Characterization of Light at Night Data from Select SkyGlowNet Nodes

NASA Astrophysics Data System (ADS)

Flurchick, K. M.; Deal, S.; Foster, C.

2013-05-01

Internet-enabled sky brightness meters (iSBMs) that continuously record and log sky brightness at the zenith have been installed at the prototype nodes of a network called SkyGlowNet. Also logged are time and weather information. These data are polled at a user-defined frequency, typically about every 45 seconds. Although the SkyGlowNetdata are used for various professional scientific studies, they are also useful for independent student research projects. In this case, the data are uploaded to the SkyGlowNetwebsite, initially to a proprietary area where the data for each institution are embargoed for one or two semesters as students conduct research projects with their data. When released from embargo, the data are moved to another area where they can be accessed by all SkyGlowNet participants. In this paper, we describe a student project in which the data collected at two SkyGlowNet sites are characterized. The data streams are parsed into homogenous segments and statistical tools are employed to describe variations observed in the data values. We demonstrate how to differentiate between natural phenomena and the effects of artificial lighting on the brightness of the night sky. In our poster we show how these effects compare between sites as separate as Arizona and North Carolina. We also have experimented with the development of statistical metrics that are used to help categorize sky brightness on select nights, and can nearly automatically provide a characterization of the quality of the night sky for astronomical purposes.

Simultaneous brightness contrast of foraging Papilio butterflies

PubMed Central

Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro

2012-01-01

This study focuses on the sense of brightness in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive brightness in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn brightness and darkness of targets independent of colour, and that they have the so-called simultaneous brightness contrast. PMID:22179808

HST Imaging of the Brightest z ∼ 8–9 Galaxies from UltraVISTA: The Extreme Bright End of the UV Luminosity Function

NASA Astrophysics Data System (ADS)

Stefanon, Mauro; Labbé, Ivo; Bouwens, Rychard J.; Brammer, Gabriel B.; Oesch, Pascal; Franx, Marijn; Fynbo, Johan P. U.; Milvang-Jensen, Bo; Muzzin, Adam; Illingworth, Garth D.; Le Fèvre, Olivier; Caputi, Karina I.; Holwerda, Benne W.; McCracken, Henry J.; Smit, Renske; Magee, Dan

2017-12-01

We report on the discovery of three especially bright candidate {z}{phot}≳ 8 galaxies. Five sources were targeted for follow-up with the Hubble Space Telescope (HST)/Wide Field Camera 3 (WFC3), selected from a larger sample of 16 bright (24.8≲ H≲ 25.5 mag) candidate z≳ 8 Lyman break galaxies (LBGs) identified over 1.6 degrees2 of the COSMOS/UltraVISTA field. These were selected as Y and J dropouts by leveraging the deep (Y-to-{K}{{S}}∼ 25.3{--}24.8 mag, 5σ ) NIR data from the UltraVISTA DR3 release, deep ground-based optical imaging from the CFHTLS and Suprime-Cam programs, and Spitzer/IRAC mosaics combining observations from the SMUVS and SPLASH programs. Through the refined spectral energy distributions, which now also include new HyperSuprimeCam g-, r-, i-, z-, and Y-band data, we confirm that 3/5 galaxies have robust {z}{phot}∼ 8.0{--}8.7, consistent with the initial selection. The remaining 2/5 galaxies have a nominal {z}{phot}∼ 2. However, with HST data alone, these objects have increased probability of being at z∼ 9. We measure mean UV continuum slopes β =-1.74+/- 0.35 for the three z∼ 8{--}9 galaxies, marginally bluer than similarly luminous z∼ 4{--}6 in CANDELS but consistent with previous measurements of similarly luminous galaxies at z∼ 7. The circularized effective radius for our brightest source is 0.9 ± 0.3 kpc, similar to previous measurements for a bright z∼ 11 galaxy and bright z∼ 7 galaxies. Finally, enlarging our sample to include the six brightest z∼ 8 LBGs identified over UltraVISTA (i.e., including three other sources from Labbé et al.) we estimate for the first time the volume density of galaxies at the extreme bright end ({M}{UV}∼ -22 mag) of the z∼ 8 UV luminosity function. Despite this exceptional result, the still large statistical uncertainties do not allow us to discriminate between a Schechter and a double-power-law form.

S193 radiometer brightness temperature precision/accuracy for SL2 and SL3

NASA Technical Reports Server (NTRS)

Pounds, D. J.; Krishen, K.

1975-01-01

The precision and accuracy with which the S193 radiometer measured the brightness temperature of ground scenes is investigated. Estimates were derived from data collected during Skylab missions. Homogeneous ground sites were selected and S193 radiometer brightness temperature data analyzed. The precision was expressed as the standard deviation of the radiometer acquired brightness temperature. Precision was determined to be 2.40 K or better depending on mode and target temperature.

Far-infrared Properties of Infrared-bright Dust-obscured Galaxies Selected with IRAS and AKARI Far-infrared All-sky Survey

NASA Astrophysics Data System (ADS)

Toba, Yoshiki; Nagao, Tohru; Wang, Wei-Hao; Matsuhara, Hideo; Akiyama, Masayuki; Goto, Tomotsugu; Koyama, Yusei; Ohyama, Youich; Yamamura, Issei

2017-05-01

We investigate the star-forming activity of a sample of infrared (IR)-bright dust-obscured galaxies (DOGs) that show an extreme red color in the optical and IR regime, {(I-[22])}{AB}> 7.0. Combining an IR-bright DOG sample with the flux at 22 μm > 3.8 mJy discovered by Toba & Nagao with the IRAS faint source catalog version 2 and AKARI far-IR (FIR) all-sky survey bright source catalog version 2, we selected 109 DOGs with FIR data. For a subsample of seven IR-bright DOGs with spectroscopic redshifts (0.07< z< 1.0) that were obtained from the literature, we estimated their IR luminosity, star formation rate (SFR), and stellar mass based on the spectral energy distribution fitting. We found that (1) the WISE 22 μm luminosity at the observed frame is a good indicator of IR luminosity for IR-bright DOGs and (2) the contribution of the active galactic nucleus to IR luminosity increases with IR luminosity. By comparing the stellar mass and SFR relation for our DOG sample and the literature, we found that most of the IR-bright DOGs lie significantly above the main sequence of star-forming galaxies at similar redshift, indicating that the majority of IRAS- or AKARI-detected IR-bright DOGs are starburst galaxies.

X-ray bright points and He I lambda 10830 dark points

NASA Technical Reports Server (NTRS)

Golub, L.; Harvey, K. L.; Herant, M.; Webb, D. F.

1989-01-01

Using near-simultaneous full disk Solar X-ray images and He I 10830 lambda, spectroheliograms from three recent rocket flights, dark points identified on the He I maps were compared with X-ray bright points identified on the X-ray images. It was found that for the largest and most obvious features there is a strong correlation: most He I dark points correspond to X-ray bright points. However, about 2/3 of the X-ray bright points were not identified on the basis of the helium data alone. Once an X-ray feature is identified it is almost always possible to find an underlying dark patch of enhanced He I absorption which, however, would not a priori have been selected as a dark point. Therefore, the He I dark points, using current selection criteria, cannot be used as a one-to-one proxy for the X-ray data. He I dark points do, however, identify the locations of the stronger X-ray bright points.

X-ray bright points and He I lambda 10830 dark points

NASA Technical Reports Server (NTRS)

Golub, L.; Harvey, K. L.; Herant, M.; Webb, D. F.

1989-01-01

Using near-simultaneous full disk Solar X-ray images and He I 10830 lambda, spectroheliograms from three recent rocket flights, dark points identified on the He I maps were compared with x-ray bright points identified on the X-ray images. It was found that for the largest and most obvious features there is a strong correlation: most He I dark points correspond to X-ray bright points. However, about 2/3 of the X-ray bright points were not identified on the basis of the helium data alone. Once an X-ray feature is identified it is almost always possible to find an underlying dark patch of enhanced He I absorption which, however, would not a priori have been selected as a dark point. Therefore, the He I dark points, using current selection criteria, cannot be used as a one-to-one proxy for the X-ray data. He I dark points do, however, identify the locations of the stronger X-ray bright points.

As-built design specification for P1A software system modified display subsystem

NASA Technical Reports Server (NTRS)

Horton, C. L.; Story, A. S. (Principal Investigator)

1980-01-01

This document contains the design of the proportional estimate processor which was written to satisfy the software requirement of Part A of the P1A experiment. The purposes of the project are: (1) to select the dots to be labelled; (2) to create tables of green numbers and brightness values for all selected dots per acquisition; (3) to create scatter plots of green numbers vs brightness for each acquisition for all selected dots. If labels have been provided then scatter plots of only categories of interest can be optionally produced; and (4) to produce trajectory plots of green number vs brightness at differing acquisition times for each dot. These plots need to be in the same order as the list of selected dots. When labels are provided only plots of dots of categories of interest are to be produced.

Effect of dim and bright light exposure on some immunological parameters measured under thermal neutral conditions.

PubMed

Hyun, Ki-Ja; Kondo, Masayuki; Koh, Taichin; Tokura, Hiromi; Tamotsu, Satoshi; Oishi, Tadashi

2005-01-01

This study assesses the effects of ambient light conditions, under a thermoneutral environment, on selected immunological parameters of 7 healthy young women (aged 19 to 22 yrs). Subjects entered the bioclimatic chamber at 11: 00 h, controlled at 26 degrees C and 60% relative humidity, a "neutral climate". They lead a well-regulated life in the climatic chamber (pre-condition) while exposed to dim (200 lux) or, on the next day, bright (5000 lux) light between 06 : 00 to 12 : 00 h. Just before the end of each period of light exposure, a blood sample was taken for later immunological assay of white blood cell count (WBC), phagocytosis, interferon-gamma (IFN-gamma), interleukin-4 (IL-4), CD69 T cells (CD69), CD4+CD25+ T cells (CD4+CD25+), and transforming growth factor-beta 1 (TGF-beta1). The results, when compared with the pre-condition, were as follows: 1) CD69 and IFN-gamma increased during normal conditions without thermal stress under dim light; 2) WBC increased and IL-4 decreased under bright light; 3) as shown by the highly significant decrease of TGF-beta1, the immune system was activated under bright light; 4) phagocytosis tended to increase under bright light exposure; 5) CD69 and IFN-gamma were significantly higher, and CD4+CD25+ tended to decrease under bright light; 6) phagocytosis tended to be lower and TGF-beta1 significantly higher under dim light, indicating a decline of immune system function. Taken together, this preliminary single time-point sampling study infers that some parameters are activated (CD69) while others are attenuated (phagocytosis, TGF-beta1) according to the environmental light intensity, dim vs. bright, in women adhering to a standardized routine in the absence of thermal stress. These findings are discussed in terms of inhibition of the sympathetic and excitation of the parasympathetic nervous system under the influence of life-style regularity and daytime bright light exposure.

Refinement in black chrome for use as a solar selective coating

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.

1974-01-01

Black chrome is significant as a solar selective coating because the current extensive use of black chrome in the electroplating industry as a durable decorative finish makes black chrome widely available on a commercial scale and potentially low in cost as a solar selective coating. Black-chrome deposits were modified by underplating with dull nickel or by being plated on rough surfaces. Both of these procedures increased the visible absorptance. There was no change in the infrared reflectance for the dull-nickel - black-chrome combination from that reported for the bright-nickel - black-chrome combination. However, the bright-nickel - black-chrome coating plated on rough surfaces indicated a slight decrease in infrared reflectance. As integrated over the solar spectrum for air mass 2, the reflectance of the dull-nickel - black-chrome coating was 0.077, of the bright-nickel - black-chrome coating plated on a 0.75-micron (30-microinch) surface was 0.070, of the bright-nickel - black-chrome coating plated on a 2.5 micron (100-microinch) surface was 0.064. The corresponding values for the bright-nickel - black-chrome coating on a 0.0125-micron (0.5-microinch) surface, two samples of black nickel, and two samples of Nextrel black paint were 0.132, 0.123, 0.133, and 0.033, respectively.

X-ray versus infrared selection of distant galaxy clusters: a case study using the XMM-LSS and SpARCS cluster samples

NASA Astrophysics Data System (ADS)

Willis, J. P.; Ramos-Ceja, M. E.; Muzzin, A.; Pacaud, F.; Yee, H. K. C.; Wilson, G.

2018-07-01

We present a comparison of two samples of z> 0.8 galaxy clusters selected using different wavelength-dependent techniques and examine the physical differences between them. We consider 18 clusters from the X-ray-selected XMM Large Scale Structure (LSS) distant cluster survey and 92 clusters from the optical-mid-infrared (MIR)-selected Spitzer Adaptation of the Red Sequence Cluster survey (SpARCS) cluster survey. Both samples are selected from the same approximately 9 sq deg sky area and we examine them using common XMM-Newton, Spitizer Wide-Area Infrared Extra-galactic (SWIRE) survey, and Canada-France-Hawaii Telescope Legacy Survey data. Clusters from each sample are compared employing aperture measures of X-ray and MIR emission. We divide the SpARCS distant cluster sample into three sub-samples: (i) X-ray bright, (ii) X-ray faint, MIR bright, and (iii) X-ray faint, MIR faint clusters. We determine that X-ray- and MIR-selected clusters display very similar surface brightness distributions of galaxy MIR light. In addition, the average location and amplitude of the galaxy red sequence as measured from stacked colour histograms is very similar in the X-ray- and MIR-selected samples. The sub-sample of X-ray faint, MIR bright clusters displays a distribution of brightest cluster galaxy-barycentre position offsets which extends to higher values than all other samples. This observation indicates that such clusters may exist in a more disturbed state compared to the majority of the distant cluster population sampled by XMM-LSS and SpARCS. This conclusion is supported by stacked X-ray images for the X-ray faint, MIR bright cluster sub-sample that display weak, centrally concentrated X-ray emission, consistent with a population of growing clusters accreting from an extended envelope of material.

Galaxy Selection and the Surface Brightness Distribution

NASA Astrophysics Data System (ADS)

McGaugh, Stacy S.; Bothun, Gregory D.; Schombert, James M.

1995-08-01

Optical surveys for galaxies are biased against the inclusion of low surface brightness (LSB) galaxies. Disney [Nature, 263,573(1976)] suggested that the constancy of disk central surface brightness noticed by Freeman [ApJ, 160,811(1970)] was not a physical result, but instead was an artifact of sample selection. Since LSB galaxies do exist, the pertinent and still controversial issue is if these newly discovered galaxies constitute a significant percentage of the general galaxy population. In this paper, we address this issue by determining the space density of galaxies as a function of disk central surface brightness. Using the physically reasonable assumption (which is motivated by the data) that central surface brightness is independent of disk scale length, we arrive at a distribution which is roughly flat (i.e., approximately equal numbers of galaxies at each surface brightness) faintwards of the Freeman (1970) value. Brightwards of this, we find a sharp decline in the distribution which is analogous to the turn down in the luminosity function at L^*^. An intrinsically sharply peaked "Freeman law" distribution can be completely ruled out, and no Gaussian distribution can fit the data. Low surface brightness galaxies (those with central surface brightness fainter than 22 B mag arcsec^-2^) comprise >~ 1/2 the general galaxy population, so a representative sample of galaxies at z = 0 does not really exist at present since past surveys have been insensitive to this component of the general galaxy population.

Properties of an H I-selected galaxy sample

NASA Technical Reports Server (NTRS)

Szomoru, Arpad; Guhathakurta, Puragra; Van Gorkom, Jacqueline H.; Knapen, Johan H.; Weinberg, David H.; Fruchter, Andrew S.

1994-01-01

We analyze the properties of a sample of galaxies identified in a 21cm, H I-line survey of selected areas in the Perseus-Pisces supercluster and its foreground void. Twelve fields were observed in the supercluster, five of them (target fields) centered on optically bright galaxies, and the other seven (blank fields) selected to contain no bright galaxies within 45 min. of their centers. We detected nine previously uncatalogued, gas-rich galaxies, six of them in the target fields. We also detected H I from seven previously catalogued galaxies in these fields. Observations in the void covered the same volume as the 12 supercluster fields at the same H I-mass sensitivity, but no objects were detected. Combining out H I data with optical broadband and H alpha imaging, we conclude that the properties of H I-selected galaxies do not differ substantially from those of late-type galaxies found in optical surveys. In particular, the galaxies in our sample do not appear to be unusually faint for their H I mass, or for their circular velocity. We find tentative evidence for a connection between optical surface brightness and degree of isolation, in the sense that low surface brightness galaxies tend to be more isolated. The previously catalogued, optically bright galaxies in our survey volume dominate the total H I mass density and cross section; the uncatalogued galaxies contribute only approximately 19 percent of the mass and approximately 12 percent of the cross section. Thus, existing estimates of the density and cross section of neutral hydrogen, most of which are based on optically selected galaxy samples, are probably accurate. Such estimates can be used to compare the nearby universe to the high-redshift universe probed by quasar absorption lines.

The bright-bright and bright-dark mode coupling-based planar metamaterial for plasmonic EIT-like effect

NASA Astrophysics Data System (ADS)

Yu, Wei; Meng, Hongyun; Chen, Zhangjie; Li, Xianping; Zhang, Xing; Wang, Faqiang; Wei, Zhongchao; Tan, Chunhua; Huang, Xuguang; Li, Shuti

2018-05-01

In this paper, we propose a novel planar metamaterial structure for the electromagnetically induced transparency (EIT)-like effect, which consists of a split-ring resonator (SRR) and a pair of metal strips. The simulated results indicate that a single transparency window can be realized in the symmetry situation, which originates from the bright-bright mode coupling. Further, a dual-band EIT-like effect can be achieved in the asymmetry situation, which is due to the bright-bright mode coupling and bright-dark mode coupling, respectively. Different EIT-like effect can be simultaneously achieved in the proposed structure with the different situations. It is of certain significance for the study of EIT-like effect.

Novel approaches to increasing the brightness of broad area lasers

NASA Astrophysics Data System (ADS)

Crump, P.; Winterfeldt, M.; Decker, J.; Ekterai, M.; Fricke, J.; Knigge, S.; Maaßdorf, A.; Erbert, G.

2016-03-01

Progress in studies to increase the lateral brightness Blat of broad area lasers is reviewed. Blat=Pout/BPPlat is maximized by developing designs and technology for lowest lateral beam parameter product, BPPlat, at highest optical output power Pout. This can be achieved by limiting the number of guided lateral modes and by improving the beam quality of low-order lateral modes. Important effects to address include process and packaging induced wave-guiding, lateral carrier accumulation and the thermal lens profile. A careful selection of vertical design is also shown to be important, as are advanced techniques to filter out higher order modes.

Ornament size and colour as alternative strategies for effective communication in gliding lizards.

