque shroud. The support assemblies each include primary support structure, a mounting element for removably connecting the apparatus to the electronic device, and a support member depending from the primary support structure for retaining the apparatus in an upright orientation. The cross member couples the left and right support assemblies together and spaces them apart according to the size and shape of the electronic device. The shroud may be removably and adjustably connectablemore » to the left and right support assemblies and configured to take a cylindrical dome shape so as to form a central space covered from above. The opaque shroud prevents light from entering the central space and contacting sensitive elements of the electronic device.« less

Optical design of tunnel lighting with white light-emitting diodes.

PubMed

Tsai, Ming-Shiou; Lee, Xuan-Hao; Lo, Yi-Chien; Sun, Ching-Cherng

2014-10-10

This paper presents a tunnel lighting design consisting of a cluster light-emitting diode and a free-form lens. Most of the energy emitted from the proposed luminaire is transmitted onto the surface of the road in front of drivers, and the probability that that energy is emitted directly into drivers' eyes is low. Compared with traditional fluorescent lamps, the proposed luminaire, of which the optical utilization factor, optical efficiency, and uniformity are, respectively, 44%, 92.5%, and 0.72, exhibits favorable performance in energy saving, glare reduction, and traffic safety.

Summary of spin technology as related to light general-aviation airplanes

NASA Technical Reports Server (NTRS)

Bowman, J. S., Jr.

1971-01-01

A summary was made of all NASA (and NACA) research and experience related to the spin and recovery characteristics of light personal-owner-type general-aviation airplanes. Very little of the research deals with light general-aviation airplanes as such, but many of the airplanes and models tested before and during World War II were similar to present-day light general-aviation airplanes with regard to the factors that are important in spinning. The material is based mainly on the results of spin-tunnel tests of free-spinning dynamically scaled models of about 100 different airplane designs and, whenever possible, includes correlation with full-scale spin tests. The research results are discussed in terms of airplane design considerations and the proper use of controls for recovery.

Redox-Dependent Modulation of Anthocyanin Biosynthesis by the TCP Transcription Factor TCP15 during Exposure to High Light Intensity Conditions in Arabidopsis.

PubMed

Viola, Ivana L; Camoirano, Alejandra; Gonzalez, Daniel H

2016-01-01

TCP proteins integrate a family of transcription factors involved in the regulation of developmental processes and hormone responses. It has been shown that most members of class I, one of the two classes in which the TCP family is divided, contain a conserved Cys that leads to inhibition of DNA binding when oxidized. In this work, we describe that the class-I TCP protein TCP15 inhibits anthocyanin accumulation during exposure of plants to high light intensity by modulating the expression of transcription factors involved in the induction of anthocyanin biosynthesis genes, as suggested by the study of plants that express TCP15 from the 35SCaMV promoter and mutants in TCP15 and the related gene TCP14. In addition, the effect of TCP15 on anthocyanin accumulation is lost after prolonged incubation under high light intensity conditions. We provide evidence that this is due to inactivation of TCP15 by oxidation of Cys-20 of the TCP domain. Thus, redox modulation of TCP15 activity in vivo by high light intensity may serve to adjust anthocyanin accumulation to the duration of exposure to high irradiation conditions. © 2016 American Society of Plant Biologists. All Rights Reserved.

Observation of coherent backscattering of light in ultracold ^85Rb

NASA Astrophysics Data System (ADS)

Kulatunga, P.; Sukenik, C. I.; Havey, M. D.; Kupriyanov, D. V.; Sokolov, I. M.

2002-05-01

We report investigation of multiple coherent light scattering from ^85Rb atoms confined in a magneto-optic trap. In experimental studies, measurements are made of coherent backscattering of a low-intensity probe beam tuned near the F = 3 - F' = 4 transition in ^85Rb atoms. Polarization of backscattered light is determined by a backscattering polarimeter; the spatial distribution of light intensity is measured by a liquid-nitrogen cooled CCD camera set in the focal plane of the analyzing optics. The instrument has angular resolution of about 100 micro-radians, and a polarization analyzing power of roughly 1000. In this paper we describe the instrument details, including calibration procedures, and our measurements of atomic coherent backscattering. In a theoretical study of intensity enhancement of near-resonant backscattered light from cold ^85,87Rb atoms, we consider scattering orders up to 8 and a Gaussian atom distribution in the MOT. Enhancement factors are calculated for all D1 and D2 hyperfine components and for both isotopes.

Optimization of Light-Harvesting Pigment Improves Photosynthetic Efficiency1[OPEN

PubMed Central

Jin, Honglei; Li, Mengshu; Duan, Sujuan; Fu, Mei; Dong, Xiaoxiao; Feng, Dongru; Wang, Jinfa

2016-01-01

Maximizing light capture by light-harvesting pigment optimization represents an attractive but challenging strategy to improve photosynthetic efficiency. Here, we report that loss of a previously uncharacterized gene, HIGH PHOTOSYNTHETIC EFFICIENCY1 (HPE1), optimizes light-harvesting pigments, leading to improved photosynthetic efficiency and biomass production. Arabidopsis (Arabidopsis thaliana) hpe1 mutants show faster electron transport and increased contents of carbohydrates. HPE1 encodes a chloroplast protein containing an RNA recognition motif that directly associates with and regulates the splicing of target RNAs of plastid genes. HPE1 also interacts with other plastid RNA-splicing factors, including CAF1 and OTP51, which share common targets with HPE1. Deficiency of HPE1 alters the expression of nucleus-encoded chlorophyll-related genes, probably through plastid-to-nucleus signaling, causing decreased total content of chlorophyll (a+b) in a limited range but increased chlorophyll a/b ratio. Interestingly, this adjustment of light-harvesting pigment reduces antenna size, improves light capture, decreases energy loss, mitigates photodamage, and enhances photosynthetic quantum yield during photosynthesis. Our findings suggest a novel strategy to optimize light-harvesting pigments that improves photosynthetic efficiency and biomass production in higher plants. PMID:27609860

Nanoscale determination of the mass enhancement factor in the lightly doped bulk insulator lead selenide

DOE PAGES

Zeljkovic, Ilija; Scipioni, Kane L.; Walkup, Daniel; ...

2015-03-27

Bismuth chalcogenides and lead telluride/selenide alloys exhibit exceptional thermoelectric properties that could be harnessed for power generation and device applications. Since phonons play a significant role in achieving these desired properties, quantifying the interaction between phonons and electrons, which is encoded in the Eliashberg function of a material, is of immense importance. However, its precise extraction has in part been limited due to the lack of local experimental probes. Here we construct a method to directly extract the Eliashberg function using Landau level spectroscopy, and demonstrate its applicability to lightly doped thermoelectric bulk insulator PbSe. In addition to its highmore » energy resolution only limited by thermal broadening, this novel experimental method could be used to detect variations in mass enhancement factor at the nanoscale level. Finally, this opens up a new pathway for investigating the local effects of doping and strain on the mass enhancement factor.« less

142. ARAIII General plan of GCRE area, including electrical distribution ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

142. ARA-III General plan of GCRE area, including electrical distribution plan for power and lighting. Includes detail of floodlight and security lighting poles and fixtures. Aerojet-general 880-area/GCRE-406-1. Date: February 1958. Ineel index code no. 063-0406-00-013-102539. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

On-road emission factors of PM pollutants for light-duty vehicles (LDVs) based on urban street driving conditions

NASA Astrophysics Data System (ADS)

Kam, Winnie; Liacos, James W.; Schauer, James J.; Delfino, Ralph J.; Sioutas, Constantinos

2012-12-01

An on-road sampling campaign was conducted on two major surface streets (Wilshire and Sunset Boulevards) in Los Angeles, CA, to characterize PM components including metals, trace elements, and organic species for three PM size fractions (PM10-2.5, PM2.5-0.25, and PM0.25). Fuel-based emission factors (mass of pollutant per kg of fuel) were calculated to assess the emissions profile of a light-duty vehicle (LDV) traffic fleet characterized by stop-and-go driving conditions that are reflective of urban street driving. Emission factors for metals and trace elements were highest in PM10-2.5 while emission factors for PAHs and hopanes and steranes were highest in PM0.25. PM2.5 emission factors were also compared to previous freeway, roadway tunnel, and dynamometer studies based on an LDV fleet to determine how various environments and driving conditions may influence concentrations of PM components. The on-road sampling methodology deployed in the current study captured substantially higher levels of metals and trace elements associated with vehicular abrasion (Fe, Ca, Cu, and Ba) and crustal origins (Mg and Al) than previous LDV studies. The semi-volatile nature of PAHs resulted in higher levels of PAHs in the particulate phase for LDV tunnel studies (Phuleria et al., 2006) and lower levels of PAHs in the particulate phase for freeway studies (Ning et al., 2008). With the exception of a few high molecular weight PAHs, the current study's emission factors were in between the LDV tunnel and LDV freeway studies. In contrast, hopane and sterane emission factors were generally comparable between the current study, the LDV tunnel, and LDV freeway, as expected given the greater atmospheric stability of these organic compounds. Overall, the emission factors from the dynamometer studies for metals, trace elements, and organic species are lower than the current study. Lastly, n-alkanes (C19-C40) were quantified and alkane carbon preference indices (CPIs) were determined to be in

In-Medium K^+ Electromagnetic Form Factor with a Symmetric Vertex in a Light Front Approach

NASA Astrophysics Data System (ADS)

Yabusaki, George H. S.; de Melo, J. P. B. C.; de Paula, Wayne; Tsushima, K.; Frederico, T.

2018-05-01

Using the light-front K^ +-Meson wave function based on a Bethe-Salpeter amplitude model for the Quark-Antiquark bound state, we study the Electromagnetic Form Factor (EMFF) of the K^ +-Meson in nuclear medium within the framework of light-front field theory. The K^ +-Meson model we adopt is well constrained by previous and recent studies to explain its properties in vacuum. The in-medium K^ +-Meson EMFF is evaluated for the plus-component of the electromagnetic current, J^+, in the Breit frame. In order to consistently incorporate the constituent up and antistrange Quarks of the K^ +-Meson immersed in symmetric nuclear matter, we use the Quark-Meson coupling model, which has been widely applied to various hadronic and nuclear phenomena in a nuclear medium with success. We predict the in-medium modification of the K^ +-Meson EMFF in symmetric nuclear matter. It is found that, after a fine tuning of the regulator mass, i.e. m_R = 0.600 GeV, the model is suitable to fit the available experimental data in vacuum within the theoretical uncertainties, and based on this we predict the in-medium modification of the K^ +-Meson EMFF.

Road crossing behavior under traffic light conflict: Modulating effects of green light duration and signal congruency.

PubMed

Lange, Florian; Haiduk, Michael; Boos, Moritz; Tinschert, Peter; Schwarze, Anke; Eggert, Frank

2016-10-01

A large number of pedestrians and cyclists regularly ignore the traffic lights to cross the road illegally. In a recent analysis, illegal road crossing behavior has been shown to be enhanced in the presence of incongruent stimulus configurations. Pedestrians and cyclists are more likely to cross against a red light when exposed to an irrelevant conflicting green light. Here, we present experimental and observational data on the factors moderating the risk associated with incongruent traffic lights. In an observational study, we demonstrated that the conflict-related increase in illegal crossing rates is reduced when pedestrian and cyclist green light periods are long. In a laboratory experiment, we manipulated the color of the irrelevant signals to expose participants to different degrees of incongruency. Results revealed that individuals' performance gradually varied as a function of incongruency, suggesting that the negative impact of a conflicting green light can be reduced by slightly adjusting its color. Our findings highlight that the observation of real-world behavior at intersections and the experimental analysis of psychological processes under controlled laboratory conditions can complement each other in identifying risk factors of risky road crossing behavior. Based on this combination, our study elaborates on promising measures to improve safety at signalized intersections. Copyright © 2016 Elsevier Ltd. All rights reserved.

SCHOOL LIGHTING APPLICATION DATA. EXCERPTS FROM THE IES LIGHTING HANDBOOK, 3RD EDITION.

ERIC Educational Resources Information Center

Illuminating Engineering Society, New York, NY.

THIS PUBLICATION REGARDING SCHOOL LIGHTING WAS PREPARED AS A USEFUL ADDITION TO THE AMERICAN STANDARD GUIDE FOR SCHOOL LIGHTING. THE MATERIAL HAS BEEN EXTRACTED FROM THE IES LIGHTING HANDBOOK TO INCLUDE A MORE DETAILED TREATMENT OF SUBJECTS TO WHICH THE DESIGNER MUST GIVE IMPORTANT CONSIDERATION. THERE IS A MORE EXTENSIVE TREATMENT OF REFLECTED…

Computational Modeling to Limit the Impact Displays and Indicator Lights Have on Habitable Volume Operational Lighting Constraints

NASA Technical Reports Server (NTRS)

Clark, T. A.; Brainard, G.; Salazar, G.; Johnston, S.; Schwing, B.; Litaker, H.; Kolomenski, A.; Venus, D.; Tran, K.; Hanifin, J.;

European road lighting technologies

DOT National Transportation Integrated Search

2001-09-01

The objective of this scanning tour was to gather information from European transportation ministries and lighting professionals regarding cutting-edge research and technologies in highway and roadway lighting systems, including tunnel illumination, ...

Session 21.2 - Measurement of Light at Night

NASA Astrophysics Data System (ADS)

Wainscoat, Richard J.

2016-10-01

The introduction of the mercury vapor lamp for general lighting in the 1930s probably marked the beginning of significant light pollution. Lighting levels have increased slowly, year-to-year, with sky brightness levels increasing only slowly on timescales of a year; no measurement protocols or instruments existed to quantify this increase. However, on timescales of 10-20 years, or on generational timescales, the increases in night sky levels, particularly in urban areas, have been dramatic. Younger people speak with their parents or grandparents who remark how beautiful the sky used to be, and how many stars they could see when they when they were younger. Older people can themselves remember how many stars were visible in the sky when they were younger. Whole generations of children now grow up without ever seeing the Milky Way. Society has not had tools to easily measure sky brightness, and monitoring from space has only recently become available. A subtle increase of 10% sky brightness per year, for example, is not noticeable to the human eye on the time scale of a year, and has been tolerated by society. But such an increase compounds to an increase of a factor 2.6 in 10 years, 6.7 in 20 years, and a factor 45 in 40 years, corresponding to a dramatic increase in sky brightness, an almost complete loss in ability to see faint objects in the night sky, and rendering the sky unusable for most forms of astronomy. The most striking examples are the urban observatories found in many major cities that can no longer be used. Session 2 was primarily focused on measurement of light at night, with an emphasis on measurement of light pollution. It comprised of 6 papers that are summarized below. Over the last decade, our ability to measure light pollution has grown tremendously, and the instrumentation needed to produce reliable quantitative measurements has become much more affordable, and now includes consumer grade digital cameras and even smart phones. During this same

Fluorescence of bioaerosols: mathematical model including primary fluorescing and absorbing molecules in bacteria.

PubMed

Hill, Steven C; Pan, Yong-Le; Williamson, Chatt; Santarpia, Joshua L; Hill, Hanna H

2013-09-23

This paper describes a mathematical model of fluorescent biological particles composed of bacteria, viruses, or proteins. The fluorescent and/or light absorbing molecules included in the model are amino acids (tryptophan, etc.); nucleic acids (DNA, RNA, etc.); coenzymes (nicotinamide adenine dinucleotides, flavins, and vitamins B₆ and K and variants of these); and dipicolinates. The concentrations, absorptivities, and fluorescence quantum yields are estimated from the literature, often with large uncertainties. The bioparticles in the model are spherical and homogeneous. Calculated fluorescence cross sections for particles excited at 266, 280, and 355 nm are compared with measured values from the literature for several bacteria, bacterial spores and albumins. The calculated 266- and 280-nm excited fluorescence is within a factor of 3.2 of the measurements for the vegetative cells and proteins, but overestimates the fluorescence of spores by a factor of 10 or more. This is the first reported modeling of the fluorescence of bioaerosols in which the primary fluorophores and absorbing molecules are included.

Promises and challenges in solid-state lighting

NASA Astrophysics Data System (ADS)

Schubert, Fred

2010-03-01

Lighting technologies based on semiconductor light-emitting diodes (LEDs) offer unprecedented promises that include three major benefits: (i) Gigantic energy savings enabled by efficient conversion of electrical energy to optical energy; (ii) Substantial positive contributions to sustainability through reduced emissions of global-warming gases, acid-rain gases, and toxic substances such as mercury; and (iii) The creation of new paradigms in lighting driven by the unique controllability of solid-state lighting sources. Due to the powerful nature of these benefits, the transition from conventional lighting sources to solid-state lighting is virtually assured. This presentation will illustrate the new world of lighting and illustrate the pervasive changes to be expected in lighting, displays, communications, and biotechnology. The presentation will also address the formidable challenges that must be addressed to continue the further advancement of solid-state lighting technology. These challenges offer opportunities for research and innovation. Specific challenges include light management, carrier transport, and optical design. We will present some innovative approaches in order to solve known technical challenges faced by solid-state lighting. These approaches include the demonstration and use of new optical thin-film materials with a continuously tunable refractive index. These approaches also include the use of polarization-matched structures that reduce the polarization fields in GaInN LEDs and the hotly debated efficiency droop, that is, the decreasing LED efficiency at high currents.

Light and the laboratory mouse.

PubMed

Peirson, Stuart N; Brown, Laurence A; Pothecary, Carina A; Benson, Lindsay A; Fisk, Angus S

2018-04-15

Light exerts widespread effects on physiology and behaviour. As well as the widely-appreciated role of light in vision, light also plays a critical role in many non-visual responses, including regulating circadian rhythms, sleep, pupil constriction, heart rate, hormone release and learning and memory. In mammals, responses to light are all mediated via retinal photoreceptors, including the classical rods and cones involved in vision as well as the recently identified melanopsin-expressing photoreceptive retinal ganglion cells (pRGCs). Understanding the effects of light on the laboratory mouse therefore depends upon an appreciation of the physiology of these retinal photoreceptors, including their differing sens itivities to absolute light levels and wavelengths. The signals from these photoreceptors are often integrated, with different responses involving distinct retinal projections, making generalisations challenging. Furthermore, many commonly used laboratory mouse strains carry mutations that affect visual or non-visual physiology, ranging from inherited retinal degeneration to genetic differences in sleep and circadian rhythms. Here we provide an overview of the visual and non-visual systems before discussing practical considerations for the use of light for researchers and animal facility staff working with laboratory mice. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Mapping algorithm for freeform construction using non-ideal light sources

NASA Astrophysics Data System (ADS)

Li, Chen; Michaelis, D.; Schreiber, P.; Dick, L.; Bräuer, A.

2015-09-01

Using conventional mapping algorithms for the construction of illumination freeform optics' arbitrary target pattern can be obtained for idealized sources, e.g. collimated light or point sources. Each freeform surface element generates an image point at the target and the light intensity of an image point is corresponding to the area of the freeform surface element who generates the image point. For sources with a pronounced extension and ray divergence, e.g. an LED with a small source-freeform-distance, the image points are blurred and the blurred patterns might be different between different points. Besides, due to Fresnel losses and vignetting, the relationship between light intensity of image points and area of freeform surface elements becomes complicated. These individual light distributions of each freeform element are taken into account in a mapping algorithm. To this end the method of steepest decent procedures are used to adapt the mapping goal. A structured target pattern for a optics system with an ideal source is computed applying corresponding linear optimization matrices. Special weighting factor and smoothing factor are included in the procedures to achieve certain edge conditions and to ensure the manufacturability of the freefrom surface. The corresponding linear optimization matrices, which are the lighting distribution patterns of each of the freeform surface elements, are gained by conventional raytracing with a realistic source. Nontrivial source geometries, like LED-irregularities due to bonding or source fine structures, and a complex ray divergence behavior can be easily considered. Additionally, Fresnel losses, vignetting and even stray light are taken into account. After optimization iterations, with a realistic source, the initial mapping goal can be achieved by the optics system providing a structured target pattern with an ideal source. The algorithm is applied to several design examples. A few simple tasks are presented to discussed

NASA Space Human Factors Program

NASA Technical Reports Server (NTRS)

1992-01-01

This booklet briefly and succinctly treats 23 topics of particular interest to the NASA Space Human Factors Program. Most articles are by different authors who are mainly NASA Johnson or NASA Ames personnel. Representative topics covered include mental workload and performance in space, light effects on Circadian rhythms, human sleep, human reasoning, microgravity effects and automation and crew performance.

Light field imaging and application analysis in THz

NASA Astrophysics Data System (ADS)

Zhang, Hongfei; Su, Bo; He, Jingsuo; Zhang, Cong; Wu, Yaxiong; Zhang, Shengbo; Zhang, Cunlin

2018-01-01

The light field includes the direction information and location information. Light field imaging can capture the whole light field by single exposure. The four-dimensional light field function model represented by two-plane parameter, which is proposed by Levoy, is adopted in the light field. Acquisition of light field is based on the microlens array, camera array and the mask. We calculate the dates of light-field to synthetize light field image. The processing techniques of light field data include technology of refocusing rendering, technology of synthetic aperture and technology of microscopic imaging. Introducing the technology of light field imaging into THz, the efficiency of 3D imaging is higher than that of conventional THz 3D imaging technology. The advantages compared with visible light field imaging include large depth of field, wide dynamic range and true three-dimensional. It has broad application prospects.

Two-loop matching factors for light quark masses and three-loop mass anomalous dimensions in the regularization invariant symmetric momentum-subtraction schemes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almeida, Leandro G.; Physics Department, Brookhaven National Laboratory, Upton, New York 11973; Sturm, Christian

2010-09-01

Light quark masses can be determined through lattice simulations in regularization invariant momentum-subtraction (RI/MOM) schemes. Subsequently, matching factors, computed in continuum perturbation theory, are used in order to convert these quark masses from a RI/MOM scheme to the MS scheme. We calculate the two-loop corrections in QCD to these matching factors as well as the three-loop mass anomalous dimensions for the RI/SMOM and RI/SMOM{sub {gamma}{sub {mu}} }schemes. These two schemes are characterized by a symmetric subtraction point. Providing the conversion factors in the two different schemes allows for a better understanding of the systematic uncertainties. The two-loop expansion coefficients ofmore » the matching factors for both schemes turn out to be small compared to the traditional RI/MOM schemes. For n{sub f}=3 quark flavors they are about 0.6%-0.7% and 2%, respectively, of the leading order result at scales of about 2 GeV. Therefore, they will allow for a significant reduction of the systematic uncertainty of light quark mass determinations obtained through this approach. The determination of these matching factors requires the computation of amputated Green's functions with the insertions of quark bilinear operators. As a by-product of our calculation we also provide the corresponding results for the tensor operator.« less

Shedding Light on Nanomedicine

PubMed Central

Tong, Rong

2012-01-01

Light is electromagnetic radiation that can convert its energy into different forms (e.g., heat, chemical energy, and acoustic waves). This property has been exploited in phototherapy (e.g., photothermal therapy and photodynamic therapy) and optical imaging (e.g., fluorescence imaging) for therapeutic and diagnostic purposes. Light-controlled therapies can provide minimally or non-invasive spatiotemporal control as well as deep tissue penetration. Nanotechnology provides a numerous advantages, including selective targeting of tissues, prolongation of therapeutic effect, protection of active payloads, and improved therapeutic indices. This review explores the advances that nanotechnology can bring to light-based therapies and diagnostics, and vice versa, including photo-triggered systems, nanoparticles containing photoactive molecules, and nanoparticles that are themselves photoactive. Limitations of light-based therapies such as photic injury and phototoxicity will be discussed. PMID:22887840

Light on curved backgrounds

NASA Astrophysics Data System (ADS)

Batic, D.; Nelson, S.; Nowakowski, M.

2015-05-01

We consider the motion of light on different spacetime manifolds by calculating the deflection angle, lensing properties and by probing into the possibility of bound states. The metrics in which we examine the light motion include, among other items, a general relativistic dark matter metric, a dirty black hole, and a worm hole metric, the last two inspired by noncommutative geometry. The lensing in a holographic screen metric is discussed in detail. We study also the bending of light around naked singularities like, e.g., the Janis-Newman-Winicour metric and include other cases. A generic property of light behavior in these exotic metrics is pointed out. For the standard metric like the Schwarzschild and Schwarzschild-de Sitter cases, we improve the accuracy of the lensing results for the weak and strong regimes.

PFP Emergency Lighting Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

BUSCH, M.S.

2000-02-02

NFPA 101, section 5-9 mandates that, where required by building classification, all designated emergency egress routes be provided with adequate emergency lighting in the event of a normal lighting outage. Emergency lighting is to be arranged so that egress routes are illuminated to an average of 1.0 footcandle with a minimum at any point of 0.1 footcandle, as measured at floor level. These levels are permitted to drop to 60% of their original value over the required 90 minute emergency lighting duration after a power outage. The Plutonium Finishing Plant (PFP) has two designations for battery powered egress lights ''Emergencymore » Lights'' are those battery powered lights required by NFPA 101 to provide lighting along officially designated egress routes in those buildings meeting the correct occupancy requirements. Emergency Lights are maintained on a monthly basis by procedure ZSR-12N-001. ''Backup Lights'' are battery powered lights not required by NFPA, but installed in areas where additional light may be needed. The Backup Light locations were identified by PFP Safety and Engineering based on several factors. (1) General occupancy and type of work in the area. Areas occupied briefly during a shiftly surveillance do not require backup lighting while a room occupied fairly frequently or for significant lengths of time will need one or two Backup lights to provide general illumination of the egress points. (2) Complexity of the egress routes. Office spaces with a standard hallway/room configuration will not require Backup Lights while a large room with several subdivisions or irregularly placed rooms, doors, and equipment will require Backup Lights to make egress safer. (3) Reasonable balance between the safety benefits of additional lighting and the man-hours/exposure required for periodic light maintenance. In some plant areas such as building 236-Z, the additional maintenance time and risk of contamination do not warrant having Backup Lights installed in

Investigation of critical inter-related factors affecting the efficacy of pulsed light for inactivating clinically relevant bacterial pathogens.

PubMed

Farrell, H P; Garvey, M; Cormican, M; Laffey, J G; Rowan, N J

2010-05-01

To investigate critical electrical and biological factors governing the efficacy of pulsed light (PL) for the in vitro inactivation of bacteria isolated from the clinical environment. Development of this alternative PL decontamination approach is timely, as the incidence of health care-related infections remains unacceptably high. Predetermined cell numbers of clinically relevant Gram-positive and Gram-negative bacteria were inoculated separately on agar plates and were flashed with light under varying operating conditions, and their inactivation measured. Significant differences in inactivation largely occurred depending on the level of the applied lamp discharge energy (range 3.2-20 J per pulse), the amount of pulsing applied (range 0-60 pulses) and the distance between light source and treatment surface (range 8-20 cm) used. Greater decontamination levels were achieved using a combination of higher lamp discharge energies, increased number of pulses and shorter distances between treatment surface and the xenon light source. Levels of microbial sensitivity also varied depending on the population type, size and age of cultures treated. Production of pigment pyocynanin and alginate slime in mucoid strains of Pseudomonas aeruginosa afforded some protection against lethal action of PL; however, this was evident only by using a combination of reduced amount of pulsing at the lower lamp discharge energies tested. A clear pattern was observed where Gram-positive bacterial pathogens were more resistant to cidal effects of PL compared to Gram negatives. While negligible photoreactivation of PL-treated bacterial strains occurred after full pulsing regimes at the different lamp discharge energies tested, some repair was evident when using a combination of reduced pulsing at the lower lamp discharge energies. Strains harbouring genes for multiple resistances to antibiotics were not significantly more resistant to PL treatments. Slight

Conceptualizing a Dynamic Fall Risk Model Including Intrinsic Risks and Exposures.