PubMed

Klomp, D A; Ord, T J; Das, I; Diesmos, A; Ahmad, N; Stuart-Fox, D

2016-09-01

Sexual ornamentation needs to be conspicuous to be effective in attracting potential mates and defending territories and indeed, a multitude of ways exists to achieve this. Two principal mechanisms for increasing conspicuousness are to increase the ornament's colour or brightness contrast against the background and to increase the size of the ornament. We assessed the relationship between the colour and size of the dewlap, a large extendible throat-fan, across a range of species of gliding lizards (Agamidae; genus Draco) from Malaysia and the Philippines. We found a negative relationship across species between colour contrast against the background and dewlap size in males, but not in females, suggesting that males of different species use increasing colour contrast and dewlap size as alternative strategies for effective communication. Male dewlap size also increases with increasing sexual size dimorphism, and dewlap colour and brightness contrast increase with increasing sexual dichromatism in colour and brightness, respectively, suggesting that sexual selection may act on both dewlap size and colour. We further found evidence that relative predation intensity, as measured from predator attacks on models placed in the field, may play a role in the choice of strategy (high chromatic contrast or large dewlap area) a species employs. More broadly, these results highlight that each component in a signal (such as colour or size) may be influenced by different selection pressures and that by assessing components individually, we can gain a greater understanding of the evolution of signal diversity. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Beacons into the Cosmic Dark Ages: Boosted Transmission of Lyα from UV Bright Galaxies at z ≳ 7

NASA Astrophysics Data System (ADS)

Mason, Charlotte A.; Treu, Tommaso; de Barros, Stephane; Dijkstra, Mark; Fontana, Adriano; Mesinger, Andrei; Pentericci, Laura; Trenti, Michele; Vanzella, Eros

2018-04-01

Recent detections of Lyman alpha (Lyα) emission from z > 7.5 galaxies were somewhat unexpected given a dearth of previous non-detections in this era when the intergalactic medium (IGM) is still highly neutral. But these detections were from UV bright galaxies, which preferentially live in overdensities that reionize early, and have significantly Doppler-shifted Lyα line profiles emerging from their interstellar media (ISM), making them less affected by the global IGM state. Using a combination of reionization simulations and empirical ISM models we show, as a result of these two effects, that UV bright galaxies in overdensities have >2× higher transmission through the z ∼ 7 IGM than typical field galaxies, and that this boosted transmission is enhanced as the neutral fraction increases. The boosted transmission is not sufficient to explain the observed high Lyα fraction of M UV ≲ ‑22 galaxies, suggesting that Lyα emitted by these galaxies must be stronger than expected due to enhanced production and/or selection effects. Despite the bias of UV bright galaxies to reside in overdensities we show Lyα observations of such galaxies can accurately measure the global neutral hydrogen fraction, particularly when Lyα from UV faint galaxies is extinguished, making them ideal candidates for spectroscopic follow-up into the cosmic Dark Ages.

Ionized Gas Outflows in Infrared-bright Dust-obscured Galaxies Selected with WISE and SDSS

NASA Astrophysics Data System (ADS)

Toba, Yoshiki; Bae, Hyun-Jin; Nagao, Tohru; Woo, Jong-Hak; Wang, Wei-Hao; Wagner, Alexander Y.; Sun, Ai-Lei; Chang, Yu-Yen

2017-12-01

We present the ionized gas properties of infrared (IR)-bright dust-obscured galaxies (DOGs) that show an extreme optical/IR color, {(i-[22])}{AB}> 7.0, selected with the Sloan Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer (WISE). For 36 IR-bright DOGs that show [O III]λ5007 emission in the SDSS spectra, we performed a detailed spectral analysis to investigate their ionized gas properties. In particular, we measured the velocity offset (the velocity with respect to the systemic velocity measured from the stellar absorption lines) and the velocity dispersion of the [O III] line. We found that the derived velocity offset and dispersion of most IR-bright DOGs are larger than those of Seyfert 2 galaxies (Sy2s) at z< 0.3, meaning that the IR-bright DOGs show relatively strong outflows compared to Sy2s. This can be explained by the difference in IR luminosity contributed from active galactic nuclei, {L}{IR} (AGN), because we found that (i) {L}{IR} (AGN) correlates with the velocity offset and dispersion of [O III] and (ii) our IR-bright DOG sample has larger {L}{IR} (AGN) than Sy2s. Nevertheless, the fact that about 75% IR-bright DOGs have a large (>300 km s-1) velocity dispersion, which is a larger fraction compared to other AGN populations, suggests that IR-bright DOGs are good laboratories to investigate AGN feedback. The velocity offset and dispersion of [O III] and [Ne III]λ3869 are larger than those of [O II]λ3727, which indicates that the highly ionized gas tends to show stronger outflows.

A selective deficit in the appreciation and recognition of brightness: brightness agnosia?

PubMed

Nijboer, Tanja C W; Nys, Gudrun M S; van der Smagt, Maarten J; de Haan, Edward H F

2009-01-01

We report a patient with extensive brain damage in the right hemisphere who demonstrated a severe impairment in the appreciation of brightness. Acuity, contrast sensitivity as well as luminance discrimination were normal, suggesting her brightness impairment is not a mere consequence of low-level sensory impairments. The patient was not able to indicate the darker or the lighter of two grey squares, even though she was able to see that they differed. In addition, she could not indicate whether the lights in a room were switched on or off, nor was she able to differentiate between normal greyscale images and inverted greyscale images. As the patient recognised objects, colours, and shapes correctly, the impairment is specific for brightness. As low-level, sensory processing is normal, this specific deficit in the recognition and appreciation of brightness appears to be of a higher, cognitive level, the level of semantic knowledge. This appears to be the first report of 'brightness agnosia'.

``Smart'' theranostic lanthanide nanoprobes with simultaneous up-conversion fluorescence and tunable T1-T2 magnetic resonance imaging contrast and near-infrared activated photodynamic therapy

NASA Astrophysics Data System (ADS)

Zhang, Yan; Das, Gautom Kumar; Vijayaragavan, Vimalan; Xu, Qing Chi; Padmanabhan, Parasuraman; Bhakoo, Kishore K.; Tamil Selvan, Subramanian; Tan, Timothy Thatt Yang

2014-10-01

The current work reports a type of ``smart'' lanthanide-based theranostic nanoprobe, NaDyF4:Yb3+/NaGdF4:Yb3+,Er3+, which is able to circumvent the up-converting poisoning effect of Dy3+ ions to give efficient near infrared (980 nm) triggered up-conversion fluorescence, and offers not only excellent dark T2-weighted MR contrast but also tunable bright and T1-weighted MR contrast properties. Due to the efficient up-converted energy transfer from the nanocrystals to chlorin e6 (Ce6) photosensitizers loaded onto the nanocrystals, cytotoxic singlet oxygen was generated and photodynamic therapy was demonstrated. Therefore, the current multifunctional nanocrystals could be potentially useful in various image-guided diagnoses where bright or dark MRI contrast could be selectively tuned to optimize image quality, but also as an efficient and more penetrative near-infrared activated photodynamic therapy agent.The current work reports a type of ``smart'' lanthanide-based theranostic nanoprobe, NaDyF4:Yb3+/NaGdF4:Yb3+,Er3+, which is able to circumvent the up-converting poisoning effect of Dy3+ ions to give efficient near infrared (980 nm) triggered up-conversion fluorescence, and offers not only excellent dark T2-weighted MR contrast but also tunable bright and T1-weighted MR contrast properties. Due to the efficient up-converted energy transfer from the nanocrystals to chlorin e6 (Ce6) photosensitizers loaded onto the nanocrystals, cytotoxic singlet oxygen was generated and photodynamic therapy was demonstrated. Therefore, the current multifunctional nanocrystals could be potentially useful in various image-guided diagnoses where bright or dark MRI contrast could be selectively tuned to optimize image quality, but also as an efficient and more penetrative near-infrared activated photodynamic therapy agent. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr01717j

Causes of cine image quality deterioration in cardiac catheterization laboratories.

PubMed

Levin, D C; Dunham, L R; Stueve, R

1983-10-01

Deterioration of cineangiographic image quality can result from malfunctions or technical errors at a number of points along the cine imaging chain: generator and automatic brightness control, x-ray tube, x-ray beam geometry, image intensifier, optics, cine camera, cine film, film processing, and cine projector. Such malfunctions or errors can result in loss of image contrast, loss of spatial resolution, improper control of film optical density (brightness), or some combination thereof. While the electronic and photographic technology involved is complex, physicians who perform cardiac catheterization should be conversant with the problems and what can be done to solve them. Catheterization laboratory personnel have control over a number of factors that directly affect image quality, including radiation dose rate per cine frame, kilovoltage or pulse width (depending on type of automatic brightness control), cine run time, selection of small or large focal spot, proper object-intensifier distance and beam collimation, aperture of the cine camera lens, selection of cine film, processing temperature, processing immersion time, and selection of developer.

Spin dynamics in helical molecules with nonlinear interactions

NASA Astrophysics Data System (ADS)

Díaz, E.; Albares, P.; Estévez, P. G.; Cerveró, J. M.; Gaul, C.; Diez, E.; Domínguez-Adame, F.

2018-04-01

It is widely admitted that the helical conformation of certain chiral molecules may induce a sizable spin selectivity observed in experiments. Spin selectivity arises as a result of the interplay between a helicity-induced spin–orbit coupling (SOC) and electric dipole fields in the molecule. From the theoretical point of view, different phenomena might affect the spin dynamics in helical molecules, such as quantum dephasing, dissipation and the role of metallic contacts. With a few exceptions, previous studies usually neglect the local deformation of the molecule about the carrier, but this assumption seems unrealistic to describe charge transport in molecular systems. We introduce an effective model describing the electron spin dynamics in a deformable helical molecule with weak SOC. We find that the electron–lattice interaction allows the formation of stable solitons such as bright solitons with well defined spin projection onto the molecule axis. We present a thorough study of these bright solitons and analyze their possible impact on the spin dynamics in deformable helical molecules.

Bright and dark singlet excitons via linear and two-photon spectroscopy in monolayer transition metal dichalcogenides

DOE PAGES

Berkelbach, Timothy C.; Hybertsen, Mark S.; Reichmann, David R.

2015-08-10

We discuss the linear and two-photon spectroscopic selection rules for spin-singlet excitons in monolayer transition-metal dichalcogenides. Our microscopic formalism combines a fully k-dependent few-orbital band structure with a many-body Bethe-Salpeter equation treatment of the electron-hole interaction, using a model dielectric function. We show analytically and numerically that the single-particle, valley-dependent selection rules are preserved in the presence of excitonic effects. Furthermore, we definitively demonstrate that the bright (one-photon allowed) excitons have s-type azimuthal symmetry and that dark p-type excitons can be probed via two-photon spectroscopy. Thus, the screened Coulomb interaction in these materials substantially deviates from the 1/ε₀r form; thismore » breaks the “accidental” angular momentum degeneracy in the exciton spectrum, such that the 2p exciton has a lower energy than the 2s exciton by at least 50 meV. We compare our calculated two-photon absorption spectra to recent experimental measurements.« less

The Halo Occupation Distribution of obscured quasars: revisiting the unification model

NASA Astrophysics Data System (ADS)

Mitra, Kaustav; Chatterjee, Suchetana; DiPompeo, Michael A.; Myers, Adam D.; Zheng, Zheng

2018-06-01

We model the projected angular two-point correlation function (2PCF) of obscured and unobscured quasars selected using the Wide-field Infrared Survey Explorer (WISE), at a median redshift of z ˜ 1 using a five parameter Halo Occupation Distribution (HOD) parametrization, derived from a cosmological hydrodynamic simulation by Chatterjee et al. The HOD parametrization was previously used to model the 2PCF of optically selected quasars and X-ray bright active galactic nuclei (AGNs) at z ˜ 1. The current work shows that a single HOD parametrization can be used to model the population of different kinds of AGN in dark matter haloes suggesting the universality of the relationship between AGN and their host dark matter haloes. Our results show that the median halo mass of central quasar hosts increases from optically selected (4.1^{+0.3}_{-0.4} × 10^{12} h^{-1} M_{⊙}) and infra-red (IR) bright unobscured populations (6.3^{+6.2}_{-2.3} × 10^{12} h^{-1} M_{⊙}) to obscured quasars (10.0^{+2.6}_{-3.7} × 10^{12} h^{-1} M_{⊙}), signifying an increase in the degree of clustering. The projected satellite fractions also increase from optically bright to obscured quasars and tend to disfavour a simple `orientation only' theory of active galactic nuclei unification. Our results also show that future measurements of the small-scale clustering of obscured quasars can constrain current theories of galaxy evolution where quasars evolve from an IR-bright obscured phase to the optically bright unobscured phase.

The bidirectional congruency effect of brightness-valence metaphoric association in the Stroop-like and priming paradigms.

PubMed

Huang, Yanli; Tse, Chi-Shing; Xie, Jiushu

2017-11-04

The conceptual metaphor theory (Lakoff & Johnson, 1980, 1999) postulates a unidirectional metaphoric association between abstract and concrete concepts: sensorimotor experience activated by concrete concepts facilitates the processing of abstract concepts, but not the other way around. However, this unidirectional view has been challenged by studies that reported a bidirectional metaphoric association. In three experiments, we tested the directionality of the brightness-valence metaphoric association, using Stroop-like paradigm, priming paradigm, and Stroop-like paradigm with a go/no-go manipulation. Both mean and vincentile analyses of reaction time data were performed. We showed that the directionality of brightness-valence metaphoric congruency effect could be modulated by the activation level of the brightness/valence information. Both brightness-to-valence and valence-to-brightness metaphoric congruency effects occurred in the priming paradigm, which could be attributed to the presentation of prime that pre-activated the brightness or valence information. However, in the Stroop-like paradigm the metaphoric congruency effect was only observed in the brightness-to-valence direction, but not in the valence-to-brightness direction. When the go/no-go manipulation was used to boost the activation of word meaning in the Stroop-like paradigm, the valence-to-brightness metaphoric congruency effect was observed. Vincentile analyses further revealed that valence-to-brightness metaphoric congruency effect approached significance in the Stroop-like paradigm when participants' reaction times were slower (at around 490ms). The implications of the current findings on the conceptual metaphor theory and embodied cognition are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigating a population of infrared-bright gamma-ray burst host galaxies

NASA Astrophysics Data System (ADS)

Chrimes, Ashley A.; Stanway, Elizabeth R.; Levan, Andrew J.; Davies, Luke J. M.; Angus, Charlotte R.; Greis, Stephanie M. L.

2018-07-01

We identify and explore the properties of an infrared-bright gamma-ray burst (GRB) host population. Candidate hosts are selected by coincidence with sources in WISE, with matching to random coordinates and a false alarm probability analysis showing that the contamination fraction is ˜0.5. This methodology has already identified the host galaxy of GRB 080517. We combine survey photometry from Pan-STARRS, SDSS, APASS, 2MASS, GALEX, and WISE with our own WHT/ACAM and VLT/X-shooter observations to classify the candidates and identify interlopers. Galaxy SED fitting is performed using MAGPHYS, in addition to stellar template fitting, yielding 13 possible IR-bright hosts. A further seven candidates are identified from the previously published work. We report a candidate host for GRB 061002, previously unidentified as such. The remainder of the galaxies have already been noted as potential hosts. Comparing the IR-bright population properties including redshift z, stellar mass M⋆, star formation rate SFR, and V-band attenuation AV to GRB host catalogues in the literature, we find that the infrared-bright population is biased towards low z, high M⋆, and high AV. This naturally arises from their initial selection - local and dusty galaxies are more likely to have the required IR flux to be detected in WISE. We conclude that while IR-bright GRB hosts are not a physically distinct class, they are useful for constraining existing GRB host populations, particularly for long GRBs.

Investigating a population of infrared-bright gamma-ray burst host galaxies

NASA Astrophysics Data System (ADS)

Chrimes, Ashley A.; Stanway, Elizabeth R.; Levan, Andrew J.; Davies, Luke J. M.; Angus, Charlotte R.; Greis, Stephanie M. L.

2018-04-01

We identify and explore the properties of an infrared-bright gamma-ray burst (GRB) host population. Candidate hosts are selected by coincidence with sources in WISE, with matching to random coordinates and a false alarm probability analysis showing that the contamination fraction is ˜ 0.5. This methodology has already identified the host galaxy of GRB 080517. We combine survey photometry from Pan-STARRS, SDSS, APASS, 2MASS, GALEX and WISE with our own WHT/ACAM and VLT/X-shooter observations to classify the candidates and identify interlopers. Galaxy SED fitting is performed using MAGPHYS, in addition to stellar template fitting, yielding 13 possible IR-bright hosts. A further 7 candidates are identified from previously published work. We report a candidate host for GRB 061002, previously unidentified as such. The remainder of the galaxies have already been noted as potential hosts. Comparing the IR-bright population properties including redshift z, stellar mass M⋆, star formation rate SFR and V-band attenuation AV to GRB host catalogues in the literature, we find that the infrared-bright population is biased toward low z, high M⋆ and high AV. This naturally arises from their initial selection - local and dusty galaxies are more likely to have the required IR flux to be detected in WISE. We conclude that while IR-bright GRB hosts are not a physically distinct class, they are useful for constraining existing GRB host populations, particularly for long GRBs.

Circadian Phase-Shifting Effects of Bright Light, Exercise, and Bright Light + Exercise.

PubMed

Youngstedt, Shawn D; Kline, Christopher E; Elliott, Jeffrey A; Zielinski, Mark R; Devlin, Tina M; Moore, Teresa A

2016-02-26

Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) bright light alone (5,000 lux) from 2210-2340 h, (2) treadmill exercise alone from 2210-2340 h, or (3) bright light (2210-2340 h) followed by exercise from 0410-0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of bright light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following bright light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night bright light followed by early morning exercise can have an additive circadian phase-shifting effect.

Spatial Model of Sky Brightness Magnitude in Langkawi Island, Malaysia

NASA Astrophysics Data System (ADS)

Redzuan Tahar, Mohammad; Kamarudin, Farahana; Umar, Roslan; Khairul Amri Kamarudin, Mohd; Sabri, Nor Hazmin; Ahmad, Karzaman; Rahim, Sobri Abdul; Sharul Aikal Baharim, Mohd

2017-03-01

Sky brightness is an essential topic in the field of astronomy, especially for optical astronomical observations that need very clear and dark sky conditions. This study presents the spatial model of sky brightness magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter (SQM) manufactured by Unihedron are used to measure the sky brightness on a moonless night (or when the Moon is below the horizon), when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky brightness data obtained in this study were interpolated and analyzed using a Geographic Information System (GIS), thus producing a spatial model of sky brightness that clearly shows the dark and bright sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky brightness of 21.45 mag arcsec{}-2 in the Johnson-Cousins V-band, as the average of sky brightness equivalent to 2.8 × {10}-4{cd} {{{m}}}-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.

Energy-exchange collisions of dark-bright-bright vector solitons.

PubMed

Radhakrishnan, R; Manikandan, N; Aravinthan, K

2015-12-01

We find a dark component guiding the practically interesting bright-bright vector one-soliton to two different parametric domains giving rise to different physical situations by constructing a more general form of three-component dark-bright-bright mixed vector one-soliton solution of the generalized Manakov model with nine free real parameters. Moreover our main investigation of the collision dynamics of such mixed vector solitons by constructing the multisoliton solution of the generalized Manakov model with the help of Hirota technique reveals that the dark-bright-bright vector two-soliton supports energy-exchange collision dynamics. In particular the dark component preserves its initial form and the energy-exchange collision property of the bright-bright vector two-soliton solution of the Manakov model during collision. In addition the interactions between bound state dark-bright-bright vector solitons reveal oscillations in their amplitudes. A similar kind of breathing effect was also experimentally observed in the Bose-Einstein condensates. Some possible ways are theoretically suggested not only to control this breathing effect but also to manage the beating, bouncing, jumping, and attraction effects in the collision dynamics of dark-bright-bright vector solitons. The role of multiple free parameters in our solution is examined to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation of our solution. It is interesting to note that the polarization vector of our mixed vector one-soliton evolves in sphere or hyperboloid depending upon the initial parametric choices.

Effect of evening exposure to bright or dim light after daytime bright light on absorption of dietary carbohydrates the following morning.

PubMed

Hirota, Naoko; Sone, Yoshiaki; Tokura, Hiromi

2010-01-01

We had previously reported on the effect of exposure to light on the human digestive system: daytime bright light exposure has a positive effect, whereas, evening bright light exposure has a negative effect on the efficiency of dietary carbohydrate absorption from the evening meal. These results prompted us to examine whether the light intensity to which subjects are exposed in the evening affects the efficiency of dietary carbohydrate absorption the following morning. In this study, subjects were exposed to either 50 lux (dim light conditions) or 2,000 lux (bright light conditions) in the evening for 9 h (from 15:00 to 24:00) after staying under bright light in the daytime (under 2,000 lux from 07:00 to 15:00). We measured unabsorbed dietary carbohydrates using the breath-hydrogen test the morning after exposure to either bright light or dim light the previous evening. Results showed that there was no significant difference between the two conditions in the amount of breath hydrogen. This indicates that evening exposure to bright or dim light after bright light exposure in the daytime has no varying effect on digestion or absorption of dietary carbohydrates in the following morning's breakfast.

Human liver-resident CD56(bright)/CD16(neg) NK cells are retained within hepatic sinusoids via the engagement of CCR5 and CXCR6 pathways.

PubMed

Hudspeth, Kelly; Donadon, Matteo; Cimino, Matteo; Pontarini, Elena; Tentorio, Paolo; Preti, Max; Hong, Michelle; Bertoletti, Antonio; Bicciato, Silvio; Invernizzi, Pietro; Lugli, Enrico; Torzilli, Guido; Gershwin, M Eric; Mavilio, Domenico

2016-01-01

The liver-specific natural killer (NK) cell population is critical for local innate immune responses, but the mechanisms that lead to their selective homing and the definition of their functionally relevance remain enigmatic. We took advantage of the availability of healthy human liver to rigorously define the mechanisms regulating the homing of NK cells to liver and the repertoire of receptors that distinguish liver-resident NK (lr-NK) cells from circulating counterparts. Nearly 50% of the entire liver NK cell population is composed of functionally relevant CD56(bright) lr-NK cells that localize within hepatic sinusoids. CD56(bright) lr-NK cells express CD69, CCR5 and CXCR6 and this unique repertoire of chemokine receptors is functionally critical as it determines selective migration in response to the chemotactic stimuli exerted by CCL3, CCL5 and CXCL16. Here, we also show that hepatic sinusoids express CCL3(pos) Kupffer cells, CXCL16(pos) endothelial cells and CCL5(pos) T and NK lymphocytes. The selective presence of these chemokines in sinusoidal spaces creates a unique tissue niche for lr-CD56(bright) NK cells that constitutively express CCR5 and CXCR6. CD56(bright) lr-NK cells co-exist with CD56(dim) conventional NK (c-NK) cells that are, interestingly, transcriptionally and phenotypically similar to their peripheral circulating counterparts. Indeed, CD56(dim) c-NK cells lack expression of CD69, CCR5, and CXCR6 but express selectins, integrins and CX3CR1. Our findings disclosing the phenotypic and functional differences between lr-Nk cells and c-NK cells are critical to distinguish liver-specific innate immune responses. Hence, any therapeutic attempts at modifying the large population of CD56(bright) lr-NK cells will require modification of hepatic CCR5 and CXCR6. Copyright © 2015 Elsevier Ltd. All rights reserved.

Human liver-resident CD56bright/CD16neg NK cells are retained within hepatic sinusoids via the engagement of CCR5 and CXCR6 pathways

PubMed Central

Hudspeth, Kelly; Donadon, Matteo; Cimino, Matteo; Pontarini, Elena; Tentorio, Paolo; Preti, Max; Hong, Michelle; Bertoletti, Antonio; Bicciato, Silvio; Invernizzi, Pietro; Lugli, Enrico; Torzilli, Guido; Gershwin, M. Eric; Mavilio, Domenico

2015-01-01

Rationale The liver-specific natural killer (NK) cell population is critical for local innate immune responses, but the mechanisms that lead to their selective homing and the definition of their functionally relevance remain enigmatic. Objectives We took advantage of the availability of healthy human liver to rigorously define the mechanisms regulating the homing of NK cells to liver and the repertoire of receptors that distinguish liver-resident NK (lr-NK) cells from circulating counterparts. Findings Nearly 50% of the entire liver NK cell population is composed of functionally relevant CD56bright lr-NK cells that localize within hepatic sinusoids. Further, CD56bright lr-NK cells express CD69, CCR5 and CXCR6 and this unique repertoire of chemokine receptors is functionally critical as it determines selective migration in response to the chemotactic stimuli exerted by CCL3, CCL5 and CXCL16. In addition, hepatic sinusoids express CCL3pos Kupffer cells, CXCL16pos endothelial cells and CCL5pos T and NK lymphocytes. The selective presence of these chemokines in sinusoidal spaces creates a tissue niche for lr-CD56bright NK cells that constitutively express CCR5 and CXCR6. CD56bright lr-NK cells co-exist with CD56dim conventional NK (c-NK) cells that are, interestingly, transcriptionally and phenotypically similar to their peripheral circulating counterparts. Indeed, CD56dim c-NK cells lack expression of CD69, CCR5, and CXCR6 but express selectins, integrins and CX3CR1. Conclusion Our findings disclosing the phenotypic and functional differences between lr-Nk cells and c-NK cells are critical to distinguish liver-specific innate immune responses. Hence, any therapeutic attempts at modifying the large population of CD56bright lr-NK cells will require modification of hepatic CCR5 and CXCR6. PMID:26330348

The Complete Local Volume Groups Sample - I. Sample selection and X-ray properties of the high-richness subsample

NASA Astrophysics Data System (ADS)

O'Sullivan, Ewan; Ponman, Trevor J.; Kolokythas, Konstantinos; Raychaudhury, Somak; Babul, Arif; Vrtilek, Jan M.; David, Laurence P.; Giacintucci, Simona; Gitti, Myriam; Haines, Chris P.

2017-12-01

We present the Complete Local-Volume Groups Sample (CLoGS), a statistically complete optically selected sample of 53 groups within 80 Mpc. Our goal is to combine X-ray, radio and optical data to investigate the relationship between member galaxies, their active nuclei and the hot intra-group medium (IGM). We describe sample selection, define a 26-group high-richness subsample of groups containing at least four optically bright (log LB ≥ 10.2 LB⊙) galaxies, and report the results of XMM-Newton and Chandra observations of these systems. We find that 14 of the 26 groups are X-ray bright, possessing a group-scale IGM extending at least 65 kpc and with luminosity >1041 erg s-1, while a further three groups host smaller galaxy-scale gas haloes. The X-ray bright groups have masses in the range M500 ≃ 0.5-5 × 1013 M⊙, based on system temperatures of 0.4-1.4 keV, and X-ray luminosities in the range 2-200 × 1041 erg s-1. We find that ∼53-65 per cent of the X-ray bright groups have cool cores, a somewhat lower fraction than found by previous archival surveys. Approximately 30 per cent of the X-ray bright groups show evidence of recent dynamical interactions (mergers or sloshing), and ∼35 per cent of their dominant early-type galaxies host active galactic nuclei with radio jets. We find no groups with unusually high central entropies, as predicted by some simulations, and confirm that CLoGS is in principle capable of detecting such systems. We identify three previously unrecognized groups, and find that they are either faint (LX, R500 < 1042 erg s-1) with no concentrated cool core, or highly disturbed. This leads us to suggest that ∼20 per cent of X-ray bright groups in the local universe may still be unidentified.

Single bright light exposure decreases sweet taste threshold in healthy volunteers.

PubMed

Srivastava, Shrikant; Donaldson, Lucy F; Rai, Dheeraj; Melichar, Jan K; Potokar, John

2013-10-01

Bright light exposure can alter circulating serotonin levels, and alteration of available serotonin by acute selective serotonin reuptake inhibition significantly lowers sweet but not salt taste recognition thresholds. We tested the hypothesis that bright light exposure would increase sweet but not salt taste sensitivity in healthy adults. Fourteen healthy volunteers were exposed to bright (10,000 lux) and dim (<20 lux) light for 30 min each, in counterbalanced order. Measures of taste perception (salt and sweet) and mood were determined at baseline, and before and after each light exposure period. Recognition thresholds for sucrose were significantly lower after bright but not dim light exposure. Thresholds for salt were unaffected by either condition. There were no significant changes in taste acuity, intensity or pleasantness for both the taste modalities and on visual analogue scales (VASs) for mood, anxiety, sleepiness and alertness, under either light condition. Brief bright light exposure reduces sweet but not salt taste recognition thresholds in healthy humans.

Circadian Phase-Shifting Effects of Bright Light, Exercise, and Bright Light + Exercise

PubMed Central

Kline, Christopher E.; Elliott, Jeffrey A.; Zielinski, Mark R.; Devlin, Tina M.; Moore, Teresa A.

2016-01-01

Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) bright light alone (5,000 lux) from 2210–2340 h, (2) treadmill exercise alone from 2210–2340 h, or (3) bright light (2210–2340 h) followed by exercise from 0410–0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of bright light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following bright light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night bright light followed by early morning exercise can have an additive circadian phase-shifting effect. PMID:27103935

Intermittent episodes of bright light suppress myopia in the chicken more than continuous bright light.

PubMed

Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank

2014-01-01

Bright light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of bright light are the most potent in suppressing deprivation myopia in chickens. Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10:14 light:dark cycle. Episodes of bright light (15 000 lux) were super-imposed on this background as follows. Paradigm I: exposure to constant bright light for either 1 hour (n = 5), 2 hours (n = 5), 5 hours (n = 4) or 10 hours (n = 4). Paradigm II: exposure to repeated cycles of bright light with 50% duty cycle and either 60 minutes (n = 7), 30 minutes (n = 8), 15 minutes (n = 6), 7 minutes (n = 7) or 1 minute (n = 7) periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. Compared with the reference group, exposure to continuous bright light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of bright light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1:1 or 7:7 minutes of bright light enhanced the protective effect against myopia and could fully suppress its development. The protective effect of bright light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous bright light, low frequency cycles of bright light (1:1 min) provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical studies.

An analysis of source structure effects in radio interferometry measurements

NASA Technical Reports Server (NTRS)

Thomas, J. B.

1980-01-01

To begin a study of structure effects, this report presents a theoretical framework, proposes an effective position approach to structure corrections based on brightness distribution measurements, and analyzes examples of analytical and measured brightness distributions. Other topics include the effect of the frequency dependence of a brightness distribution on bandwidth synthesis (BWS) delay, the determination of the absolute location of a measured brightness distribution, and structure effects in dual frequency calibration of charged particle delays. For the 10 measured distributions analyzed, it was found that the structure effect in BWS delay at X-band (3.6 cm) can reach 30 cm, but typically falls in the range of 0 to 5 cm. A trial limit equation that is dependent on visibility was successfully tested against the 10 measured brightness distributions (seven sources). If the validity of this particular equation for an upper limit can be established for nearly all sources, the structure effect in BWS delay could be greatly reduced without supplementary measurements of brightness distributions.

Shedding light on emotional perception: Interaction of brightness and semantic content in extrastriate visual cortex.

PubMed

Schettino, Antonio; Keil, Andreas; Porcu, Emanuele; Müller, Matthias M

2016-06-01

The rapid extraction of affective cues from the visual environment is crucial for flexible behavior. Previous studies have reported emotion-dependent amplitude modulations of two event-related potential (ERP) components - the N1 and EPN - reflecting sensory gain control mechanisms in extrastriate visual areas. However, it is unclear whether both components are selective electrophysiological markers of attentional orienting toward emotional material or are also influenced by physical features of the visual stimuli. To address this question, electrical brain activity was recorded from seventeen male participants while viewing original and bright versions of neutral and erotic pictures. Bright neutral scenes were rated as more pleasant compared to their original counterpart, whereas erotic scenes were judged more positively when presented in their original version. Classical and mass univariate ERP analysis showed larger N1 amplitude for original relative to bright erotic pictures, with no differences for original and bright neutral scenes. Conversely, the EPN was only modulated by picture content and not by brightness, substantiating the idea that this component is a unique electrophysiological marker of attention allocation toward emotional material. Complementary topographic analysis revealed the early selective expression of a centro-parietal positivity following the presentation of original erotic scenes only, reflecting the recruitment of neural networks associated with sustained attention and facilitated memory encoding for motivationally relevant material. Overall, these results indicate that neural networks subtending the extraction of emotional information are differentially recruited depending on low-level perceptual features, which ultimately influence affective evaluations. Copyright © 2016 Elsevier Inc. All rights reserved.

A medium-bright quasar sample - New quasar surface densities in the magnitude range from 16.4 to 17.65 for B

NASA Technical Reports Server (NTRS)

Mitchell, K. J.; Warnock, A., III; Usher, P. D.

1984-01-01

A new medium-bright quasar sample (MBQS) is constructed from spectroscopic observations of 140 bright objects selected for varying degrees of blue and ultraviolet excess (B-UVX) in five Palomar 1.2 m Schmidt fields. The MBQS contains 32 quasars with B less than 17.65 mag. The new integral surface densities in the B range from 16.45 to 17.65 mag are approximately 40 percent (or more) higher than expected. The MBQS and its redshift distribution increase the area of the Hubble diagram covered by complete samples of quasars. The general spectroscopic results indicate that the three-color classification process used to catalog the spectroscopic candidates (1) has efficiently separated the intrinsically B-UVX stellar objects from the Population II subdwarfs and (2) has produced samples of B-UVX objects which are more complete than samples selected by (U - B) color alone.

Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size.

PubMed

Song, Chen; Sandberg, Kristian; Andersen, Lau Møller; Blicher, Jakob Udby; Rees, Geraint

2017-09-13

GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the question of whether interindividual variability in GABA reflects an overall variability in visual inhibition and has a general influence on visual perception or whether the GABA levels of different cortical regions have selective influence on perception of different visual features. Here we report a region- and feature-dependent influence of GABA level on human visual perception. Our findings suggest that GABA level of a cortical region selectively influences perception of visual features that are topographically mapped in this region through intraregional lateral connections. Copyright © 2017 Song, Sandberg et al.

Effective Detection of Low-luminosity GEO Objects Using Population and Motion Predictions

DTIC Science & Technology

2012-01-01

more assumptions made on the time, and then tracks all the points where most fragments will be in geocentric equatorial inertial coordinates over time...population. A couple of candidate points in geocentric equatorial inertial coordinates can be selected with consideration that bright stars will not be... geocentric equatorial inertial coordinates. Third, motion of fragments passing through the specified single point in geocentric equatorial

Chemical abundances in low surface brightness galaxies: Implications for their evolution

NASA Technical Reports Server (NTRS)

Mcgaugh, S. S.; Bothun, G. D.

1993-01-01

Low Surface Brightness (LSB) galaxies are an important but often neglected part of the galaxy content of the universe. Their importance stems both from the selection effects which cause them to be under-represented in galaxy catalogs, and from what they can tell us about the physical processes of galaxy evolution that has resulted in something other than the traditional Hubble sequence of spirals. An important constraint for any evolutionary model is the present day chemical abundances of LSB disks. Towards this end, spectra for a sample of 75 H 2 regions distributed in 20 LSB disks galaxies were obtained. Structurally, this sample is defined as having B(0) fainter than 23.0 mag arcsec(sup -2) and scale lengths that cluster either around 3 kpc or 10 kpc. In fact, structurally, these galaxies are very similar to the high surface brightness spirals which define the Hubble sequence. Thus, our sample galaxies are not dwarf galaxies but instead have masses comparable to or in excess of the Milky Way. The basic results from these observations are summarized.

Tunable electromagnetically induced transparency from a superconducting terahertz metamaterial

NASA Astrophysics Data System (ADS)

Zhang, Caihong; Wu, Jingbo; Jin, Biaobing; Jia, Xiaoqing; Kang, Lin; Xu, Weiwei; Wang, Huabing; Chen, Jian; Tonouchi, Masoyoshi; Wu, Peiheng

2017-06-01

We demonstrate in this paper the tunable electromagnetically induced transparency (EIT) made from a superconducting (SC) niobium nitride (NbN) film induced by an intense terahertz (THz) field. As the variation of the incident THz field alters the intrinsic ohmic loss of the SC NbN film, the field-dependent transmittance is observed. To elaborate the role of the bright and dark modes, a hybrid coupling model is introduced to fit the experimental transmission spectra and extract the characteristic parameters of each mode. It is shown that the resonator for the bright mode is altered greatly due to strong direct coupling to the incident intense THz field, whereas the dark mode resonator has little interaction with the incident THz field via a weak near-filed coupling to the bright-mode resonator. This implies that we can partially control a mode or a part of metamaterial by introducing the intense THz field, which offers an effective manner to selectively control the electromagnetic property of the metamaterial. This work may bring many potential applications for the tunable EIT-like metamaterial.

Galaxies in X-ray Selected Clusters and Groups in Dark Energy Survey Data: Stellar Mass Growth of Bright Central Galaxies Since z~1.2

DOE PAGES

Zhang, Y.; Miller, C.; McKay, T.; ...

2016-01-10

Using the science verification data of the Dark Energy Survey for a new sample of 106 X-ray selected clusters and groups, we study the stellar mass growth of bright central galaxies (BCGs) since redshift z ~ 1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into analysis of a redshift-dependent BCG-cluster mass relation.

Biobleaching of wheat straw-rich soda pulp with alkalophilic laccase from gamma-proteobacterium JB: optimization of process parameters using response surface methodology.

PubMed

Singh, Gursharan; Ahuja, Naveen; Batish, Mona; Capalash, Neena; Sharma, Prince

2008-11-01

An alkalophilic laccase from gamma-proteobacterium JB was applied to wheat straw-rich soda pulp to check its bleaching potential by using response surface methodology based on central composite design. The design was employed by selecting laccase units, ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) concentration and pH as model factors. The results of second order factorial design experiments showed that all three independent variables had significant effect on brightness and kappa number of laccase-treated pulp. Optimum conditions for biobleaching of pulp with laccase preparation (specific activity, 65 nkat mg(-1) protein) were 20 nkat g(-1) of pulp, 2mM ABTS and pH 8.0 which enhanced brightness by 5.89% and reduced kappa number by 21.1% within 4h of incubation at 55 degrees C, without further alkaline extraction of pulp. Tear index (8%) and burst index (18%) also improved for laccase-treated pulp as compared to control raw pulp. Treatment of chemically (CEH1H2) bleached pulp with laccase showed significant effect on release of chromophores, hydrophobic and reducing compounds. Laccase-prebleaching of raw pulp reduced the use of hypochlorite by 10% to achieve brightness of resultant hand sheets similar to the fully chemically bleached pulp.

Unidentified point sources in the IRAS minisurvey

NASA Technical Reports Server (NTRS)

Houck, J. R.; Soifer, B. T.; Neugebauer, G.; Beichman, C. A.; Aumann, H. H.; Clegg, P. E.; Gillett, F. C.; Habing, H. J.; Hauser, M. G.; Low, F. J.

1984-01-01

Nine bright, point-like 60 micron sources have been selected from the sample of 8709 sources in the IRAS minisurvey. These sources have no counterparts in a variety of catalogs of nonstellar objects. Four objects have no visible counterparts, while five have faint stellar objects visible in the error ellipse. These sources do not resemble objects previously known to be bright infrared sources.

Intermittent Episodes of Bright Light Suppress Myopia in the Chicken More than Continuous Bright Light

PubMed Central

Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank

2014-01-01

Purpose Bright light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of bright light are the most potent in suppressing deprivation myopia in chickens. Methods Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10∶14 light∶dark cycle. Episodes of bright light (15 000 lux) were super-imposed on this background as follows. Paradigm I: exposure to constant bright light for either 1 hour (n = 5), 2 hours (n = 5), 5 hours (n = 4) or 10 hours (n = 4). Paradigm II: exposure to repeated cycles of bright light with 50% duty cycle and either 60 minutes (n = 7), 30 minutes (n = 8), 15 minutes (n = 6), 7 minutes (n = 7) or 1 minute (n = 7) periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. Results Compared with the reference group, exposure to continuous bright light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of bright light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1∶1 or 7∶7 minutes of bright light enhanced the protective effect against myopia and could fully suppress its development. Conclusions The protective effect of bright light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous bright light, low frequency cycles of bright light (1∶1 min) provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical studies. PMID:25360635

IRAC Imaging of LSB Galaxies

NASA Astrophysics Data System (ADS)

Schombert, James; McGaugh, Stacy; Lelli, Federico

2017-04-01

We propose a program to observe a large sample of Low Surface Brightness (LSB) galaxies. Large galaxy surveys conducted with Spitzer suffer from the unavoidable selection bias against LSB systems (e.g., the S4G survey). Even those programs thathave specifically targeted LSB galaxies have usually been restricted objects of intermediate surface brightness (between 22 and 23 B mag/ []). Our sample is selected to be of a more extreme LSB nature (with central surface brightness fainter than 23 Bmag/[]). Even warm, Spitzer is the ideal instrument to image these low contrast targets in the near infrared: our sample goes a considerable way towards remedying this hole in the Spitzer legacy archive, also increasing coverage in terms of stellar mass, gas mass, and SFR. The sample will be used to address the newly discovered radial acceleration relation (RAR) in disk galaxies. While issues involving the connection between baryons and dark matter have been known since the development of the global baryonic Tully-Fisher (bTF) relation, it is only in the last six months that the particle physics and theoretical communities have recognized and responded to the local coupling between dark and baryonic matter represented by the RAR. This important new correlation is effectively a new natural law for galaxies. Spitzer photometry has been at the forefront of resolving the stellar mass component in galaxies that make-up the RAR and is the primary reason for the discovery of this new kinematic law.