PubMed

Klenk, Jochen; Becker, Clemens; Palumbo, Pierpaolo; Schwickert, Lars; Rapp, Kilan; Helbostad, Jorunn L; Todd, Chris; Lord, Stephen R; Kerse, Ngaire

2017-11-01

Falls are a major cause of injury and disability in older people, leading to serious health and social consequences including fractures, poor quality of life, loss of independence, and institutionalization. To design and provide adequate prevention measures, accurate understanding and identification of person's individual fall risk is important. However, to date, the performance of fall risk models is weak compared with models estimating, for example, cardiovascular risk. This deficiency may result from 2 factors. First, current models consider risk factors to be stable for each person and not change over time, an assumption that does not reflect real-life experience. Second, current models do not consider the interplay of individual exposure including type of activity (eg, walking, undertaking transfers) and environmental risks (eg, lighting, floor conditions) in which activity is performed. Therefore, we posit a dynamic fall risk model consisting of intrinsic risk factors that vary over time and exposure (activity in context). eHealth sensor technology (eg, smartphones) begins to enable the continuous measurement of both the above factors. We illustrate our model with examples of real-world falls from the FARSEEING database. This dynamic framework for fall risk adds important aspects that may improve understanding of fall mechanisms, fall risk models, and the development of fall prevention interventions. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

New Trends in Educational Lighting Systems.

ERIC Educational Resources Information Center

Murphy, Peter

2001-01-01

Explores technological trends for improving campus lighting, including the use of direct-indirect suspended fluorescent lighting, suspended linear lighting, high-efficiency optical systems, and occupancy and daylight sensors. (GR)

The light-induced transcriptome of the zebrafish pineal gland reveals complex regulation of the circadian clockwork by light

PubMed Central

Ben-Moshe, Zohar; Alon, Shahar; Mracek, Philipp; Faigenbloom, Lior; Tovin, Adi; Vatine, Gad D.; Eisenberg, Eli; Foulkes, Nicholas S.; Gothilf, Yoav

2014-01-01

Light constitutes a primary signal whereby endogenous circadian clocks are synchronized (‘entrained’) with the day/night cycle. The molecular mechanisms underlying this vital process are known to require gene activation, yet are incompletely understood. Here, the light-induced transcriptome in the zebrafish central clock organ, the pineal gland, was characterized by messenger RNA (mRNA) sequencing (mRNA-seq) and microarray analyses, resulting in the identification of multiple light-induced mRNAs. Interestingly, a considerable portion of the molecular clock (14 genes) is light-induced in the pineal gland. Four of these genes, encoding the transcription factors dec1, reverbb1, e4bp4-5 and e4bp4-6, differentially affected clock- and light-regulated promoter activation, suggesting that light-input is conveyed to the core clock machinery via diverse mechanisms. Moreover, we show that dec1, as well as the core clock gene per2, is essential for light-entrainment of rhythmic locomotor activity in zebrafish larvae. Additionally, we used microRNA (miRNA) sequencing (miR-seq) and identified pineal-enhanced and light-induced miRNAs. One such miRNA, miR-183, is shown to downregulate e4bp4-6 mRNA through a 3′UTR target site, and importantly, to regulate the rhythmic mRNA levels of aanat2, the key enzyme in melatonin synthesis. Together, this genome-wide approach and functional characterization of light-induced factors indicate a multi-level regulation of the circadian clockwork by light. PMID:24423866

Bridges, Lights, and Hubris: Examples of Excessive Light Pollution

NASA Astrophysics Data System (ADS)

Upgren, A. R.

2000-12-01

Recently many new lighting projects have been planned, frequently for the purpose of bringing attention to a tower or bridge, with the intent of promoting it as a tourist attraction. Examples of this form of light pollution are illustrated here. Many proceed with plans to mount new floodlights pointed upward with most of the light shining directly up into the sky. At least three of the more excessive among them have been tabled or aborted upon objections by members of the International Dark-Sky Association and other environmental groups. Opposition to the most ill-conceived of these plans centers on waste of money and energy, excessive fatalities among migratory birds, damage to the aesthetic beauty and study of the night sky, and (near seacoasts) damage to the nesting and hatching of sea turtles. Constructive opposition to lighting excess and glare may include the substitution of tracer lights, such as the ones that adorn the great suspension bridges of New York and San Francisco. Tracer lights using full-cutoff shielding outline a structure much as lights on a Christmas tree delineate its shape, but floodlights in the mix render a washed-out effect similar to a Christmas tree in broad daylight. The AAS Committee on Light Pollution, Radio Interference, and Space Debris encourages a greater role for the Society in coordinating opposition to such projects, which is too often local and inexperienced.

Factors contributing to enhanced freezing tolerance in wheat during frost hardening in the light.

PubMed

Janda, Tibor; Szalai, Gabriella; Leskó, Kornélia; Yordanova, Rusina; Apostol, Simona; Popova, Losanka Petrova

2007-06-01

The interaction between light and temperature during the development of freezing tolerance was studied in winter wheat (Triticum aestivum L. var. Mv Emese). Ten-day-old plants were cold hardened at 5 degrees C for 12 days under normal (250 micromol m(-2)s(-1)) or low light (20 micromol m(-2)s(-1)) conditions. Some of the plants were kept at 20/18 degrees C for 12 days at high light intensity (500 micromol m(-2)s(-1)), which also increased the freezing tolerance of winter wheat. The freezing survival rate, the lipid composition, the antioxidant activity, and the salicylic acid content were investigated during frost hardening. The saturation level of hexadecanoic acid decreased not only in plants hardened at low temperature, but also, to a lesser extent, in plants kept under high light irradiation at normal growth temperature. The greatest induction of the enzymes glutathione reductase (EC 1.6.4.2.) and ascorbate peroxidase (EC 1.11.1.11.) occurred when the cold treatment was carried out in normal light, but high light intensity at normal, non-hardening temperature also increased the activity of these enzymes. The catalase (EC 1.11.1.6.) activity was also higher in plants grown at high light intensity than in the controls. The greatest level of induction in the activity of the guaiacol peroxidase (EC 1.11.1.7.) enzyme occurred under cold conditions with low light. The bound ortho-hydroxy-cinnamic acid increased by up to two orders of magnitude in plants that were cold hardened in normal light. Both high light intensity and low temperature hardening caused an increase in the free and bound salicylic acid content of the leaves. This increase was most pronounced in plants that were cold treated in normal light.

Slow light enhanced gas sensing in photonic crystals

NASA Astrophysics Data System (ADS)

Kraeh, Christian; Martinez-Hurtado, J. L.; Popescu, Alexandru; Hedler, Harry; Finley, Jonathan J.

2018-02-01

Infrared spectroscopy allows for highly selective and highly sensitive detection of gas species and concentrations. Conventional gas spectrometers are generally large and unsuitable for on-chip applications. Long absorption path lengths are usually required and impose a challenge for miniaturization. In this work, a gas spectrometer is developed consisting of a microtube photonic crystal structure. This structure of millimetric form factors minimizes the required absorption path length due to slow light effects. The microtube photonic crystal allows for strong transmission in the mid-infrared and, due to its large void space fraction, a strong interaction between light and gas molecules. As a result, enhanced absorption of light increases the gas sensitivity of the device. Slow light enhanced gas absorption by a factor of 5.8 in is experimentally demonstrated at 5400 nm. We anticipate small form factor gas sensors on silicon to be a starting point for on-chip gas sensing architectures.

A study on the risk perception of light pollution and the process of social amplification of risk in Korea.

PubMed

Kim, Kyung Hee; Choi, Jae Wook; Lee, Eunil; Cho, Yong Min; Ahn, Hyung Rae

2015-05-01

In this study, the risk perception level of each light pollution type was analyzed, and the effects of the variables (e.g., psychometric paradigm factor, trust in the government, etc.) on the process of the increase in the risk perception were analyzed. For the sample population (1096 persons) in Korea, the risk perception levels of each light pollution type and other environmental and health risk factors were compared, and the relative magnitude was examined. In addition, to test which variables affect the group with high-risk perception of each light pollution type, a logistic regression analysis was performed. For the group with highest risk perception of light pollution, the odds ratios (OR) of all psychometric paradigms (excluding controllability) increased compared to those of the group with low-risk perception. Additionally, the level showing the acquisition of information from the media and the recollection level of media criticism on each light pollution type showed a statistically significant increase. Especially, the risk perception of light trespass increased as trust in the government decreased. The significance of this study includes the finding that the public's risk perception of light pollution was significantly affected by the psychometric paradigm factors. Moreover, this study analyzed the differences of the variables that affect the increase in the risk perception of each light pollution type and provided a theoretical framework that can practically reflect the strategy for the risk communication of light pollution.

Light Pollution: Outdoor lighting is a growing threat to astronomy.

PubMed

Riegel, K W

1973-03-30

There have been major qualitative and quantitative changes in outdoor lighting technology in the last decade. The level of skylight caused by outdoor lighting systems is growing at a very high rate, about 20 percent per year nationwide. In addition, the spectral distribution of man-made light pollution may change in the next decade from one containing a few mercury lines to one containing dozens of lines and a significantly increased continuum level. Light pollution is presently damaging to some astronomical programs, and it is likely to become a major factor limiting progress in the next decade. Suitable sites in the United States for new dark sky observing facilities are very difficult to find. Some of the increase in outdoor illumination is due to the character of national growth and development. Some is due to promotional campaigns, in which questionable arguments involving public safety are presented. There are protective measures which might be adopted by the government; these would significantly aid observational astronomy, without compromising the legitimate outdoor lighting needs of society. Observatories should establish programs to routinely monitor sky brightness as a function of position, wavelength, and time. The astronomical community should establish a mechanism by which such programs can be supported and coordinated.

Improving School Lighting for Video Display Units.

ERIC Educational Resources Information Center

Parker-Jenkins, Marie; Parker-Jenkins, William

1985-01-01

Provides information to identify and implement the key characteristics which contribute to an efficient and comfortable visual display unit (VDU) lighting installation. Areas addressed include VDU lighting requirements, glare, lighting controls, VDU environment, lighting retrofit, optical filters, and lighting recommendations. A checklist to…

Night of Darkness Campaign: Make Light Pollution Something Everybody Cares About

NASA Astrophysics Data System (ADS)

Pas, Friedel

2015-03-01

To battle light pollution issues, influence the market so that customers request only good lighting. An important factor in doing this is to convince decision makers that light pollution is something the whole society cares about. This article gives an overview of an existing campaign that does this and emphasizes some important factors to consider in your campaign.

Effects of ultraviolet radiation, visible light, and infrared radiation on erythema and pigmentation: a review.

PubMed

Sklar, Lindsay R; Almutawa, Fahad; Lim, Henry W; Hamzavi, Iltefat

2013-01-01

The effects of ultraviolet radiation, visible light, and infrared radiation on cutaneous erythema, immediate pigment darkening, persistent pigment darkening, and delayed tanning are affected by a variety of factors. Some of these factors include the depth of cutaneous penetration of the specific wavelength, the individual skin type, and the absorption spectra of the different chromophores in the skin. UVB is an effective spectrum to induce erythema, which is followed by delayed tanning. UVA induces immediate pigment darkening, persistent pigment darkening, and delayed tanning. At high doses, UVA (primarily UVA2) can also induce erythema in individuals with skin types I-II. Visible light has been shown to induce erythema and a tanning response in dark skin, but not in fair skinned individuals. Infrared radiation produces erythema, which is probably a thermal effect. In this article we reviewed the available literature on the effects of ultraviolet radiation, visible light, and infrared radiation on the skin in regards to erythema and pigmentation. Much remains to be learned on the cutaneous effects of visible light and infrared radiation.

75 FR 7426 - Tier 2 Light-Duty Vehicle and Light-Duty Truck Emission Standards and Gasoline Sulfur Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-19

... 2060-AI23; 2060-AQ12 Tier 2 Light-Duty Vehicle and Light-Duty Truck Emission Standards and Gasoline... February 10, 2000 (65 FR 6698), EPA published emission standards for light-duty vehicles and light-duty... new passenger cars and light trucks, including pickup trucks, vans, minivans, and sport-utility...

Light sensors for objective light measurement in ambulatory polysomnography.

PubMed

Schembri, Rachel; Spong, Jo; Peters, Allison; Rochford, Peter; Wilksch, Philip; O'Donoghue, Fergal J; Greenwood, Kenneth M; Barnes, Maree; Kennedy, Gerard A; Berlowitz, David J

2017-01-01

Ambulatory polysomnography (PSG) does not commonly include an objective measure of light to determine the time of lights off (Loff), and thus cannot be used to calculate important indices such as sleep onset latency and sleep efficiency. This study examined the technical specifications and appropriateness of a prototype light sensor (LS) for use in ambulatory Compumedics Somte PSG.Two studies were conducted. The first examined the light measurement characteristics of the LS when used with a portable PSG device, specifically recording trace range, linearity, sensitivity, and stability. This involved the LS being exposed to varying incandescent and fluorescent light levels in a light controlled room. Secondly, the LS was trialled in 24 home and 12 hospital ambulatory PSGs to investigate whether light levels in home and hospital settings were within the recording range of the LS, and to quantify the typical light intensity reduction at the time of Loff. A preliminary exploration of clinical utility was also conducted. Linearity between LS voltage and lux was demonstrated, and the LS trace was stable over 14 hours of recording. The observed maximum voltage output of the LS/PSG device was 250 mV, corresponding to a maximum recording range of 350 lux and 523 lux for incandescent and fluorescent light respectively. At the time of Loff, light levels were within the recording range of the LS, and on average dropped by 72 lux (9-245) in the home and 76 lux (4-348) in the hospital setting. Results suggest that clinical utility was greatest in hospital settings where patients are less mobile. The LS was a simple and effective objective marker of light level in portable PSG, which can be used to identify Loff in ambulatory PSG. This allows measurement of additional sleep indices and support with clinical decisions.

Stray Light Analysis

NASA Technical Reports Server (NTRS)

1997-01-01

Based on a Small Business Innovation Research contract from the Jet Propulsion Laboratory, TracePro is state-of-the-art interactive software created by Lambda Research Corporation to detect stray light in optical systems. An image can be ruined by incidental light in an optical system. To maintain image excellence from an optical system, stray light must be detected and eliminated. TracePro accounts for absorption, specular reflection and refraction, scattering and aperture diffraction of light. Output from the software consists of spatial irradiance plots and angular radiance plots. Results can be viewed as contour maps or as ray histories in tabular form. TracePro is adept at modeling solids such as lenses, baffles, light pipes, integrating spheres, non-imaging concentrators, and complete illumination systems. The firm's customer base includes Lockheed Martin, Samsung Electronics and other manufacturing, optical, aerospace, and educational companies worldwide.

Spatial Light Modulators as Optical Crossbar Switches

NASA Technical Reports Server (NTRS)

Juday, Richard

2003-01-01

A proposed method of implementing cross connections in an optical communication network is based on the use of a spatial light modulator (SLM) to form controlled diffraction patterns that connect inputs (light sources) and outputs (light sinks). Sources would typically include optical fibers and/or light-emitting diodes; sinks would typically include optical fibers and/or photodetectors. The sources and/or sinks could be distributed in two dimensions; that is, on planes. Alternatively or in addition, sources and/or sinks could be distributed in three dimensions -- for example, on curved surfaces or in more complex (including random) three-dimensional patterns.

Photonic crystal light source

DOEpatents

Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

2004-07-27

A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

Effects of monochromatic light sources on sex hormone levels in serum and on semen quality of ganders.

PubMed

Chang, Shen-Chang; Zhuang, Zi-Xuan; Lin, Min-Jung; Cheng, Chuen-Yu; Lin, Tsung-Yi; Jea, Yu-Shine; Huang, San-Yuan

2016-04-01

Light is an essential external factor influencing various physiological processes, including reproductive performance, in birds. Although several attempts have been made to understand the effect of light on poultry production, the effect of light of a particular wavelength (color) on the reproductive function in geese remains unclear. This study evaluated the effect of various monochromatic light sources on the levels of sex hormone and on semen quality of ganders. Of 30 male White Roman geese in their third reproductive season (average age=3 years), 27 were divided into three groups receiving monochromatic white or red or blue lights. The birds were kept in an environmentally controlled house with a lighting photoperiod of 7L:17D for six weeks as the adaptation period. The photoperiod was subsequently changed to 9L:15D and maintained for 24 weeks. Three ganders at the beginning of the study and three from each group at the end of the adjusting period and the 20th and 30th week of the study period were sacrificed, and their testes and blood samples were collected for determining the sex hormone levels. Semen samples were collected for determining semen quality parameters, including the semen collection index, sperm concentration, semen volume, sperm motility, sperm viability, sperm morphology, and semen quality factor. The results showed that the testosterone and estradiol levels remained unchanged in all three groups at all time points. The ratio of testosterone to estradiol of ganders exposed to white light was significantly higher than that of ganders exposed to red light at the 30th week (P<0.05). Semen collection index and sperm viability of ganders exposed to blue light were significantly the lowest (P<0.05). Moreover, sperm motility, sperm viability, and percentage of morphologically normal spermatozoa of ganders in white light were the highest (P<0.05). In conclusion, the results of this study suggested that artificial illumination with white light may

Bright Ideas for Measuring Light.

ERIC Educational Resources Information Center

Amend, John R.; Schuler, John A.

1983-01-01

Describes an inexpensive device (around $8.00) for measuring light. The circuit used includes five resistors, three small capacitors, a cadmium sulfide light sensor, two integrated circuits, and two light-emitting diodes. The unit is constructed on a small perforated circuit board and powered by a 9-V transistor radio battery. (JN)

Modulation of light-driven arousal by LIM-homeodomain transcription factor Apterous in large PDF-positive lateral neurons of the Drosophila brain

PubMed Central

Shimada, Naoto; Inami, Show; Sato, Shoma; Kitamoto, Toshihiro; Sakai, Takaomi

2016-01-01

Apterous (Ap), the best studied LIM-homeodomain transcription factor in Drosophila, cooperates with the cofactor Chip (Chi) to regulate transcription of specific target genes. Although Ap regulates various developmental processes, its function in the adult brain remains unclear. Here, we report that Ap and Chi in the neurons expressing PDF, a neuropeptide, play important roles in proper sleep/wake regulation in adult flies. PDF-expressing neurons consist of two neuronal clusters: small ventral-lateral neurons (s-LNvs) acting as the circadian pacemaker and large ventral-lateral neurons (l-LNvs) regulating light-driven arousal. We identified that Ap localizes to the nuclei of s-LNvs and l-LNvs. In light-dark (LD) cycles, RNAi knockdown or the targeted expression of dominant-negative forms of Ap or Chi in PDF-expressing neurons or l-LNvs promoted arousal. In contrast, in constant darkness, knockdown of Ap in PDF-expressing neurons did not promote arousal, indicating that a reduced Ap function in PDF-expressing neurons promotes light-driven arousal. Furthermore, Ap expression in l-LNvs showed daily rhythms (peaking at midnight), which are generated by a direct light-dependent mechanism rather than by the endogenous clock. These results raise the possibility that the daily oscillation of Ap expression in l-LNvs may contribute to the buffering of light-driven arousal in wild-type flies. PMID:27853240

Modulation of light-driven arousal by LIM-homeodomain transcription factor Apterous in large PDF-positive lateral neurons of the Drosophila brain.

PubMed

Shimada, Naoto; Inami, Show; Sato, Shoma; Kitamoto, Toshihiro; Sakai, Takaomi

2016-11-17

Apterous (Ap), the best studied LIM-homeodomain transcription factor in Drosophila, cooperates with the cofactor Chip (Chi) to regulate transcription of specific target genes. Although Ap regulates various developmental processes, its function in the adult brain remains unclear. Here, we report that Ap and Chi in the neurons expressing PDF, a neuropeptide, play important roles in proper sleep/wake regulation in adult flies. PDF-expressing neurons consist of two neuronal clusters: small ventral-lateral neurons (s-LNvs) acting as the circadian pacemaker and large ventral-lateral neurons (l-LNvs) regulating light-driven arousal. We identified that Ap localizes to the nuclei of s-LNvs and l-LNvs. In light-dark (LD) cycles, RNAi knockdown or the targeted expression of dominant-negative forms of Ap or Chi in PDF-expressing neurons or l-LNvs promoted arousal. In contrast, in constant darkness, knockdown of Ap in PDF-expressing neurons did not promote arousal, indicating that a reduced Ap function in PDF-expressing neurons promotes light-driven arousal. Furthermore, Ap expression in l-LNvs showed daily rhythms (peaking at midnight), which are generated by a direct light-dependent mechanism rather than by the endogenous clock. These results raise the possibility that the daily oscillation of Ap expression in l-LNvs may contribute to the buffering of light-driven arousal in wild-type flies.

International Lighting in Controlled Environments Workshop

NASA Technical Reports Server (NTRS)

Tibbits, Ted W. (Editor)

1994-01-01

Lighting is a central and critical aspect of control in environmental research for plant research and is gaining recognition as a significant factor to control carefully for animal and human research. Thus this workshop was convened to reevaluate the technology that is available today and to work toward developing guidelines for the most effective use of lighting in controlled environments with emphasis on lighting for plants but also to initiate interest in the development of improved guidelines for human and animal research.

Strange nucleon electromagnetic form factors from lattice QCD

NASA Astrophysics Data System (ADS)

Alexandrou, C.; Constantinou, M.; Hadjiyiannakou, K.; Jansen, K.; Kallidonis, C.; Koutsou, G.; Avilés-Casco, A. Vaquero

2018-05-01

We evaluate the strange nucleon electromagnetic form factors using an ensemble of gauge configurations generated with two degenerate maximally twisted mass clover-improved fermions with mass tuned to approximately reproduce the physical pion mass. In addition, we present results for the disconnected light quark contributions to the nucleon electromagnetic form factors. Improved stochastic methods are employed leading to high-precision results. The momentum dependence of the disconnected contributions is fitted using the model-independent z-expansion. We extract the magnetic moment and the electric and magnetic radii of the proton and neutron by including both connected and disconnected contributions. We find that the disconnected light quark contributions to both electric and magnetic form factors are nonzero and at the few percent level as compared to the connected. The strange form factors are also at the percent level but more noisy yielding statistical errors that are typically within one standard deviation from a zero value.

Early light reduction for preventing retinopathy of prematurity in very low birth weight infants.

PubMed

Jorge, Eliane C; Jorge, Edson N; El Dib, Regina P

2013-08-06

Retinopathy of prematurity (ROP) is a complex condition of the developing retinal blood vessels and is one of the leading causes of preventable childhood blindness. Several risk factors for ROP have been studied over the past 50 years. Among them, general immaturity (low birth weight and low gestational age) and prolonged oxygen therapy have been consistently related to disease onset. However, it is understood that the progression of the disease is multifactorial and may be associated with others risk factors, such as multiple gestation, apnoea, intracranial haemorrhage, anaemia, sepsis, prolonged mechanical ventilation, multiple transfusions and light exposure. Furthermore, the precise role of these individual factors in the development of the disease has not yet been well established. To determine whether the reduction of early environmental light exposure reduces the incidence of retinopathy of prematurity (ROP) or poor ROP outcomes among very low birth weight infants. We searched the following databases: the Cochrane Neonatal Group Specialised Register, CENTRAL (The Cochrane Library), MEDLINE, EMBASE, CINAHL, HealthSTAR, Science Citation Index Database, CANCERLIT, the Oxford Database of Perinatal Trials and www.clinicaltrials.gov. We also searched previous reviews including cross-references, abstracts, conference and symposia proceedings, and contacted expert informants. This search was updated in October 2012. Randomised or quasi-randomised controlled trials that reduced light exposure to premature infants within the first seven days following birth were considered for this review. We also considered cluster-randomised controlled trials. Data on clinical outcomes including any acute ROP and poor ROP outcome were extracted by both review authors independently and consensus reached. We conducted data analysis according to the standards of the Cochrane Neonatal Review Group. Data from four randomised trials with a total of 897 participants failed to show any

Light emitting device having peripheral emissive region

DOEpatents

Forrest, Stephen R

2013-05-28

Light emitting devices are provided that include one or more OLEDs disposed only on a peripheral region of the substrate. An OLED may be disposed only on a peripheral region of a substantially transparent substrate and configured to emit light into the substrate. Another surface of the substrate may be roughened or include other features to outcouple light from the substrate. The edges of the substrate may be beveled and/or reflective. The area of the OLED(s) may be relatively small compared to the substrate surface area through which light is emitted from the device. One or more OLEDs also or alternatively may be disposed on an edge of the substrate about perpendicular to the surface of the substrate through which light is emitted, such that they emit light into the substrate. A mode expanding region may be included between each such OLED and the substrate.