Genetic basis and fitness correlates of dynamic carotenoid-based ornamental coloration in male and female common kestrels Falco tinnunculus.

PubMed

Vergara, P; Fargallo, J A; Martínez-Padilla, J

2015-01-01

Knowledge of the genetic basis of sexual ornaments is essential to understand their evolution through sexual selection. Although carotenoid-based ornaments have been instrumental in the study of sexual selection, given the inability of animals to synthesize carotenoids de novo, they are generally assumed to be influenced solely by environmental variation. However, very few studies have directly estimated the role of genes and the environment in shaping variation in carotenoid-based traits. Using long-term individual-based data, we here explore the evolutionary potential of a dynamic, carotenoid-based ornament (namely skin coloration), in male and female common kestrels. We first estimate the amount of genetic variation underlying variation in hue, chroma and brightness. After correcting for sex differences, the chroma of the orange-yellow eye ring coloration was significantly heritable (h2±SE=0.40±0.17), whereas neither hue (h2=0) nor brightness (h2=0.02) was heritable. Second, we estimate the strength and shape of selection acting upon chromatic (hue and chroma) and achromatic (brightness) variation and show positive and negative directional selection on female but not male chroma and hue, respectively, whereas brightness was unrelated to fitness in both sexes. This suggests that different components of carotenoid-based signals traits may show different evolutionary dynamics. Overall, we show that carotenoid-based coloration is a complex and multifaceted trait. If we are to gain a better understanding of the processes responsible for the generation and maintenance of variation in carotenoid-based coloration, these complexities need to be taken into account. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Spectral and spatial selectivity of luminance vision in reef fish.

PubMed

Siebeck, Ulrike E; Wallis, Guy Michael; Litherland, Lenore; Ganeshina, Olga; Vorobyev, Misha

2014-01-01

Luminance vision has high spatial resolution and is used for form vision and texture discrimination. In humans, birds and bees luminance channel is spectrally selective-it depends on the signals of the long-wavelength sensitive photoreceptors (bees) or on the sum of long- and middle-wavelength sensitive cones (humans), but not on the signal of the short-wavelength sensitive (blue) photoreceptors. The reasons of such selectivity are not fully understood. The aim of this study is to reveal the inputs of cone signals to high resolution luminance vision in reef fish. Sixteen freshly caught damselfish, Pomacentrus amboinensis, were trained to discriminate stimuli differing either in their color or in their fine patterns (stripes vs. cheques). Three colors ("bright green", "dark green" and "blue") were used to create two sets of color and two sets of pattern stimuli. The "bright green" and "dark green" were similar in their chromatic properties for fish, but differed in their lightness; the "dark green" differed from "blue" in the signal for the blue cone, but yielded similar signals in the long-wavelength and middle-wavelength cones. Fish easily learned to discriminate "bright green" from "dark green" and "dark green" from "blue" stimuli. Fish also could discriminate the fine patterns created from "dark green" and "bright green". However, fish failed to discriminate fine patterns created from "blue" and "dark green" colors, i.e., the colors that provided contrast for the blue-sensitive photoreceptor, but not for the long-wavelength sensitive one. High resolution luminance vision in damselfish, Pomacentrus amboinensis, does not have input from the blue-sensitive cone, which may indicate that the spectral selectivity of luminance channel is a general feature of visual processing in both aquatic and terrestrial animals.

Brightness perception of unrelated self-luminous colors.

PubMed

Withouck, Martijn; Smet, Kevin A G; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Koenderink, Jan; Hanselaer, Peter

2013-06-01

The perception of brightness of unrelated self-luminous colored stimuli of the same luminance has been investigated. The Helmholtz-Kohlrausch (H-K) effect, i.e., an increase in brightness perception due to an increase in saturation, is clearly observed. This brightness perception is compared with the calculated brightness according to six existing vision models, color appearance models, and models based on the concept of equivalent luminance. Although these models included the H-K effect and half of them were developed to work with unrelated colors, none of the models seemed to be able to fully predict the perceived brightness. A tentative solution to increase the prediction accuracy of the color appearance model CAM97u, developed by Hunt, is presented.

Color and emotion: effects of hue, saturation, and brightness.

PubMed

Wilms, Lisa; Oberfeld, Daniel

2017-06-13

Previous studies on emotional effects of color often failed to control all the three perceptual dimensions of color: hue, saturation, and brightness. Here, we presented a three-dimensional space of chromatic colors by independently varying hue (blue, green, red), saturation (low, medium, high), and brightness (dark, medium, bright) in a factorial design. The 27 chromatic colors, plus 3 brightness-matched achromatic colors, were presented via an LED display. Participants (N = 62) viewed each color for 30 s and then rated their current emotional state (valence and arousal). Skin conductance and heart rate were measured continuously. The emotion ratings showed that saturated and bright colors were associated with higher arousal. The hue also had a significant effect on arousal, which increased from blue and green to red. The ratings of valence were the highest for saturated and bright colors, and also depended on the hue. Several interaction effects of the three color dimensions were observed for both arousal and valence. For instance, the valence ratings were higher for blue than for the remaining hues, but only for highly saturated colors. Saturated and bright colors caused significantly stronger skin conductance responses. Achromatic colors resulted in a short-term deceleration in the heart rate, while chromatic colors caused an acceleration. The results confirm that color stimuli have effects on the emotional state of the observer. These effects are not only determined by the hue of a color, as is often assumed, but by all the three color dimensions as well as their interactions.

VizieR Online Data Catalog: FIR data of IR-bright dust-obscured galaxies (DOGs) (Toba+, 2017)

NASA Astrophysics Data System (ADS)

Toba, Y.; Nagao, T.; Wang, W.-H.; Matsuhara, H.; Akiyama, M.; Goto, T.; Koyama, Y.; Ohyama, Y.; Yamamura, I.

2017-11-01

We investigate the star-forming activity of a sample of infrared (IR)-bright dust-obscured galaxies (DOGs) that show an extreme red color in the optical and IR regime, (i-[22])AB>7.0. Combining an IR-bright DOG sample with the flux at 22μm>3.8mJy discovered by Toba & Nagao (2016ApJ...820...46T) with the IRAS faint source catalog version 2 and AKARI far-IR (FIR) all-sky survey bright source catalog version 2, we selected 109 DOGs with FIR data. For a subsample of seven IR-bright DOGs with spectroscopic redshifts (0.07

High brightness electrodeless Z-Pinch EUV source for mask inspection tools

NASA Astrophysics Data System (ADS)

Horne, Stephen F.; Partlow, Matthew J.; Gustafson, Deborah S.; Besen, Matthew M.; Smith, Donald K.; Blackborow, Paul A.

2012-03-01

Energetiq Technology has been shipping the EQ-10 Electrodeless Z-pinchTM light source since 1995. The source is currently being used for metrology, mask inspection, and resist development. Energetiq's higher brightness source has been selected as the source for pre-production actinic mask inspection tools. This improved source enables the mask inspection tool suppliers to build prototype tools with capabilities of defect detection and review down to 16nm design rules. In this presentation we will present new source technology being developed at Energetiq to address the critical source brightness issue. The new technology will be shown to be capable of delivering brightness levels sufficient to meet the HVM requirements of AIMS and ABI and potentially API tools. The basis of the source technology is to use the stable pinch of the electrodeless light source and have a brightness of up to 100W/mm(carat)2-sr. We will explain the source design concepts, discuss the expected performance and present the modeling results for the new design.

Photometric calibration of T40 telescope system at Ankara University Kreiken Observatory (AUKR)

NASA Astrophysics Data System (ADS)

Karakuş, O.; Ekmekçi, F.

2017-07-01

We aim to present the photometric calibration of T40 telescope system at Ankara University Kreiken Observatory(AUKR) in the Johnson BVRI bands system through CCD observations of selected Landolt stars on the clearest 11 nights. Ten more stars with a magnitude of V< 11 were also observed in order to check up on standard transformation coefficients. Using these coefficients, we present standard brightness and color magnitudes for these 10 selected stars. These standard brightness values of these 10 stars are also compared with the previously published ones. It is clearly seen that the calibration results are sufficiently reliable.

Differential color brightness as a body orientation cue

NASA Technical Reports Server (NTRS)

Barbour, Christopher G.; Coss, Richard G.

1988-01-01

Ninety male and female college students reclining on their backs in the dark were disoriented when positioned on a rotating platform under a slowly rotating disk that filled their entire visual field. Half of the disk was painted with a brighter value (about 69 percent higher luminance level) of the color on the other half. The effects of red, blue, and yellow were examined. Subjects wearing frosted goggles viewed the illuminated disk for three rotations. The disk was stopped when the subjects felt that they were right side up. A significant proportion of subjects selected the disk position in which the brighter side of each of the three colors filled their upper visual field. These results suggest that color brightness as well as lighting variation could provide Space Station crew members with body orientation cues as they move around.

Model Development for MODIS Thermal Band Electronic Crosstalk

NASA Technical Reports Server (NTRS)

Chang, Tiejun; Wu, Aisheng; Geng, Xu; Li, Yonghonh; Brinkman, Jake; Keller, Graziela; Xiong, Xiaoxiong

2016-01-01

MODerate-resolution Imaging Spectroradiometer (MODIS) has 36 bands. Among them, 16 thermal emissive bands covering a wavelength range from 3.8 to 14.4 m. After 16 years on-orbit operation, the electronic crosstalk of a few Terra MODIS thermal emissive bands developed substantial issues that cause biases in the EV brightness temperature measurements and surface feature contamination. The crosstalk effects on band 27 with center wavelength at 6.7 m and band 29 at 8.5 m increased significantly in recent years, affecting downstream products such as water vapor and cloud mask. The crosstalk effect is evident in the near-monthly scheduled lunar measurements, from which the crosstalk coefficients can be derived. The development of an alternative approach is very helpful for independent verification.In this work, a physical model was developed to assess the crosstalk impact on calibration as well as in Earth view brightness temperature retrieval. This model was applied to Terra MODIS band 29 empirically to correct the Earth brightness temperature measurements. In the model development, the detectors nonlinear response is considered. The impact of the electronic crosstalk is assessed in two steps. The first step consists of determining the impact on calibration using the on-board blackbody (BB). Due to the detectors nonlinear response and large background signal, both linear and nonlinear coefficients are affected by the crosstalk from sending bands. The second step is to calculate the effects on the Earth view brightness temperature retrieval. The effects include those from affected calibration coefficients and the contamination of Earth view measurements. This model links the measurement bias with crosstalk coefficients, detector non-linearity, and the ratio of Earth measurements between the sending and receiving bands. The correction of the electronic cross talk can be implemented empirically from the processed bias at different brightness temperature. The implementation can be done through two approaches. As routine calibration assessment for thermal infrared bands, the trending over select Earth scenes is processed for all the detectors in a band and the band averaged bias is derived at a certain time. In this case, the correction of an affected band can be made using the regression of the model with band averaged bias and then corrections of detector differences are applied. The second approach requires the trending for individual detectors and the bias for each detector is used for regression with the model. A test using the first approach was made for Terra MODIS band 29 with the biases derived from long-term trending of brightness temperature over ocean and Dome-C.

The invisible AGN catalogue: a mid-infrared-radio selection method for optically faint active galactic nuclei

NASA Astrophysics Data System (ADS)

Truebenbach, Alexandra E.; Darling, Jeremy

2017-06-01

A large fraction of active galactic nuclei (AGN) are 'invisible' in extant optical surveys due to either distance or dust-obscuration. The existence of this large population of dust-obscured, infrared (IR)-bright AGN is predicted by models of galaxy-supermassive black hole coevolution and is required to explain the observed X-ray and IR backgrounds. Recently, IR colour cuts with Wide-field Infrared Survey Explorer have identified a portion of this missing population. However, as the host galaxy brightness relative to that of the AGN increases, it becomes increasingly difficult to differentiate between IR emission originating from the AGN and from its host galaxy. As a solution, we have developed a new method to select obscured AGN using their 20-cm continuum emission to identify the objects as AGN. We created the resulting invisible AGN catalogue by selecting objects that are detected in AllWISE (mid-IR) and FIRST (20 cm), but are not detected in SDSS (optical) or 2MASS (near-IR), producing a final catalogue of 46 258 objects. 30 per cent of the objects are selected by existing selection methods, while the remaining 70 per cent represent a potential previously unidentified population of candidate AGN that are missed by mid-IR colour cuts. Additionally, by relying on a radio continuum detection, this technique is efficient at detecting radio-loud AGN at z ≥ 0.29, regardless of their level of dust obscuration or their host galaxy's relative brightness.

Assessment of the broca-sulzer phenomenon via inter- and intra-modality matching procedures : studies of signal-light brightness.

DOT National Transportation Integrated Search

1968-10-01

Signal lights are presented to an observer as flashes with finite duration; thus, the effect of flash duration on the apparent brightness of the signal is important. The relation of effective signal brightness to flash duration and luminance finds ex...

Effect of bright light at night on core temperature, subjective alertness and performance as a function of exposure time.

PubMed

Foret, J; Daurat, A; Tirilly, G

1998-01-01

This simulated night shift study measured the effects of moderate bright light (a 4-hour pulse starting at 2000 or 0400) during the exposure night and subsequent night (dim light). Eight young males remained confined with little physical activity to a laboratory in groups of 4. After a night of reference, they were active for 24 hours; then after a morning recovery sleep, they were active again for 16 hours. Continuously measured rectal temperature proved to be immediately sensitive to 4 hours of bright light, particularly when given at the end of the night. Self-assessed alertness and also performance on a task with a high requirement for short-term memory were improved by the exposure to bright light. During the subsequent night the subjects were exposed only to dim light. Core temperature, subjective alertness and performance continued to show a time course depending on the preceding bright light exposure. Probably because evening exposure to bright light and morning sleep both had a phase-delaying effect, the effects on the circadian pacemaker were more pronounced. Thus, for practical applications in long night shifts, bright light can be considered to improve mood and alertness immediately but the possibility of modifying the circadian "clock" during subsequent nights should be taken into consideration, in particular after exposure to bright light in the evening.

Microwave Properties of Ice-Phase Hydrometeors for Radar and Radiometers: Sensitivity to Model Assumptions

NASA Technical Reports Server (NTRS)

Johnson, Benjamin T.; Petty, Grant W.; Skofronick-Jackson, Gail

2012-01-01

A simplied framework is presented for assessing the qualitative sensitivities of computed microwave properties, satellite brightness temperatures, and radar reflectivities to assumptions concerning the physical properties of ice-phase hydrometeors. Properties considered included the shape parameter of a gamma size distribution andthe melted-equivalent mass median diameter D0, the particle density, dielectric mixing formula, and the choice of complex index of refraction for ice. We examine these properties at selected radiometer frequencies of 18.7, 36.5, 89.0, and 150.0 GHz; and radar frequencies at 2.8, 13.4, 35.6, and 94.0 GHz consistent with existing and planned remote sensing instruments. Passive and active microwave observables of ice particles arefound to be extremely sensitive to the melted-equivalent mass median diameter D0 ofthe size distribution. Similar large sensitivities are found for variations in the ice vol-ume fraction whenever the geometric mass median diameter exceeds approximately 1/8th of the wavelength. At 94 GHz the two-way path integrated attenuation is potentially large for dense compact particles. The distribution parameter mu has a relatively weak effect on any observable: less than 1-2 K in brightness temperature and up to 2.7 dB difference in the effective radar reflectivity. Reversal of the roles of ice and air in the MaxwellGarnett dielectric mixing formula leads to a signicant change in both microwave brightness temperature (10 K) and radar reflectivity (2 dB). The choice of Warren (1984) or Warren and Brandt (2008) for the complex index of refraction of ice can produce a 3%-4% change in the brightness temperature depression.

Naturally together: pitch-height and brightness as coupled factors for eliciting the SMARC effect in non-musicians.

PubMed

Pitteri, Marco; Marchetti, Mauro; Priftis, Konstantinos; Grassi, Massimo

2017-01-01

Pitch-height is often labeled spatially (i.e., low or high) as a function of the fundamental frequency of the tone. This correspondence is highlighted by the so-called Spatial-Musical Association of Response Codes (SMARC) effect. However, the literature suggests that the brightness of the tone's timbre might contribute to this spatial association. We investigated the SMARC effect in a group of non-musicians by disentangling the role of pitch-height and the role of tone-brightness. In three experimental conditions, participants were asked to judge whether the tone they were listening to was (or was not) modulated in amplitude (i.e., vibrato). Participants were required to make their response in both the horizontal and the vertical axes. In a first condition, tones varied coherently in pitch (i.e., manipulation of the tone's F0) and brightness (i.e., manipulation of the tone's spectral centroid); in a second condition, pitch-height varied whereas brightness was fixed; in a third condition, pitch-height was fixed whereas brightness varied. We found the SMARC effect only in the first condition and only in the vertical axis. In contrast, we did not observe the effect in any of the remaining conditions. The present results suggest that, in non-musicians, the SMARC effect is not due to the manipulation of the pitch-height alone, but arises because of a coherent change of pitch-height and brightness; this effect emerges along the vertical axis only.

Selective attention to perceptual dimensions and switching between dimensions.

PubMed

Meiran, Nachshon; Dimov, Eduard; Ganel, Tzvi

2013-02-01

In the present experiments, the question being addressed was whether switching attention between perceptual dimensions and selective attention to dimensions are processes that compete over a common resource? Attention to perceptual dimensions is usually studied by requiring participants to ignore a never-relevant dimension. Selection failure (Garner's Interference, GI) is indicated by poorer performance in the filtering condition (when this dimension varies) as compared with baseline (when it is fixed). Switching between perceptual dimensions is usually studied with the task switching paradigm. In the present experiments, attention switching was manipulated by using single-task blocks and blocks in which participants switched between tasks or dimensions in reaction to task cues, and attention to dimensions was assessed by including a third, never-relevant dimension that was either fixed or varied randomly. In Experiments 1 (long cue-target interval, CTI) and 2 (short CTI), the tasks involved shape and color and the never-relevant dimension (texture) was chosen to be separable from them. In Experiments 3 (long CTI) and 4 (short CTI), the tasks involved shape and brightness and the never-relevant dimension, saturation, was chosen to be separable from shape and integral with brightness. Task switching did not generate GI but a short CTI did. Thus, switching and filtering generally do not compete over central limited resources unless under tight time pressure. Experiment 3 shows GI in the brightness task but not in the shape task, suggesting that participants switched their attention between brightness and shape when they switched tasks. PsycINFO Database Record (c) 2013 APA, all rights reserved.

The modulation of delta responses in the interaction of brightness and emotion.

PubMed

Kurt, Pınar; Eroğlu, Kübra; Bayram Kuzgun, Tubanur; Güntekin, Bahar

2017-02-01

The modulation of delta oscillations (0.5-3.5Hz) by emotional stimuli is reported. Physical attributes such as color, brightness and spatial frequency of emotional visual stimuli have crucial effect on the perception of complex scene. Brightness is intimately related with emotional valence. Here we explored the effect of brightness on delta oscillatory responses upon presentation of pleasant, unpleasant and neutral pictures. We found that bright unpleasant pictures elicited lower amplitude of delta response than original unpleasant pictures. The electrophysiological finding of the study was in accordance with behavioral data. These results denoted the importance of delta responses on the examination of the association between perceptual and conceptual processes while in the question of brightness and emotion. Copyright © 2016 Elsevier B.V. All rights reserved.

Crop moisture estimation over the southern Great Plains with dual polarization 1.66 centimeter passive microwave data from Nimbus 7

NASA Technical Reports Server (NTRS)

Mcfarland, M. J.; Harder, P. H., II; Wilke, G. D.; Huebner, G. L., Jr.

1984-01-01

Moisture content of snow-free, unfrozen soil is inferred using passive microwave brightness temperatures from the scanning multichannel microwave radiometer (SMMR) on Nimbus-7. Investigation is restricted to the two polarizations of the 1.66 cm wavelength sensor. Passive microwave estimates of soil moisture are of two basic categories; those based upon soil emissivity and those based upon the polarization of soil emission. The two methods are compared and contrasted through the investigation of 54 potential functions of polarized brightness temperatures and, in some cases, ground-based temperature measurements. Of these indices, three are selected for the estimated emissivity, the difference between polarized brightness temperatures, and the normalized polarization difference. Each of these indices is about equally effective for monitoring soil moisture. Using an antecedent precipitation index (API) as ground control data, temporal and spatial analyses show that emissivity data consistently give slightly better soil moisture estimates than depolarization data. The difference, however, is not statistically significant. It is concluded that polarization data alone can provide estimates of soil moisture in areas where the emissivity cannot be inferred due to nonavailability of surface temperature data.

The detection of Giardia muris and Giardia lamblia cysts by immunofluorescence in animal tissues and fecal samples subjected to cycles of freezing and thawing.

PubMed

Erlandsen, S L; Sherlock, L A; Bemrick, W J

1990-04-01

The effects of freezing and thawing on the detection of selected Giardia spp. cysts were investigated using immunofluorescence, bright field microscopy, and low voltage scanning electron microscopy (SEM). Giardia muris cysts were obtained from either animal carcasses, fecal pellets, or isolated cyst preparations, whereas Giardia lamblia cysts were isolated from fecal samples. These samples were stained using an immunofluorescence technique after 1-3 freezing (-16 C) and thawing (20 C) cycles. Cysts were detected successfully by immunofluorescence in all samples. However, in those samples subjected to freeze-thawing, the cyst walls often became distorted and then were not detectable by bright field microscopy. Low voltage SEM demonstrated that the filaments in the distorted cyst wall underwent rearrangements of interfilament spacing. Quantitation of cyst recovery after freezing and thawing demonstrated that a substantial loss occurred after 1 cycle of alternating temperature when low concentrations of cysts were used, but not with high concentrations of cysts. Cyst recovery, after 3 freezing and thawing cycles, was dramatically lowered irrespective of the initial cyst concentration. These results demonstrated that immunofluorescence was an effective technique for the detection of Giardia spp. cysts in frozen samples and would suggest that freezing and thawing of fecal samples could prevent the detection of cysts when only bright field microscopy was employed.

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

Jester, Sebastian; Schneider, Donald P.; Richards, Gordon T.

The author investigates the extent to which the Palomar-Green (PG) Bright Quasar Survey (BQS) is complete and representative of the general quasar population by comparing with imaging and spectroscopy from the Sloan Digital Sky Survey. A comparison of SDSS and PG photometry of both stars and quasars reveals the need to apply a color and magnitude recalibration to the PG data. Using the SDSS photometric catalog, they define the PG's parent sample of objects that are not main-sequence stars and simulate the selection of objects from this parent sample using the PG photometric criteria and errors. This simulation shows thatmore » the effective U-B cut in the PG survey is U-B < -0.71, implying a color-related incompleteness. As the color distribution of bright quasars peaks near U-B = -0.7 and the 2-{sigma} error in U-B is comparable to the full width of the color distribution of quasars, the color incompleteness of the BQS is approximately 50% and essentially random with respect to U-B color for z < 0.5. There is however, a bias against bright quasars at 0.5 < z < 1, which is induced by the color-redshift relation of quasars (although quasars at z > 0.5 are inherently rare in bright surveys in any case). They find no evidence for any other systematic incompleteness when comparing the distributions in color, redshift, and FIRST radio properties of the BQS and a BQS-like subsample of the SDSS quasar sample. However, the application of a bright magnitude limit biases the BQS toward the inclusion of objects which are blue in g-i, in particular compared to the full range of g-i colors found among the i-band limited SDSS quasars, and even at i-band magnitudes comparable to those of the BQS objects.« less

Low-Surface-Brightness Galaxies: Hidden Galaxies Revealed

NASA Astrophysics Data System (ADS)

Bothun, G.; Impey, C.; McGaugh, S.

1997-07-01

In twenty years, low surface brightness (LSB) galaxies have evolved from being an idiosyncratic notion to being one of the major baryonic repositories in the Universe. The story of their discovery and the characterization of their properties is told here. Their recovery from the noise of the night sky background is a strong testament to the severity of surface brightness selection effects. LSB galaxies have a number of remarkable properties which distinguish them from the more familiar Hubble Sequence of spirals. The two most important are 1) they evolve at a significantly slower rate and may well experience star formation outside of the molecular cloud environment, 2) they are embedded in dark matter halos which are of lower density and more extended than the halos around high surface brightness (HSB) disk galaxies. Compared to HSB disks, LSB disks are strongly dark matter dominated at all radii and show a systematic increase in $M/L$ with decreasing central surface brightness. In addition, the recognition that large numbers of LSB galaxies actually exist has changed the form of the galaxy luminosity function and has clearly increased the space density of galaxies at z =0. Recent CCD surveys have uncovered a population of red LSB disks that may be related to the excess of faint blue galaxies detected at moderate redshifts. LSB galaxies offer us a new window into galaxy evolution and formation which is every bit as important as those processes which have produced easy to detect galaxies. Indeed, the apparent youth of some LSB galaxies suggest that galaxy formation is a greatly extended process. While the discovery of LSB galaxies have lead to new insights, it remains unwise to presume that we now have a representative sample which encompasses all galaxy types and forms. (SECTION: Invited Review Paper)

Brightness and transparency in the early visual cortex.

PubMed

Salmela, Viljami R; Vanni, Simo

2013-06-24

Several psychophysical studies have shown that transparency can have drastic effects on brightness and lightness. However, the neural processes generating these effects have remained unresolved. Several lines of evidence suggest that the early visual cortex is important for brightness perception. While single cell recordings suggest that surface brightness is represented in the primary visual cortex, the results of functional magnetic resonance imaging (fMRI) studies have been discrepant. In addition, the location of the neural representation of transparency is not yet known. We investigated whether the fMRI responses in areas V1, V2, and V3 correlate with brightness and transparency. To dissociate the blood oxygen level-dependent (BOLD) response to brightness from the response to local border contrast and mean luminance, we used variants of White's brightness illusion, both opaque and transparent, in which luminance increments and decrements cancel each other out. The stimuli consisted of a target surface and a surround. The surround luminance was always sinusoidally modulated at 0.5 Hz to induce brightness modulation to the target. The target luminance was constant or modulated in counterphase to null brightness modulation. The mean signal changes were calculated from the voxels in V1, V2, and V3 corresponding to the retinotopic location of the target surface. The BOLD responses were significantly stronger for modulating brightness than for stimuli with constant brightness. In addition, the responses were stronger for transparent than for opaque stimuli, but there was more individual variation. No interaction between brightness and transparency was found. The results show that the early visual areas V1-V3 are sensitive to surface brightness and transparency and suggest that brightness and transparency are represented separately.

Manakins can produce iridescent and bright feather colours without melanosomes.

PubMed

Igic, Branislav; D'Alba, Liliana; Shawkey, Matthew D

2016-06-15

Males of many species often use colourful and conspicuous ornaments to attract females. Among these, male manakins (family: Pipridae) provide classic examples of sexual selection favouring the evolution of bright and colourful plumage coloration. The highly iridescent feather colours of birds are most commonly produced by the periodic arrangement of melanin-containing organelles (melanosomes) within barbules. Melanin increases the saturation of iridescent colours seen from optimal viewing angles by absorbing back-scattered light; however, this may reduce the wide-angle brightness of these signals, contributing to a dark background appearance. We examined the nanostructure of four manakin species (Lepidothrix isidorei, L. iris, L. nattereri and L. coeruleocapilla) to identify how they produce their bright plumage colours. Feather barbs of all four species were characterized by dense and fibrous internal spongy matrices that likely increase scattering of light within the barb. The iridescent, yet pale or whitish colours of L. iris and L. nattereri feathers were produced not by periodically arranged melanosomes within barbules, but by periodic matrices of air and β-keratin within barbs. Lepidothrix iris crown feathers were able to produce a dazzling display of colours with small shifts in viewing geometry, likely because of a periodic nanostructure, a flattened barb morphology and disorder at a microstructural level. We hypothesize that iridescent plumage ornaments of male L. iris and L. nattereri are under selection to increase brightness or luminance across wide viewing angles, which may potentially increase their detectability by females during dynamic and fast-paced courtship displays in dim light environments. © 2016. Published by The Company of Biologists Ltd.

Unexpectedly Fast Phonon-Assisted Exciton Hopping between Carbon Nanotubes

DOE PAGES

Davoody, A. H.; Karimi, F.; Arnold, M. S.; ...

2017-06-05

Carbon-nanotube (CNT) aggregates are promising light-absorbing materials for photovoltaics. The hopping rate of excitons between CNTs directly affects the efficiency of these devices. We theoretically investigate phonon-assisted exciton hopping, where excitons scatter with phonons into a same-tube transition state, followed by intertube Coulomb scattering into the final state. Second-order hopping between bright excitonic states is as fast as the first-order process (~1 ps). For perpendicular CNTs, the high rate stems from the high density of phononic states; for parallel CNTs, the reason lies in relaxed selection rules. Moreover, second-order exciton transfer between dark and bright states, facilitated by phonons withmore » large angular momentum, has rates comparable to bright-to-bright transfer, so dark excitons provide an additional pathway for energy transfer in CNT composites. Furthermore, as dark excitons are difficult to probe in experiment, predictive theory is critical for understanding exciton dynamics in CNT composites.« less

Unexpectedly Fast Phonon-Assisted Exciton Hopping between Carbon Nanotubes

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

Davoody, A. H.; Karimi, F.; Arnold, M. S.

Carbon-nanotube (CNT) aggregates are promising light-absorbing materials for photovoltaics. The hopping rate of excitons between CNTs directly affects the efficiency of these devices. We theoretically investigate phonon-assisted exciton hopping, where excitons scatter with phonons into a same-tube transition state, followed by intertube Coulomb scattering into the final state. Second-order hopping between bright excitonic states is as fast as the first-order process (~1 ps). For perpendicular CNTs, the high rate stems from the high density of phononic states; for parallel CNTs, the reason lies in relaxed selection rules. Moreover, second-order exciton transfer between dark and bright states, facilitated by phonons withmore » large angular momentum, has rates comparable to bright-to-bright transfer, so dark excitons provide an additional pathway for energy transfer in CNT composites. Furthermore, as dark excitons are difficult to probe in experiment, predictive theory is critical for understanding exciton dynamics in CNT composites.« less

Music for a Brighter World: Brightness Judgment Bias by Musical Emotion.

PubMed

Bhattacharya, Joydeep; Lindsen, Job P

2016-01-01

A prevalent conceptual metaphor is the association of the concepts of good and evil with brightness and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate brightness judgment in a metaphor consistent fashion. In three separate experiments, participants judged the brightness of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that short musical excerpts are effective emotional primes that cross-modally influence brightness judgment of visual stimuli. Grey squares were consistently judged as brighter after listening to music with a positive valence, as compared to music with a negative valence. The results of Experiment 2 revealed that the bias in brightness judgment does not require an active evaluation of the emotional content of the music. By applying a different experimental procedure in Experiment 3, we showed that this brightness judgment bias is indeed a robust effect. Altogether, our findings demonstrate a powerful role of musical emotion in biasing brightness judgment and that this bias is aligned with the metaphor viewpoint.

Music for a Brighter World: Brightness Judgment Bias by Musical Emotion

PubMed Central

2016-01-01

A prevalent conceptual metaphor is the association of the concepts of good and evil with brightness and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate brightness judgment in a metaphor consistent fashion. In three separate experiments, participants judged the brightness of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that short musical excerpts are effective emotional primes that cross-modally influence brightness judgment of visual stimuli. Grey squares were consistently judged as brighter after listening to music with a positive valence, as compared to music with a negative valence. The results of Experiment 2 revealed that the bias in brightness judgment does not require an active evaluation of the emotional content of the music. By applying a different experimental procedure in Experiment 3, we showed that this brightness judgment bias is indeed a robust effect. Altogether, our findings demonstrate a powerful role of musical emotion in biasing brightness judgment and that this bias is aligned with the metaphor viewpoint. PMID:26863420

Dynamic resetting of the human circadian pacemaker by intermittent bright light

NASA Technical Reports Server (NTRS)

Rimmer, D. W.; Boivin, D. B.; Shanahan, T. L.; Kronauer, R. E.; Duffy, J. F.; Czeisler, C. A.

2000-01-01

In humans, experimental studies of circadian resetting typically have been limited to lengthy episodes of exposure to continuous bright light. To evaluate the time course of the human endogenous circadian pacemaker's resetting response to brief episodes of intermittent bright light, we studied 16 subjects assigned to one of two intermittent lighting conditions in which the subjects were presented with intermittent episodes of bright-light exposure at 25- or 90-min intervals. The effective duration of bright-light exposure was 31% or 63% compared with a continuous 5-h bright-light stimulus. Exposure to intermittent bright light elicited almost as great a resetting response compared with 5 h of continuous bright light. We conclude that exposure to intermittent bright light produces robust phase shifts of the endogenous circadian pacemaker. Furthermore, these results demonstrate that humans, like other species, exhibit an enhanced sensitivity to the initial minutes of bright-light exposure.

New solitary wave solutions of (3 + 1)-dimensional nonlinear extended Zakharov-Kuznetsov and modified KdV-Zakharov-Kuznetsov equations and their applications

NASA Astrophysics Data System (ADS)

Lu, Dianchen; Seadawy, A. R.; Arshad, M.; Wang, Jun

In this paper, new exact solitary wave, soliton and elliptic function solutions are constructed in various forms of three dimensional nonlinear partial differential equations (PDEs) in mathematical physics by utilizing modified extended direct algebraic method. Soliton solutions in different forms such as bell and anti-bell periodic, dark soliton, bright soliton, bright and dark solitary wave in periodic form etc are obtained, which have large applications in different branches of physics and other areas of applied sciences. The obtained solutions are also presented graphically. Furthermore, many other nonlinear evolution equations arising in mathematical physics and engineering can also be solved by this powerful, reliable and capable method. The nonlinear three dimensional extended Zakharov-Kuznetsov dynamica equation and (3 + 1)-dimensional modified KdV-Zakharov-Kuznetsov equation are selected to show the reliability and effectiveness of the current method.

Improving the photostability of bright monomeric orange and red fluorescent proteins.

PubMed

Shaner, Nathan C; Lin, Michael Z; McKeown, Michael R; Steinbach, Paul A; Hazelwood, Kristin L; Davidson, Michael W; Tsien, Roger Y

2008-06-01

All organic fluorophores undergo irreversible photobleaching during prolonged illumination. Although fluorescent proteins typically bleach at a substantially slower rate than many small-molecule dyes, in many cases the lack of sufficient photostability remains an important limiting factor for experiments requiring large numbers of images of single cells. Screening methods focusing solely on brightness or wavelength are highly effective in optimizing both properties, but the absence of selective pressure for photostability in such screens leads to unpredictable photobleaching behavior in the resulting fluorescent proteins. Here we describe an assay for screening libraries of fluorescent proteins for enhanced photostability. With this assay, we developed highly photostable variants of mOrange (a wavelength-shifted monomeric derivative of DsRed from Discosoma sp.) and TagRFP (a monomeric derivative of eqFP578 from Entacmaea quadricolor) that maintain most of the beneficial qualities of the original proteins and perform as reliably as Aequorea victoria GFP derivatives in fusion constructs.

Effect of DCB extraction on Mossbauer and spectral data for a Hawaiian palagonitic soil (PN-9): Iden tification of pigmentary phases

NASA Technical Reports Server (NTRS)

Morris, Richard V.; Golden, D. C.; Bell, J. F., III; Lauer, H. V., Jr.; Adams, J. B.

1992-01-01

The study of palagonitic soils is an active area of research in martian geoscience because the spectral and magnetic properties of a subset are spectral and/or magnetic analogues of martian bright regions. An understanding of the composition, distribution, and mineralogy of ferric-bearing phases for palagonitic soils forms, through spectral and magnetic data, a basis for inferring the nature of ferric-bearing phases on Mars. Progress has been made in this area, but the data set is incomplete, especially with respect to the nature of pigmenting phases. The purpose of this study is to identify the nature of the pigment for Hawaiian palagonitic soil PN-9 by using extraction procedures to selectively remove iron oxide phases. This soil was collected at the same locale as samples Hawaii 34 and VOL02. All three soils are good spectral analogues for martian bright regions.

Microwave brightness temperature features of lunar craters: observation from Chang'E-1 mission

NASA Astrophysics Data System (ADS)

Hu, Guo-Ping; Chen, Ke; Guo, Wei; Li, Qing-Xia; Su, Hong-Yan

2013-01-01

Topographic features of lunar craters have been found from the brightness temperature (TB) observed by the multichannel (3.0, 7.8, 19.35, and 37 GHz) microwave radiometer (MRM) aboard Chang'E-1 (CE-1) in a single track view. As the topographic effect is more obvious at 37 GHz, 37 GHz TB has been focused on in this work. The variation of 37 GHz daytime (nighttime) TB along the profile of a crater is found to show an oscillatory behavior. The amplitude of daytime TB is significantly affected by the observation time and the shape of the crater, whose diameter is bigger than the spatial resolution of MRM onboard CE-1. The large and typical diurnal TB difference (nighttime TB minus daytime TB) at 37 GHz over selected young craters due to the large rock abundance in craters, have been discussed and compared with the altitude profile.

The Munich Near-Infrared Cluster Survey - IV. Biases in the completeness of near-infrared imaging data

NASA Astrophysics Data System (ADS)

Snigula, J.; Drory, N.; Bender, R.; Botzler, C. S.; Feulner, G.; Hopp, U.

2002-11-01

We present the results of completeness simulations for the detection of point sources as well as redshifted elliptical and spiral galaxies in the K'-band images of the Munich Near-Infrared Cluster Survey (MUNICS). The main focus of this work is to quantify the selection effects introduced by threshold-based object detection algorithms used in deep imaging surveys. Therefore, we simulate objects obeying the well-known scaling relations between effective radius and central surface brightness, for both de Vaucouleurs and exponential profiles. The results of these simulations, while presented for the MUNICS project, are applicable in a much wider context to deep optical and near-infrared selected samples. We investigate the detection probability as well as the reliability for recovering the true total magnitude with Kron-like (adaptive) aperture photometry. The results are compared with the predictions of the visibility theory of Disney and Phillipps in terms of the detection rate and the lost-light fraction. Additionally, the effects attributable to seeing are explored. The results show a bias against detecting high-redshifted massive elliptical galaxies in comparison to disc galaxies with exponential profiles, and that the measurements of the total magnitudes for intrinsically bright elliptical galaxies are systematically too faint. Disc galaxies, in contrast, show no significant offset in the magnitude measurement of luminous objects. Finally, we present an analytic formula to predict the completeness of point sources using only basic image parameters.

Two- and 4-hour bright-light exposures differentially effect sleepiness and performance the subsequent night.