Effects of a Weakly Interacting Light U Boson on Protoneutron Stars Including the Hyperon-Hyperon Interactions

NASA Astrophysics Data System (ADS)

Yu, Zi; Xu, Yan; Zhang, Gui-Qing; Hu, Tao-Ping

2018-04-01

In the framework of the relativistic mean field theory including the hyperon-hyperon (YY) interactions, protoneutron stars with a weakly interacting light U boson are studied. The U-boson leads to the increase of the star maximum mass. The modification to the maximum mass by the U-boson with the strong YY interaction is larger than that with the weak YY interaction. The maximum mass of the protoneutron star is less sensitive to the U-boson than that of the neutron star. The inclusion of the U-boson narrows down the mass window for the hyperonized protoneutron stars. As g 2/μ 2 increases, the species of hyperons, which can appear in a stable protoneutron star decrease. The rotation frequency, the red shift, the momentum of inertia and the total neutrino fraction of PSR J1903-0327 are sensitive to the U-boson and change with g 2/μ 2 in an approximate linear trend. The possible way to constrain the coupling constants of the U-boson is discussed. Supported by Jiangsu Province Natural Science Foundation Youth Fund of China under Grant No. Bk20140982, National Natural Science Foundation of China under Grant No. 11447165, and Youth Innovation Promotion Association, Chinese Academy of Sciences under Grant No. 2016056, and the Development Project of Science and Technology of Jilin Province under Grant No. 20180520077JH

Measuring Light with Useful Tools

ERIC Educational Resources Information Center

Peek, Gina; Hebert, Paulette; Frazier, Robert Scott; Knag, Mihyun

2013-01-01

Lighting, a necessary part of our home and work environment, is often considered as an afterthought. This article describes tools that Extension educators (Agriculture, Family and Consumer Sciences, and 4-H) can use to measure light levels. 4-H youth may also participate. These tools include light meters and Illuminating Engineering Society (IES)…

Predicting and Managing Lighting and Visibility for Human Operations in Space

NASA Technical Reports Server (NTRS)

Maida, James C.; Peacock, Brian

2003-01-01

Lighting is critical to human visual performance. On earth this problem is well understood and solutions are well defined and executed. Because the sun rises and sets on average every 45 minutes during Earth orbit, humans working in space must cope with extremely dynamic lighting conditions varying from very low light conditions to severe glare and contrast conditions. For critical operations, it is essential that lighting conditions be predictable and manageable. Mission planners need to detelmine whether low-light video cameras are required or whether additional luminaires, or lamps, need to be flown . Crew and flight directors need to have up to date daylight orbit time lines showing the best and worst viewing conditions for sunlight and shadowing. Where applicable and possible, lighting conditions need to be part of crew training. In addition, it is desirable to optimize the quantity and quality of light because of the potential impacts on crew safety, delivery costs, electrical power and equipment maintainability for both exterior and interior conditions. Addressing these issues, an illumination modeling system has been developed in the Space Human Factors Laboratory at ASA Johnson Space Center. The system is the integration of a physically based ray-tracing package ("Radiance"), developed at the Lawrence Berkeley Laboratories, a human factors oriented geometric modeling system developed by NASA and an extensive database of humans and their work environments. Measured and published data has been collected for exterior and interior surface reflectivity; luminaire beam spread distribution, color and intensity and video camera light sensitivity and has been associated with their corresponding geometric models. Selecting an eye-point and one or more light sources, including sun and earthshine, a snapshot of the light energy reaching the surfaces or reaching the eye point is computed. This energy map is then used to extract the required information needed for

S-factor for radiative capture reactions for light nuclei at astrophysical energies

NASA Astrophysics Data System (ADS)

Ghasemi, Reza; Sadeghi, Hossein

2018-06-01

The astrophysical S-factors of thermonuclear reactions, including radiative capture reactions and their analysis in the frame of different theoretical models, are the main source of nuclear processes. We have done research on the radiative capture reactions importance in the framework of a potential model. Investigation of the reactions in the astrophysical energies is of great interest in the aspect of astrophysics and nuclear physics for developing correct models of burning and evolution of stars. The experimental measurements are very difficult and impossible because of these reactions occurrence at low-energies. In this paper we do a calculation on radiative capture astrophysical S-factors for nuclei in the mass region A < 17. We calculate the astrophysical factor for the dipole electronic transition E1 and magnetic dipole transition M1 and electric quadrupole transition E2 by using the M3Y potential for non-resonances and resonances captures. Then we have got the parameter of a central part and spin-orbit part of M3Y potential and spectroscopic factor for reaction channels. For the astrophysical S-factor of this article the good agreement is achieved In comparison with experimental data and other theoretical methods.

The CST: Its Achievements and Its Connection to the Light Cone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gross, Franz

since its inception in 1969, I have reviewed applications of the Covariant Spectator Theory (CST). The applications I discuss here include calculations of NN scattering, 3N bound states, electro- magnetic form factors of few-nucleon systems, and the recent successes in describing the dynamical generation of quark mass and the meson spectrum using a chirially invariant quark-antiquark interaction that includes confinement. Furthermore I will discuss the common origin of the Light Cone technique and the CST, which dates back to the 1970's.

The CST: Its Achievements and Its Connection to the Light Cone

DOE PAGES

Gross, Franz

2017-01-19

since its inception in 1969, I have reviewed applications of the Covariant Spectator Theory (CST). The applications I discuss here include calculations of NN scattering, 3N bound states, electro- magnetic form factors of few-nucleon systems, and the recent successes in describing the dynamical generation of quark mass and the meson spectrum using a chirially invariant quark-antiquark interaction that includes confinement. Furthermore I will discuss the common origin of the Light Cone technique and the CST, which dates back to the 1970's.

Spectral method for the correction of the Cerenkov light effect in plastic scintillation detectors: A comparison study of calibration procedures and validation in Cerenkov light-dominated situations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guillot, Mathieu; Gingras, Luc; Archambault, Louis

2011-04-15

Purpose: The purposes of this work were: (1) To determine if a spectral method can accurately correct the Cerenkov light effect in plastic scintillation detectors (PSDs) for situations where the Cerenkov light is dominant over the scintillation light and (2) to develop a procedural guideline for accurately determining the calibration factors of PSDs. Methods: The authors demonstrate, by using the equations of the spectral method, that the condition for accurately correcting the effect of Cerenkov light is that the ratio of the two calibration factors must be equal to the ratio of the Cerenkov light measured within the two differentmore » spectral regions used for analysis. Based on this proof, the authors propose two new procedures to determine the calibration factors of PSDs, which were designed to respect this condition. A PSD that consists of a cylindrical polystyrene scintillating fiber (1.6 mm{sup 3}) coupled to a plastic optical fiber was calibrated by using these new procedures and the two reference procedures described in the literature. To validate the extracted calibration factors, relative dose profiles and output factors for a 6 MV photon beam from a medical linac were measured with the PSD and an ionization chamber. Emphasis was placed on situations where the Cerenkov light is dominant over the scintillation light and on situations dissimilar to the calibration conditions. Results: The authors found that the accuracy of the spectral method depends on the procedure used to determine the calibration factors of the PSD and on the attenuation properties of the optical fiber used. The results from the relative dose profile measurements showed that the spectral method can correct the Cerenkov light effect with an accuracy level of 1%. The results obtained also indicate that PSDs measure output factors that are lower than those measured with ionization chambers for square field sizes larger than 25x25 cm{sup 2}, in general agreement with previously

A lighting assembly based on red and blue light-emitting diodes as a lighting source for space agriculture

NASA Astrophysics Data System (ADS)

Avercheva, Olga; Berkovich, Yuliy A.; Smolyanina, Svetlana; Bassarskaya, Elizaveta; Zhigalova, Tatiana; Ptushenko, Vasiliy; Erokhin, Alexei

Light-emitting diodes (LEDs) are a promising lighting source for space agriculture due to their high efficiency, longevity, safety, and other factors. Assemblies based on red and blue LEDs have been recommended in literature, although not all plants show sufficient productivity in such lighting conditions. Adding of green LEDs proposed in some works was aimed at psychological support for the crew, and not at the improvement of plant growth. We studied the growth and the state of the photosynthetic apparatus in Chinese cabbage (Brassica chinensis L.) plants grown under red (650 nm) and blue (470 nm) light-emitting diodes (LEDs). Plants grown under a high-pressure sodium lamp (HPS lamp) were used as a control. The plants were illuminated with two photosynthetic photon flux levels: nearly 400 µE and about 100 µE. Plants grown under LEDs with 400 µE level, as compared to control plants, showed lower fresh weight, edible biomass, growth rate, and sugar content. The difference in fresh weight and edible biomass was even more pronounced in plants grown with 100 µE level; the data indicate that the adaptability of the test plants to insufficient lighting decreased. Under LEDs, we observed the decreasing of root growth and the absence of transition to the flowering stage, which points to a change in the hormonal balance in plants grown in such lighting conditions. We also found differences in the functioning of the photosynthetic apparatus and its reaction to a low lighting level. We have concluded that a lighting assembly with red and blue LEDs only is insufficient for the plant growth and productivity, and can bring about alterations in their adaptive and regulatory mechanisms. Further studies are needed to optimize the lighting spectrum for space agriculture, taking into account the photosynthetic, phototropic and regulatory roles of light. Using white LEDs or adding far-red and green LEDs might be a promising approach.

The Role of Light in the Emergence of Weeds: Using Camelina microcarpa as an Example.

PubMed

Royo-Esnal, Aritz; Gesch, Russell W; Forcella, Frank; Torra, Joel; Recasens, Jordi; Necajeva, Jevgenija

2015-01-01

When modelling the emergence of weeds, two main factors are considered that condition this process: temperature and soil moisture. Optimum temperature is necessary for metabolic processes that generate energy for growth, while turgor pressure is necessary for root and shoot elongation which eventually leads to seedling emergence from the soil. Most emergence models do not usually consider light as a residual factor, but it could have an important role as it can alter directly or indirectly the dormancy and germination of seeds. In this paper, inclusion of light as an additional factor to photoperiod and radiation in emergence models is explored and compared with the classical hydrothermal time (HTT) model using Camelina microcarpa as an example. HTT based on hourly estimates is also compared with that based on daily estimates. Results suggest that, although HTT based models are accurate enough for local applications, the precision of these models is improved when HTT is estimated hourly and solar radiation is included as a factor.

Development of real-world driving cycles and estimation of emission factors for in-use light-duty gasoline vehicles in urban areas.

PubMed

Hwa, Mei-Yin; Yu, Tai-Yi

2014-07-01

This investigation adopts vehicle tracking manner to establish real-world driving patterns and estimates emission factors with dynamometers with 23 traffic-driving variables for 384 in-use light-duty passenger vehicles during non-rush hour. Adequate numbers of driving variables were decided with factor analysis and cluster analysis. The dynamometer tests were performed on FTP75 cycle and five local driving cycles derived from real-world speed profiles. Results presented that local driving cycles and FTP75 cycle were completely different in driving characteristic parameters of typical driving cycles and emission factors. The highest values of emission factor ratios of local driving cycle and FTP75 cycle for CO, NMHC, NO x , CH4, and CO2 were 1.38, 1.65, 1.58, 1.39, and 1.14, respectively.

Daily Profiles of Light Exposure and Evening Use of Light-emitting Devices in Young Adults Complaining of a Delayed Sleep Schedule.

PubMed

Van der Maren, Solenne; Moderie, Christophe; Duclos, Catherine; Paquet, Jean; Daneault, Véronique; Dumont, Marie

2018-04-01

A number of factors can contribute to a delayed sleep schedule. An important factor could be a daily profile of light exposure favoring a later circadian phase. This study aimed to compare light exposure between 14 young adults complaining of a delayed sleep schedule and 14 matched controls and to identify possible associations between habitual light exposure and circadian phase. Exposure to white and blue light was recorded with ambulatory monitors for 7 consecutive days. Participants also noted their daily use of light-emitting devices before bedtime. Endogenous circadian phase was estimated with the dim light melatonin onset (DLMO) in the laboratory. The amplitude of the light-dark cycle to which the subjects were exposed was smaller in delayed than in control subjects, and smaller amplitude was associated with a later DLMO. Smaller amplitude was due to both decreased exposure in the daytime and increased exposure at night. Total exposure to blue light, but not to white light, was lower in delayed subjects, possibly due to lower exposure to blue-rich outdoor light. Lower daily exposure to blue light was associated with a later DLMO. Timing of relative increases and decreases of light exposure in relation to endogenous circadian phase was also compared between the 2 groups. In delayed subjects, there was a relatively higher exposure to white and blue light 2 h after DLMO, a circadian time with maximal phase-delaying effect. Delayed participants also had higher exposure to light 8 to 10 h after DLMO, which occurred mostly during their sleep episode but may have some phase-advancing effects. Self-reported use of light-emitting devices before bedtime was higher in delayed than in control subjects and was associated with a later DLMO. This study suggests that individuals complaining of a delayed sleep schedule engage in light-related behaviors favoring a later circadian phase and a later bedtime.

Enriching lighting design.

PubMed

Brawley, Elizabeth C

2009-01-01

Good lighting is perhaps the most important and least understood element in designing healthcare environments. Both physically and mentally challenged individuals become more vulnerable and dependent on their environment to compensate for sensory impairments, including dimming eyesight, which interferes to some degree with daily activities as well as social and leisure activities - the things that provide emotional and social well-being. Too few building designs today result in lighting that meets the needs of these individuals, regardless of age. Typical lighting in most care environments is inadequate to meet lighting needs affecting both vision and the photobiological (non-visual) needs of synchronization of circadian rhythm, which impacts sleep and depression. Well-designed lighting is one of the most important design elements that will support an individual's ability to perform normal daily activities and decrease the level of disability associated with these impairments. Daylight contains the spectrum to which the circadian clock is most sensitive and provides higher light levels during the day. Easily accessible outdoor gardens encourage individuals outside, providing the necessary regular exposure to direct bright light that sunlight provides. The combination good interior lighting and regular daylight exposure contributes to regaining and maintaining an active and fulfilling lifestyle - greatly improving quality of life.

Redox-Dependent Modulation of Anthocyanin Biosynthesis by the TCP Transcription Factor TCP15 during Exposure to High Light Intensity Conditions in Arabidopsis1[OPEN

PubMed Central

Viola, Ivana L.; Gonzalez, Daniel H.

2016-01-01

TCP proteins integrate a family of transcription factors involved in the regulation of developmental processes and hormone responses. It has been shown that most members of class I, one of the two classes in which the TCP family is divided, contain a conserved Cys that leads to inhibition of DNA binding when oxidized. In this work, we describe that the class-I TCP protein TCP15 inhibits anthocyanin accumulation during exposure of plants to high light intensity by modulating the expression of transcription factors involved in the induction of anthocyanin biosynthesis genes, as suggested by the study of plants that express TCP15 from the 35SCaMV promoter and mutants in TCP15 and the related gene TCP14. In addition, the effect of TCP15 on anthocyanin accumulation is lost after prolonged incubation under high light intensity conditions. We provide evidence that this is due to inactivation of TCP15 by oxidation of Cys-20 of the TCP domain. Thus, redox modulation of TCP15 activity in vivo by high light intensity may serve to adjust anthocyanin accumulation to the duration of exposure to high irradiation conditions. PMID:26574599

Association of Selected Intersection Factors with Red-Light-Running Crashes

DOT National Transportation Integrated Search

2000-05-01

Red-Light-Running (RLR) crashes represent a significant safety problem that warrants attention. It can be hypothesized that the majority of these crashes result from inadvertent driver error or intentional violation. However, very little is known abo...

Liquid crystal light valve technologies for display applications

NASA Astrophysics Data System (ADS)

Kikuchi, Hiroshi; Takizawa, Kuniharu

2001-11-01

The liquid crystal (LC) light valve, which is a spatial light modulator that uses LC material, is a very important device in the area of display development, image processing, optical computing, holograms, etc. In particular, there have been dramatic developments in the past few years in the application of the LC light valve to projectors and other display technologies. Various LC operating modes have been developed, including thin film transistors, MOS-FETs and other active matrix drive techniques to meet the requirements for higher resolution, and substantial improvements have been achieved in the performance of optical systems, resulting in brighter display images. Given this background, the number of applications for the LC light valve has greatly increased. The resolution has increased from QVGA (320 x 240) to QXGA (2048 x 1536) or even super- high resolution of eight million pixels. In the area of optical output, projectors of 600 to 13,000 lm are now available, and they are used for presentations, home theatres, electronic cinema and other diverse applications. Projectors using the LC light valve can display high- resolution images on large screens. They are now expected to be developed further as part of hyper-reality visual systems. This paper provides an overview of the needs for large-screen displays, human factors related to visual effects, the way in which LC light valves are applied to projectors, improvements in moving picture quality, and the results of the latest studies that have been made to increase the quality of images and moving images or pictures.

Light-induced vegetative anthocyanin pigmentation in Petunia

PubMed Central

Albert, Nick W.; Lewis, David H.; Zhang, Huaibi; Irving, Louis J.; Jameson, Paula E.; Davies, Kevin M.

2009-01-01

The Lc petunia system, which displays enhanced, light-induced vegetative pigmentation, was used to investigate how high light affects anthocyanin biosynthesis, and to assess the effects of anthocyanin pigmentation upon photosynthesis. Lc petunia plants displayed intense purple anthocyanin pigmentation throughout the leaves and stems when grown under high-light conditions, yet remain acyanic when grown under shade conditions. The coloured phenotypes matched with an accumulation of anthocyanins and flavonols, as well as the activation of the early and late flavonoid biosynthetic genes required for flavonol and anthocyanin production. Pigmentation in Lc petunia only occurred under conditions which normally induce a modest amount of anthocyanin to accumulate in wild-type Mitchell petunia [Petunia axillaris×(Petunia axillaris×Petunia hybrida cv. ‘Rose of Heaven’)]. Anthocyanin pigmentation in Lc petunia leaves appears to screen underlying photosynthetic tissues, increasing light saturation and light compensation points, without reducing the maximal photosynthetic assimilation rate (Amax). In the Lc petunia system, where the bHLH factor Leaf colour is constitutively expressed, expression of the bHLH (Lc) and WD40 (An11) components of the anthocyanin regulatory system were not limited, suggesting that the high-light-induced anthocyanin pigmentation is regulated by endogenous MYB transcription factors. PMID:19380423

Size-controllable nanopyramids photonic crystal selectively grown on p-GaN for enhanced light-extraction of light-emitting diodes.

PubMed

Du, Chengxiao; Wei, Tongbo; Zheng, Haiyang; Wang, Liancheng; Geng, Chong; Yan, Qingfeng; Wang, Junxi; Li, Jinmin

2013-10-21

Size-controllable p-GaN hexagonal nanopyramids (HnPs)-photonic crystal (PhC) structures were selectively grown on flat p-GaN layer for the elimination of total internal reflection of light-emitting diodes (LEDs). The LEDs with HnPs-PhC of 46.3% bottom fill factor (PhC lattice constant is 730 nm) showed an improved light output power by 99.9% at forward current of 350 mA compared to the reference LEDs with flat p-GaN layer. We confirmed the effect of HnPs-PhC with different bottom fill factors and the effect of nanopyramid-shaped and nanocolumn-shaped PhC on the light-extraction of LEDs was also investigated by using three-dimensional finite-difference time-domain simulations.

Light intensity and quality from sole-source light-emitting diodes impact growth, morphology, and nutrient content of Brassica microgreens

USDA-ARS?s Scientific Manuscript database

Multi-layer vertical production systems using sole-source (SS) lighting can be used for microgreen production; however, traditional SS lighting can consume large amounts of electrical energy. Light-emitting diodes (LEDs) offer many advantages over conventional light sources including: high photoelec...

Solid state lighting component

DOEpatents

Yuan, Thomas; Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald

2010-10-26

An LED component comprising an array of LED chips mounted on a planar surface of a submount with the LED chips capable of emitting light in response to an electrical signal. The LED chips comprise respective groups emitting at different colors of light, with each of the groups interconnected in a series circuit. A lens is included over the LED chips. Other embodiments can comprise thermal spreading structures included integral to the submount and arranged to dissipate heat from the LED chips.

Solid state lighting component

DOEpatents

Yuan, Thomas; Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald

2015-07-07

An LED component comprising an array of LED chips mounted on a planar surface of a submount with the LED chips capable of emitting light in response to an electrical signal. The LED chips comprise respective groups emitting at different colors of light, with each of the groups interconnected in a series circuit. A lens is included over the LED chips. Other embodiments can comprise thermal spreading structures included integral to the submount and arranged to dissipate heat from the LED chips.

Solid state lighting component

DOEpatents

Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald; Yuan, Thomas

2012-07-10

An LED component comprising an array of LED chips mounted on a planar surface of a submount with the LED chips capable of emitting light in response to an electrical signal. The LED chips comprise respective groups emitting at different colors of light, with each of the groups interconnected in a series circuit. A lens is included over the LED chips. Other embodiments can comprise thermal spreading structures included integral to the submount and arranged to dissipate heat from the LED chips.

Solid state lighting component

DOEpatents

Yuan, Thomas; Keller, Bernd; Tarsa, Eric; Ibbetson, James; Morgan, Frederick; Dowling, Kevin; Lys, Ihor

2017-10-17

An LED component according to the present invention comprising an array of LED chips mounted on a submount with the LED chips capable of emitting light in response to an electrical signal. The array can comprise LED chips emitting at two colors of light wherein the LED component emits light comprising the combination of the two colors of light. A single lens is included over the array of LED chips. The LED chip array can emit light of greater than 800 lumens with a drive current of less than 150 milli-Amps. The LED chip component can also operate at temperatures less than 3000 degrees K. In one embodiment, the LED array is in a substantially circular pattern on the submount.

Light Learning.

ERIC Educational Resources Information Center

Cutshall, Sandy

2002-01-01

Describes a career and technical education program on photonics, the study, research, and development of equipment and concepts used in the transmission of information through light, including fiber optics and experimental laser technologies. (JOW)

Nonimaging light concentrator with uniform irradiance

DOEpatents

Winston, Roland; Gee, Randy C.

2003-04-01

A nonimaging light concentrator system including a primary collector of light, an optical mixer disposed near the focal zone for collecting light from the primary collector, the optical mixer having a transparent entrance aperture, an internally reflective housing for substantially total internal reflection of light, a transparent exit aperture and an array of photovoltaic cells disposed near the transparent exit aperture.

Documentation of incidental factors affecting the home healthcare work environment.

PubMed

Sitzman, Kathleen L; Leiss, Jack K

2009-10-01

Working conditions related to unrestrained pets, unruly children, clutter, and poor lighting during home healthcare visits are considered normal aspects of care providers' jobs. To date, there has been no documentation related to how often these factors are present in the home healthcare setting during home visits. In this study, 833 home healthcare nurses practicing in North Carolina answered a questionnaire that included items related to how often unrestrained pets, unruly children, poor lighting, and clutter existed in the homes they visited. Results showed that one-third to one-half of the respondents usually or always visited homes with unrestrained pets, clutter, or poor lighting and few nurses usually or always visited homes with uncontrolled children. Better understanding of the prevalence of these factors will facilitate further study related to their effects on safety, efficiency, and job satisfaction for home healthcare workers.

Phototropin 1 and dim-blue light modulate the red light de-etiolation response.

PubMed

Wang, Yihai; M Folta, Kevin

2014-01-01

Light signals regulate seedling morphological changes during de-etiolation through the coordinated actions of multiple light-sensing pathways. Previously we have shown that red-light-induced hypocotyl growth inhibition can be reversed by addition of dim blue light through the action of phototropin 1 (phot1). Here we further examine the fluence-rate relationships of this blue light effect in short-term (hours) and long-term (days) hypocotyl growth assays. The red stem-growth inhibition and blue promotion is a low-fluence rate response, and blue light delays or attenuates both the red light and far-red light responses. These de-etiolation responses include blue light reversal of red or far-red induced apical hook opening. This response also requires phot1. Cryptochromes (cry1 and cry2) are activated by higher blue light fluence-rates and override phot1's influence on hypocotyl growth promotion. Exogenous application of auxin transport inhibitor naphthylphthalamic acid abolished the blue light stem growth promotion in both hypocotyl growth and hook opening. Results from the genetic tests of this blue light effect in auxin transporter mutants, as well as phytochrome kinase substrate mutants indicated that aux1 may play a role in blue light reversal of red light response. Together, the phot1-mediated adjustment of phytochrome-regulated photomorphogenic events is most robust in dim blue light conditions and is likely modulated by auxin transport through its transporters.

Phototropin 1 and dim-blue light modulate the red light de-etiolation response

PubMed Central

Wang, Yihai; M Folta, Kevin

2014-01-01

Light signals regulate seedling morphological changes during de-etiolation through the coordinated actions of multiple light-sensing pathways. Previously we have shown that red-light-induced hypocotyl growth inhibition can be reversed by addition of dim blue light through the action of phototropin 1 (phot1). Here we further examine the fluence-rate relationships of this blue light effect in short-term (hours) and long-term (days) hypocotyl growth assays. The red stem-growth inhibition and blue promotion is a low-fluence rate response, and blue light delays or attenuates both the red light and far-red light responses. These de-etiolation responses include blue light reversal of red or far-red induced apical hook opening. This response also requires phot1. Cryptochromes (cry1 and cry2) are activated by higher blue light fluence-rates and override phot1's influence on hypocotyl growth promotion. Exogenous application of auxin transport inhibitor naphthylphthalamic acid abolished the blue light stem growth promotion in both hypocotyl growth and hook opening. Results from the genetic tests of this blue light effect in auxin transporter mutants, as well as phytochrome kinase substrate mutants indicated that aux1 may play a role in blue light reversal of red light response. Together, the phot1-mediated adjustment of phytochrome-regulated photomorphogenic events is most robust in dim blue light conditions and is likely modulated by auxin transport through its transporters. PMID:25482790

Physics of Efficiency Droop in GaN:Eu Light-Emitting Diodes.

PubMed

Fragkos, Ioannis E; Dierolf, Volkmar; Fujiwara, Yasufumi; Tansu, Nelson

2017-12-01

The internal quantum efficiency (IQE) of an electrically-driven GaN:Eu based device for red light emission is analyzed in the framework of a current injection efficiency model (CIE). The excitation path of the Eu +3 ion is decomposed in a multiple level system, which includes the carrier transport phenomena across the GaN/GaN:Eu/GaN active region of the device, and the interactions among traps, Eu +3 ions and the GaN host. The identification and analysis of the limiting factors of the IQE are accomplished through the CIE model. The CIE model provides a guidance for high IQE in the electrically-driven GaN:Eu based red light emitters.

Learning templates for artistic portrait lighting analysis.

PubMed

Chen, Xiaowu; Jin, Xin; Wu, Hongyu; Zhao, Qinping

2015-02-01

Lighting is a key factor in creating impressive artistic portraits. In this paper, we propose to analyze portrait lighting by learning templates of lighting styles. Inspired by the experience of artists, we first define several novel features that describe the local contrasts in various face regions. The most informative features are then selected with a stepwise feature pursuit algorithm to derive the templates of various lighting styles. After that, the matching scores that measure the similarity between a testing portrait and those templates are calculated for lighting style classification. Furthermore, we train a regression model by the subjective scores and the feature responses of a template to predict the score of a portrait lighting quality. Based on the templates, a novel face illumination descriptor is defined to measure the difference between two portrait lightings. Experimental results show that the learned templates can well describe the lighting styles, whereas the proposed approach can assess the lighting quality of artistic portraits as human being does.

[LED LIGHTING AS A FACTOR FOR THE STIMULATION OF THE HORMONE SYSTEM].

PubMed

Deynego, V N; Kaptsov, V A

2015-01-01

There are considered questions of non-visual effects of blue LED light sources on hormonal systems (cortisol, glucose, insulin) providing the high human performance. In modern conditions hygiene strategy for child and adolescent health strategy was shown to be replaced by a strategy of light stimulation of the hormonal profile. There was performed a systematic analysis of the axis "light stimulus-hypothalamus-pituitary-adrenals-cortisol-glucose-insulin". The elevation of the content of cortisol leads to the increase of the glucose level in the blood and the stimulation of the production of insulin, which can, like excessive consumption of food, give rise to irreversible decline in the number of insulin receptors on the cell surface, and thus--to a steady reduction in the ability of cells to utilize glucose, i.e. to type 2 diabetes or its aggravation.

Combatant Eye Protection: An Introduction to the Blue Light Hazard

DTIC Science & Technology

2015-12-01

visible solar radiation (i.e., blue light ), as well as from light - emitting diode (LED)-generated radiant energy remains a questionable factor under...Garcia, M., Picaud, S., Attia D. 2011. Light - emitting diodes (LED) for domestic lighting : Any risks for the eye?. Progress in retinal and eye research...C., Sliney, D. H., Rollag, M., D., Hanifin, J. P., and Brainard, G. C. 2011. Blue light from light - emitting diodes elicits a dose-dependent

Lighting system with thermal management system

DOEpatents

Arik, Mehmet; Weaver, Stanton Earl; Stecher, Thomas Elliot; Seeley, Charles Erklin; Kuenzler, Glenn Howard; Wolfe, Jr., Charles Franklin; Utturkar, Yogen Vishwas; Sharma, Rajdeep; Prabhakaran, Satish; Icoz, Tunc

2015-02-24

Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system is configured to provide an air flow, such as a unidirectional air flow, through the housing structure in order to cool the light source. The driver electronics are configured to provide power to each of the light source and the thermal management system.