PubMed

Thessing, V C; Anch, A M; Muehlbach, M J; Schweitzer, P K; Walsh, J K

1994-03-01

The effect of two durations of bright light upon sleepiness and performance during typical night shift hours was assessed. Thirty normal, healthy young adults participated in a 2-night protocol. On the 1st night subjects were exposed to bright or dim light beginning at 2400 hours, under one of the following three conditions: bright light for 4 hours, dim light for 2 hours followed by bright light for 2 hours or dim light for 4 hours. Following light exposure, subjects remained awake until 0800 hours in a dimly lit room and slept in the laboratory between 0800 and 1600 hours, during which time sleep was estimated with actigraphy. Throughout the 2nd night, the multiple sleep latency test (MSLT), simulated assembly line task (SALT) performance, and subjective sleepiness were recorded. The single, 4-hour exposure to bright light was found to significantly increase MSLT scores and improve SALT performance during the early morning hours on the night following bright-light exposure. No significant effects were noted with a 2-hour exposure. The most likely explanation for these findings is a phase delay in the circadian rhythm of sleepiness-alertness.

Chemical structures of coal lithotypes before and after CO2 adsorption as investigated by advanced solid-state 13C nuclear magnetic resonance spectroscopy

USGS Publications Warehouse

Cao, X.; Mastalerz, Maria; Chappell, M.A.; Miller, L.F.; Li, Y.; Mao, J.

2011-01-01

Four lithotypes (vitrain, bright clarain, clarain, and fusain) of a high volatile bituminous Springfield Coal from the Illinois Basin were characterized using advanced solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. The NMR techniques included quantitative direct polarization/magic angle spinning (DP/MAS), cross polarization/total sideband suppression (CP/TOSS), dipolar dephasing, CHn selection, and recoupled C-H long-range dipolar dephasing techniques. The lithotypes that experienced high-pressure CO2 adsorption isotherm analysis were also analyzed to determine possible changes in coal structure as a result of CO2 saturation at high pressure and subsequent evacuation. The main carbon functionalities present in original vitrain, bright clarain, clarain and fusain were aromatic carbons (65.9%-86.1%), nonpolar alkyl groups (9.0%-28.9%), and aromatic C-O carbons (4.1%-9.5%). Among these lithotypes, aromaticity increased in the order of clarain, bright clarain, vitrain, and fusain, whereas the fraction of alkyl carbons decreased in the same order. Fusain was distinct from other three lithotypes in respect to its highest aromatic composition (86.1%) and remarkably small fraction of alkyl carbons (11.0%). The aromatic cluster size in fusain was larger than that in bright clarain. The lithotypes studied responded differently to high pressure CO2 saturation. After exposure to high pressure CO2, vitrain and fusain showed a decrease in aromaticity but an increase in the fraction of alkyl carbons, whereas bright clarain and clarain displayed an increase in aromaticity but a decrease in the fraction of alkyl carbons. Aromatic fused-rings were larger for bright clarain but smaller for fusain in the post-CO2 adsorption samples compared to the original lithotypes. These observations suggested chemical CO2-coal interactions at high pressure and the selectivity of lithotypes in response to CO2 adsorption. ?? 2011 Elsevier B.V.

Indication of the Hanle Effect by Comparing the Scattering Polarization Observed by CLASP in the Ly α and Si iii 120.65 nm Lines

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

Ishikawa, R.; Kubo, M.; Kano, R.

The Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding rocket experiment that has provided the first successful measurement of the linear polarization produced by scattering processes in the hydrogen Ly α line (121.57 nm) radiation of the solar disk. In this paper, we report that the Si iii line at 120.65 nm also shows scattering polarization and we compare the scattering polarization signals observed in the Ly α and Si iii lines in order to search for observational signatures of the Hanle effect. We focus on four selected bright structures and investigate how the U / I spatial variations vary between themore » Ly α wing, the Ly α core, and the Si iii line as a function of the total unsigned photospheric magnetic flux estimated from Solar Dynamics Observatory /Helioseismic and Magnetic Imager observations. In an internetwork region, the Ly α core shows an antisymmetric spatial variation across the selected bright structure, but it does not show it in other more magnetized regions. In the Si iii line, the spatial variation of U / I deviates from the above-mentioned antisymmetric shape as the total unsigned photospheric magnetic flux increases. A plausible explanation of this difference is the operation of the Hanle effect. We argue that diagnostic techniques based on the scattering polarization observed simultaneously in two spectral lines with very different sensitivities to the Hanle effect, like Ly α and Si iii, are of great potential interest for exploring the magnetism of the upper solar chromosphere and transition region.« less

Generalized dark-bright vector soliton solution to the mixed coupled nonlinear Schrödinger equations.

PubMed

Manikandan, N; Radhakrishnan, R; Aravinthan, K

2014-08-01

We have constructed a dark-bright N-soliton solution with 4N+3 real parameters for the physically interesting system of mixed coupled nonlinear Schrödinger equations. Using this as well as an asymptotic analysis we have investigated the interaction between dark-bright vector solitons. Each colliding dark-bright one-soliton at the asymptotic limits includes more coupling parameters not only in the polarization vector but also in the amplitude part. Our present solution generalizes the dark-bright soliton in the literature with parametric constraints. By exploiting the role of such coupling parameters we are able to control certain interaction effects, namely beating, breathing, bouncing, attraction, jumping, etc., without affecting other soliton parameters. Particularly, the results of the interactions between the bound state dark-bright vector solitons reveal oscillations in their amplitudes under certain parametric choices. A similar kind of effect was also observed experimentally in the BECs. We have also characterized the solutions with complicated structure and nonobvious wrinkle to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation. It is interesting to identify that the polarization vector of the dark-bright one-soliton evolves on a spherical surface instead of a hyperboloid surface as in the bright-bright case of the mixed coupled nonlinear Schrödinger equations.

A spectral k-means approach to bright-field cell image segmentation.

PubMed

Bradbury, Laura; Wan, Justin W L

2010-01-01

Automatic segmentation of bright-field cell images is important to cell biologists, but difficult to complete due to the complex nature of the cells in bright-field images (poor contrast, broken halo, missing boundaries). Standard approaches such as level set segmentation and active contours work well for fluorescent images where cells appear as round shape, but become less effective when optical artifacts such as halo exist in bright-field images. In this paper, we present a robust segmentation method which combines the spectral and k-means clustering techniques to locate cells in bright-field images. This approach models an image as a matrix graph and segment different regions of the image by computing the appropriate eigenvectors of the matrix graph and using the k-means algorithm. We illustrate the effectiveness of the method by segmentation results of C2C12 (muscle) cells in bright-field images.

The universal and automatic association between brightness and positivity.

PubMed

Specker, Eva; Leder, Helmut; Rosenberg, Raphael; Hegelmaier, Lisa Mira; Brinkmann, Hanna; Mikuni, Jan; Kawabata, Hideaki

2018-05-01

The present study investigates the hypothesis that brightness of colors is associated with positivity, postulating that this is an automatic and universal effect. The Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) was used in all studies. Study 1 used color patches varying on brightness, Study 2 used achromatic stimuli to eliminate the potential confounding effects of hue and saturation. Study 3 replicated Study 2 in a different cultural context (Japan vs. Austria), both studies also included a measure of explicit association. All studies confirmed the hypothesis that brightness is associated with positivity, at a significance level of p < .001 and Cohen's D varying from 0.90 to 3.99. Study 1-3 provided support for the notion that this is an automatic effect. Additionally, Study 2 and Study 3 showed that people also have an explicit association of brightness with positivity. However, as expected, our results also show that the implicit association was stronger than the explicit association. Study 3 shows clear support for the universality of our effects. In sum, our results support the idea that brightness is associated with positivity and that these associations are automatic and universal. Copyright © 2018 Elsevier B.V. All rights reserved.

Bright-light effects on cognitive performance in elderly persons working simulated night shifts: psychological well-being as a mediator?

PubMed

Kretschmer, Veronika; Schmidt, Klaus-Helmut; Griefahn, Barbara

2013-11-01

The present study examined whether the relationship between light exposure and cognitive functioning is mediated by psychological well-being in elderly persons working night shifts. The role of psychological well-being has been neglected so far in the relationship between bright light and cognitive performance. Sleepiness and mood were applied as indicators of psychological well-being. Cognitive functioning was examined in terms of concentration, working memory, and divided attention. A total of thirty-two test persons worked in three consecutive simulated night shifts, 16 under bright light (3,000 lux) and 16 under room light (300 lux). Concentration, working memory, and divided attention were measured by computerised tasks. The hypothesised mediators were recorded by questionnaires. Mediation analyses were conducted for estimating direct, total, and indirect effects in simple mediation models. Results indicate that sleepiness and mood did not function as mediators in the prediction of concentration, working memory, and/or divided attention by light exposure. Sleepiness led to an underestimation of the positive bright-light effect on concentration performance. Mood showed only a random effect due to the positive bright-light effect on working memory. Sleepiness and mood could completely be excluded as mediators in the relationship between light exposure and cognitive functioning. This study underlines that psychological well-being of elderly persons is not a critical component in the treatment of bright light on cognitive performance in the night shift workplace. In summary, it becomes evident that bright light has a strong direct and independent effect on cognitive performance, particularly on working memory and concentration.

The 'dark side' and 'bright side' of personality: when too much conscientiousness and too little anxiety are detrimental with respect to the acquisition of medical knowledge and skill.

PubMed

Ferguson, Eamonn; Semper, Heather; Yates, Janet; Fitzgerald, J Edward; Skatova, Anya; James, David

2014-01-01

Theory suggests that personality traits evolved to have costs and benefits, with the effectiveness of a trait dependent on how these costs and benefits relate to the present circumstances. This suggests that traits that are generally viewed as positive can have a 'dark side' and those generally viewed as negative can have a 'bright side' depending on changes in context. We test this in a sample of 220 UK medical students with respect to associations between the Big 5 personality traits and learning outcomes across the 5 years of a medical degree. The medical degree offers a changing learning context from pre-clinical years (where a more methodical approach to learning is needed) to the clinical years (where more flexible learning is needed, in a more stressful context). We argue that while trait conscientiousness should enhance pre-clinical learning, it has a 'dark side' reducing the acquisition of knowledge in the clinical years. We also suggest that anxiety has a 'bright side' enhancing the acquisition of skills in the clinical years. We also explore if intelligence enhances learning across the medical degree. Using confirmatory factor analysis and structural equation modelling we show that medical skills and knowledge assessed in the pre-clinical and clinical years are psychometrically distinguishable, forming a learning 'backbone', whereby subsequent learning outcomes are predicted by previous ones. Consistent with our predictions conscientiousness enhanced preclinical knowledge acquisition but reduced the acquisition of clinical knowledge and anxiety enhanced the acquisition of clinical skills. We also identified a curvilinear U shaped association between Surgency (extraversion) and pre-clinical knowledge acquisition. Intelligence predicted initial clinical knowledge, and had a positive total indirect effect on clinical knowledge and clinical skill acquisition. For medical selection, this suggests that selecting students high on conscientiousness may be problematic, as it may be excluding those with some degree of moderate anxiety.

The ‘Dark Side’ and ‘Bright Side’ of Personality: When Too Much Conscientiousness and Too Little Anxiety Are Detrimental with Respect to the Acquisition of Medical Knowledge and Skill

PubMed Central

Ferguson, Eamonn; Semper, Heather; Yates, Janet; Fitzgerald, J. Edward; Skatova, Anya; James, David

2014-01-01

Theory suggests that personality traits evolved to have costs and benefits, with the effectiveness of a trait dependent on how these costs and benefits relate to the present circumstances. This suggests that traits that are generally viewed as positive can have a ‘dark side’ and those generally viewed as negative can have a ‘bright side’ depending on changes in context. We test this in a sample of 220 UK medical students with respect to associations between the Big 5 personality traits and learning outcomes across the 5 years of a medical degree. The medical degree offers a changing learning context from pre-clinical years (where a more methodical approach to learning is needed) to the clinical years (where more flexible learning is needed, in a more stressful context). We argue that while trait conscientiousness should enhance pre-clinical learning, it has a ‘dark side’ reducing the acquisition of knowledge in the clinical years. We also suggest that anxiety has a ‘bright side’ enhancing the acquisition of skills in the clinical years. We also explore if intelligence enhances learning across the medical degree. Using confirmatory factor analysis and structural equation modelling we show that medical skills and knowledge assessed in the pre-clinical and clinical years are psychometrically distinguishable, forming a learning ‘backbone’, whereby subsequent learning outcomes are predicted by previous ones. Consistent with our predictions conscientiousness enhanced preclinical knowledge acquisition but reduced the acquisition of clinical knowledge and anxiety enhanced the acquisition of clinical skills. We also identified a curvilinear U shaped association between Surgency (extraversion) and pre-clinical knowledge acquisition. Intelligence predicted initial clinical knowledge, and had a positive total indirect effect on clinical knowledge and clinical skill acquisition. For medical selection, this suggests that selecting students high on conscientiousness may be problematic, as it may be excluding those with some degree of moderate anxiety. PMID:24586353

Effect of bright light on EEG activities and subjective sleepiness to mental task during nocturnal sleep deprivation.

PubMed

Yokoi, Mari; Aoki, Ken; Shimomura, Yoshihiro; Iwanaga, Koichi; Katsuura, Tetsuo; Shiomura, Yoshihiro

2003-11-01

The purpose of this study was to investigate the effect of the exposure to bright light on EEG activity and subjective sleepiness at rest and at the mental task during nocturnal sleep deprivation. Eight male subjects lay awake in semi-supine in a reclining seat from 21:00 to 04:30 under the bright (BL; >2500 lux) or the dim (DL; <150 lux) light conditions. During the sleep deprivation, the mental task (Stroop color-word conflict test: CWT) was performed each 15 min in one hour. EEG, subjective sleepiness, rectal and mean skin temperatures and urinary melatonin concentrations were measured. The subjective sleepiness increased with time of sleep deprivation during both rest and CWT under the DL condition. The exposure to bright light delayed for 2 hours the increase in subjective sleepiness at rest and suppressed the increase in that during CWT. The bright light exposure also delayed the increase in the theta and alpha wave activities in EEG at rest. In contrast, the effect of the bright light exposure on the theta and alpha wave activities disappeared by CWT. Additionally, under the BL condition, the entire theta activity during CWT throughout nocturnal sleep deprivation increased significantly from that in a rest condition. Our results suggest that the exposure to bright light throughout nocturnal sleep deprivation influences the subjective sleepiness during the mental task and the EEG activity, as well as the subjective sleepiness at rest. However, the effect of the bright light exposure on the EEG activity at the mental task diminishes throughout nocturnal sleep deprivation.

IRAS variables as galactic structure tracers - Classification of the bright variables

NASA Technical Reports Server (NTRS)

Allen, L. E.; Kleinmann, S. G.; Weinberg, M. D.

1993-01-01

The characteristics of the 'bright infrared variables' (BIRVs), a sample consisting of the 300 brightest stars in the IRAS Point Source Catalog with IRAS variability index VAR of 98 or greater, are investigated with the purpose of establishing which of IRAS variables are AGB stars (e.g., oxygen-rich Miras and carbon stars, as was assumed by Weinberg (1992)). Results of the analysis of optical, infrared, and microwave spectroscopy of these stars indicate that, out of 88 stars in the BIRV sample identified with cataloged variables, 86 can be classified as Miras. Results of a similar analysis performed for a color-selected sample of stars, using the color limits employed by Habing (1988) to select AGB stars, showed that, out of 52 percent of classified stars, 38 percent are non-AGB stars, including H II regions, planetary nebulae, supergiants, and young stellar objects, indicating that studies using color-selected samples are subject to misinterpretation.

Photic effects on sustained performance

NASA Technical Reports Server (NTRS)

French, J.; Whitmore, J.; Hannon, P. J.; Brainard, G.; Schiflett, S.

1992-01-01

Research is described which evaluates manipulating environmental light intensity as a means to attenuate fatigue. A counter balanced, within-subjects design was used to compare nine male subjects exposed to dim (100 lux) and bright (3000 lux) light conditions. Oral temperature values were greater for the bright light group over the dim light condition. Melatonin levels were suppressed by bright light treatment. Also, the frequency of eye blink rate was less for subjects during bright over dim light exposure. Light exposure was without effect on subjective fatigue. However, irrespective of light condition, significant effects on confusion, fatigue, and vigor mood dimensions were found as a result of 30 hour sleep deprivation. The findings suggest that bright lights may be used to help sustain nocturnal activity otherwise susceptible to fatigue. Such findings may have implications for the lighting arrangements on space flights during the subjective night for astronauts.

The effect of bright light on sleepiness among rapid-rotating 12-hour shift workers.

PubMed

Sadeghniiat-Haghighi, Khosro; Yazdi, Zohreh; Jahanihashemi, Hassan; Aminian, Omid

2011-01-01

About 20% of workers in industrialized countries are shift workers and more than half of them work on night or rotating shifts. Most night workers complain of sleepiness due to lack of adjustment of the circadian rhythm. In simulated night-work experiments, scheduled exposure to bright light has been shown to reduce these complaints. Our study assessed the effects of bright light exposure on sleepiness during night work in an industrial setting. In a cross-over design, 94 workers at a ceramic factory were exposed to either bright (2500 lux) or normal light (300 lux) during breaks on night shifts. We initiated 20-minute breaks between 24.00 and 02.00 hours. Sleepiness ratings were determined using the Stanford Sleepiness Scale at 22.00, 24.00, 02.00 and 04.00 hours. Under normal light conditions, sleepiness peaked at 02:00 hours. A significant reduction (22% compared to normal light conditions) in sleepiness was observed after workers were exposed to bright light. Exposure to bright light may be effective in reducing sleepiness among night workers.

Where have all the blue flowers gone: pollinator responses and selection on flower colour in New Zealand Wahlenbergia albomarginata.

PubMed

Campbell, D R; Bischoff, M; Lord, J M; Robertson, A W

2012-02-01

Although pollinators are thought to select on flower colour, few studies have experimentally decoupled effects of colour from correlated traits on pollinator visitation and pollen transfer. We combined selection analysis and phenotypic manipulations to measure the effect of petal colour on visitation and pollen export at two spatial scales in Wahlenbergia albomarginata. This species is representative of many New Zealand alpine herbs that have secondarily evolved white or pale flowers. The major pollinators, solitary bees, exerted phenotypic selection on flower size but not colour, quantified by bee vision. When presented with manipulated flowers, bees visited flowers painted blue to resemble a congener over white flowers in large, but not small, experimental arrays. Pollen export was higher for blue flowers in large arrays. Pollinator preference does not explain the pale colouration of W. albomarginata, as commonly hypothesized. Absence of bright blue could be driven instead by indirect selection of correlated characters. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

Pinacate-gran Desierto Region, Mexico: SIR-A Data Analysis

NASA Technical Reports Server (NTRS)

Christensen, P.; Greeley, R.; Mchone, J.; Asmerom, Y.; Barnett, S.

1984-01-01

Radar images (SIR-A) from the Columbia space shuttle were used to assess the radar returns of terrain shaped by volcanic, aeolian, and fluvial processes in northwest Sonora. Field studies and photointerpretation show that sand dunes are poorly imaged by SIR-A, in contrast to SEASAT, evidently a consequence of the greater SIR-A incidence angle; star dunes are visible only as small bright spots representing merging arms at dune apices which may act as corner reflectors. Desert grasses and bushes (approx. 2 m high) have little effect on radar brightness. Only larger trees with woody trunks approx. 0.5 m across are effective radar reflectors; their presence contributes to radar bright zones along some arroyos. The radar brightness of lava flows decreases with surface roughness and presence of mantling windblown sediments and weathering products; however, old uplifted (faulted) flows are of equal brightness to fresh, unmantled aa flows. Maar craters display circular patterns of varying radar brightness which represent a combination of geometry, slope, and distribution of surface materials. Some radar bright rings in the Pinacates resemble craters on radar but are observed to be playas encircled by trees.

POST ASYMPTOTIC GIANT BRANCH BIPOLAR REFLECTION NEBULAE: RESULT OF DYNAMICAL EJECTION OR SELECTIVE ILLUMINATION?

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

Koning, N.; Kwok, Sun; Steffen, W., E-mail: nico.koning@ucalgary.ca, E-mail: sunkwok@hku.hk, E-mail: wsteffen@astrosen.unam.mx

2013-03-10

A model for post asymptotic giant branch bipolar reflection nebulae has been constructed based on a pair of evacuated cavities in a spherical dust envelope. Many of the observed features of bipolar nebulae, including filled bipolar lobes, an equatorial torus, searchlight beams, and a bright central light source, can be reproduced. The effects on orientation and dust densities are studied and comparisons with some observed examples are offered. We suggest that many observed properties of bipolar nebulae are the result of optical effects and any physical modeling of these nebulae has to take these factors into consideration.

Statics and dynamics of atomic dark-bright solitons in the presence of impurities

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

Achilleos, V.; Frantzeskakis, D. J.; Kevrekidis, P. G.

2011-11-15

Adopting a mean-field description for a two-component atomic Bose-Einstein condensate, we study the statics and dynamics of dark-bright solitons in the presence of localized impurities. We use adiabatic perturbation theory to derive an equation of motion for the dark-bright soliton center. We show that, counterintuitively, an attractive (repulsive) delta-like impurity, acting solely on the bright-soliton component, induces an effective localized barrier (well) in the effective potential felt by the soliton; this way, dark-bright solitons are reflected from (transmitted through) attractive (repulsive) impurities. Our analytical results for the small-amplitude oscillations of solitons are found to be in good agreement with resultsmore » obtained via a Bogoliubov-de Gennes analysis and direct numerical simulations.« less

Randomized placebo-controlled field study of the effects of bright light and melatonin in adaptation to night work.

PubMed

Bjorvatn, Bjørn; Stangenes, Kristine; Oyane, Nicolas; Forberg, Knut; Lowden, Arne; Holsten, Fred; Akerstedt, Torbjørn

2007-06-01

This study evaluated the effects of bright light and melatonin on adaptation to night work on an oil rig in the North Sea. Seventeen persons working a schedule of 2 weeks on a 12-hour shift, with the first week on night shift and the second week on day shift (ie, the swing shift schedule) participated. In a randomized controlled crossover design, the shift workers received a placebo, melatonin (3 mg, 1 hour before bedtime), or bright light (30-minute exposure, individually scheduled) during the first 4 days on the night shift and during the first 4 days on the day shift. Subjective and objective measures of sleepiness (Karolinska Sleepiness Scale and a simple serial reaction-time test) and sleep (diary and actigraphy) were recorded. Subjective measures indicated that melatonin modestly reduced sleepiness at work during the day shift and increased sleep by 15-20 minutes per day. Bright light gave values in between those of melatonin and the placebo, but with few significant results. According to the objective measures, bright light improved sleep to a minor degree during the night shift. Hardly any side-effects were reported. Melatonin and bright light modestly improved sleep and sleepiness in this field study. In well-controlled simulated nightwork studies, both melatonin and bright light are more effective in alleviating sleepiness and sleep problems. The less effect in this field study may be due to competing or conflicting factors present in real life or to an inoptimal timing and duration of the treatments.

Optimum Image Formation for Spaceborne Microwave Radiometer Products.

PubMed

Long, David G; Brodzik, Mary J

2016-05-01

This paper considers some of the issues of radiometer brightness image formation and reconstruction for use in the NASA-sponsored Calibrated Passive Microwave Daily Equal-Area Scalable Earth Grid 2.0 Brightness Temperature Earth System Data Record project, which generates a multisensor multidecadal time series of high-resolution radiometer products designed to support climate studies. Two primary reconstruction algorithms are considered: the Backus-Gilbert approach and the radiometer form of the scatterometer image reconstruction (SIR) algorithm. These are compared with the conventional drop-in-the-bucket (DIB) gridded image formation approach. Tradeoff study results for the various algorithm options are presented to select optimum values for the grid resolution, the number of SIR iterations, and the BG gamma parameter. We find that although both approaches are effective in improving the spatial resolution of the surface brightness temperature estimates compared to DIB, SIR requires significantly less computation. The sensitivity of the reconstruction to the accuracy of the measurement spatial response function (MRF) is explored. The partial reconstruction of the methods can tolerate errors in the description of the sensor measurement response function, which simplifies the processing of historic sensor data for which the MRF is not known as well as modern sensors. Simulation tradeoff results are confirmed using actual data.

Acute Effects of Morning Light on Plasma Glucose and Triglycerides in Healthy Men and Men with Type 2 Diabetes.

PubMed

Versteeg, Ruth I; Stenvers, Dirk J; Visintainer, Dana; Linnenbank, Andre; Tanck, Michael W; Zwanenburg, Gooitzen; Smilde, Age K; Fliers, Eric; Kalsbeek, Andries; Serlie, Mireille J; la Fleur, Susanne E; Bisschop, Peter H

2017-04-01

Ambient light intensity is signaled directly to hypothalamic areas that regulate energy metabolism. Observational studies have shown associations between ambient light intensity and plasma glucose and lipid levels, but human data on the acute metabolic effects of light are scarce. Since light is the main signal indicating the onset of the diurnal phase of physical activity and food intake in humans, we hypothesized that bright light would affect glucose and lipid metabolism. Therefore, we determined the acute effects of bright light on plasma glucose and lipid concentrations in 2 randomized crossover trials: (1) in 8 healthy lean men and (2) in 8 obese men with type 2 diabetes. From 0730 h, subjects were exposed to either bright light (4000 lux) or dim light (10 lux) for 5 h. After 1 h of light exposure, subjects consumed a 600-kcal mixed meal. Primary endpoints were fasting and postprandial plasma glucose levels. In healthy men, bright light did not affect fasting or postprandial plasma glucose levels. However, bright light increased fasting and postprandial plasma triglycerides. In men with type 2 diabetes, bright light increased fasting and postprandial glucose levels. In men with type 2 diabetes, bright light did not affect fasting triglyceride levels but increased postprandial triglyceride levels. We show that ambient light intensity acutely affects human plasma glucose and triglyceride levels. Our findings warrant further research into the consequences of the metabolic effects of light for the diagnosis and prevention of hyperglycemia and dyslipidemia.

Sub-millimetre properties of massive star-forming galaxies at z ~ 2 in SHADES/SXDF

NASA Astrophysics Data System (ADS)

Takagi, T.; Mortier, A. M. J.; Shimasaku, K.; Coppin, K.; Pope, A.; Ivison, R. J.; Hanami, H.; Serjeant, S.; Dunlop, J. S.

2007-05-01

We study the submillimetre (submm) properties of the following NIR-selected massive galaxies at high redshifts: BzK-selected star-forming galaxies (BzKs), distant red galaxies (DRGs) and extremely red objects (EROs). We used the SCUBA HAlf Degree Extragalactic Survey (SHADES), the largest uniform submm survey to date. We detected 6 NIR-selected galaxies in our SCUBA map. Four submm-detected galaxies out of six are found to be detected both at 24 micron and in radio (1.4 GHz), and therefore confirmed as genuine submm-bright galaxies. We identify two submm-bright NIR-selected galaxies are the BzK-DRG-ERO overlapping population. Although this overlapping population is rare, about 12% of this population could be submm galaxies. With a stacking analysis, we detected the 850-micron flux of submm-faint BzKs and EROs in our SCUBA maps. While the contribution from BzKs at z˜2 to submm background is about 10 - 15 % and similar to that from EROs typically at z˜1, BzKs have a higher fraction (˜30%) of flux in resolved sources than EROs do. Therefore, submm flux of BzKs seems to be biased high. From the SED fitting using an evolutionary model of starbursts with radiative transfer, submm-bright NIR-selected galaxies, mostly BzKs, are found to have the stellar mass of >5x1010M[sun] with the bolometric luminosity of >3x1012L[sun]. On the other hand, an average SED of submm-faint BzKs indicates the typical stellar mass of <6x1010M[sun] and therefore less massive.

Circadian rhythm of acute phase proteins under the influence of bright/dim light during the daytime.

PubMed

Kanikowska, Dominika; Hyun, Ki-Ja; Tokura, Hiromi; Azama, Takashi; Nishimura, Shinya

2005-01-01

We investigated the influence of two different light intensities, dim (100 lx) and bright (5000 lx), during the daytime on the circadian rhythms of selected acute phase proteins of C-reactive protein (CRP), alpha1-acid glycoprotein (AGP), alpha1-antichymotrypsin (ACT), transfferin (TF), alpha2-macroglobulin (alpha2-m), haptoglobin (HP), and ceruloplasmin (CP). Serum samples were collected from 7 healthy volunteers at 4 h intervals during two separate single 24 h spans during which they were exposed to the respective light intensity conditions. A circadian rhythm was detected only in ACT concentration in the bright light condition. The concentration of ACT, a positive acute phase protein (APP), increased (significantly significant differences in the ACT concentration were detected at 14:00 and 22:00 h) and AGP showed a tendency to be higher under the daytime bright compared to dim light conditions. There were no significant differences between the time point means under daytime dim and bright light conditions for alpha2-M, AGP, Tf, Cp, or Hp. The findings suggest that some, but not all, APP may be influenced by the environmental light intensity.

Daytime exposure to bright light, as compared to dim light, decreases sleepiness and improves psychomotor vigilance performance.

PubMed

Phipps-Nelson, Jo; Redman, Jennifer R; Dijk, Derk-Jan; Rajaratnam, Shantha M W

2003-09-01

This study examined the effects of bright light exposure, as compared to dim light, on daytime subjective sleepiness, incidences of slow eye movements (SEMs), and psychomotor vigilance task (PVT) performance following 2 nights of sleep restriction. The study had a mixed factorial design with 2 independent variables: light condition (bright light, 1,000 lux; dim light, < 5 lux) and time of day. The dependent variables were subjective sleepiness, PVT performance, incidences of SEMs, and salivary melatonin levels. Sleep research laboratory at Monash University. Sixteen healthy adults (10 women and 6 men) aged 18 to 35 years (mean age 25 years, 3 months). Following 2 nights of sleep restriction (5 hours each night), participants were exposed to modified constant routine conditions. Eight participants were exposed to bright light from noon until 5:00 pm. Outside the bright light exposure period (9:00 am to noon, 5:00 pm to 9:00 pm) light levels were maintained at less than 5 lux. A second group of 8 participants served as controls for the bright light exposure and were exposed to dim light throughout the entire protocol. Bright light exposure reduced subjective sleepiness, decreased SEMs, and improved PVT performance compared to dim light. Bright lights had no effect on salivary melatonin. A significant positive correlation between PVT reaction times and subjective sleepiness was observed for both groups. Changes in SEMs did not correlate significantly with either subjective sleepiness or PVT performance. Daytime bright light exposure can reduce the impact of sleep loss on sleepiness levels and performance, as compared to dim light. These effects appear to be mediated by mechanisms that are separate from melatonin suppression. The results may assist in the development of treatments for daytime sleepiness.

A high brightness proton injector for the Tandetron accelerator at Jožef Stefan Institute

NASA Astrophysics Data System (ADS)

Pelicon, Primož; Podaru, Nicolae C.; Vavpetič, Primož; Jeromel, Luka; Ogrinc Potocnik, Nina; Ondračka, Simon; Gottdang, Andreas; Mous, Dirk J. M.

2014-08-01

Jožef Stefan Institute recently commissioned a high brightness H- ion beam injection system for its existing tandem accelerator facility. Custom developed by High Voltage Engineering Europa, the multicusp ion source has been tuned to deliver at the entrance of the Tandetron™ accelerator H- ion beams with a measured brightness of 17.1 A m-2 rad-2 eV-1 at 170 μA, equivalent to an energy normalized beam emittance of 0.767 π mm mrad MeV1/2. Upgrading the accelerator facility with the new injection system provides two main advantages. First, the high brightness of the new ion source enables the reduction of object slit aperture and the reduction of acceptance angle at the nuclear microprobe, resulting in a reduced beam size at selected beam intensity, which significantly improves the probe resolution for micro-PIXE applications. Secondly, the upgrade strongly enhances the accelerator up-time since H and He beams are produced by independent ion sources, introducing a constant availability of 3He beam for fusion-related research with NRA. The ion beam particle losses and ion beam emittance growth imply that the aforementioned beam brightness is reduced by transport through the ion optical system. To obtain quantitative information on the available brightness at the high-energy side of the accelerator, the proton beam brightness is determined in the nuclear microprobe beamline. Based on the experience obtained during the first months of operation for micro-PIXE applications, further necessary steps are indicated to obtain optimal coupling of the new ion source with the accelerator to increase the normalized high-energy proton beam brightness at the JSI microprobe, currently at 14 A m-2 rad-2 eV-1, with the output current at 18% of its available maximum.

The Acute Effects of Intermittent Light Exposure in the Evening on Alertness and Subsequent Sleep Architecture.

PubMed

Yang, Minqi; Ma, Ning; Zhu, Yingying; Su, Ying-Chu; Chen, Qingwei; Hsiao, Fan-Chi; Ji, Yanran; Yang, Chien-Ming; Zhou, Guofu

2018-03-15

Exposure to bright light is typically intermittent in our daily life. However, the acute effects of intermittent light on alertness and sleep have seldom been explored. To investigate this issue, we employed within-subject design and compared the effects of three light conditions: intermittent bright light (30-min pulse of blue-enriched bright light (~1000 lux, ~6000 K) alternating with 30-min dim normal light (~5 lux, ~3600 K) three times); continuous bright light; and continuous dim light on subjective and objective alertness and subsequent sleep structure. Each light exposure was conducted during the three hours before bedtime. Fifteen healthy volunteers (20 ± 3.4 years; seven males) were scheduled to stay in the sleep laboratory for four separated nights (one for adaptation and the others for the light exposures) with a period of at least one week between nights. The results showed that when compared with dim light, both intermittent light and continuous bright light significantly increased subjective alertness and decreased sleep efficiency (SE) and total sleep time (TST). Intermittent light significantly increased objective alertness than dim light did during the second half of the light-exposure period. Our results suggested that intermittent light was as effective as continuous bright light in their acute effects in enhancing subjective and objective alertness and in negatively impacting subsequent sleep.

Discriminative detection of deposited radon daughters on CR-39 track detectors using TRIAC II code

NASA Astrophysics Data System (ADS)

Patiris, D. L.; Ioannides, K. G.

2009-07-01

A method for detecting deposited 218Po and 214Po by a spectrometric study of CR-39 solid state nuclear track detectors is described. The method is based on the application of software imposed selection criteria, concerning the geometrical and optical properties of the tracks, which correspond to tracks created by alpha particles of specific energy falling on the detector at given angles of incidence. The selection criteria were based on a preliminary study of tracks' parameters (major and minor axes and mean value of brightness), using the TRIAC II code. Since no linear relation was found between the energy and the geometric characteristics of the tracks (major and minor axes), we resorted to the use of an additional parameter in order to classify the tracks according to the particles' energy. Since the brightness of tracks is associated with the tracks' depth, the mean value of brightness was chosen as the parameter of choice. To reduce the energy of the particles, which are emitted by deposited 218Po and 214Po into a quantifiable range, the detectors were covered with an aluminum absorber material. In this way, the discrimination of radon's daughters was finally accomplished by properly selecting amongst all registered tracks. This method could be applied as a low cost tool for the study of the radon's daughters behavior in air.

Tidal Disruption Event Host Galaxies in the Context of the Local Galaxy Population

NASA Astrophysics Data System (ADS)

Law-Smith, Jamie; Ramirez-Ruiz, Enrico; Ellison, Sara L.; Foley, Ryan J.

2017-11-01

We study the properties of tidal disruption event (TDE) host galaxies in the context of a catalog of ˜500,000 galaxies from the Sloan Digital Sky Survey. We explore whether selection effects can account for the overrepresentation of TDEs in E+A/post-starburst galaxies by creating matched galaxy samples. Accounting for possible selection effects due to black hole (BH) mass, redshift completeness, strong active galactic nucleus presence, bulge colors, and surface brightness can reduce the apparent overrepresentation of TDEs in E+A host galaxies by a factor of ˜4 (from ˜×100-190 to ˜×25-48), but cannot fully explain the preference. We find that TDE host galaxies have atypical photometric properties compared to similar, “typical” galaxies. In particular, TDE host galaxies tend to live in or near the “green valley” between star-forming and passive galaxies, and have bluer bulge colors ({{Δ }}(g-r)≈ 0.3 mag), lower half-light surface brightnesses (by ˜1 mag/arcsec2), higher Sérsic indices ({{Δ }}{n}{{g}}≈ 3), and higher bulge-to-total-light ratios ({{Δ }}B/T≈ 0.5) than galaxies with matched BH masses. We find that TDE host galaxies appear more centrally concentrated and that all have high galaxy Sérsic indices and B/T fractions—on average in the top 10% of galaxies of the same BH mass—suggesting a higher nuclear stellar density. We identify a region in the Sérsic index and BH mass parameter space that contains ˜2% of our reference catalog galaxies but ≥slant 60 % of TDE host galaxies. The unique photometric properties of TDE host galaxies may be useful for selecting candidate TDEs for spectroscopic follow-up observations in large transient surveys.

Chirped bright and dark solitons of (3 + 1)-dimensional coupled nonlinear Schrödinger equations in negative-index metamaterials with both electric and magnetic nonlinearity of Kerr type

NASA Astrophysics Data System (ADS)

Dai, Chao-Qing; Fan, Yan; Wang, Yue-Yue; Zheng, Jun

2018-02-01

The (3 + 1)-dimensional generalized coupled nonlinear Schrödinger equation with electric and magnetic nonlinearities of Kerr type and self-steepening effects is studied, and bright and dark soliton solutions are derived. Based on these analytical solutions, dynamical behaviors of bright and dark solitons are discussed. The amplitudes, widths and velocities of bright and dark solitons are all constants determined by the self-steepening effect parameters SE, SH. The phase chirp of a bright soliton diminishes in the pulse front of y-direction, however, it increases in the pulse back edge of y-direction. On the contrary, the phase chirp of a dark soliton increases in the pulse front of y-direction, however, it diminishes in the pulse back edge of y-direction. The phase chirps of a bright and dark soliton both shift along positive y -axis as time goes on. Moreover, the stability of the solutions is discussed.

Effects of evening bright light exposure on melatonin, body temperature and sleep.

PubMed

Bunnell; Treiber; Phillips; Berger

1992-03-01

Five male subjects were exposed to a single 2-h period of bright (2500 lux) or dim (<100 lux) light prior to sleep on two consecutive nights. The two conditions were repeated the following week in opposite order. Bright light significantly suppressed salivary melatonin and raised rectal temperature 0.3 degrees C (which remained elevated during the first 1.5 h of sleep), without affecting tympanic temperature. Bright light also increased REM latency, NREM period length, EEG spectral power in low frequency, 0.75-8 Hz and sigma, 12-14 Hz (sleep spindle) bandwidths during the first hour of sleep, and power of all frequency bands (0.5-32 Hz) within the first NREMP. Potentiation of EEG slow wave activity (0.5-4.0 Hz) by bright light persisted through the end of the second NREMP. The enhanced low-frequency power and delayed REM sleep after bright light exposure could represent a circadian phase-shift and/or the effect of an elevated rectal temperature, possibly mediated by the suppression of melatonin.