Lighting system with thermal management system

DOEpatents

Arik, Mehmet; Weaver, Stanton Earl; Stecher, Thomas Elliot; Seeley, Charles Erklin; Kuenzler, Glenn Howard; Wolfe, Jr., Charles Franklin; Utturkar, Yogen Vishwas; Sharma, Rajdeep; Prabhakaran, Satish; Icoz, Tunc

2015-08-25

Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system is configured to provide an air flow, such as a unidirectional air flow, through the housing structure in order to cool the light source. The driver electronics are configured to provide power to each of the light source and the thermal management system.

Lighting system with thermal management system

DOEpatents

Arik, Mehmet; Weaver, Stanton; Stecher, Thomas; Seeley, Charles; Kuenzler, Glenn; Wolfe, Jr., Charles; Utturkar, Yogen; Sharma, Rajdeep; Prabhakaran, Satish; Icoz, Tunc

2013-05-07

Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system is configured to provide an air flow, such as a unidirectional air flow, through the housing structure in order to cool the light source. The driver electronics are configured to provide power to each of the light source and the thermal management system.

Lighting system with thermal management system

DOEpatents

Arik, Mehmet; Weaver, Stanton Earl; Stecher, Thomas Elliot; Seeley, Charles Erklin; Kuenzler, Glenn Howard; Wolfe, Jr, Charles Franklin; Utturkar, Yogen Vishwas; Sharma, Rajdeep; Prabhakaran, Satish; Icoz, Tunc

2016-10-11

Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system is configured to provide an air flow, such as a unidirectional air flow, through the housing structure in order to cool the light source. The driver electronics are configured to provide power to each of the light source and the thermal management system.

Multiwalled carbon nanotubes for stray light suppression in space flight instruments

NASA Astrophysics Data System (ADS)

Hagopian, John G.; Getty, Stephanie A.; Quijada, Manuel; Tveekrem, June; Shiri, Ron; Roman, Patrick; Butler, James; Georgiev, Georgi; Livas, Jeff; Hunt, Cleophus; Maldonado, Alejandro; Talapatra, Saikat; Zhang, Xianfeng; Papadakis, Stergios J.; Monica, Andrew H.; Deglau, David

2010-08-01

Observations of the Earth are extremely challenging; its large angular extent floods scientific instruments with high flux within and adjacent to the desired field of view. This bright light diffracts from instrument structures, rattles around and invariably contaminates measurements. Astrophysical observations also are impacted by stray light that obscures very dim objects and degrades signal to noise in spectroscopic measurements. Stray light is controlled by utilizing low reflectance structural surface treatments and by using baffles and stops to limit this background noise. In 2007 GSFC researchers discovered that Multiwalled Carbon Nanotubes (MWCNTs) are exceptionally good absorbers, with potential to provide order-of-magnitude improvement over current surface treatments and a resulting factor of 10,000 reduction in stray light when applied to an entire optical train. Development of this technology will provide numerous benefits including: a.) simplification of instrument stray light controls to achieve equivalent performance, b.) increasing observational efficiencies by recovering currently unusable scenes in high contrast regions, and c.) enabling low-noise observations that are beyond current capabilities. Our objective was to develop and apply MWCNTs to instrument components to realize these benefits. We have addressed the technical challenges to advance the technology by tuning the MWCNT geometry using a variety of methods to provide a factor of 10 improvement over current surface treatments used in space flight hardware. Techniques are being developed to apply the optimized geometry to typical instrument components such as spiders, baffles and tubes. Application of the nanostructures to alternate materials (or by contact transfer) is also being investigated. In addition, candidate geometries have been tested and optimized for robustness to survive integration, testing, launch and operations associated with space flight hardware. The benefits of this

Modeling of lighting behaviour of a hybrid lighting system in inner spaces of Building of Electrical Engineering

NASA Astrophysics Data System (ADS)

Amado, L.; Osma, G.; Villamizar, R.

2016-07-01

This paper presents the modelling of lighting behaviour of a hybrid lighting system - HLS in inner spaces for tropical climate. HLS aims to mitigate the problem of high electricity consumption used by artificial lighting in buildings. These systems integrate intelligently the daylight and artificial light through control strategies. However, selection of these strategies usually depends on expertise of designer and of available budget. In order to improve the selection process of the control strategies, this paper analyses the Electrical Engineering Building (EEB) case, initially modelling of lighting behaviour is established for the HLS of a classroom and an office. This allows estimating the illuminance level of the mixed lighting in the space, and energy consumption by artificial light according to different lighting control techniques, a control strategy based on occupancy and a combination of them. The model considers the concept of Daylight Factor (DF) for the estimating of daylight illuminance on the work plane for tropical climatic conditions. The validation of the model was carried out by comparing the measured and model-estimated indoor illuminances.

Light Sources and Ballast Circuits

NASA Astrophysics Data System (ADS)

Yorifuji, Takashi; Sakai, Makoto; Yasuda, Takeo; Maehara, Akiyoshi; Okada, Atsunori; Gouriki, Takeshi; Mannami, Tomoaki

According to the machinery statistics by Ministry of Economy, Trade and Industry (METI), the total of domestic light bulb production in 2006 was 1,101 million (88.5% year-on-year). Production for general purpose illumination light bulbs and halogen light bulbs accounted for 122 million (99.2% y/y) and 45 million (96.3% y/y), respectively. The total of fluorescent lamp production was 988 million (114.9%) and the production of general purpose fluorescent lamps excluding backlights accounted for 367 million (101.7% y/y). Further, HID lamp production was 10 million (106.3% y/y). What is noteworthy regarding such lamp production is that, similar to the previous year, the sales volume (amount) of lamps for general illumination exceeded 100% against the previous year, indicating a steady shift to high value added products. Major lighting exhibitions in 2006 included the Light + Building Trade Fair held in Frankfurt in April and the Light Fair International 2006 held in Las Vegas, U.S.A. in May, both of which demonstrated signs of acceleration toward energy saving, high efficiency and resource saving. As for incandescent lamps, products filled with larger atomic weight gases aiming at higher efficiency/longer life are becoming the mainstream. As for new technologies, it was experimentally demonstrated that infrared radiation can be suppressed by processing micro cavities to metal plates made of tungsten, tantalum, etc. For fluorescent lamps, straight and circular fluorescent lamps achieving a longer life/higher luminous flux maintenance factor continued to be widely developed/launched again this year. For compact fluorescent lamps, energy saving/high efficiency products, multifunctional type products combined with LED and new shaped products were launched. As to HID lamps, ceramic metal halide lamps with high efficiency, improved color rendering, longer life and higher luminous flux maintenance factor were commercialized one after another. Numerous studies and analyses, on

Cellular chromophores and signaling in low level light therapy

NASA Astrophysics Data System (ADS)

Hamblin, Michael R.; Demidova-Rice, Tatiana N.

2007-02-01

The use of low levels of visible or near infrared light (LLLT) for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing tissue damage by reducing cellular apoptosis has been known for almost forty years since the invention of lasers. Originally thought to be a peculiar property of laser light (soft or cold lasers), the subject has now broadened to include photobiomodulation and photobiostimulation using non-coherent light. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial. This likely is due to two main reasons; firstly the biochemical mechanisms underlying the positive effects are incompletely understood, and secondly the complexity of rationally choosing amongst a large number of illumination parameters such as wavelength, fluence, power density, pulse structure and treatment timing has led to the publication of a number of negative studies as well as many positive ones. In recent years major advances have been made in understanding the mechanisms that operate at the cellular and tissue levels during LLLT. Mitochondria are thought to be the main site for the initial effects of light and specifically cytochrome c oxidase that has absorption peaks in the red and near infrared regions of the electromagnetic spectrum matches the action spectra of LLLT effects. The discovery that cells employ nitric oxide (NO) synthesized in the mitochondria by neuronal nitric oxide synthase, to regulate respiration by competitive binding to the oxygen binding of cytochrome c oxidase, now suggests how LLLT can affect cell metabolism. If LLLT photodissociates inhibitory NO from cytochrome c oxidase, this would explain increased ATP production, modulation of reactive oxygen species, reduction and prevention of apoptosis, stimulation of angiogenesis, increase of blood flow and induction of transcription factors. In

Refrigerated display case lighting with LEDs

NASA Astrophysics Data System (ADS)

Raghavan, Ramesh; Narendran, Nadarajah

2002-11-01

The rapid development of high brightness light emitting diodes (LEDs) has triggered many applications, especially in the area of display lighting. This paper focuses on the application of white LEDs in refrigerated display cases. The fluorescent lighting presently used in commercial refrigerators is inefficient in the application and also it provides poor lighting for merchandising. A laboratory human factors experiment was conducted to assess the preference for the different lighting systems, namely, fluorescent and LED. Two refrigerated display cases, one with the traditional fluorescent lighting system and the other with a prototype LED lighting system, were placed side-by-side in a laboratory setting. Illuminance measurements made within the two display cases showed that the lighting was more uniform with the LED system compared to the traditional fluorescent system. Sixteen human subjects participated in this study and rated their preference for the two lighting systems. The results show that human subjects strongly preferred the display case with the LED lighting. The authors of this manuscript believe a field study would be greatly beneficial to further confirm these results and to understand the relationship between preference and sales. Considering the luminous efficacy of white LEDs presently available in the marketplace, it is possible to develop a LED based lighting system for commercial refrigerators that is competitive with fluorescent lighting system in terms of energy use. The LED based lighting would provide better lighting than traditional fluorescent lighting.

Study of Selecting on Light Source Used for Micro-algae Cultivation in Space

NASA Astrophysics Data System (ADS)

Ai, Weidang; Ai, Weidang; Guo, Shuang-Sheng; Gao, Feng; Tang, Yong-Kang; Qin, Li-Feng

To select suitable light source for micro-algae cultivation in future space station, the selected Spirulina plastensis(No.7) were cultured under different lightening qualities, including six light sources that were made up of different combinations of red and blue light-emitting diode(LED). The growth, photosynthetic efficiency and nutrition quality of the Spirulina, were analyzed. From the experiments, the red light may promote the cumulation of biomass of the Spirulina, and the cumulating rate was the highest under all red light source, but the syntheses of protein, phycobiliprotein, β-carotene, VE and other nutrients needs a certain portion of blue light; yet, the complete blue light condition is not favorable to the growth of Spirulina, and may bring pollution by chlorella and other kinds of micro-algae. It is concluded that the LEDs can be used as the light resource of micro-algae cultivation. The normal growth and development of microalgae need two light sources of both red and blue LEDs. The comprehensive analyses of the various factors that affect the growth of Spirulina, such as nutrition quality and photosynthetic activities, etc., showed that the combination of 80% red and 20% blue LED is the optimum one among those tested combinations. Key word: light-emitting diode; micro-algae; controlled ecological life support system (CELSS); space cultivation

High efficiency light source using solid-state emitter and down-conversion material

DOEpatents

Narendran, Nadarajah; Gu, Yimin; Freyssinier, Jean Paul

2010-10-26

A light emitting apparatus includes a source of light for emitting light; a down conversion material receiving the emitted light, and converting the emitted light into transmitted light and backward transmitted light; and an optic device configured to receive the backward transmitted light and transfer the backward transmitted light outside of the optic device. The source of light is a semiconductor light emitting diode, a laser diode (LD), or a resonant cavity light emitting diode (RCLED). The down conversion material includes one of phosphor or other material for absorbing light in one spectral region and emitting light in another spectral region. The optic device, or lens, includes light transmissive material.

Exposure of fluid milk to LED light negatively affects consumer perception and alters underlying sensory properties.

PubMed

Martin, Nicole; Carey, Nancy; Murphy, Steven; Kent, David; Bang, Jae; Stubbs, Tim; Wiedmann, Martin; Dando, Robin

2016-06-01

Fluid milk consumption per capita in the United States has been steadily declining since the 1940s. Many factors have contributed to this decline, including the increasing consumption of carbonated beverages and bottled water. To meet the challenge of stemming the decline in consumption of fluid milk, the dairy industry must take a systematic approach to identifying and correcting for factors that negatively affect consumers' perception of fluid milk quality. To that end, samples of fluid milk were evaluated to identify factors, with a particular focus on light-emitting diode (LED) light exposure, which negatively affect the perceived sensory quality of milk, and to quantify their relative effect on the consumer's experience. Fluid milk samples were sourced from 3 processing facilities with varying microbial postprocessing contamination patterns based on historical testing. The effect of fat content, light exposure, age, and microbiological content were assayed across 23 samples of fluid milk, via consumer, descriptive sensory, and instrumental analyses. Most notably, light exposure resulted in a broad negative reaction from consumers, more so than samples with microbiological contamination exceeding 20,000 cfu/mL on days approaching code. The predominant implication of the study is that a component of paramount importance in ensuring the success of the dairy industry would be to protect fluid milk from all sources of light exposure, from processing plant to consumer. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Purchasing and Selecting School Lighting.

ERIC Educational Resources Information Center

Berman, Tim

2003-01-01

Discusses factors for schools to consider when deciding on a lighting system: purchase price, installation charges, maintenance costs, energy costs, and ensuring optimal educational environment. Presents best practices in these areas. (EV)

Light deprivation damages monoamine neurons and produces a depressive behavioral phenotype in rats

PubMed Central

Gonzalez, M. M. C.; Aston-Jones, G.

2008-01-01

Light is an important environmental factor for regulation of mood. There is a high frequency of seasonal affective disorder in high latitudes where light exposure is limited, and bright light therapy is a successful antidepressant treatment. We recently showed that rats kept for 6 weeks in constant darkness (DD) have anatomical and behavioral features similar to depressed patients, including dysregulation of circadian sleep–waking rhythms and impairment of the noradrenergic (NA)-locus coeruleus (LC) system. Here, we analyzed the cell viability of neural systems related to the pathophysiology of depression after DD, including NA-LC, serotoninergic-raphe nuclei and dopaminergic-ventral tegmental area neurons, and evaluated the depressive behavioral profile of light-deprived rats. We found increased apoptosis in the three aminergic systems analyzed when compared with animals maintained for 6 weeks in 12:12 light-dark conditions. The most apoptosis was observed in NA-LC neurons, associated with a significant decrease in the number of cortical NA boutons. Behaviorally, DD induced a depression-like condition as measured by increased immobility in a forced swim test (FST). DD did not appear to be stressful (no effect on adrenal or body weights) but may have sensitized responses to subsequent stressors (increased fecal number during the FST). We also found that the antidepressant desipramine decreases these neural and behavioral effects of light deprivation. These findings indicate that DD induces neural damage in monoamine brain systems and this damage is associated with a depressive behavioral phenotype. Our results suggest a mechanism whereby prolonged limited light intensity could negatively impact mood. PMID:18347342

Stellar occultation of polarized light from circumstellar electrons. I - Flat envelopes viewed edge on

NASA Technical Reports Server (NTRS)

Brown, John C.; Fox, Geoffrey K.

1989-01-01

The depolarizing and occultation effects of a finite spherical light source on the polarization of light Thomson-scattered from a flat circumstellar envelope seen edge-on are analyzed. The analysis shows that neglect of the finite size of the light source leads to a gross overestimate of the polarization for a given disk geometry. By including occultation and depolarization, it is found that B-star envelopes are necessarily highly flattened disk-type structures. For a disk viewed edge-on, the effect of occultation reduces the polarization more than the inclusion of the depolarization factor alone. Analysis of a one-dimensional plume leads to a powerful technique that permits the electron density distribution to be explicitly obtained from the polarimetric data.

Dynamic light scattering homodyne probe

NASA Technical Reports Server (NTRS)

Meyer, William V. (Inventor); Cannell, David S. (Inventor); Smart, Anthony E. (Inventor)

2002-01-01

An optical probe for analyzing a sample illuminated by a laser includes an input optical fiber operably connectable to the laser where the input optical fiber has an entrance end and an exit end. The probe also includes a first beam splitter where the first beam splitter is adapted to transmit an alignment portion of a light beam from the input fiber exit end and to reflect a homodyning portion of the light beam from the input fiber. The probe also includes a lens between the input fiber exit end and the first beam splitter and a first and a second output optical fiber, each having an entrance end and an exit end, each exit end being operably connectable to respective optical detectors. The probe also includes a second beam splitter which is adapted to reflect at least a portion of the reflected homodyning portion into the output fiber entrance ends and to transmit light from the laser scattered by the sample into the entrance ends.

Correcting the Relative Bias of Light Obscuration and Flow Imaging Particle Counters.

PubMed

Ripple, Dean C; Hu, Zhishang

2016-03-01

Industry and regulatory bodies desire more accurate methods for counting and characterizing particles. Measurements of proteinaceous-particle concentrations by light obscuration and flow imaging can differ by factors of ten or more. We propose methods to correct the diameters reported by light obscuration and flow imaging instruments. For light obscuration, diameters were rescaled based on characterization of the refractive index of typical particles and a light scattering model for the extinction efficiency factor. The light obscuration models are applicable for either homogeneous materials (e.g., silicone oil) or for chemically homogeneous, but spatially non-uniform aggregates (e.g., protein aggregates). For flow imaging, the method relied on calibration of the instrument with silica beads suspended in water-glycerol mixtures. These methods were applied to a silicone-oil droplet suspension and four particle suspensions containing particles produced from heat stressed and agitated human serum albumin, agitated polyclonal immunoglobulin, and abraded ethylene tetrafluoroethylene polymer. All suspensions were measured by two flow imaging and one light obscuration apparatus. Prior to correction, results from the three instruments disagreed by a factor ranging from 3.1 to 48 in particle concentration over the size range from 2 to 20 μm. Bias corrections reduced the disagreement from an average factor of 14 down to an average factor of 1.5. The methods presented show promise in reducing the relative bias between light obscuration and flow imaging.

Electroluminescent device having improved light output

DOEpatents

Tyan,; Yuan-Sheng, [Webster, NY; Preuss, Donald R [Rochester, NY; Farruggia, Giuseppe [Webster, NY; Kesel, Raymond A [Avon, NY; Cushman, Thomas R [Rochester, NY

2011-03-22

An OLED device including a transparent substrate having a first surface and a second surface, a transparent electrode layer disposed over the first surface of the substrate, a short reduction layer disposed over the transparent electrode layer, an organic light-emitting element disposed over the short reduction layer and including at least one light-emitting layer and a charge injection layer disposed over the light emitting layer, a reflective electrode layer disposed over the charge injection layer and a light extraction enhancement structure disposed over the first or second surface of the substrate; wherein the short reduction layer is a transparent film having a through-thickness resistivity of 10.sup.-9 to 10.sup.2 ohm-cm.sup.2; wherein the reflective electrode layer includes Ag or Ag alloy containing more than 80% of Ag; and the total device size is larger than 10 times the substrate thickness.

White light velocity interferometer

DOEpatents

Erskine, D.J.

1999-06-08

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

White light velocity interferometer

DOEpatents

Erskine, David J.

1997-01-01

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

White light velocity interferometer

DOEpatents

Erskine, David J.

1999-01-01

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

White light velocity interferometer

DOEpatents

Erskine, D.J.

1997-06-24

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

Factors affecting the growth of Didymosphenia geminata in New Zealand rivers: Flow, bed disturbance, nutrients, light, and seasonal dynamics. (Invited)

NASA Astrophysics Data System (ADS)

Cullis, J. D.; Gillis, C.; Drummond, J. D.; Garcia, T.; Kilroy, C.; Larned, S.; Hassan, M. A.

2010-12-01

Didymosphenia geminata (didymo) was introduced into a New Zealand river in 2004, and since then has dramatically spread to cover the beds of many rivers with extremely dense and extensive mats. Successful management is hampered by the fact that much is still unknown about the factors affecting the growth of this nuisance species. We synthesized available data on the distribution of D. geminata in New Zealand rivers to determine how physical and chemical system conditions (flow, bed disturbance, nutrients, and light) affect the growth and persistence of this organism. Here we assess results from bi-weekly surveys performed over a full year on two rivers where didymo was first observed in New Zealand; the Oreti and Mararoa. We used the data to test the hypotheses that the development of thick, dense mats requires high light levels but is inversely proportional to nutrient levels, and that mat persistence is controlled by the frequency of flow events that produce bed sediment transport. Observed regrowth between disturbance events was found to be inversely correlated with nutrient availability. The seasonal availability of light did not correlate with variations in growth rate, but this did not account for specific characteristics of the different sites such as aspect, shading, flow depth and turbidity that will all impact on the amount of available light reaching the streambed. The results clearly indicate that the time-history of flow and nutrient levels is critical to evaluating the growth and persistence of D. geminata and that additional site specific information is necessary to determine the role of bed stability and the amount of available light reaching the streambed.

Shoot phototropism in higher plants: new light through old concepts.

PubMed

Christie, John M; Murphy, Angus S

2013-01-01

Light is a key environmental factor that drives many aspects of plant growth and development. Phototropism, the reorientation of growth toward or away from light, represents one of these important adaptive processes. Modern studies of phototropism began with experiments conducted by Charles Darwin demonstrating that light perception at the shoot apex of grass coleoptiles induces differential elongation in the lower epidermal cells. This led to the discovery of the plant growth hormone auxin and the Cholodny-Went hypothesis attributing differential tropic bending to lateral auxin relocalization. In the past two decades, molecular-genetic analyses in the model flowering plant Arabidopsis thaliana has identified the principal photoreceptors for phototropism and their mechanism of activation. In addition, several protein families of auxin transporters have been identified. Despite extensive efforts, however, it still remains unclear as to how photoreceptor activation regulates lateral auxin transport to establish phototropic growth. This review aims to summarize major developments from over the last century and how these advances shape our current understanding of higher plant phototropism. Recent progress in phototropism research and the way in which this research is shedding new light on old concepts, including the Cholodny-Went hypothesis, is also highlighted.

Children and adolescents' internal models of food-sharing behavior include complex evaluations of contextual factors.

PubMed

Markovits, Henry; Benenson, Joyce F; Kramer, Donald L

2003-01-01

This study examined internal representations of food sharing in 589 children and adolescents (8-19 years of age). Questionnaires, depicting a variety of contexts in which one person was asked to share a resource with another, were used to examine participants' expectations of food-sharing behavior. Factors that were varied included the value of the resource, the relation between the two depicted actors, the quality of this relation, and gender. Results indicate that internal models of food-sharing behavior showed systematic patterns of variation, demonstrating that individuals have complex contextually based internal models at all ages, including the youngest. Examination of developmental changes in use of individual patterns is consistent with the idea that internal models reflect age-specific patterns of interactions while undergoing a process of progressive consolidation.

Light Pollution | CTIO

Science.gov Websites

important product so far is Cinzano et al.'s 'First World Atlas of the Artificial Night-Sky Brightness reduction of a factor of two in artificial night-sky brightness will extend the current lifetime of any again reached. A pragmatic, more pessimistic estimate of 7%/annum growth in artificial light pollution

Scatter Measurements Made With Ultraviolet Light

NASA Astrophysics Data System (ADS)

Anthon, Erik W.

1985-09-01

The quality of optical surfaces is generally evaluated by how much light (normally visible light) is scattered by the surface. Most optical glasses and many coating materials are completely opaque to ultraviolet light (253.7 nm). Ultraviolet light tends to scatter much more than visible light. Scatter measurements made with ultraviolet light are therefore very sensitive and the scatter from second surfaces and from the interior (bulk) of the optical material is eliminated by the opacity. A novel scattermeter that operates with ultraviolet light has been developed. The construction and operation of this scattermeter will be described. Cleaning soon becomes the limiting factor when measuring the surfaces with very low level of scatter. Sensitivity to repeated cleaning has been investigated. Different surfaces are compared and uniformity of surfaces is measured by mapping a surface area with an x-y stage. Polished glass surfaces generally have much higher scatter than natural glass surfaces (fire polished, drawn or floated surfaces). Very low scatter levels have been found on thin drawn glass.

Organic electroluminescent devices having improved light extraction

DOEpatents

Shiang, Joseph John [Niskayuna, NY

2007-07-17

Organic electroluminescent devices having improved light extraction include a light-scattering medium disposed adjacent thereto. The light-scattering medium has a light scattering anisotropy parameter g in the range from greater than zero to about 0.99, and a scatterance parameter S less than about 0.22 or greater than about 3.

Cloud coverage acts as an amplifier for ecological light pollution in urban ecosystems.

PubMed

Kyba, Christopher C M; Ruhtz, Thomas; Fischer, Jürgen; Hölker, Franz

2011-03-02

The diurnal cycle of light and dark is one of the strongest environmental factors for life on Earth. Many species in both terrestrial and aquatic ecosystems use the level of ambient light to regulate their metabolism, growth, and behavior. The sky glow caused by artificial lighting from urban areas disrupts this natural cycle, and has been shown to impact the behavior of organisms, even many kilometers away from the light sources. It could be hypothesized that factors that increase the luminance of the sky amplify the degree of this "ecological light pollution". We show that cloud coverage dramatically amplifies the sky luminance, by a factor of 10.1 for one location inside of Berlin and by a factor of 2.8 at 32 km from the city center. We also show that inside of the city overcast nights are brighter than clear rural moonlit nights, by a factor of 4.1. These results have important implications for choronobiological and chronoecological studies in urban areas, where this amplification effect has previously not been considered.

Cloud Coverage Acts as an Amplifier for Ecological Light Pollution in Urban Ecosystems

PubMed Central

Kyba, Christopher C. M.; Ruhtz, Thomas; Fischer, Jürgen; Hölker, Franz

2011-01-01

The diurnal cycle of light and dark is one of the strongest environmental factors for life on Earth. Many species in both terrestrial and aquatic ecosystems use the level of ambient light to regulate their metabolism, growth, and behavior. The sky glow caused by artificial lighting from urban areas disrupts this natural cycle, and has been shown to impact the behavior of organisms, even many kilometers away from the light sources. It could be hypothesized that factors that increase the luminance of the sky amplify the degree of this “ecological light pollution”. We show that cloud coverage dramatically amplifies the sky luminance, by a factor of 10.1 for one location inside of Berlin and by a factor of 2.8 at 32 km from the city center. We also show that inside of the city overcast nights are brighter than clear rural moonlit nights, by a factor of 4.1. These results have important implications for choronobiological and chronoecological studies in urban areas, where this amplification effect has previously not been considered. PMID:21399694

Retinal Effects Of Blue Light Exposure

NASA Astrophysics Data System (ADS)

Ham, William T.; Mueller, Harold A.; Ruffolo, J. J.

1980-10-01

Recent research has shown that blue light exposure is an important factor in certain types of retinal injury. The mammalian ocular media transmits the spectral band 400-1400 nm to the retina. The short wavelengths (400-550 nm) produce a photochemical or actinic type of damage, while the longer wavelengths (550-1400 nm) produce thermal damage. Distinction between the two types of retinal damage are discussed briefly and the importance of the blue light effect for solar retinitis and eclipse blindness is emphasized. The significance of blue light retinal injury is summarized for various environmental and occupational exposures.

ZOSTERA MARINA IN A PACIFIC NORTHWEST ESTUARY: WHAT FACTORS CONTROL INTERTIDAL DISTRIBUTION?

EPA Science Inventory

The impact of four factors (desiccation, macroalgae, erosion, light) on the distribution of Zostera marina was examined across tidal and bathymetric slope gradients. Data detailing seagrass characteristics, including 1 production, macroalgae biomass and sediment characteristics ...

Reflector system for a lighting fixture

DOEpatents

Siminovitch, Michael J.; Page, Erik; Gould, Carl T.

1998-01-01

Disclosed herein is a reflector system for a lighting fixture having a illumination source surrounded by an envelope. The reflector system includes a first reflector surrounding the illumination source. The reflector system also includes a second reflector which is non-contiguous with the first reflector and which surrounds the illumination source. The illumination source creates light rays which are reflected by the first and second reflectors. The first reflector directs light rays toward the center line of the fixture. However, the reflected rays despite being so reflected do not substantially intersect the envelope. The reflected light rays from the second reflector being directed so that they diverge from the center line of the fixture avoiding intersection with the semi-transparent envelope.

Reflector system for a lighting fixture

DOEpatents

Siminovitch, Michael J.; Page, Erik; Gould, Carl T.

2001-01-01

Disclosed herein is a reflector system for a lighting fixture having a illumination source surrounded by an envelope. The reflector system includes a first reflector surrounding the illumination source. The reflector system also includes a second reflector which is non-contiguous with the first reflector and which surrounds the illumination source. The illumination source creates light rays which are reflected by the first and second reflectors. The first reflector directs light rays toward the center line of the fixture. However, the reflected rays despite being so reflected do not substantially intersect the envelope. The reflected light rays from the second reflector being directed so that they diverge from the center line of the fixture avoiding intersection with the semi-transparent envelope.

Reflector system for a lighting fixture

DOEpatents

Siminovitch, M.J.; Page, E.; Gould, C.T.

1998-09-08

Disclosed herein is a reflector system for a lighting fixture having a illumination source surrounded by an envelope. The reflector system includes a first reflector surrounding the illumination source. The reflector system also includes a second reflector which is non-contiguous with the first reflector and which surrounds the illumination source. The illumination source creates light rays which are reflected by the first and second reflectors. The first reflector directs light rays toward the center line of the fixture. However, the reflected rays despite being so reflected do not substantially intersect the envelope. The reflected light rays from the second reflector being directed so that they diverge from the center line of the fixture avoiding intersection with the semi-transparent envelope. 5 figs.

Advanced lighting guidelines: 1993. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eley, C.; Tolen, T.M.; Benya, J.R.

1993-12-31

The 1993 Advanced Lighting Guidelines document consists of twelve guidelines that provide an overview of specific lighting technologies and design application techniques utilizing energy-efficient lighting practice. Lighting Design Practice assesses energy-efficient lighting strategies, discusses lighting issues, and explains how to obtain quality lighting design and consulting services. Luminaires and Lighting Systems surveys luminaire equipment designed to take advantage of advanced technology lamp products and includes performance tables that allow for accurate estimation of luminaire light output and power input. The additional ten guidelines -- Computer-Aided Lighting Design, Energy-Efficient Fluorescent Ballasts, Full-Size Fluorescent Lamps, Compact Fluorescent Lamps, Tungsten-Halogen Lamps, Metal Halidemore » and HPS Lamps, Daylighting and Lumen Maintenance, Occupant Sensors, Time Scheduling Systems, and Retrofit Control Technologies -- each provide a product technology overview, discuss current products on the lighting equipment market, and provide application techniques. This document is intended for use by electric utility personnel involved in lighting programs, lighting designers, electrical engineers, architects, lighting manufacturers` representatives, and other lighting professionals.« less

Blue and Red Light Modulates SigB-Dependent Gene Transcription, Swimming Motility and Invasiveness in Listeria monocytogenes

PubMed Central

Ondrusch, Nicolai; Kreft, Jürgen

2011-01-01

Background In a number of gram-positive bacteria, including Listeria, the general stress response is regulated by the alternative sigma factor B (SigB). Common stressors which lead to the activation of SigB and the SigB-dependent regulon are high osmolarity, acid and several more. Recently is has been shown that also blue and red light activates SigB in Bacillus subtilis. Methodology/Principal Findings By qRT-PCR we analyzed the transcriptional response of the pathogen L. monocytogenes to blue and red light in wild type bacteria and in isogenic deletion mutants for the putative blue-light receptor Lmo0799 and the stress sigma factor SigB. It was found that both blue (455 nm) and red (625 nm) light induced the transcription of sigB and SigB-dependent genes, this induction was completely abolished in the SigB mutant. The blue-light effect was largely dependent on Lmo0799, proving that this protein is a genuine blue-light receptor. The deletion of lmo0799 enhanced the red-light effect, the underlying mechanism as well as that of SigB activation by red light remains unknown. Blue light led to an increased transcription of the internalin A/B genes and of bacterial invasiveness for Caco-2 enterocytes. Exposure to blue light also strongly inhibited swimming motility of the bacteria in a Lmo0799- and SigB-dependent manner, red light had no effect there. Conclusions/Significance Our data established that visible, in particular blue light is an important environmental signal with an impact on gene expression and physiology of the non-phototrophic bacterium L. monocytogenes. In natural environments these effects will result in sometimes random but potentially also cyclic fluctuations of gene activity, depending on the light conditions prevailing in the respective habitat. PMID:21264304

Mesenchymal stem cell therapy ameliorates diabetic nephropathy via the paracrine effect of renal trophic factors including exosomes

PubMed Central

Nagaishi, Kanna; Mizue, Yuka; Chikenji, Takako; Otani, Miho; Nakano, Masako; Konari, Naoto; Fujimiya, Mineko

2016-01-01

Bone marrow-derived mesenchymal stem cells (MSCs) have contributed to the improvement of diabetic nephropathy (DN); however, the actual mediator of this effect and its role has not been characterized thoroughly. We investigated the effects of MSC therapy on DN, focusing on the paracrine effect of renal trophic factors, including exosomes secreted by MSCs. MSCs and MSC-conditioned medium (MSC-CM) as renal trophic factors were administered in parallel to high-fat diet (HFD)-induced type 2 diabetic mice and streptozotocin (STZ)-induced insulin-deficient diabetic mice. Both therapies showed approximately equivalent curative effects, as each inhibited the exacerbation of albuminuria. They also suppressed the excessive infiltration of BMDCs into the kidney by regulating the expression of the adhesion molecule ICAM-1. Proinflammatory cytokine expression (e.g., TNF-α) and fibrosis in tubular interstitium were inhibited. TGF-β1 expression was down-regulated and tight junction protein expression (e.g., ZO-1) was maintained, which sequentially suppressed the epithelial-to-mesenchymal transition of tubular epithelial cells (TECs). Exosomes purified from MSC-CM exerted an anti-apoptotic effect and protected tight junction structure in TECs. The increase of glomerular mesangium substrate was inhibited in HFD-diabetic mice. MSC therapy is a promising tool to prevent DN via the paracrine effect of renal trophic factors including exosomes due to its multifactorial action. PMID:27721418

The relevance of light diffusion profiles for interstitial PDT using light-diffusing optical fibers

NASA Astrophysics Data System (ADS)

Stringasci, Mirian D.; Fortunato, Thereza C.; Moriyama, Lilian T.; Vollet Filho, José Dirceu; Bagnato, Vanderlei S.; Kurachi, Cristina

2017-02-01

Photodynamic therapy (PDT) is a technique used for several tumor types treatment. Light penetration on biological tissue is one limiting factor for PDT applied to large tumors. An alternative is using interstitial PDT, in which optical fibers are inserted into tumors. Cylindrical diffusers have been used in interstitial PDT. Light emission of different diffusers depends on the manufacturing process, size and optical properties of fibers, which make difficult to establish an adequate light dosimetry, since usually light profile is not designed for direct tissue-fiber contact. This study discusses the relevance of light distribution by a cylindrical diffuser into a turbid lipid emulsion solution, and how parts of a single diffuser contribute to illumination. A 2 cm-long cylindrical diffuser optical fiber was connected to a diode laser (630 nm), and the light spatial distribution was measured by scanning the solution with a collection probe. From the light field profile generated by a 1 mm-long intermediary element of a 20 mm-long cylindrical diffuser, recovery of light distribution for the entire diffuser was obtained. PDT was performed in rat healthy liver for a real treatment outcome analysis. By using computational tools, a typical necrosis profile generated by the irradiation with such a diffuser fiber was reconstructed. The results showed that it was possible predicting theoretically the shape of a necrosis profile in a healthy, homogeneous tissue with reasonable accuracy. The ability to predict the necrosis profile obtained from an interstitial illumination by optical diffusers has the potential improve light dosimetry for interstitial PDT.

Multiple wavelength light collimator and monitor

NASA Technical Reports Server (NTRS)

Gore, Warren J. (Inventor)

2011-01-01

An optical system for receiving and collimating light and for transporting and processing light received in each of N wavelength ranges, including near-ultraviolet, visible, near-infrared and mid-infrared wavelengths, to determine a fraction of light received, and associated dark current, in each wavelength range in each of a sequence of time intervals.

What Can We Learn from Hadronic and Radiative Decays of Light Mesons?

NASA Astrophysics Data System (ADS)

Kubis, Bastian

2013-04-01

Chiral perturbation theory offers a powerful tool for the investigation of light pseudoscalar mesons. It incorporates the fundamental symmetries of QCD, interrelates various processes, and allows to link these to the light quark masses. Its shortcomings lie in a limited energy range: the radius of convergence of the chiral expansion is confined to below resonance scales. Furthermore, the strongest consequences of chiral symmetry are manifest for pseudoscalars (pions, kaons, eta) only: vector mesons, e.g., have a severe impact in particular for reactions involving photons. In this talk, I advocate dispersions relations as another model-independent tool to extend the applicability range of chiral perturbation theory. They even allow to tackle the physics of vector mesons in a rigorous way. It will be shown how dispersive methods can be used to resum large rescattering effects, and to provide model-independent links between hadronic and radiative decay modes. Examples to be discussed will include decays of the eta meson, giving access to light-quark-mass ratios or allowing to test the chiral anomaly; and meson transition form factors, which have an important impact on the hadronic light-by-light-scattering contribution to the anomalous magnetic moment of the muon.

Synchrotron Light Sources in Developing Countries

NASA Astrophysics Data System (ADS)

Winick, Herman; Pianetta, Piero

The more than 50 light sources in operation include facilities in Brazil, Korea, and Taiwan which started in the 1980's when they were developing countries. They came on line in the 1990's and have since trained hundreds of graduate students. They have attracted mid-career diaspora scientists to return. Growing user communities have demanded more advanced facilities, leading to higher performance new light sources that are now coming into operation. Light sources in the developing world now include the following: ∖textbf{SESAME}in the Middle East which is scheduled to start research in 2017 (∖underline {www.sesame.org}); ∖textbf{The African Light Source}, in the planning stage (∖underline {www.safricanlightsource.org}); and ∖textbf{The Mexican Light Source}, in the planning stage (∖underline {http://www.aps.org/units/fip/newsletters/201509/mexico.cfm}). See: http://wpj.sagepub.com/content/32/4/92.full.pdf +html; http://www.lightsources.org/press-release/2015/11/20/grenoble-resolutions-mark-historical-step-towards-african-light-source..

Permafrost and land cover as controlling factors for light fraction organic matter on the southern Qinghai-Tibetan plateau.

PubMed

Wu, Xiaodong; Zhao, Lin; Hu, Guojie; Liu, Guimin; Li, Wangping; Ding, Yongjian

2018-02-01

Permafrost degradation can stimulate the decomposition of organic soil matter and cause a large amount of greenhouse gas emissions into the atmosphere. The light fraction organic matter (LFOM) is a labile substrate for microbial decomposition and probably plays an important role in future permafrost carbon cycles. However, little is known about the distribution of LFOM and its relationship with permafrost and environmental factors. Here, we investigated the light fraction carbon (LFC) and nitrogen (LFN) contents and stocks under meadows and wet meadows with different permafrost conditions on the southern Qinghai-Tibetan Plateau. Our results showed that LFC and LFN were mainly distributed in the upper 30cm of soils, and the sites with permafrost had significantly higher contents of LFC and LFN than those from the sites without existing permafrost. The LFC and LFN decreased sharply with depth, suggesting that the soil organic matter (SOM) in this area was highly decomposed in deep soils. Soil moisture and bulk density explained approximately 50% of the variances in LFC and LFN for all the sampling sites, while soil moisture explained approximately 30% of the variance in permafrost sites. Both the C:N ratios and LFC:LFN ratios in the sites with permafrost were higher than those in the sites without permafrost. The results suggested that the permafrost and land cover types are the main factors controlling LFOM content and stock, and that permafrost degradation would lead to a decrease of LFOM and soil C:N ratios, thus accelerating the decomposition of SOM. Copyright © 2017 Elsevier B.V. All rights reserved.

Development and Implementation of a Battery-Electric Light-Duty Class 2a Truck including Hybrid Energy Storage

NASA Astrophysics Data System (ADS)

Kollmeyer, Phillip J.

This dissertation addresses two major related research topics: 1) the design, fabrication, modeling, and experimental testing of a battery-electric light-duty Class 2a truck; and 2) the design and evaluation of a hybrid energy storage system (HESS) for this and other vehicles. The work begins with the determination of the truck's peak power and wheel torque requirements (135kW/4900Nm). An electric traction system is then designed that consists of an interior permanent magnet synchronous machine, two-speed gearbox, three-phase motor drive, and LiFePO4 battery pack. The battery pack capacity is selected to achieve a driving range similar to the 2011 Nissan Leaf electric vehicle (73 miles). Next, the demonstrator electric traction system is built and installed in the vehicle, a Ford F150 pickup truck, and an extensive set of sensors and data acquisition equipment is installed. Detailed loss models of the battery pack, electric traction machine, and motor drive are developed and experimentally verified using the driving data. Many aspects of the truck's performance are investigated, including efficiency differences between the two-gear configuration and the optimal gear selection. The remainder focuses on the application of battery/ultracapacitor hybrid energy storage systems (HESS) to electric vehicles. First, the electric truck is modeled with the addition of an ultracapacitor pack and a dc/dc converter. Rule-based and optimal battery/ultracapacitor power-split control algorithms are then developed, and the performance improvements achieved for both algorithms are evaluated for operation at 25°C. The HESS modeling is then extended to low temperatures, where battery resistance increases substantially. To verify the accuracy of the model-predicted results, a scaled hybrid energy storage system is built and the system is tested for several drive cycles and for two temperatures. The HESS performance is then modeled for three variants of the vehicle design, including the

The Fungal Pathogen Aspergillus fumigatus Regulates Growth, Metabolism, and Stress Resistance in Response to Light

PubMed Central

Fuller, Kevin K.; Ringelberg, Carol S.; Loros, Jennifer J.; Dunlap, Jay C.

2013-01-01

ABSTRACT Light is a pervasive environmental factor that regulates development, stress resistance, and even virulence in numerous fungal species. Though much research has focused on signaling pathways in Aspergillus fumigatus, an understanding of how this pathogen responds to light is lacking. In this report, we demonstrate that the fungus does indeed respond to both blue and red portions of the visible spectrum. Included in the A. fumigatus light response is a reduction in conidial germination rates, increased hyphal pigmentation, enhanced resistance to acute ultraviolet and oxidative stresses, and an increased susceptibility to cell wall perturbation. By performing gene deletion analyses, we have found that the predicted blue light receptor LreA and red light receptor FphA play unique and overlapping roles in regulating the described photoresponsive behaviors of A. fumigatus. However, our data also indicate that the photobiology of this fungus is complex and likely involves input from additional photosensory pathways beyond those analyzed here. Finally, whole-genome microarray analysis has revealed that A. fumigatus broadly regulates a variety of metabolic genes in response to light, including those involved in respiration, amino acid metabolism, and metal homeostasis. Together, these data demonstrate the importance of the photic environment on the physiology of A. fumigatus and provide a basis for future studies into this unexplored area of its biology. PMID:23532976

Light organ symbioses in fishes.

PubMed

Haygood, M G

1993-01-01

Most bioluminescent fishes are self-luminescent, but a substantial minority of bioluminescent teleosts produce light that is due to symbiotic luminous bacteria housed in elaborate light organs. The majority of symbiotically bioluminescent fishes (ten families in five orders) harbors common free-living species of marine luminous bacteria: Photobacterium phosphoreum, P. leiognathi, and P. fischeri (= Vibrio fischeri). Others, associated with the beryciform family Anomalopidae and nine families in the lophiiform suborder Ceratioidei, have apparently obligate symbionts that have recently been identified by small subunit (16S) rRNA analysis as new groups within the genus Vibrio. This article summarizes what is currently known about relationships between light organ symbionts and their hosts, including characteristics of light organ environments, physiology of light organ symbionts, and the evolution of light organ symbionts and their associations.

Night-sky brightness monitoring in Hong Kong: a city-wide light pollution assessment.

PubMed

Pun, Chun Shing Jason; So, Chu Wing

2012-04-01

Results of the first comprehensive light pollution survey in Hong Kong are presented. The night-sky brightness was measured and monitored around the city using a portable light-sensing device called the Sky Quality Meter over a 15-month period beginning in March 2008. A total of 1,957 data sets were taken at 199 distinct locations, including urban and rural sites covering all 18 Administrative Districts of Hong Kong. The survey shows that the environmental light pollution problem in Hong Kong is severe-the urban night skies (sky brightness at 15.0 mag arcsec(- 2)) are on average ~ 100 times brighter than at the darkest rural sites (20.1 mag arcsec(- 2)), indicating that the high lighting densities in the densely populated residential and commercial areas lead to light pollution. In the worst polluted urban location studied, the night-sky at 13.2 mag arcsec(- 2) can be over 500 times brighter than the darkest sites in Hong Kong. The observed night-sky brightness is found to be affected by human factors such as land utilization and population density of the observation sites, together with meteorological and/or environmental factors. Moreover, earlier night skies (at 9:30 p.m. local time) are generally brighter than later time (at 11:30 p.m.), which can be attributed to some public and commercial lightings being turned off later at night. On the other hand, no concrete relationship between the observed sky brightness and air pollutant concentrations could be established with the limited survey sampling. Results from this survey will serve as an important database for the public to assess whether new rules and regulations are necessary to control the use of outdoor lightings in Hong Kong.

Soft lithography microlens fabrication and array for enhanced light extraction from organic light emitting diodes (OLEDs)

DOEpatents

Leung, Wai Y.; Park, Joong-Mok; Gan, Zhengqing; Constant, Kristen P.; Shinar, Joseph; Shinar, Ruth; ho, Kai-Ming

2014-06-03

Provided are microlens arrays for use on the substrate of OLEDs to extract more light that is trapped in waveguided modes inside the devices and methods of manufacturing same. Light extraction with microlens arrays is not limited to the light emitting area, but is also efficient in extracting light from the whole microlens patterned area where waveguiding occurs. Large microlens array, compared to the size of the light emitting area, extract more light and result in over 100% enhancement. Such a microlens array is not limited to (O)LEDs of specific emission, configuration, pixel size, or pixel shape. It is suitable for all colors, including white, for microcavity OLEDs, and OLEDs fabricated directly on the (modified) microlens array.

Scaling laws for light weight optics, studies of light weight mirrors mounting and dynamic mirror stress, and light weight mirror and mount designs

NASA Technical Reports Server (NTRS)

Vukobratovich, Daniel; Richard, Ralph M.; Valente, Tina M.; Cho, Myung K.

1990-01-01

Scaling laws for light-weight optical systems are examined. A cubic relationship between mirror diameter and weight has been suggested and used by many designers of optical systems as the best description for all light-weight mirrors. A survey of existing light-weight systems in the open literature was made to clarify this issue. Fifty existing optical systems were surveyed with all varieties of light-weight mirrors including glass and beryllium structured mirrors, contoured mirrors, and very thin solid mirrors. These mirrors were then categorized and weight to diameter ratio was plotted to find a best curve for each case. A best fitting curve program tests nineteen different equations and ranks a goodness-to-fit for each of these equations. The resulting relationship found for each light-weight mirror category helps to quantify light-weight optical systems and methods of fabrication and provides comparisons between mirror types.

The bias of experimental design, including strain background, in the determination of critical Streptococcus suis serotype 2 virulence factors

PubMed Central

Auger, Jean-Philippe; Chuzeville, Sarah; Roy, David; Mathieu-Denoncourt, Annabelle; Xu, Jianguo; Grenier, Daniel

2017-01-01

Streptococcus suis serotype 2 is an important porcine bacterial pathogen and emerging zoonotic agent mainly responsible for sudden death, septic shock, and meningitis. However, serotype 2 strains are genotypically and phenotypically heterogeneous. Though a multitude of virulence factors have been described for S. suis serotype 2, the lack of a clear definition regarding which ones are truly “critical” has created inconsistencies that have only recently been highlighted. Herein, the involvement of two factors previously described as being critical for S. suis serotype 2 virulence, whether the dipeptidyl peptidase IV and autolysin, were evaluated with regards to different ascribed functions using prototype strains belonging to important sequence types. Results demonstrate a lack of reproducibility with previously published data. In fact, the role of the dipeptidyl peptidase IV and autolysin as critical virulence factors could not be confirmed. Though certain in vitro functions may be ascribed to these factors, their roles are not unique for S. suis, probably due to compensation by other factors. As such, variations and discrepancies in experimental design, including in vitro assays, cell lines, and animal models, are an important source of differences between results. Moreover, the use of different sequence types in this study demonstrates that the role attributed to a virulence factor may vary according to the S. suis serotype 2 strain background. Consequently, it is necessary to establish standard experimental designs according to the experiment and purpose in order to facilitate comparison between laboratories. Alongside, studies should include strains of diverse origins in order to prevent erroneous and biased conclusions that could affect future studies. PMID:28753679

Silicon micromachined broad band light source

NASA Technical Reports Server (NTRS)

George, Thomas (Inventor); Jones, Eric (Inventor); Tuma, Margaret L. (Inventor); Eastwood, Michael (Inventor); Hansler, Richard (Inventor)

2004-01-01

A micro electromechanical system (MEMS) broad band incandescent light source includes three layers: a top transmission window layer; a middle filament mount layer; and a bottom reflector layer. A tungsten filament with a spiral geometry is positioned over a hole in the middle layer. A portion of the broad band light from the heated filament is reflective off the bottom layer. Light from the filament and the reflected light of the filament are transmitted through the transmission window. The light source may operate at temperatures of 2500 K or above. The light source may be incorporated into an on board calibrator (OBC) for a spectrometer.

Fever in trauma patients: evaluation of risk factors, including traumatic brain injury.

PubMed

Bengualid, Victoria; Talari, Goutham; Rubin, David; Albaeni, Aiham; Ciubotaru, Ronald L; Berger, Judith

2015-03-01

The role of fever in trauma patients remains unclear. Fever occurs as a response to release of cytokines and prostaglandins by white blood cells. Many factors, including trauma, can trigger release of these factors. To determine whether (1) fever in the first 48 hours is related to a favorable outcome in trauma patients and (2) fever is more common in patients with head trauma. Retrospective study of trauma patients admitted to the intensive care unit for at least 2 days. Data were analyzed by using multivariate analysis. Of 162 patients studied, 40% had fever during the first 48 hours. Febrile patients had higher mortality rates than did afebrile patients. When adjusted for severity of injuries, fever did not correlate with mortality. Neither the incidence of fever in the first 48 hours after admission to the intensive care unit nor the number of days febrile in the unit differed between patients with and patients without head trauma (traumatic brain injury). About 70% of febrile patients did not have a source found for their fever. Febrile patients without an identified source of infection had lower peak white blood cell counts, lower maximum body temperature, and higher minimum platelet counts than did febrile patients who had an infectious source identified. The most common infection was pneumonia. No relationship was found between the presence of fever during the first 48 hours and mortality. Patients with traumatic brain injury did not have a higher incidence of fever than did patients without traumatic brain injury. About 30% of febrile patients had an identifiable source of infection. Further studies are needed to understand the origin and role of fever in trauma patients. ©2015 American Association of Critical-Care Nurses.

A Guide to the Librarian's Responsibility in Achieving Quality in Lighting and Ventilation.

ERIC Educational Resources Information Center

Mason, Ellsworth

1967-01-01

Quality, not intensity, is the keystone to good library lighting. The single most important problem in lighting is glare caused by extremely intense centers of light. Multiple interfiling of light rays is a factor required in library lighting. A fixture that diffuses light well is basic when light emerges from the fixture. It scatters widely,…

Lighting for Our Schools.

ERIC Educational Resources Information Center

Rankin, John C.

In this speech, the author traces the history of lighting in schools, discusses the variables affecting the amount of illuminance needed, and provides a table of illuminances recommended for Ontario schools. Other factors that affect vision--glare, veiling reflection, color, and brightness balance--are outlined. Planners are admonished to…

Development of Hot Exhaust Emission Factors for Iranian-Made Euro-2 Certified Light-Duty Vehicles.

PubMed

Banitalebi, Ehsan; Hosseini, Vahid

2016-01-05

Emission factors (EFs) are fundamental, necessary data for air pollution research and scenario implementation. With the vision of generating national EFs of the Iranian transportation system, a portable emission measurement system (PEMS) was used to develop the basic EFs for a statistically significant sample of Iranian gasoline-fueled privately owned light duty vehicles (LDVs) operated in Tehran. A smaller sample size of the same fleet was examined by chassis dynamometer (CD) bag emission measurement tests to quantify the systematic differences between the PEMS and CD methods. The selected fleet was tested over four different routes of uphill highways, flat highways, uphill urban streets, and flat urban streets. Real driving emissions (RDEs) and fuel consumption (FC) rates were calculated by weighted averaging of the results from each route. The activity of the fleet over each route type was assumed as a weighting factor. The activity data were obtained from a Tehran traffic model. The RDEs of the selected fleet were considerably higher than the certified emission levels of all vehicles. Differences between Tehran real driving cycles and the New European Driving Cycle (NEDC) was attributed to the lower loading of NEDC. A table of EFs based on RDEs was developed for the sample fleet.

Glass light pipes for solar concentration

NASA Astrophysics Data System (ADS)

Madsen, C. K.; Dogan, Y.; Morrison, M.; Hu, C.; Atkins, R.

2018-02-01

Glass waveguides are fabricated using laser processing techniques that have low optical loss with >90% optical throughput. Advanced light pipes are demonstrated, including angled facets for turning mirrors used for lens-to-light pipe coupling, tapers that increase the concentration, and couplers for combining the outputs from multiple lens array elements. Because they are fabricated from glass, these light pipes can support large optical concentrations and propagate broadband solar over long distances with minimal loss and degradation compared to polymer waveguides. Applications include waveguiding solar concentrators using multi-junction PV cells, solar thermal applications and remoting solar energy, such as for daylighting. Ray trace simulations are used to estimate the surface smoothness required to achieve low loss. Optical measurements for fabricated light pipes are reported for use in waveguiding solar concentrator architectures.

The ecological impacts of nighttime light pollution: a mechanistic appraisal.

PubMed

Gaston, Kevin J; Bennie, Jonathan; Davies, Thomas W; Hopkins, John

2013-11-01

The ecological impacts of nighttime light pollution have been a longstanding source of concern, accentuated by realized and projected growth in electrical lighting. As human communities and lighting technologies develop, artificial light increasingly modifies natural light regimes by encroaching on dark refuges in space, in time, and across wavelengths. A wide variety of ecological implications of artificial light have been identified. However, the primary research to date is largely focused on the disruptive influence of nighttime light on higher vertebrates, and while comprehensive reviews have been compiled along taxonomic lines and within specific research domains, the subject is in need of synthesis within a common mechanistic framework. Here we propose such a framework that focuses on the cross-factoring of the ways in which artificial lighting alters natural light regimes (spatially, temporally, and spectrally), and the ways in which light influences biological systems, particularly the distinction between light as a resource and light as an information source. We review the evidence for each of the combinations of this cross-factoring. As artificial lighting alters natural patterns of light in space, time and across wavelengths, natural patterns of resource use and information flows may be disrupted, with downstream effects to the structure and function of ecosystems. This review highlights: (i) the potential influence of nighttime lighting at all levels of biological organisation (from cell to ecosystem); (ii) the significant impact that even low levels of nighttime light pollution can have; and (iii) the existence of major research gaps, particularly in terms of the impacts of light at population and ecosystem levels, identification of intensity thresholds, and the spatial extent of impacts in the vicinity of artificial lights. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

Computational Modeling to Limit the Impact Displays and Indicator Lights Have on Habitable Volume Operational Lighting Constraints

NASA Technical Reports Server (NTRS)

Clark, T. A.; Salazar, G. A.; Brainard, G. C.; Litaker, H. L.; Hanifin, J.; Schwing, B. M.

2016-01-01

Even with no ambient lighting system "on", the International Space Station glows at night. The glow is caused by indicator lamps and displays that are not included with the specification of the ambient lighting system. How does this impact efforts to improve the astronaut's lighting environment to promote more effective sleep patterns? Do the extra indicators and displays add enough light to change the spectrum of light the crew sees during the day as well? If spacecraft environments are specifically engineered to have an ambient lighting system that emits a spectrum promoting a healthy circadian response, is there a way control the impact? The goal of this project is to investigate how additional light sources, such as displays and indicators change the effective light spectrum of the architectural lighting system and how impacts can be mitigated.

Plant Growth under Natural Light Conditions Provides Highly Flexible Short-Term Acclimation Properties toward High Light Stress

PubMed Central

Schumann, Tobias; Paul, Suman; Melzer, Michael; Dörmann, Peter; Jahns, Peter

2017-01-01

Efficient acclimation to different growth light intensities is essential for plant fitness. So far, most studies on light acclimation have been conducted with plants grown under different constant light regimes, but more recent work indicated that acclimation to fluctuating light or field conditions may result in different physiological properties of plants. Thale cress (Arabidopsis thaliana) was grown under three different constant light intensities (LL: 25 μmol photons m−2 s−1; NL: 100 μmol photons m−2 s−1; HL: 500 μmol photons m−2 s−1) and under natural fluctuating light (NatL) conditions. We performed a thorough characterization of the morphological, physiological, and biochemical properties focusing on photo-protective mechanisms. Our analyses corroborated the known properties of LL, NL, and HL plants. NatL plants, however, were found to combine characteristics of both LL and HL grown plants, leading to efficient and unique light utilization capacities. Strikingly, the high energy dissipation capacity of NatL plants correlated with increased dynamics of thylakoid membrane reorganization upon short-term acclimation to excess light. We conclude that the thylakoid membrane organization and particularly the light-dependent and reversible unstacking of grana membranes likely represent key factors that provide the basis for the high acclimation capacity of NatL grown plants to rapidly changing light intensities. PMID:28515734

Non-label bioimaging utilizing scattering lights

NASA Astrophysics Data System (ADS)

Watanabe, Tomonobu M.; Ichimura, Taro; Fujita, Hideaki

2017-04-01

Optical microscopy is an indispensable tool for medical and life sciences. Especially, the microscopes utilized with scattering light offer a detailed internal observation of living specimens in real time because of their non-labeling and non-invasive capability. We here focus on two kinds of scattering lights, Raman scattering light and second harmonic generation light. Raman scattering light includes the information of all the molecular vibration modes of the molecules, and can be used to distinguish types and/or state of cell. Second harmonic generation light is derived from electric polarity of proteins in the specimen, and enables to detect their structural change. In this conference, we would like to introduce our challenges to extract biological information from those scattering lights.

Hadronic light-by-light scattering contribution to the muon anomalous magnetic moment from lattice QCD

DOE PAGES

Blum, Thomas; Chowdhury, Saumitra; Hayakawa, Masashi; ...

2015-01-07

The form factor that yields the light-by-light scattering contribution to the muon anomalous magnetic moment is computed in lattice QCD+QED and QED. A non-perturbative treatment of QED is used and is checked against perturbation theory. The hadronic contribution is calculated for unphysical quark and muon masses, and only the diagram with a single quark loop is computed. Statistically significant signals are obtained. Initial results appear promising, and the prospect for a complete calculation with physical masses and controlled errors is discussed.

High-performance lighting evaluated by photobiological parameters.

PubMed

Rebec, Katja Malovrh; Gunde, Marta Klanjšek

2014-08-10

The human reception of light includes image-forming and non-image-forming effects which are triggered by spectral distribution and intensity of light. Ideal lighting is similar to daylight, which could be evaluated by spectral or chromaticity match. LED-based and CFL-based lighting were analyzed here, proposed according to spectral and chromaticity match, respectively. The photobiological effects were expressed by effectiveness for blue light hazard, cirtopic activity, and photopic vision. Good spectral match provides light with more similar effects to those obtained by the chromaticity match. The new parameters are useful for better evaluation of complex human responses caused by lighting.

Measures of Light in Studies on Light-Driven Plant Plasticity in Artificial Environments

PubMed Central

Niinemets, Ülo; Keenan, Trevor F.

2012-01-01

Within-canopy variation in light results in profound canopy profiles in foliage structural, chemical, and physiological traits. Studies on within-canopy variations in key foliage traits are often conducted in artificial environments, including growth chambers with only artificial light, and greenhouses with and without supplemental light. Canopy patterns in these systems are considered to be representative to outdoor conditions, but in experiments with artificial and supplemental lighting, the intensity of artificial light strongly deceases with the distance from the light source, and natural light intensity in greenhouses is less than outdoors due to limited transmittance of enclosure walls. The implications of such changes in radiation conditions on canopy patterns of foliage traits have not yet been analyzed. We developed model-based methods for retrospective estimation of distance vs. light intensity relationships, for separation of the share of artificial and natural light in experiments with combined light and for estimation of average enclosure transmittance, and estimated daily integrated light at the time of sampling (Qint,C), at foliage formation (Qint,G), and during foliage lifetime (Qint,av). The implications of artificial light environments were analyzed for altogether 25 studies providing information on within-canopy gradients of key foliage traits for 70 species × treatment combinations. Across the studies with artificial light, Qint,G for leaves formed at different heights in the canopy varied from 1.8- to 6.4-fold due to changing the distance between light source and growing plants. In experiments with combined lighting, the share of natural light at the top of the plants varied threefold, and the share of natural light strongly increased with increasing depth in the canopy. Foliage nitrogen content was most strongly associated with Qint,G, but photosynthetic capacity with Qint,C, emphasizing the importance of explicit description of light

Low Light Diagnostics in Thin-Film Photovoltaics

NASA Astrophysics Data System (ADS)

Shvydka, Diana; Karpov, Victor; Compaan, Alvin

2003-03-01

We study statistics of the major photovoltaic (PV) parameters such as open circuit voltage, short circuit current and fill factor vs. light intensity on a set of nominally identical CdTe/CdS solar cells. We found the most probable parameter values to change with the light intensity as predicted by the standard diode model, while their relative fluctuations increase dramatically under low light. The crossover light intensity is found below which the relative fluctuations of the PV parameters diverge inversely proportional to the square root of the light intensity. We propose a model where the observed fluctuations are due to lateral nonuniformities in the device structure. In particular, the crossover is attributed to the lateral nonuniformity screening length exceeding the device size. >From the practical standpoint, our study introduces a simple uniformity diagnostic technique.

Twin-Mirrored-Galvanometer Laser-Light-Sheet Generator

NASA Technical Reports Server (NTRS)

Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

1991-01-01

Multiple, rotating laser-light sheets generated to illuminate flows in wind tunnels. Designed and developed to provide flexibility and adaptability to wide range of applications. Design includes capability to control size and location of laser-light sheet in real time, to generate horizontal or vertical sheets, to sweep sheet repeatedly through volume, to generate multiple sheets with controllable separation, and to rotate single or multiple laser-light sheets. Includes electronic equipment and laser mounted on adjustable-height platform. Twin-mirrored galvanometer unit supported by tripod to reduce vibration. Other possible applications include use in construction industry to align beams of building. Artistic or display applications also possible.

A new parameterization for surface ocean light attenuation in Earth System Models: assessing the impact of light absorption by colored detrital material

NASA Astrophysics Data System (ADS)

Kim, G. E.; Pradal, M.-A.; Gnanadesikan, A.

2015-03-01

Light limitation can affect the distribution of biota and nutrients in the ocean. Light absorption by colored detrital material (CDM) was included in a fully coupled Earth System Model using a new parameterization for shortwave attenuation. Two model runs were conducted, with and without light attenuation by CDM. In a global average sense, greater light limitation associated with CDM increased surface chlorophyll, biomass and nutrients together. These changes can be attributed to the movement of biological productivity higher up the water column, which increased surface chlorophyll and biomass while simultaneously decreasing total biomass. Meanwhile, the reduction in biomass resulted in greater nutrient availability throughout the water column. Similar results were found on a regional scale in an analysis of the oceans by biome. In coastal regions, surface chlorophyll increased by 35% while total integrated phytoplankton biomass diminished by 18%. The largest relative increases in modeled surface chlorophyll and biomass in the open ocean were found in the equatorial biomes, while largest decreases in depth-integrated biomass and chlorophyll were found in the subpolar and polar biomes. This mismatch of surface and subsurface trends and their regional dependence was analyzed by comparing the competing factors of diminished light availability and increased nutrient availability on phytoplankton growth in the upper 200 m. Overall, increases in surface biomass were expected to accompany greater nutrient uptake and therefore diminish surface nutrients, but changes in light limitation decoupled trends between these two variables. Understanding changes in biological productivity requires both surface and depth-resolved information. Surface trends may be minimal or of the opposite sign to depth-integrated amounts, depending on the vertical structure of phytoplankton abundance.

Interactive Effects of UV-B Light with Abiotic Factors on Plant Growth and Chemistry, and Their Consequences for Defense against Arthropod Herbivores

PubMed Central

Escobar-Bravo, Rocio; Klinkhamer, Peter G. L.; Leiss, Kirsten A.

2017-01-01

Ultraviolet-B (UV-B) light plays a crucial role in plant–herbivorous arthropods interactions by inducing changes in constitutive and inducible plant defenses. In particular, constitutive defenses can be modulated by UV-B-induced photomorphogenic responses and changes in the plant metabolome. In accordance, the prospective use of UV-B light as a tool to increase plant protection in agricultural practice has gained increasing interest. Changes in the environmental conditions might, however, modulate the UV-B -induced plant responses. While in some cases plant responses to UV-B can increase adaptation to changes in certain abiotic factors, UV-B-induced responses might be also antagonized by the changing environment. The outcome of these interactions might have a great influence on how plants interact with their enemies, e.g., herbivorous arthropods. Here, we provide a review on the interactive effects of UV-B and light quantity and quality, increased temperature and drought stress on plant biochemistry, and we discuss the implications of the outcome of these interactions for plant resistance to arthropod pests. PMID:28303147

Light transmission through intraocular lenses with or without yellow chromophore (blue light filter) and its potential influence on functional vision in everyday environmental conditions.

PubMed

Owczarek, Grzegorz; Gralewicz, Grzegorz; Skuza, Natalia; Jurowski, Piotr

2016-01-01

In this research the factors used to evaluate the light transmission through two types of acrylic hydrophobic intraocular lenses, one that contained yellow chromophore that blocks blue light transmission and the other which did not contain that filter, were defined according to various light condition, e.g., daylight and at night. The potential influence of light transmission trough intraocular lenses with or without yellow chromophore on functional vision in everyday environmental conditions was analysed.

Real-world emission factors for antimony and other brake wear related trace elements: size-segregated values for light and heavy duty vehicles.

PubMed

Bukowiecki, Nicolas; Lienemann, Peter; Hill, Matthias; Figi, Renato; Richard, Agnes; Furger, Markus; Rickers, Karen; Falkenberg, Gerald; Zhao, Yongjing; Cliff, Steven S; Prevot, Andre S H; Baltensperger, Urs; Buchmann, Brigitte; Gehrig, Robert

2009-11-01

Hourly trace element measurements were performed in an urban street canyon and next to an interurban freeway in Switzerland during more than one month each, deploying a rotating drum impactor (RDI) and subsequent sample analysis by synchrotron radiation X-ray fluorescence spectrometry (SR-XRF). Antimony and other brake wear associated elements were detected in three particle size ranges (2.5-10, 1-2.5, and 0.1-1 microm). The hourly measurements revealed that the effect of resuspended road dust has to be taken into account for the calculation of vehicle emission factors. Individual values for light and heavy duty vehicles were obtained for stop-and-go traffic in the urban street canyon. Mass based brake wear emissions were predominantly found in the coarse particle fraction. For antimony, determined emission factors were 11 +/- 7 and 86 +/- 42 microg km(-1) vehicle(-1) for light and heavy duty vehicles, respectively. Antimony emissions along the interurban freeway with free-flowing traffic were significantly lower. Relative patterns for brake wear related elements were very similar for both considered locations. Beside vehicle type specific brake wear emissions, road dust resuspension was found to be a dominant contributor of antimony in the street canyon.

JWST NIRSpec Cryogenic Light Shield Mechanism

NASA Technical Reports Server (NTRS)

Hale, Kathleen; Sharma, Rajeev

2006-01-01

The focal plane detectors for the Near-Infrared Spectrometer (NIRSpec) instrument on the James Webb Space Telescope (JWST) require a light tight cover for calibration along with an open field-of-view during ground performance testing within a cryogenic dewar. In order to meet the light attenuation requirements and provide open and closed fields of view without breaking vacuum, a light shield mechanism was designed. This paper describes the details of the light shield mechanism design and test results. Included is information on the labyrinth light path design, motor capability and performance, dry film lubrication, mechanism control, and mechanism cryogenic performance results.

A molecular framework of light-controlled phytohormone action in Arabidopsis.

PubMed

Zhong, Shangwei; Shi, Hui; Xue, Chang; Wang, Lei; Xi, Yanpeng; Li, Jigang; Quail, Peter H; Deng, Xing Wang; Guo, Hongwei

2012-08-21

Environmental changes strongly affect plant growth and development. Phytohormones, endogenous plant-made small molecules such as ethylene, regulate a wide range of processes throughout the lifetime of plants. The ability of plants to integrate external signals with endogenous regulatory pathways is vital for their survival. Ethylene has been found to suppress hypocotyl elongation in darkness while promoting it in light. How ethylene regulates hypocotyl elongation in such opposite ways is largely unknown. In particular, how light modulates and even reverses the function of ethylene has yet to be characterized. Here we show that the basic-helix-loop-helix transcription factor phytochrome-interacting factor 3 (PIF3) is directly activated by ETHYLENE-INSENSITIVE 3 (EIN3) and is indispensible for ethylene-induced hypocotyl elongation in light. Ethylene via EIN3 concomitantly activates two contrasting pathways: the PIF3-dependent growth-promoting pathway and an ethylene response factor 1 (ERF1)-mediated growth-inhibiting pathway. In the light, growth-promoting PIFs are limiting due to light-dependent destabilization, and thus ethylene stimulates growth under these conditions. In contrast, ERF1 is destabilized, and thus limiting, under dark conditions, explaining why ethylene inhibits growth in the dark. Our findings provide a mechanistic insight into how light modulates internal hormone-regulated plant growth. Copyright © 2012 Elsevier Ltd. All rights reserved.

Front lighted optical tooling method and apparatus

DOEpatents

Stone, W.J.

1983-06-30

An optical tooling method and apparatus uses a front lighted shadowgraphic technique to enhance visual contrast of reflected light. The apparatus includes an optical assembly including a fiducial mark, such as cross hairs, reflecting polarized light with a first polarization, a polarizing element backing the fiducial mark and a reflective surface backing the polarizing element for reflecting polarized light bypassing the fiducial mark and traveling through the polarizing element. The light reflected by the reflecting surface is directed through a second pass of the polarizing element toward the frontal direction with a polarization differing from the polarization of the light reflected by the fiducial mark. When used as a tooling target, the optical assembly may be mounted directly to a reference surface or may be secured in a mounting, such as a magnetic mounting. The optical assembly may also be mounted in a plane defining structure and used as a spherometer in conjunction with an optical depth measuring instrument.

SEUSS and PIF4 Coordinately Regulate Light and Temperature Signaling Pathways to Control Plant Growth.

PubMed

Huai, Junling; Zhang, Xinyu; Li, Jialong; Ma, Tingting; Zha, Ping; Jing, Yanjun; Lin, Rongcheng

2018-05-02

Plants continuously monitor environmental conditions (such as light and temperature) and adjust their growth and development accordingly. The transcription factor PHYTOCHROME-INTERACTING FACTOR4 (PIF4) regulates both light and temperature signaling pathways. Here, we identified ENHANCED PHOTOMORPHOGENIC2 (EPP2) as a new repressor of photomorphogenesis in red, far-red, and blue light. Map-based cloning revealed that EPP2 encodes the SEUSS (SEU) transcription regulator. The C-terminus of SEU has transcriptional activation activity and SEU physically interacts with PIF4. Moreover, SEU promotes the expression of many genes, including auxin biosynthetic and responsive genes, and regulates IAA levels in plants. SEU associates with regulatory regions in INDOLE-3-ACETIC ACID INDUCIBLE6 (IAA6) and IAA19 in a PIF4-independent manner, whereas the binding of PIF4 to these genes requires SEU. Furthermore, mutations in SEU affect H3K4me3 methylation at IAA6 and IAA19, and SEU positively regulates warm temperature-mediated hypocotyl growth together with PIF4. Therefore, our results reveal that SEU acts as a central regulator to integrate light and temperature signals to control plant growth by coordinating with PIF4. Copyright © 2018 The Author. Published by Elsevier Inc. All rights reserved.

Contrasting light spectra constrain the macro and microstructures of scleractinian corals.

PubMed

Rocha, Rui J M; Silva, Ana M B; Fernandes, M Helena Vaz; Cruz, Igor C S; Rosa, Rui; Calado, Ricardo

2014-01-01

The morphological plasticity of scleractinian corals can be influenced by numerous factors in their natural environment. However, it is difficult to identify in situ the relative influence of a single biotic or abiotic factor, due to potential interactions between them. Light is considered as a major factor affecting coral skeleton morphology, due to their symbiotic relation with photosynthetic zooxanthellae. Nonetheless, most studies addressing the importance of light on coral morphological plasticity have focused on photosynthetically active radiation (PAR) intensity, with the effect of light spectra remaining largely unknown. The present study evaluated how different light spectra affect the skeleton macro- and microstructures in two coral species (Acropora formosa sensu Veron (2000) and Stylophora pistillata) maintained under controlled laboratory conditions. We tested the effect of three light treatments with the same PAR but with a distinct spectral emission: 1) T5 fluorescent lamps with blue emission; 2) Light Emitting Diodes (LED) with predominantly blue emission; and 3) Light Emitting Plasma (LEP) with full spectra emission. To exclude potential bias generated by genetic variability, the experiment was performed with clonal fragments for both species. After 6 months of experiment, it was possible to detect in coral fragments of both species exposed to different light spectra significant differences in morphometry (e.g., distance among corallites, corallite diameter, and theca thickness), as well as in the organization of their skeleton microstructure. The variability found in the skeleton macro- and microstructures of clonal organisms points to the potential pitfalls associated with the exclusive use of morphometry on coral taxonomy. Moreover, the identification of a single factor influencing the morphology of coral skeletons is relevant for coral aquaculture and can allow the optimization of reef restoration efforts.

On the Hadronic light-by-light contribution to the muon g - 2

NASA Astrophysics Data System (ADS)

Bijnens, Johan

2018-05-01

This talk is about the hadronic light-by-light contribution to the muon anomalous magnetic moment, mainly our old work but including some newer results as well. It concentrates on the model calculations. Most attention is paid to pseudo-scalar exchange and the pion loop contribution. Scalar, a1-exchange and other contributions are shortly discussed as well. For the π0-exchange a possible large cancellation between connected and disconnected diagrams is expected.

Calibrating excitation light fluxes for quantitative light microscopy in cell biology

PubMed Central

Grünwald, David; Shenoy, Shailesh M; Burke, Sean; Singer, Robert H

2011-01-01

Power output of light bulbs changes over time and the total energy delivered will depend on the optical beam path of the microscope, filter sets and objectives used, thus making comparison between experiments performed on different microscopes complicated. Using a thermocoupled power meter, it is possible to measure the exact amount of light applied to a specimen in fluorescence microscopy, regardless of the light source, as the light power measured can be translated into a power density at the sample. This widely used and simple tool forms the basis of a new degree of calibration precision and comparability of results among experiments and setups. Here we describe an easy-to-follow protocol that allows researchers to precisely estimate excitation intensities in the object plane, using commercially available opto-mechanical components. The total duration of this protocol for one objective and six filter cubes is 75 min including start-up time for the lamp. PMID:18974739

Do dry roasting, lightly salting nuts affect their cardioprotective properties and acceptability?

PubMed

Tey, Siew Ling; Robinson, Terryn; Gray, Andrew R; Chisholm, Alexandra W; Brown, Rachel Clare

2017-04-01

Previous studies have reported improvements in cardiovascular disease (CVD) risk factors with the consumption of raw nuts. However, around one-third of nuts consumed are roasted and salted. Thus, it is important to determine whether roasting and salting nuts affect the health benefits observed with raw nuts. This study aimed to compare the effects of consuming two different forms of hazelnuts on cardiovascular risk factors and acceptance. Using a randomised crossover design, 72 participants were asked to consume 30 g/day of either raw or dry roasted, lightly salted hazelnuts for 28 days each. CVD risk factors were measured at the beginning and end of each treatment period. "Desire to consume" and "overall liking" for both forms of hazelnuts were assessed daily using a 150-mm visual analogue scale. Body composition, blood pressure, plasma total and low-density lipoprotein-cholesterol, apolipoprotein A1 and B100, glucose and α-tocopherol concentrations did not differ between forms of hazelnuts (all P ≥ 0.054). High-density lipoprotein (HDL)-cholesterol (P = 0.037) and triacylglycerol (P < 0.001) concentrations were significantly lower following the consumption of dry roasted, lightly salted hazelnuts when compared to the raw hazelnuts. Compared with baseline, consuming both forms of hazelnuts significantly improved HDL-cholesterol and apolipoprotein A1 concentrations, total-C/HDL-C ratio, and systolic blood pressure without significantly changing body composition. Acceptance ratings did not differ between forms of hazelnuts and remained high throughout the study. Dry roasting and lightly salting nuts do not appear to negate the cardioprotective effects observed with raw nut consumption, and both forms of nuts are resistant to monotony. Public health messages could be extended to include dry roasted and lightly salted nuts as part of a heart healthy diet.

Joliet Junior College and the 2015 International Year of Light's Cosmic Light Theme

NASA Astrophysics Data System (ADS)

D'Cruz, Noella L.

2015-01-01

We teach "Descriptive Astronomy" and "Life in the Universe" courses for non-science majors at Joliet Junior College, Joliet IL. We also occasionally present planetarium shows at the college's planetarium. In 2015, we plan to highlight the "Cosmic Light" theme of the 2015 International Year of Light through some of our teaching and outreach activities. For several years, together with our students, we have participated in the Globe at Night light pollution program. In 2015, we plan to continue our participation in this program and we will continue to encourage our students to participate on their own from other locations. We will present a live planetarium show on Light Pollution in Spring 2015 as part of the college's Brown Bag Lecture Series. We plan to develop and present one or two live planetarium presentations that focus on studying astronomical objects across the electromagnetic spectrum during 2015. Also in Spring 2015, we plan to include projects that highlight the International Year of Light in our Descriptive Astronomy course offerings. Our poster will provide details of these "Cosmic Light" activities.

Genomic Analysis of Circadian Clock-, Light-, and Growth-Correlated Genes Reveals PHYTOCHROME-INTERACTING FACTOR5 as a Modulator of Auxin Signaling in Arabidopsis1[C][W][OA

PubMed Central

Nozue, Kazunari; Harmer, Stacey L.; Maloof, Julin N.

2011-01-01

Plants exhibit daily rhythms in their growth, providing an ideal system for the study of interactions between environmental stimuli such as light and internal regulators such as the circadian clock. We previously found that two basic loop-helix-loop transcription factors, PHYTOCHROME-INTERACTING FACTOR4 (PIF4) and PIF5, integrate light and circadian clock signaling to generate rhythmic plant growth in Arabidopsis (Arabidopsis thaliana). Here, we use expression profiling and real-time growth assays to identify growth regulatory networks downstream of PIF4 and PIF5. Genome-wide analysis of light-, clock-, or growth-correlated genes showed significant overlap between the transcriptomes of clock-, light-, and growth-related pathways. Overrepresentation analysis of growth-correlated genes predicted that the auxin and gibberellic acid (GA) hormone pathways both contribute to diurnal growth control. Indeed, lesions of GA biosynthesis genes retarded rhythmic growth. Surprisingly, GA-responsive genes are not enriched among genes regulated by PIF4 and PIF5, whereas auxin pathway and response genes are. Consistent with this finding, the auxin response is more severely affected than the GA response in pif4 pif5 double mutants and in PIF5-overexpressing lines. We conclude that at least two downstream modules participate in diurnal rhythmic hypocotyl growth: PIF4 and/or PIF5 modulation of auxin-related pathways and PIF-independent regulation of the GA pathway. PMID:21430186

Environment in pediatric wards: light, sound, and temperature.

PubMed

Oliveira, Lia; Gomes, Cláudia; Bacelar Nicolau, Leonor; Ferreira, Luís; Ferreira, Rosário

2015-09-01

The mutual relationship between sleep and disease is well known, becoming more relevant whenever the disease leads to hospitalization. We intend to describe patterns of environmental factors of some pediatric wards, and to verify if these are in line with those recommended. As a secondary aim, we characterize sleep quality during hospitalization. Five pediatric wards of a tertiary-level hospital were included. Light, sound, and temperature were measured and assessed through descriptive statistics. The following recommended values were considered: maximum light 100 Lux, maximum sound 45 dB, and optimal temperature 20-24 °C. A questionnaire was prepared to assess children's sleep, and it was completed by a caregiver. Light values were within the desirable limits for 86% of evaluated time. In all wards, the intensity of sound was much higher than desirable, being above 45 dB during 85% of evaluated time. The temperature was above 24 °C during 78% of total time. Based on 34 answered questionnaires (out of 50 distributed), almost half of the respondents believe that sleep quality and restlessness are worse at the hospital. Most children slept for a longer time at home. Eighteen children awoke more times at the hospital, and those awakenings were mostly attributed to noise. The sound and temperature were higher than recommended. The different values between these wards may be due to different levels of care, but this shows that there are no standard rules on this matter. A worse quality and shorter duration of sleep at hospital were reported. Comprehensive studies are necessary to evaluate the impact of environmental factors on disease recovery. Copyright © 2015 Elsevier B.V. All rights reserved.

Emission factors and light absorption properties of brown carbon from household coal combustion in China

NASA Astrophysics Data System (ADS)

Sun, Jianzhong; Zhi, Guorui; Hitzenberger, Regina; Chen, Yingjun; Tian, Chongguo; Zhang, Yayun; Feng, Yanli; Cheng, Miaomiao; Zhang, Yuzhe; Cai, Jing; Chen, Feng; Qiu, Yiqin; Jiang, Zhiming; Li, Jun; Zhang, Gan; Mo, Yangzhi

2017-04-01

Brown carbon (BrC) draws increasing attention due to its effects on climate and other environmental factors. In China, household coal burned for heating and cooking purposes releases huge amounts of carbonaceous particles every year; however, BrC emissions have rarely been estimated in a persuasive manner due to the unavailable emission characteristics. Here, seven coals jointly covering geological maturity from low to high were burned in four typical stoves as both chunk and briquette styles. The optical integrating sphere (IS) method was applied to measure the emission factors (EFs) of BrC and black carbon (BC) via an iterative process using the different spectral dependence of light absorption for BrC and BC and using humic acid sodium salt (HASS) and carbon black (CarB) as reference materials. The following results have been found: (i) the average EFs of BrC for anthracite coal chunks and briquettes are 1.08 ± 0.80 and 1.52 ± 0.16 g kg-1, respectively, and those for bituminous coal chunks and briquettes are 8.59 ± 2.70 and 4.01 ± 2.19 g kg-1, respectively, reflecting a more significant decline in BrC EFs for bituminous coals than for anthracites due to briquetting. (ii) The BrC EF peaks at the middle of coal's geological maturity, displaying a bell-shaped curve between EF and volatile matter (Vdaf). (iii) The calculated BrC emissions from China's residential coal burning amounted to 592 Gg (1 Gg = 109 g) in 2013, which is nearly half of China's total BC emissions. (iv) The absorption Ångström exponents (AAEs) of all coal briquettes are higher than those of coal chunks, indicating that the measure of coal briquetting increases the BrC / BC emission ratio and thus offsets some of the climate cooling effect of briquetting. (v) In the scenario of current household coal burning in China, solar light absorption by BrC (350-850 nm in this study) accounts for more than a quarter (0.265) of the total absorption. This implies the significance of BrC to climate

Light history modulates antioxidant and photosynthetic responses of biofilms to both natural (light) and chemical (herbicides) stressors.

PubMed

Bonnineau, Chloé; Sague, Irene Gallardo; Urrea, Gemma; Guasch, Helena

2012-05-01

In multiple stress situations, the co-occurrence of environmental and chemical factors can influence organisms' ability to cope with toxicity. In this context, the influence of light adaptation on the response of freshwater biofilms to sudden light changes or to herbicides exposure was investigated by determining various parameters: diatom community composition, photosynthetic parameters, chlorophyll a content, antioxidant enzyme activities. Biofilms were grown in microcosms under sub-optimal, saturating, and high light intensities and showed already described characteristics of shade/light adaptation (community structure, photosynthetic adaptation, etc.). Light history modulated antioxidant and photosynthetic responses of biofilms to the stress caused by short-term exposure to sudden light changes or to herbicides. First biofilms adapted to sub-optimal light intensity (shade-adapted) were found to be more sensitive to an increase in light intensity than high-light adapted ones to a reduction in light intensity. Second, while light history influenced biofilms' response to glyphosate, it had little influence on biofilms' response to copper and none on its response to oxyfluorfen. Indeed glyphosate exposure led to a stronger decrease in photosynthetic efficiency of shade-adapted biofilms (EC(50) = 11.7 mg L(-1)) than of high-light adapted communities (EC(50) = 35.6 mg L(-1)). Copper exposure led to an activation of ascorbate peroxidase (APX) in biofilms adapted to sub-optimal and saturating light intensity while the protein content decreased in all biofilms exposed to copper. Oxyfluorfen toxicity was independent of light history provoking an increase in APX activity. In conclusion this study showed that both previous exposure to contaminants and physical habitat characteristics might influence community tolerance to disturbances strongly.

The system analysis of light field information collection based on the light field imaging

NASA Astrophysics Data System (ADS)

Wang, Ye; Li, Wenhua; Hao, Chenyang

2016-10-01

Augmented reality(AR) technology is becoming the study focus, and the AR effect of the light field imaging makes the research of light field camera attractive. The micro array structure was adopted in most light field information acquisition system(LFIAS) since emergence of light field camera, micro lens array(MLA) and micro pinhole array(MPA) system mainly included. It is reviewed in this paper the structure of the LFIAS that the Light field camera commonly used in recent years. LFIAS has been analyzed based on the theory of geometrical optics. Meanwhile, this paper presents a novel LFIAS, plane grating system, we call it "micro aperture array(MAA." And the LFIAS are analyzed based on the knowledge of information optics; This paper proves that there is a little difference in the multiple image produced by the plane grating system. And the plane grating system can collect and record the amplitude and phase information of the field light.

On-road assessment of light duty vehicles in Delhi city: Emission factors of CO, CO2 and NOX

NASA Astrophysics Data System (ADS)

Jaiprakash; Habib, Gazala

2018-02-01

This study presents the technology based emission factors of gaseous pollutants (CO, CO2, and NOX) measured during on-road operation of nine passenger cars of diesel, gasoline, and compressed natural gas (CNG). The emissions from two 3-wheelers, and three 2-wheelers were measured by putting the vehicles on jacks and operating them according to Modified Indian Driving Cycle (MIDC) at no load condition. The emission factors observed in the present work were significantly higher than values reported from dynamometer study by Automotive Research Association of India (ARAI). Low CO (0.34 ± 0.08 g km-1) and high NOX (1.0 ± 0.4 g km-1) emission factors were observed for diesel passenger cars, oppositely high CO (2.2 ± 2.6 g km-1) and low NOX (1.0 ± 1.6 g km-1) emission factors were seen for gasoline powered cars. The after-treatment technology in diesel vehicles was effective in CO reduction. While the use of turbocharger in diesel vehicles to generate high combustion temperature and pressure produces more NOx, probably which may not be effectively controlled by after-treatment device. The after-treatment devices in gasoline powered Post-2010, Post-2005 vehicles can be acclaimed for reduced CO emissions compared to Post-2000 vehicles. This work presents a limited data set of emission factors from on-road operations of light duty vehicles, this limitation can be improved by further measurements of emissions from similar vehicles.

[Investigation of emission characteristics for light duty vehicles with a portable emission measurement system].

PubMed

Wang, Hai-Kun; Fu, Li-Xin; Zhou, Yu; Lin, Xin; Chen, Ai-Zhong; Ge, Wei-hu; Du, Xuan

2008-10-01

Emission from 7 typical light-duty vehicles under actual driving conditions was monitored using a portable emission measurement system to gather data for characterization of the real world vehicle emission in Shenzhen, including the effects of driving modes on vehicle emission, comparison of fuel consumption based emission factors (g x L(-1) with mileage based emission factors (g x km(-1)), and the average emission factors of the monitored vehicles. The acceleration and deceleration modes accounted for 66.7% of total travel time, 80.3% of traveling distance and 74.6%-79.2% of vehicle emission; the acceleration mode contributed more than other driving modes. The fuel based emission factors were less dependent on the driving speed; they may be utilized in building macro-scale vehicle emission inventory with smaller sensitivity to the vehicle driving conditions. The effect of vehicle technology on vehicle emission was significant; the emission factors of CO, HC and NO(x) of carbureted vehicles were 19.9-20.5, 5.6-26.1 and 1.8-2.0 times the more advanced vehicles of Euro II, respectively. Using the ECE + EUDC driving cycle would not produce the desired real-world emission rates of light duty vehicles in a typical Chinese city.

A high affinity monoclonal antibody recognizing the light chain of human coagulating factor VII.

PubMed

Sarial, Sheila; Asadi, Farzad; Jeddi-Tehrani, Mahmood; Hadavi, Reza; Bayat, Ali Ahmad; Mahmoudian, Jafar; Taghizadeh-Jahed, Masoud; Shokri, Fazel; Rabbani, Hodjattallah

2012-12-01

Factor VII (FVII) is a serine protease-coagulating element responsible for the initiation of an extrinsic pathway of clot formation. Here we generated and characterized a high affinity monoclonal antibody that specifically recognizes human FVII. Recombinant human FVII (rh-FVII) was used for the production of a monoclonal antibody using BALB/c mice. The specificity of the antibody was determined by Western blot using plasma samples from human, mouse, sheep, goat, bovine, rabbit, and rat. Furthermore, the antibody was used to detect transiently expressed rh-FVII in BHK21 cell line using Western blot and sandwich ELISA. A mouse IgG1 (kappa chain) monoclonal antibody clone 1F1-B11 was produced against rh-FVII. The affinity constant (K(aff)) of the antibody was calculated to be 6.4×10(10) M(-1). The antibody could specifically recognize an epitope on the light chain of hFVII, with no reactivity with factor VII from several other animals. In addition, transiently expressed rh-FVII in BHK21 cells was recognized by 1F1-B11. The high affinity as well as the specificity of 1F1-B11 for hFVII will facilitate the affinity purification of hFVII and also production of FVII deficient plasma and minimizes the risk of bovine FVII contamination when fetal bovine serum-supplemented media are used for production and subsequent purification of rh-FVII.

Evaluation of emission factors for light-duty gasoline vehicles based on chassis dynamometer and tunnel studies in Shanghai, China

NASA Astrophysics Data System (ADS)

Huang, Cheng; Tao, Shikang; Lou, Shengrong; Hu, Qingyao; Wang, Hongli; Wang, Qian; Li, Li; Wang, Hongyu; Liu, Jian'gang; Quan, Yifeng; Zhou, Lanlan

2017-11-01

CO, THC, NOx, and PM emission factors of 51 light-duty gasoline vehicles (LDGVs) spanning the emission standards from Euro 2 to Euro 5 were measured by a chassis dynamometer. High frequencies of high-emitting vehicles were observed in Euro 2 and Euro 3 LDGV fleet. 56% and 33% of high-emitting vehicles contributed 81%-92% and 82%-85% of the emissions in Euro 2 and Euro 3 test fleet, respectively. Malfunctions of catalytic convertors after high strength use are the main cause of the high emissions. Continuous monitoring of a gasoline vehicle dominated tunnel in Shanghai, China was conducted to evaluate the average emission factors of vehicles in real-world. The results indicated that the emission factors of LDGVs were considerably underestimated in EI guidebook in China. The overlook of high-emitting vehicles in older vehicle fleet is the main reason for this underestimation. Enhancing the supervision of high emission vehicles and strengthening the compliance tests of in-use vehicles are essential measures to control the emissions of in-use gasoline vehicles at the present stage in China.

Hadronic light-by-light contribution to the muon g — 2

NASA Astrophysics Data System (ADS)

Guevara, Adolfo

2016-10-01

We have computed the hadronic light-by-light (LbL) contribution to the muon anomalous magnetic moment aμ in the frame of Chiral Perturbation Theory with the inclusion of the lightest resonance multiplets as dynamical fields (RχT). It is essential to give a more accurate prediction of this hadronic contribution due to the future projects of J-Parc and FNAL on reducing the uncertainty in this observable. We, therefore, computed the pseudoscalar transition form factor and proposed the measurement of the e+ e - →μ+ μ- π0 cross section and dimuon invariant mass spectrum to determine more accurately its parameters. Then, we evaluated the pion exchange contribution to αμ, obtaining (6.66 ± 0.21) • 10-10. By comparing the pion exchange contribution and the pion-pole approximation to the corresponding transition form factor (πTFF) we recalled that the latter underestimates the complete πTFF by (15-20)%. Then, we obtained the η(') TFF, obtaining a total contribution of the lightest pseudoscalar exchanges of (10.47 ± 0.54) • 10-10, in agreement with previous results and with smaller error.

Factors parents use in selecting play spaces for young children.

PubMed

Sallis, J F; McKenzie, T L; Elder, J P; Broyles, S L; Nader, P R

1997-04-01

The amount of time children spend in play spaces (ie, physical locations that are appropriate for children's physical activity) near their homes is correlated with their level of physical activity. To examine factors used in parents' decisions about the selection of play spaces for their children. Parents (primarily mothers) of 178 Mexican American and 122 white children who were a mean age of 4.9 years old at the first measurement. In individual interviews, parents rated 24 factors on their importance in selecting for their children a play space that is away from their home or yard. Decision factors were rated from 1 (ie, not important at all) to 5 (ie, very important). The most important factors, with ratings ranging from 4.8 to 4.2, were safety and availability of toilets, drinking water, lighting, and shade. Mexican American parents rated 8 of 24 items significantly higher than did white parents, including lighted at night, organized activities, play supplies, and drinking water. White parents rated 5 of 24 items significantly higher than did Mexican American parents, including distance from home, cost of admission, and child's friends go there. The rated importance of 7 of 24 items increased during 1 year, including play supplies, drinking water, distance from home, and parents' friends or relatives go there. These results indicate that parents can identify factors they use in selecting places for their young children to play, and selection factors differ somewhat by ethnicity or socioeconomic status. Further studies are needed to determine whether improvements on the most important selection factors might be effective in increasing the use of play spaces by children and their parents. Clinicians may be able to use the most highly rated decision factors to help parents assess the acceptability of play spaces in their areas.

Illumination of interior spaces by bended hollow light guides: Application of the theoretical light propagation method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darula, Stanislav; Kocifaj, Miroslav; Kittler, Richard

2010-12-15

To ensure comfort and healthy conditions in interior spaces the thermal, acoustics and daylight factors of the environment have to be considered in the building design. Due to effective energy performance in buildings the new technology and applications also in daylight engineering are sought such as tubular light guides. These allow the transport of natural light into the building core reducing energy consumption. A lot of installations with various geometrical and optical properties can be applied in real buildings. The simplest set of tubular light guide consists of a transparent cupola, direct tube with high reflected inner surface and amore » ceiling cover or diffuser redistributing light into the interior. Such vertical tubular guide is often used on flat roofs. When the roof construction is inclined a bend in the light guide system has to be installed. In this case the cupola is set on the sloped roof which collects sunlight and skylight from the seen part of the sky hemisphere as well as that reflected from the ground and opposite facades. In comparison with the vertical tube some additional light losses and distortions of the propagated light have to be expected in bended tubular light guides. Recently the theoretical model of light propagation was already published and its applications are presented in this study solving illuminance distributions on the ceiling cover interface and further illuminance distribution on the working plane in the interior. (author)« less

Prognostic factors for head and neck cancer of unknown primary including the impact of human papilloma virus infection.

PubMed

Axelsson, Lars; Nyman, Jan; Haugen-Cange, Hedda; Bove, Mogens; Johansson, Leif; De Lara, Shahin; Kovács, Anikó; Hammerlid, Eva

2017-06-10

Head and neck cancer of unknown primary (HNCUP) is rare and prospective studies are lacking. The impact of different prognostic factors such as age and N stage is not completely known, the optimal treatment is not yet established, and the reported survival rates vary. In the last decade, human papilloma virus (HPV) has been identified as a common cause of and important prognostic factor in oropharyngeal cancer, and there is now growing interest in the importance of HPV for HNCUP. The aim of the present study on curatively treated HNCUP was to investigate the prognostic importance of different factors, including HPV status, treatment, and overall survival. A search for HNCUP was performed in the Swedish Cancer Registry, Western health district, between the years 1992-2009. The medical records were reviewed, and only patients with squamous cell carcinoma or undifferentiated carcinoma treated with curative intent were included. The tumor specimens were retrospectively analyzed for HPV with p16 immunostaining. Sixty-eight patients were included. The mean age was 59 years. The majority were males, and had N2 tumors. Sixty-nine percent of the tumors were HPV positive using p16 staining. Patients who were older than 70 years, patients with N3-stage tumors, and patients with tumors that were p16 negative had a significantly worse prognosis. The overall 5-year survival rate for patients with p16-positive tumors was 88% vs 61% for p16-negative tumors. Treatment with neck dissection and postoperative radiation or (chemo) radiation had 81 and 88% 5-year survival rates, respectively. The overall and disease-free 5-year survival rates for all patients in the study were 82 and 74%. Curatively treated HNCUP had good survival. HPV infection was common. Independent prognostic factors for survival were age over 70 years, HPV status and N3 stage. We recommend that HPV analysis should be performed routinely for HNCUP. Treatment with neck dissection and postoperative radiation or

Advances in Light-Front QCD: Supersymmetric Properties of Hadron Physics from Light-Front Holography and Superconformal Algebra

NASA Astrophysics Data System (ADS)

Brodsky, Stanley J.

2017-05-01

A remarkable feature of QCD is that the mass scale κ which controls color confinement and light-quark hadron mass scales does not appear explicitly in the QCD Lagrangian. However, de Alfaro, Fubini, and Furlan have shown that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the same procedure to the light-front Hamiltonian, it leads uniquely to a confinement potential κ ^4 ζ ^2 for mesons, where ζ ^2 is the LF radial variable conjugate to the q \\bar{q} invariant mass. The same result, including spin terms, is obtained using light-front holography—the duality between the front form and AdS_5, the space of isometries of the conformal group—if one modifies the action of AdS_5 by the dilaton e^{κ ^2 z^2} in the fifth dimension z. When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions predict a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric relations between the masses of mesons and baryons of the same parity. One also predicts observables such as hadron structure functions, transverse momentum distributions, and the distribution amplitudes defined from the hadronic light-front wavefunctions. The mass scale κ underlying confinement and hadron masses can be connected to the parameter Λ _{\\overline{MS}} in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling α _s(Q^2) defined at all momenta. The matching of the high and low momentum transfer regimes determines a scale Q_0 which sets the interface between perturbative and nonperturbative hadron dynamics. The use of Q_0 to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with the

Advances in Light-Front QCD: Supersymmetric Properties of Hadron Physics from Light-Front Holography and Superconformal Algebra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.

A remarkable feature of QCD is that the mass scalemore » $k$ which controls color confinement and light-quark hadron mass scales does not appear explicitly in the QCD Lagrangian. However, de Alfaro, Fubini, and Furlan have shown that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the same procedure to the light-front Hamiltonian, it leads uniquely to a confinement potential κ 4ζ 2 for mesons, where ζ 2 is the LF radial variable conjugate to the $$q\\bar{q}$$ invariant mass. The same result, including spin terms, is obtained using light-front holography$-$the duality between the front form and AdS 5, the space of isometries of the conformal group$-$if one modifies the action of AdS 5 by the dilaton e $κ^2z^2$ in the fifth dimension z. When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions predict a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric relations between the masses of mesons and baryons of the same parity. One also predicts observables such as hadron structure functions, transverse momentum distributions, and the distribution amplitudes defined from the hadronic light-front wavefunctions. The mass scale κκ underlying confinement and hadron masses can be connected to the parameter Λ $$\\overline{MS}$$ in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling α s (Q 2) defined at all momenta. The matching of the high and low momentum transfer regimes determines a scale Q 0 which sets the interface between perturbative and nonperturbative hadron dynamics. The use of Q 0 to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with

Advances in Light-Front QCD: Supersymmetric Properties of Hadron Physics from Light-Front Holography and Superconformal Algebra

DOE PAGES

Brodsky, Stanley J.

2017-04-19

A remarkable feature of QCD is that the mass scalemore » $k$ which controls color confinement and light-quark hadron mass scales does not appear explicitly in the QCD Lagrangian. However, de Alfaro, Fubini, and Furlan have shown that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the same procedure to the light-front Hamiltonian, it leads uniquely to a confinement potential κ 4ζ 2 for mesons, where ζ 2 is the LF radial variable conjugate to the $$q\\bar{q}$$ invariant mass. The same result, including spin terms, is obtained using light-front holography$-$the duality between the front form and AdS 5, the space of isometries of the conformal group$-$if one modifies the action of AdS 5 by the dilaton e $κ^2z^2$ in the fifth dimension z. When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions predict a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric relations between the masses of mesons and baryons of the same parity. One also predicts observables such as hadron structure functions, transverse momentum distributions, and the distribution amplitudes defined from the hadronic light-front wavefunctions. The mass scale κκ underlying confinement and hadron masses can be connected to the parameter Λ $$\\overline{MS}$$ in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling α s (Q 2) defined at all momenta. The matching of the high and low momentum transfer regimes determines a scale Q 0 which sets the interface between perturbative and nonperturbative hadron dynamics. The use of Q 0 to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with

Leaf Morphology, Photosynthetic Performance, Chlorophyll Fluorescence, Stomatal Development of Lettuce (Lactuca sativa L.) Exposed to Different Ratios of Red Light to Blue Light.

PubMed

Wang, Jun; Lu, Wei; Tong, Yuxin; Yang, Qichang

2016-01-01

Red and blue light are both vital factors for plant growth and development. We examined how different ratios of red light to blue light (R/B) provided by light-emitting diodes affected photosynthetic performance by investigating parameters related to photosynthesis, including leaf morphology, photosynthetic rate, chlorophyll fluorescence, stomatal development, light response curve, and nitrogen content. In this study, lettuce plants (Lactuca sativa L.) were exposed to 200 μmol⋅m(-2)⋅s(-1) irradiance for a 16 h⋅d(-1) photoperiod under the following six treatments: monochromatic red light (R), monochromatic blue light (B) and the mixture of R and B with different R/B ratios of 12, 8, 4, and 1. Leaf photosynthetic capacity (A max) and photosynthetic rate (P n) increased with decreasing R/B ratio until 1, associated with increased stomatal conductance, along with significant increase in stomatal density and slight decrease in stomatal size. P n and A max under B treatment had 7.6 and 11.8% reduction in comparison with those under R/B = 1 treatment, respectively. The effective quantum yield of PSII and the efficiency of excitation captured by open PSII center were also significantly lower under B treatment than those under the other treatments. However, shoot dry weight increased with increasing R/B ratio with the greatest value under R/B = 12 treatment. The increase of shoot dry weight was mainly caused by increasing leaf area and leaf number, but no significant difference was observed between R and R/B = 12 treatments. Based on the above results, we conclude that quantitative B could promote photosynthetic performance or growth by stimulating morphological and physiological responses, yet there was no positive correlation between P n and shoot dry weight accumulation.

Leaf Morphology, Photosynthetic Performance, Chlorophyll Fluorescence, Stomatal Development of Lettuce (Lactuca sativa L.) Exposed to Different Ratios of Red Light to Blue Light

PubMed Central

Wang, Jun; Lu, Wei; Tong, Yuxin; Yang, Qichang

2016-01-01

Red and blue light are both vital factors for plant growth and development. We examined how different ratios of red light to blue light (R/B) provided by light-emitting diodes affected photosynthetic performance by investigating parameters related to photosynthesis, including leaf morphology, photosynthetic rate, chlorophyll fluorescence, stomatal development, light response curve, and nitrogen content. In this study, lettuce plants (Lactuca sativa L.) were exposed to 200 μmol⋅m−2⋅s−1 irradiance for a 16 h⋅d−1 photoperiod under the following six treatments: monochromatic red light (R), monochromatic blue light (B) and the mixture of R and B with different R/B ratios of 12, 8, 4, and 1. Leaf photosynthetic capacity (Amax) and photosynthetic rate (Pn) increased with decreasing R/B ratio until 1, associated with increased stomatal conductance, along with significant increase in stomatal density and slight decrease in stomatal size. Pn and Amax under B treatment had 7.6 and 11.8% reduction in comparison with those under R/B = 1 treatment, respectively. The effective quantum yield of PSII and the efficiency of excitation captured by open PSII center were also significantly lower under B treatment than those under the other treatments. However, shoot dry weight increased with increasing R/B ratio with the greatest value under R/B = 12 treatment. The increase of shoot dry weight was mainly caused by increasing leaf area and leaf number, but no significant difference was observed between R and R/B = 12 treatments. Based on the above results, we conclude that quantitative B could promote photosynthetic performance or growth by stimulating morphological and physiological responses, yet there was no positive correlation between Pn and shoot dry weight accumulation. PMID:27014285

Can dendritic cells see light?

NASA Astrophysics Data System (ADS)

Chen, Aaron C.-H.; Huang, Ying-Ying; Sharma, Sulbha K.; Hamblin, Michael R.

2010-02-01

There are many reports showing that low-level light/laser therapy (LLLT) can enhance wound healing, upregulate cell proliferation and has anti-apoptotic effects by activating intracellular protective genes. In the field of immune response study, it is not known with any certainty whether light/laser is proinflammatory or anti-inflammatory. Increasingly in recent times dendritic cells have been found to play an important role in inflammation and the immunological response. In this study, we try to look at the impact of low level near infrared light (810-nm) on murine bone-marrow derived dendritic cells. Changes in surface markers, including MHC II, CD80 and CD11c and the secretion of interleukins induced by light may provide additional evidence to reveal the mystery of how light affects the maturation of dendritic cells as well how these light-induced mature dendritic cells would affect the activation of adaptive immune response.

Effects of weather conditions, light conditions, and road lighting on vehicle speed.

PubMed

Jägerbrand, Annika K; Sjöbergh, Jonas

2016-01-01

Light conditions are known to affect the number of vehicle accidents and fatalities but the relationship between light conditions and vehicle speed is not fully understood. This study examined whether vehicle speed on roads is higher in daylight and under road lighting than in darkness, and determined the combined effects of light conditions, posted speed limit and weather conditions on driving speed. The vehicle speed of passenger cars in different light conditions (daylight, twilight, darkness, artificial light) and different weather conditions (clear weather, rain, snow) was determined using traffic and weather data collected on an hourly basis for approximately 2 years (1 September 2012-31 May 2014) at 25 locations in Sweden (17 with road lighting and eight without). In total, the data included almost 60 million vehicle passes. The data were cleaned by removing June, July, and August, which have different traffic patterns than the rest of the year. Only data from the periods 10:00 A.M.-04:00 P.M. and 06:00 P.M.-10:00 P.M. were used, to remove traffic during rush hour and at night. Multivariate adaptive regression splines was used to evaluate the overall influence of independent variables on vehicle speed and nonparametric statistical testing was applied to test for speed differences between dark-daylight, dark-twilight, and twilight-daylight, on roads with and without road lighting. The results show that vehicle speed in general depends on several independent variables. Analyses of vehicle speed and speed differences between daylight, twilight and darkness, with and without road lighting, did not reveal any differences attributable to light conditions. However, vehicle speed decreased due to rain or snow and the decrease was higher on roads without road lighting than on roads with lighting. These results suggest that the strong association between traffic accidents and darkness or low light conditions could be explained by drivers failing to adjust their

21 CFR 872.4630 - Dental operating light.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dental operating light. 872.4630 Section 872.4630...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4630 Dental operating light. (a) Identification. A dental operating light, including the surgical headlight, is an AC-powered device intended to illuminate...

21 CFR 872.4630 - Dental operating light.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental operating light. 872.4630 Section 872.4630...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4630 Dental operating light. (a) Identification. A dental operating light, including the surgical headlight, is an AC-powered device intended to illuminate...

21 CFR 872.4630 - Dental operating light.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dental operating light. 872.4630 Section 872.4630...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4630 Dental operating light. (a) Identification. A dental operating light, including the surgical headlight, is an AC-powered device intended to illuminate...

21 CFR 872.4630 - Dental operating light.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dental operating light. 872.4630 Section 872.4630...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4630 Dental operating light. (a) Identification. A dental operating light, including the surgical headlight, is an AC-powered device intended to illuminate...

21 CFR 872.4630 - Dental operating light.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dental operating light. 872.4630 Section 872.4630...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4630 Dental operating light. (a) Identification. A dental operating light, including the surgical headlight, is an AC-powered device intended to illuminate...

Lighting system with heat distribution face plate

DOEpatents

Arik, Mehmet; Weaver, Stanton Earl; Stecher, Thomas Elliot; Kuenzler, Glenn Howard; Wolfe, Jr., Charles Franklin; Li, Ri

2013-09-10

Lighting systems having a light source and a thermal management system are provided. The thermal management system includes synthetic jet devices, a heat sink and a heat distribution face plate. The synthetic jet devices are arranged in parallel to one and other and are configured to actively cool the lighting system. The heat distribution face plate is configured to radially transfer heat from the light source into the ambient air.

Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting, I-35W Bridge, Minneapolis, Minnesota, Phase I Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinzey, B. R.; Myer, M. A.

2009-08-01

On the I-35W Bridge in Minneapolis, Minnesota, the GATEWAY program conducted a two-phase demonstration of LED roadway lighting on the main span, which is one of the country's oldest continuously operated exterior LED lighting installations. The Phase I report provides an overview of initial project results including lighting performance, economic performance, and potential energy savings.

Laterally injected light-emitting diode and laser diode

DOEpatents

Miller, Mary A.; Crawford, Mary H.; Allerman, Andrew A.

2015-06-16

A p-type superlattice is used to laterally inject holes into an III-nitride multiple quantum well active layer, enabling efficient light extraction from the active area. Laterally-injected light-emitting diodes and laser diodes can enable brighter, more efficient devices that impact a wide range of wavelengths and applications. For UV wavelengths, applications include fluorescence-based biological sensing, epoxy curing, and water purification. For visible devices, applications include solid state lighting and projection systems.

Solid-state lighting for the International Space Station: Tests of visual performance and melatonin regulation

NASA Astrophysics Data System (ADS)

Brainard, George C.; Coyle, William; Ayers, Melissa; Kemp, John; Warfield, Benjamin; Maida, James; Bowen, Charles; Bernecker, Craig; Lockley, Steven W.; Hanifin, John P.

2013-11-01

The International Space Station (ISS) uses General Luminaire Assemblies (GLAs) that house fluorescent lamps for illuminating the astronauts' working and living environments. Solid-state light emitting diodes (LEDs) are attractive candidates for replacing the GLAs on the ISS. The advantages of LEDs over conventional fluorescent light sources include lower up-mass, power consumption and heat generation, as well as fewer toxic materials, greater resistance to damage and long lamp life. A prototype Solid-State Lighting Assembly (SSLA) was developed and successfully installed on the ISS. The broad aim of the ongoing work is to test light emitted by prototype SSLAs for supporting astronaut vision and assessing neuroendocrine, circadian, neurobehavioral and sleep effects. Three completed ground-based studies are presented here including experiments on visual performance, color discrimination, and acute plasma melatonin suppression in cohorts of healthy, human subjects under different SSLA light exposure conditions within a high-fidelity replica of the ISS Crew Quarters (CQ). All visual tests were done under indirect daylight at 201 lx, fluorescent room light at 531 lx and 4870 K SSLA light in the CQ at 1266 lx. Visual performance was assessed with numerical verification tests (NVT). NVT data show that there are no significant differences in score (F=0.73, p=0.48) or time (F=0.14, p=0.87) for subjects performing five contrast tests (10%-100%). Color discrimination was assessed with Farnsworth-Munsell 100 Hue tests (FM-100). The FM-100 data showed no significant differences (F=0.01, p=0.99) in color discrimination for indirect daylight, fluorescent room light and 4870 K SSLA light in the CQ. Plasma melatonin suppression data show that there are significant differences (F=29.61, p<0.0001) across the percent change scores of plasma melatonin for five corneal irradiances, ranging from 0 to 405 μW/cm2 of 4870 K SSLA light in the CQ (0-1270 lx). Risk factors for the health and

Timing of light exposure affects mood and brain circuits

PubMed Central

Bedrosian, T A; Nelson, R J

2017-01-01

Temporal organization of physiology is critical for human health. In the past, humans experienced predictable periods of daily light and dark driven by the solar day, which allowed for entrainment of intrinsic circadian rhythms to the environmental light–dark cycles. Since the adoption of electric light, however, pervasive exposure to nighttime lighting has blurred the boundaries of day and night, making it more difficult to synchronize biological processes. Many systems are under circadian control, including sleep–wake behavior, hormone secretion, cellular function and gene expression. Circadian disruption by nighttime light perturbs those processes and is associated with increasing incidence of certain cancers, metabolic dysfunction and mood disorders. This review focuses on the role of artificial light at night in mood regulation, including mechanisms through which aberrant light exposure affects the brain. Converging evidence suggests that circadian disruption alters the function of brain regions involved in emotion and mood regulation. This occurs through direct neural input from the clock or indirect effects, including altered neuroplasticity, neurotransmission and clock gene expression. Recently, the aberrant light exposure has been recognized for its health effects. This review summarizes the evidence linking aberrant light exposure to mood. PMID:28140399

Green light in photomorphogenic development

NASA Astrophysics Data System (ADS)

Maruhnich, Stefanie Anne

Light quality, quantity, and duration provide essential environmental cues that shape plant growth and development. Over the last century, researchers have worked to discover how plants sense, integrate, and respond to red, blue, and far-red light. Green light is often considered a “benign” wavelength with little to no effect in plant development. However, sparse experiments in the literature demonstrate that green effects are often counterintuitive to normal light responses and oppose red- and blue-light-induced responses. Green light effects on plant growth and development are described here through the use of custom, tunable LED, light-emitting diode, chambers. These light sources allow for specific light qualities and quantities to be administered. The effects of green wavebands were assessed when red and blue photomorphogenic systems were active to answer the question: Are the effects of an inhibitor (green light) more evident in the presence of inducers (red and blue light)? In seedlings, supplemental green light increased hypocotyl elongation opposite to classical inhibition of hypocotyl elongation associated with growth in light and induced by red and blue wavebands. Results indicate that added green light induced a reversion of light-grown phenotypes. In mature plants, supplemental green light induced phenotypes typical of the shade-avoidance syndrome, including elongated petioles, smaller leaf areas, and leaf hyponasty. These responses are typical of lower-light conditions or far-red enriched environments. Contrary to far-red-light-induced shade-avoidance, data indicate green delays flowering. In Arabidopsis and strawberry plants, anthocyanin levels also decreased when green light was added to red and blue light treatments, which is again opposite to normal light-induced phenotypes. Photoreceptor mutants were tested and indicate green light effects in early development are cryptochromedependent. However, green-light-induced shade-avoidance responses

Cost and energy-efficient (LED, induction and plasma) roadway lighting.

DOT National Transportation Integrated Search

2013-11-01

There is an increasing interest in using new lighting technologies such as light emitting diode (LED), Induction, and Plasma light sources : in roadway lighting. The most commonly claimed benefits of the new lighting systems include increased reliabi...

Method for making a photodetector with enhanced light absorption

DOEpatents

Kane, James

1987-05-05

A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

Bacterial Identification Using Light Scattering Measurements: a Preliminary Report

NASA Technical Reports Server (NTRS)

Wilkins, J. R.

1971-01-01

The light scattering properties of single bacterial cells were examined as a possible means of identification. Three species were studied with streptococcus faecalis exhibiting a unique pattern; the light-scattering traces for staphylococcus aureus and escherichia coli were quite similar although differences existed. Based on preliminary investigations, the light scattering approach appeared promising with additional research needed to include a wide variety of bacterial species, computer capability to handle and analyze data, and expansion of light scattering theory to include bacterial cells.

Light-induced morphological alteration in anthocyanin-accumulating vacuoles of maize cells

PubMed Central

Irani, Niloufer G; Grotewold, Erich

2005-01-01

Background Plant pigmentation is affected by a variety of factors. Light, an important plant developmental signal, influences the accumulation of anthocyanins primarily through the activation of the transcription factors that regulate the flavonoid biosynthetic pathway. In this study, we utilized maize Black Mexican Sweet (BMS) cells expressing the R and C1 regulators of anthocyanin biosynthesis from a light-insensitive promoter as a means to investigate the existence of additional levels of control of pigmentation by light. Results BMS cells expressing the R and C1 regulators from the CaMV 35S constitutive promoter accumulate anthocyanins when grown in complete darkness, suggesting that the transcription factors R and C1 are sufficient for the transcription of the genes corresponding to the structural enzymes of the pathway, with no requirement for additional light-induced regulators. Interestingly, light induces a "darkening" in the color of the purple anthocyanin pigmentation of transgenic BMS cells expressing R and C1. This change in the pigment hue is not associated with a variation in the levels or types of anthocyanins present, or with an alteration of the transcript levels of several flavonoid biosynthetic genes. However, cytological observations show that light drives unexpected changes in the morphology and distribution of the anthocyanins-containing vacuolar compartments. Conclusion By uncoupling the effect of light on anthocyanin accumulation, we have found light to induce the fusion of anthocyanin-containing vacuoles, the coalescence of anthocyanic vacuolar inclusion (AVI)-like structures contained, and the spread of anthocyanins from the inclusions into the vacuolar sap. Similar light-induced alterations in vacuolar morphology are also evident in the epidermal cells of maize floral whorls accumulating anthocyanins. Our findings suggest a novel mechanism for the action of light on the vacuolar storage of anthocyanin. PMID:15907203

Elevated Ambient Light and Temperature Constrain Light Perception in Arctic Krill

NASA Astrophysics Data System (ADS)

Cohen, J.; Jørgen, B.; Moline, M. A.; Johnsen, G.

2016-02-01

Krill play an important role in polar ecosystems as grazers on phytoplankton and microzooplankton, as well as in the subsequent transfer of this energy to higher trophic levels including fish, birds, and marine mammals. In the Barents Sea ecosystem, krill are a particularly important food source sustaining the region's extensive fisheries production. Climate variability over the past half-century, including advection of warmer North Atlantic water and boreal euphausiid taxa, has impacted both krill and fish populations in the Barents Sea, as well as dependencies between them. To better understand these dependencies in the context of climate warming, sea ice loss, and increased winter/spring light levels, we examined temperature- and light-acclimation effects on the visual physiology of krill, which utilize vision for both capturing prey and avoiding predators. Here we show that both elevated temperature and light acclimation lead to changes in visual function in krill Thysanoessa inermis collected from Kongsfjord (Svalbard) in late winter. We found that krill eyes were faster, but less sensitive, in warmer and brighter conditions. Predicting the ecological implications of such physiological shifts is challenging. When coupled with models of the underwater light field and visual perception, these findings suggest that krill in the Barents Sea may be more effective at evading fish predators under future climate scenarios with increased North Atlantic water influence. However, shoaling of krill during the daytime phase of their diel vertical migration could oppose this and favor visual predation on krill by fish.

Plant lighting system with five wavelength-band light-emitting diodes providing photon flux density and mixing ratio control

PubMed Central

2012-01-01

Background Plant growth and development depend on the availability of light. Lighting systems therefore play crucial roles in plant studies. Recent advancements of light-emitting diode (LED) technologies provide abundant opportunities to study various plant light responses. The LED merits include solidity, longevity, small element volume, radiant flux controllability, and monochromaticity. To apply these merits in plant light response studies, a lighting system must provide precisely controlled light spectra that are useful for inducing various plant responses. Results We have developed a plant lighting system that irradiated a 0.18 m2 area with a highly uniform distribution of photon flux density (PFD). The average photosynthetic PFD (PPFD) in the irradiated area was 438 micro-mol m–2 s–1 (coefficient of variation 9.6%), which is appropriate for growing leafy vegetables. The irradiated light includes violet, blue, orange-red, red, and far-red wavelength bands created by LEDs of five types. The PFD and mixing ratio of the five wavelength-band lights are controllable using a computer and drive circuits. The phototropic response of oat coleoptiles was investigated to evaluate plant sensitivity to the light control quality of the lighting system. Oat coleoptiles irradiated for 23 h with a uniformly distributed spectral PFD (SPFD) of 1 micro-mol m–2 s–1 nm–1 at every peak wavelength (405, 460, 630, 660, and 735 nm) grew almost straight upwards. When they were irradiated with an SPFD gradient of blue light (460 nm peak wavelength), the coleoptiles showed a phototropic curvature in the direction of the greater SPFD of blue light. The greater SPFD gradient induced the greater curvature of coleoptiles. The relation between the phototropic curvature (deg) and the blue-light SPFD gradient (micro-mol m–2 s–1 nm–1 m–1) was 2 deg per 1 micro-mol m–2 s–1 nm–1 m–1. Conclusions The plant lighting system, with a computer with a graphical user interface

Response of bats to light with different spectra: light-shy and agile bat presence is affected by white and green, but not red light

PubMed Central

van Grunsven, Roy H. A.; Ramakers, Jip J. C.; Ferguson, Kim B.; Raap, Thomas; Donners, Maurice; Veenendaal, Elmar M.; Visser, Marcel E.

2017-01-01

Artificial light at night has shown a remarkable increase over the past decades. Effects are reported for many species groups, and include changes in presence, behaviour, physiology and life-history traits. Among these, bats are strongly affected, and how bat species react to light is likely to vary with light colour. Different spectra may therefore be applied to reduce negative impacts. We used a unique set-up of eight field sites to study the response of bats to three different experimental light spectra in an otherwise dark and undisturbed natural habitat. We measured activity of three bat species groups around transects with light posts emitting white, green and red light with an intensity commonly used to illuminate countryside roads. The results reveal a strong and spectrum-dependent response for the slow-flying Myotis and Plecotus and more agile Pipistrellus species, but not for Nyctalus and Eptesicus species. Plecotus and Myotis species avoided white and green light, but were equally abundant in red light and darkness. The agile, opportunistically feeding Pipistrellus species were significantly more abundant around white and green light, most likely because of accumulation of insects, but equally abundant in red illuminated transects compared to dark control. Forest-dwelling Myotis and Plecotus species and more synanthropic Pipistrellus species are thus least disturbed by red light. Hence, in order to limit the negative impact of light at night on bats, white and green light should be avoided in or close to natural habitat, but red lights may be used if illumination is needed. PMID:28566484

Response of bats to light with different spectra: light-shy and agile bat presence is affected by white and green, but not red light.

PubMed

Spoelstra, Kamiel; van Grunsven, Roy H A; Ramakers, Jip J C; Ferguson, Kim B; Raap, Thomas; Donners, Maurice; Veenendaal, Elmar M; Visser, Marcel E

2017-05-31

Artificial light at night has shown a remarkable increase over the past decades. Effects are reported for many species groups, and include changes in presence, behaviour, physiology and life-history traits. Among these, bats are strongly affected, and how bat species react to light is likely to vary with light colour. Different spectra may therefore be applied to reduce negative impacts. We used a unique set-up of eight field sites to study the response of bats to three different experimental light spectra in an otherwise dark and undisturbed natural habitat. We measured activity of three bat species groups around transects with light posts emitting white, green and red light with an intensity commonly used to illuminate countryside roads. The results reveal a strong and spectrum-dependent response for the slow-flying Myotis and Plecotus and more agile Pipistrellus species, but not for Nyctalus and Eptesicus species. Plecotus and Myotis species avoided white and green light, but were equally abundant in red light and darkness. The agile, opportunistically feeding Pipistrellus species were significantly more abundant around white and green light, most likely because of accumulation of insects, but equally abundant in red illuminated transects compared to dark control. Forest-dwelling Myotis and Plecotus species and more synanthropic Pipistrellus species are thus least disturbed by red light. Hence, in order to limit the negative impact of light at night on bats, white and green light should be avoided in or close to natural habitat, but red lights may be used if illumination is needed. © 2017 The Author(s).

Evaluating white LEDs for outdoor landscape lighting application

NASA Astrophysics Data System (ADS)

Shakir, Insiya; Narendran, Nadarajah

2002-11-01

A laboratory experiment was conducted to understand the acceptability of different white light emitting diodes (LEDs) for outdoor landscape lighting. The study used a scaled model setup. The scene was designed to replicate the exterior of a typical upscale suburban restaurant including the exterior facade of the building, an approach with steps, and a garden. The lighting was designed to replicate light levels commonly found in nighttime outdoor conditions. The model had a central dividing partition with symmetrical scenes on both sides for side-by-side evaluations of the two scenes with different light sources. While maintaining equal luminance levels and distribution between the two scenes, four types of light sources were evaluated. These include, halogen, phosphor white LED, and two white light systems using RGB LEDs. These light sources were tested by comparing two sources at a time placed side-by-side and by individual assessment of each lighting condition. The results showed that the RGB LEDs performed equal or better than the most widely used halogen light source in this given setting. A majority of the subjects found slightly dimmer ambient lighting to be more typical for restaurants and therefore found RGB LED and halogen light sources to be more inviting. The phosphor white LEDs made the space look brighter, however a majority of the subjects disliked them.

Microbiota of Healthy Corals Are Active against Fungi in a Light-Dependent Manner

PubMed Central

2015-01-01

Coral reefs are intricate ecosystems that harbor diverse organisms, including 25% of all marine fish. Healthy corals exhibit a complex symbiosis between coral polyps, endosymbiotic alga, and an array of microorganisms, called the coral holobiont. Secretion of specialized metabolites by coral microbiota is thought to contribute to the defense of this sessile organism against harmful biotic and abiotic factors. While few causative agents of coral diseases have been unequivocally identified, fungi have been implicated in the massive destruction of some soft corals worldwide. Because corals are nocturnal feeders, they may be more vulnerable to fungal infection at night, and we hypothesized that the coral microbiota would have the capability to enhance their defenses against fungi in the dark. A Pseudoalteromonas sp. isolated from a healthy octocoral displayed light-dependent antifungal properties when grown adjacent to Penicilliumcitrinum (P. citrinum) isolated from a diseased Gorgonian octocoral. Microbial MALDI-imaging mass spectrometry (IMS) coupled with molecular network analyses revealed that Pseudoalteromonas produced higher levels of antifungal polyketide alteramides in the dark than in the light. The alteramides were inactivated by light through a photoinduced intramolecular cyclization. Further NMR studies led to a revision of the stereochemical structure of the alteramides. Alteramide A exhibited antifungal properties and elicited changes in fungal metabolite distributions of mycotoxin citrinin and citrinadins. These data support the hypothesis that coral microbiota use abiotic factors such as light to regulate the production of metabolites with specialized functions to combat opportunistic pathogens at night. PMID:25058318

Emergency Lighting Technology Evolves To Save Lives.

ERIC Educational Resources Information Center

Gregory, Dennis

2001-01-01

Explores the benefits of including high-brightness Light Emitting Diodes (LEDs) for emergency systems and its use in residence halls. LED emergency lighting options and their qualifications are also highlighted.(GR)

Optical filter including a sub-wavelength periodic structure and method of making

DOEpatents

Kaushik, Sumanth; Stallard, Brian R.

1998-01-01

An optical filter includes a dielectric layer formed within a resonant optical cavity, with the dielectric layer having formed therein a sub-wavelength periodic structure to define, at least in part, a wavelength for transmission of light through the resonant optical cavity. The sub-wavelength periodic structure can be formed either by removing material from the dielectric layer (e.g. by etching through an electron-beam defined mask), or by altering the composition of the layer (e.g. by ion implantation). Different portions of the dielectric layer can be patterned to form one or more optical interference filter elements having different light transmission wavelengths so that the optical filter can filter incident light according to wavelength and/or polarization. For some embodiments, the optical filter can include a detector element in optical alignment with each optical interference filter element to quantify or measure the filtered light for analysis thereof. The optical filter has applications to spectrometry, colorimetry, and chemical sensing.

Optical filter including a sub-wavelength periodic structure and method of making

DOEpatents

Kaushik, S.; Stallard, B.R.

1998-03-10

An optical filter includes a dielectric layer formed within a resonant optical cavity, with the dielectric layer having formed therein a sub-wavelength periodic structure to define, at least in part, a wavelength for transmission of light through the resonant optical cavity. The sub-wavelength periodic structure can be formed either by removing material from the dielectric layer (e.g. by etching through an electron-beam defined mask), or by altering the composition of the layer (e.g. by ion implantation). Different portions of the dielectric layer can be patterned to form one or more optical interference filter elements having different light transmission wavelengths so that the optical filter can filter incident light according to wavelength and/or polarization. For some embodiments, the optical filter can include a detector element in optical alignment with each optical interference filter element to quantify or measure the filtered light for analysis thereof. The optical filter has applications to spectrometry, colorimetry, and chemical sensing. 17 figs.

Photonic Switching Devices Using Light Bullets

NASA Technical Reports Server (NTRS)

Goorjian, Peter M. (Inventor)

1999-01-01

A unique ultra-fast, all-optical switching device or switch is made with readily available, relatively inexpensive, highly nonlinear optical materials. which includes highly nonlinear optical glasses, semiconductor crystals and/or multiple quantum well semiconductor materials. At the specified wavelengths. these optical materials have a sufficiently negative group velocity dispersion and high nonlinear index of refraction to support stable light bullets. The light bullets counter-propagate through, and interact within the waveguide to selectively change each others' directions of propagation into predetermined channels. In one embodiment, the switch utilizes a rectangularly planar slab waveguide. and further includes two central channels and a plurality of lateral channels for guiding the light bullets into and out of the waveguide. An advantage of the present all-optical switching device lies in its practical use of light bullets, thus preventing the degeneration of the pulses due to dispersion and diffraction at the front and back of the pulses. Another advantage of the switching device is the relative insensitivity of the collision process to the time difference in which the counter-propagating pulses enter the waveguide. since. contrary to conventional co-propagating spatial solitons, the relative phase of the colliding pulses does not affect the interaction of these pulses. Yet another feature of the present all-optical switching device is the selection of the light pulse parameters which enables the generation of light bullets in nonlinear optical materials. including highly nonlinear optical glasses and semiconductor materials such as semiconductor crystals and/or multiple quantum well semiconductor materials.

Exploring unobserved heterogeneity in bicyclists' red-light running behaviors at different crossing facilities.

PubMed

Guo, Yanyong; Li, Zhibin; Wu, Yao; Xu, Chengcheng

2018-06-01

Bicyclists running the red light at crossing facilities increase the potential of colliding with motor vehicles. Exploring the contributing factors could improve the prediction of running red-light probability and develop countermeasures to reduce such behaviors. However, individuals could have unobserved heterogeneities in running a red light, which make the accurate prediction more challenging. Traditional models assume that factor parameters are fixed and cannot capture the varying impacts on red-light running behaviors. In this study, we employed the full Bayesian random parameters logistic regression approach to account for the unobserved heterogeneous effects. Two types of crossing facilities were considered which were the signalized intersection crosswalks and the road segment crosswalks. Electric and conventional bikes were distinguished in the modeling. Data were collected from 16 crosswalks in urban area of Nanjing, China. Factors such as individual characteristics, road geometric design, environmental features, and traffic variables were examined. Model comparison indicates that the full Bayesian random parameters logistic regression approach is statistically superior to the standard logistic regression model. More red-light runners are predicted at signalized intersection crosswalks than at road segment crosswalks. Factors affecting red-light running behaviors are gender, age, bike type, road width, presence of raised median, separation width, signal type, green ratio, bike and vehicle volume, and average vehicle speed. Factors associated with the unobserved heterogeneity are gender, bike type, signal type, separation width, and bike volume. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fast Light Optical Gyroscopes

NASA Technical Reports Server (NTRS)

Smith, David D.

2015-01-01

Next-generation space missions are currently constrained by existing spacecraft navigation systems which are not fully autonomous. These systems suffer from accumulated dead-reckoning errors and must therefore rely on periodic corrections provided by supplementary technologies that depend on line-of-sight signals from Earth, satellites, or other celestial bodies for absolute attitude and position determination, which can be spoofed, incorrectly identified, occluded, obscured, attenuated, or insufficiently available. These dead-reckoning errors originate in the ring laser gyros themselves, which constitute inertial measurement units. Increasing the time for standalone spacecraft navigation therefore requires fundamental improvements in gyroscope technologies. One promising solution to enhance gyro sensitivity is to place an anomalous dispersion or fast light material inside the gyro cavity. The fast light essentially provides a positive feedback to the gyro response, resulting in a larger measured beat frequency for a given rotation rate as shown in figure 1. Game Changing Development has been investing in this idea through the Fast Light Optical Gyros (FLOG) project, a collaborative effort which began in FY 2013 between NASA Marshall Space Flight Center (MSFC), the U.S. Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC), and Northwestern University. MSFC and AMRDEC are working on the development of a passive FLOG (PFLOG), while Northwestern is developing an active FLOG (AFLOG). The project has demonstrated new benchmarks in the state of the art for scale factor sensitivity enhancement. Recent results show cavity scale factor enhancements of approx.100 for passive cavities.

Investigation of light scattering as a technique for detecting discrete soot particles in a luminous flame

NASA Technical Reports Server (NTRS)

1978-01-01

The practicability of using a classical light-scattering technique, involving comparison of angular scattering intensity patterns with theoretically determined Mie and Rayleight patterns, to detect discrete soot particles (diameter less than 50 nm) in premixed propane/air and propane/oxygen-helium flames is considered. The experimental apparatus employed in this investigation included a laser light source, a flat-flame burner, specially coated optics, a cooled photomultiplier detector, and a lock-in voltmeter readout. Although large, agglomerated soot particles were detected and sized, it was not possible to detect small, discrete particles. The limiting factor appears to be background scattering by the system's optics.

Constructivism, Factoring, and Beliefs.

ERIC Educational Resources Information Center

Rauff, James V.

1994-01-01

Discusses errors made by remedial intermediate algebra students in factoring polynomials in light of student definitions of factoring. Found certain beliefs about factoring to logically imply many of the errors made. Suggests that belief-based teaching can be successful in teaching factoring. (16 references) (Author/MKR)

Protection from visible light by commonly used textiles is not predicted by ultraviolet protection.

PubMed

Van den Keybus, Caroline; Laperre, Jan; Roelandts, Rik

2006-01-01

Interest is increasing in the prevention of acute and chronic actinic damage provided by clothing. This interest has focused mainly on protection against ultraviolet irradiation, but it has now also turned to protection against visible light. This change is mainly due to the action spectrum in the visible light range of some photodermatoses and the increasing interest in photodynamic therapy. The ultraviolet protection provided by commercially available textiles can be graded by determining an ultraviolet protection factor. Several methods have already been used to determine the ultraviolet protection factor. The fact that protection from visible light by textiles cannot be predicted by their ultraviolet protection makes the situation more complicated. This study attempts to determine whether or not the ultraviolet protection factor value of a particular textile is a good parameter for gauging its protection in the visible light range and concludes that a protection factor of textile materials against visible light needs to be developed. This development should go beyond the protection factor definition used in this article, which has some limitations, and should take into account the exact action spectrum for which the protection is needed.