The Extremely Luminous Quasar Survey (ELQS) in SDSS and the high-z bright-end Quasar Luminosity Function

NASA Astrophysics Data System (ADS)

Schindler, Jan-Torge; Fan, Xiaohui; McGreer, Ian

2018-01-01

Studies of the most luminous quasars at high redshift directly probe the evolution of the most massive black holes in the early Universe and their connection to massive galaxy formation. Unfortunately, extremely luminous quasars at high redshift are very rare objects. Only wide area surveys have a chance to constrain their population. The Sloan Digital Sky Survey (SDSS) nd the Baryon Oscillation Spectroscopic Survey (BOSS) have so far provided the most widely adopted measurements of the type I quasar luminosity function (QLF) at z>3. However, a careful re-examination of the SDSS quasar sample revealed that the SDSS quasar selection is in fact missing a significant fraction of $z~3$ quasars at the brightest end.We have identified the purely optical color selection of SDSS, where quasars at these redshifts are strongly contaminated by late-type dwarfs, and the spectroscopic incompleteness of the SDSS footprint as the main reasons. Therefore we have designed the Extremely Luminous Quasar Survey (ELQS), based on a novel near-infrared JKW2 color cut using WISE AllWISE and 2MASS all-sky photometry, to yield high completeness for very bright (i < 18.0) quasars in the redshift range of 2.8<= z<=5.0. It effectively uses Random Forest machine-learning algorithms on SDSS and WISE photometry for quasar-star classification and photometric redshift estimation.The ELQS is spectroscopically following up ~230 new quasar candidates in an area of ~12000 deg2 in the SDSS footprint, to obtain a well-defined and complete quasar sample for an accurate measurement of the bright-end quasar luminosity function (QLF) at 2.8<= z<=5.0. So far the ELQS has identified 75 bright new quasars in this redshift range and observations of the fall sky will continue until the end of the year. At the AAS winter meeting we will present the full spectroscopic results of the survey, including a re-estimation and extension of the high-z QLF toward higher luminosities.

Image quality evaluation for smart-phone displays at lighting levels of indoor and outdoor conditions

NASA Astrophysics Data System (ADS)

Gong, Rui; Xu, Haisong; Wang, Binyu; Luo, Ming Ronnier

2012-08-01

The image quality of two active matrix organic light emitting diode (AMOLED) smart-phone displays and two in-plane switching (IPS) ones was visually assessed at two levels of ambient lighting conditions corresponding to indoor and outdoor applications, respectively. Naturalness, colorfulness, brightness, contrast, sharpness, and overall image quality were evaluated via psychophysical experiment by categorical judgment method using test images selected from different application categories. The experimental results show that the AMOLED displays perform better on colorfulness because of their wide color gamut, while the high pixel resolution and high peak luminance of the IPS panels help the perception of brightness, contrast, and sharpness. Further statistical analysis of ANOVA indicates that ambient lighting levels have significant influences on the attributes of brightness and contrast.

Effects of tryptophan-rich breakfast and light exposure during the daytime on melatonin secretion at night.

PubMed

Fukushige, Haruna; Fukuda, Yumi; Tanaka, Mizuho; Inami, Kaoru; Wada, Kai; Tsumura, Yuki; Kondo, Masayuki; Harada, Tetsuo; Wakamura, Tomoko; Morita, Takeshi

2014-11-19

The purpose of the present study is to investigate effects of tryptophan intake and light exposure on melatonin secretion and sleep by modifying tryptophan ingestion at breakfast and light exposure during the daytime, and measuring sleep quality (by using actigraphy and the OSA sleep inventory) and melatonin secretion at night. Thirty three male University students (mean ± SD age: 22 ± 3.1 years) completed the experiments lasting 5 days and 4 nights. The subjects were randomly divided into four groups: Poor*Dim (n = 10), meaning a tryptophan-poor breakfast (55 mg/meal) in the morning and dim light environment (<50 lx) during the daytime; Rich*Dim (n = 7), tryptophan-rich breakfast (476 mg/meal) and dim light environment; Poor*Bright (n = 9), tryptophan-poor breakfast and bright light environment (>5,000 lx); and Rich*Bright (n = 7), tryptophan-rich breakfast and bright light. Saliva melatonin concentrations on the fourth day were significantly lower than on the first day in the Poor*Dim group, whereas they were higher on the fourth day in the Rich*Bright group. Creatinine-adjusted melatonin in urine showed the same direction as saliva melatonin concentrations. These results indicate that the combination of a tryptophan-rich breakfast and bright light exposure during the daytime could promote melatonin secretion at night; further, the observations that the Rich*Bright group had higher melatonin concentrations than the Rich*Dim group, despite no significant differences being observed between the Poor*Dim and Rich*Dim groups nor the Poor*Bright and Rich*Bright groups, suggest that bright light exposure in the daytime is an important contributor to raised melatonin levels in the evening. This study is the first to report the quantitative effects of changed tryptophan intake at breakfast combined with daytime light exposure on melatonin secretion and sleep quality. Evening saliva melatonin secretion changed significantly and indicated that a tryptophan-rich breakfast and bright light exposure during the daytime promoted melatonin secretion at this time.

Liquid crystal based optical platform for the detection of Pb2+ ions using NiFe2O4 nanoparticles

NASA Astrophysics Data System (ADS)

Zehra, Saman; Gul, Iftikhar Hussain; Hussain, Zakir

2018-06-01

A simple, sensitive, selective and real time detection protocol was developed for Pb2+ ions in water using liquid crystals (LCs). In this method, NiFe2O4 nanoparticles were synthesized using chemical co-precipitation method. Crystallite size, morphological, functional groups and magnetization studies were confirmed using X-ray diffraction, Scanning Electron Microscopy, and Fourier transform infrared spectroscopy techniques, respectively. The nanoparticles were mono dispersed with average particle size of 20 ± 2 nm. The surfactant stabilized magnetic nanoparticles were incubated in liquid crystal based sensor system for the detection of Pb+2 ions. The bright to dark transition of LC was observed through optical microscope. When this system was further immersed with a solution containing Pb2+ ions, it caused homeotropic to planar orientation of LC. This interaction is attributed to the presence of abundant hydroxyl groups in such as M-OH, Fe-OH on the surface of spinel ferrites nanoparticles. These groups interact with metal ions at aqueous interface, causing disruption in LCs orientation giving bright texture. This sensor showed higher selectivity towards Pb2+ ions. The detection limit was estimated to be 100 ppb. The cheap and effective protocol reported here should make promising development of LC based sensor for lead ion detection.

Bright ideas. Some rules of thumb for interior lighting design and selection.

PubMed

Hunter, Claudia M

2002-07-01

Interior lighting design and selection can be a demanding assignment for a health facilities manager or department head. It requires a balance between conflicting needs, such as providing good task lighting for a nursing station while also shielding luminaires that are visible from patients' rooms to avoid glare.

Acute effects of bright light and caffeine on nighttime melatonin and temperature levels in women taking and not taking oral contraceptives

NASA Technical Reports Server (NTRS)

Wright, K. P. Jr; Myers, B. L.; Plenzler, S. C.; Drake, C. L.; Badia, P.; Czeisler, C. A. (Principal Investigator)

2000-01-01

Caffeine and bright light effects on nighttime melatonin and temperature levels in women were tested during the luteal phase of the menstrual cycle (n=30) or the pseudo luteal phase for oral contraceptive users (n=32). Participants were randomly assigned to receive either bright (5000 lux) or dim room light (<88 lux) between 20:00 and 08:00 h under a modified constant routine protocol. Half the subjects in each lighting condition were administered either caffeine (100 mg) or placebo in a double-blind manner at 20:00, 23:00, 02:00 and 05:00 h. Results showed that the combination of bright light and caffeine enhanced nighttime temperature levels to a greater extent than did either caffeine or bright light alone. Both of the latter groups had higher temperature levels relative to the dim light placebo condition and the two groups did not differ. Temperature levels in the bright light caffeine condition were maintained at near peak circadian levels the entire night in the luteal and pseudo luteal phase. Melatonin levels were reduced throughout the duration of bright light exposure for all women. Caffeine reduced the onset of melatonin levels for women in the luteal phase, but it had little effect on melatonin levels for oral contraceptive users. The results for women in the luteal phase of the menstrual cycle are consistent with our previous findings in men. The results also suggest that oral contraceptives may alter the effects of caffeine on nighttime melatonin levels.

Acute Effects of Morning Light on Plasma Glucose and Triglycerides in Healthy Men and Men with Type 2 Diabetes

PubMed Central

Versteeg, Ruth I.; Stenvers, Dirk J.; Visintainer, Dana; Linnenbank, Andre; Tanck, Michael W.; Zwanenburg, Gooitzen; Smilde, Age K.; Fliers, Eric; Kalsbeek, Andries; Serlie, Mireille J.; la Fleur, Susanne E.; Bisschop, Peter H.

2017-01-01

Ambient light intensity is signaled directly to hypothalamic areas that regulate energy metabolism. Observational studies have shown associations between ambient light intensity and plasma glucose and lipid levels, but human data on the acute metabolic effects of light are scarce. Since light is the main signal indicating the onset of the diurnal phase of physical activity and food intake in humans, we hypothesized that bright light would affect glucose and lipid metabolism. Therefore, we determined the acute effects of bright light on plasma glucose and lipid concentrations in 2 randomized crossover trials: (1) in 8 healthy lean men and (2) in 8 obese men with type 2 diabetes. From 0730 h, subjects were exposed to either bright light (4000 lux) or dim light (10 lux) for 5 h. After 1 h of light exposure, subjects consumed a 600-kcal mixed meal. Primary endpoints were fasting and postprandial plasma glucose levels. In healthy men, bright light did not affect fasting or postprandial plasma glucose levels. However, bright light increased fasting and postprandial plasma triglycerides. In men with type 2 diabetes, bright light increased fasting and postprandial glucose levels. In men with type 2 diabetes, bright light did not affect fasting triglyceride levels but increased postprandial triglyceride levels. We show that ambient light intensity acutely affects human plasma glucose and triglyceride levels. Our findings warrant further research into the consequences of the metabolic effects of light for the diagnosis and prevention of hyperglycemia and dyslipidemia. PMID:28470119

Tuning optical radiation for visual and nonvisual impact

NASA Astrophysics Data System (ADS)

Royer, Michael P.

2011-12-01

Spectral tuning---the allocation of radiant energy emitted by a lamp---is a fundamental element of illuminating engineering. Proper placement of optical radiation allows for reduced energy consumption, increased brightness perception, and improved color rendition. It can also result in lamps that have a greater impact on nonvisual human functions such as circadian rhythms, sleep, mood, and cognition. For an architectural lighting system, careful consideration must be given to all of these areas; recent advancements in understanding nonvisual photoreception must be balanced with the traditional emphasis on visual quality and energy efficiency. The three research projects described herein investigated spectral tuning by examining the effects of optical radiation or seeking ideal spectral power distributions. In all three cases, emphasis was placed on developing an architectural lighting system based on red, green, and blue (RGB) light emitting diodes (LEDs) that is capable of providing maximum stimulation to nonvisual systems while maintaining visual quality standards. In particular, the elderly were considered as a target population because they have an increased risk of developing disorders linked to illumination deficits. The three endeavors can be summarized as follows: Light Therapy for Seniors in Long-term Care AIM: To examine the effect of optical radiation on circadian rhythms, sleep, mood, and cognition for frail elderly in a long-term care environment. METHODOLOGY: A double-blind, placebo-controlled clinical trial of light therapy was conducted using circadian-effective short-wavelength (blue) optical radiation to treat a sample of residents recruited for participation without bias for existing medical diagnoses. KEY FINDINGS: Light therapy treatment improved cognitive functioning compared to placebo but no changes were detected in nighttime sleep statistics, reports of daytime sleepiness, circadian rhythms, or depression inventory parameters. Perceived Brightness of Trichromatic Light Sources AIM: To examine the effect of tuning optical radiation on brightness perception for younger (18-25 years of age) and older (50 years of age or older) observers. METHODOLOGY: Participants made forced-choice evaluations of the brightness of a full factorial of stimulus pairs selected from two groups of four metameric stimuli. The large-field stimuli were created by systematically varying either the red or the blue primary of an RGB LED mixture. KEY FINDINGS: Light stimuli of equal illuminance and chromaticity do not appear equally bright to either younger or older subjects. The rank-order of brightness is not predicted by any current model of human vision or theory of brightness perception including Scotopic to Photopic or Cirtopic to Photopic ratio theory, prime color theory, correlated color temperature, photometry, color quality metrics, linear brightness models, or color appearance models. Age may affect brightness perception when short-wavelength primaries are used, especially those with a peak wavelength shorter than 450 nm. Optimizing RGB LED Mixtures AIM: To investigate potential tradeoffs between luminous efficacy, nonvisual efficacy, and color quality of RGB LED mixtures when the peak wavelength and full with half maximum of the primaries are varied. To identify mixtures suitable for architectural lighting which provide increased circadian stimulation. METHODOLOGY: Software to calculate the properties of RGB LED mixtures matching the chromaticity of blackbody radiation was developed using Microsoft Excel and Visual Basic. Excel Solver was used to perform a series of optimization routines, identifying high-performing mixtures that were then compared to traditional lamps. KEY FINDINGS: Trichromatic mixtures suitable for architectural interiors can outperform traditional lamps when luminous efficacy, nonvisual efficacy, and color quality are considered simultaneously. However, misplacement of radiant energy can result in poor performing trichromatic systems. When radiant energy is manipulated, tradeoffs may occur between luminous efficacy, nonvisual efficacy, and color quality.

Using the Chandra Source-Finding Algorithm to Automatically Identify Solar X-ray Bright Points

NASA Technical Reports Server (NTRS)

Adams, Mitzi L.; Tennant, A.; Cirtain, J. M.

2009-01-01

This poster details a technique of bright point identification that is used to find sources in Chandra X-ray data. The algorithm, part of a program called LEXTRCT, searches for regions of a given size that are above a minimum signal to noise ratio. The algorithm allows selected pixels to be excluded from the source-finding, thus allowing exclusion of saturated pixels (from flares and/or active regions). For Chandra data the noise is determined by photon counting statistics, whereas solar telescopes typically integrate a flux. Thus the calculated signal-to-noise ratio is incorrect, but we find we can scale the number to get reasonable results. For example, Nakakubo and Hara (1998) find 297 bright points in a September 11, 1996 Yohkoh image; with judicious selection of signal-to-noise ratio, our algorithm finds 300 sources. To further assess the efficacy of the algorithm, we analyze a SOHO/EIT image (195 Angstroms) and compare results with those published in the literature (McIntosh and Gurman, 2005). Finally, we analyze three sets of data from Hinode, representing different parts of the decline to minimum of the solar cycle.

"Smart" theranostic lanthanide nanoprobes with simultaneous up-conversion fluorescence and tunable T1-T2 magnetic resonance imaging contrast and near-infrared activated photodynamic therapy.

PubMed

Zhang, Yan; Das, Gautom Kumar; Vijayaragavan, Vimalan; Xu, Qing Chi; Padmanabhan, Parasuraman; Bhakoo, Kishore K; Selvan, Subramanian Tamil; Tan, Timothy Thatt Yang

2014-11-07

The current work reports a type of "smart" lanthanide-based theranostic nanoprobe, NaDyF4:Yb(3+)/NaGdF4:Yb(3+),Er(3+), which is able to circumvent the up-converting poisoning effect of Dy(3+) ions to give efficient near infrared (980 nm) triggered up-conversion fluorescence, and offers not only excellent dark T2-weighted MR contrast but also tunable bright and T1-weighted MR contrast properties. Due to the efficient up-converted energy transfer from the nanocrystals to chlorin e6 (Ce6) photosensitizers loaded onto the nanocrystals, cytotoxic singlet oxygen was generated and photodynamic therapy was demonstrated. Therefore, the current multifunctional nanocrystals could be potentially useful in various image-guided diagnoses where bright or dark MRI contrast could be selectively tuned to optimize image quality, but also as an efficient and more penetrative near-infrared activated photodynamic therapy agent.

Evolution of the anti-truncated stellar profiles of S0 galaxies since z = 0.6 in the SHARDS survey. I. Sample and methods

NASA Astrophysics Data System (ADS)

Borlaff, Alejandro; Eliche-Moral, M. Carmen; Beckman, John E.; Ciambur, Bogdan C.; Pérez-González, Pablo G.; Barro, Guillermo; Cava, Antonio; Cardiel, Nicolas

2017-08-01

Context. The controversy about the origin of the structure of early-type S0-E/S0 galaxies may be due to the difficulty of comparing surface brightness profiles with different depths, photometric corrections and point spread function (PSF) effects (which are almost always ignored). Aims: We aim to quantify the properties of Type-III (anti-truncated) discs in a sample of S0 galaxies at 0.2

VizieR Online Data Catalog: Galaxies and QSOs FIR size and surface brightness (Lutz+, 2016)

NASA Astrophysics Data System (ADS)

Lutz, D.; Berta, S.; Contursi, A.; Forster Schreiber, N. M.; Genzel, R.; Gracia-Carpio, J.; Herrera-Camus, R.; Netzer, H.; Sturm, E.; Tacconi, L. J.; Tadaki, K.; Veilleux, S.

2016-08-01

We use 70, 100, and 160um images from scan maps obtained with PACS on board Herschel, collecting archival data from various projects. In order to cover a wide range of galaxy properties, we first obtain an IR-selected local sample ranging from normal galaxies up to (ultra)luminous infrared galaxies. For that purpose, we searched the Herschel archive for all cz>=2000km/s objects from the IRAS Revised Bright Galaxy Sample (RBGS, Sanders et al., 2003, Cat. J/AJ/126/1607). (1 data file).

BROADBAND TIME-RESOLVED E{sub p,i}-L{sub iso} CORRELATION IN GAMMA-RAY BURSTS

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

Frontera, F.; Guidorzi, C.; Amati, L.

We report the results of a systematic study of the broadband (2-2000 keV) time-resolved prompt emission spectra of a sample of gamma-ray bursts (GRBs) detected with both Wide Field Cameras on board the BeppoSAX satellite and the BATSE experiment on board CGRO. In this first paper, we study the time-resolved dependence of the intrinsic peak energy E{sub p,i} of the E F(E) spectrum on the corresponding isotropic bolometric luminosity L{sub iso}. The E{sub p,i}-L{sub iso} relation or the equivalent relation between E{sub p,i} and the bolometric released energy E{sub iso}, derived using the time-averaged spectra of long GRBs with knownmore » redshift, is well established, but its physical origin is still a subject of discussion. In addition, some authors maintain that these relations are the result of instrumental selection effects. We find that not only a relation between the measured peak energy E{sub p} and the corresponding energy flux, but also a strong E{sub p,i} versus L{sub iso} correlation are found not only within each burst, but also are merging together the time-resolved data points from different GRBs. We do not expect significant instrumental selection effects that can affect the results obtained, apart from the fact that the GRBs in our sample are sufficiently bright to perform a time-resolved spectroscopy and that they have known redshift. If the fundamental physical process that gives rise to the GRB phenomenon does not depend on its brightness, we conclude that the E{sub p,i} versus L{sub iso} correlation found within each GRB is intrinsic to the emission process and that the correlations discovered by Amati et al. and Yonetoku et al. are likely not the result of selection effects. We also discuss the properties of the correlations found.« less

Micro Coronal Bright Points Observed in the Quiet Magnetic Network by SOHO/EIT

NASA Technical Reports Server (NTRS)

Falconer, D. A.; Moore, R. L.; Porter, J. G.

1997-01-01

When one looks at SOHO/EIT Fe XII images of quiet regions, one can see the conventional coronal bright points (> 10 arcsec in diameter), but one will also notice many smaller faint enhancements in brightness (Figure 1). Do these micro coronal bright points belong to the same family as the conventional bright points? To investigate this question we compared SOHO/EIT Fe XII images with Kitt Peak magnetograms to determine whether the micro bright points are in the magnetic network and mark magnetic bipoles within the network. To identify the coronal bright points, we applied a picture frame filter to the Fe XII images; this brings out the Fe XII network and bright points (Figure 2) and allows us to study the bright points down to the resolution limit of the SOHO/EIT instrument. This picture frame filter is a square smoothing function (hlargelyalf a network cell wide) with a central square (quarter of a network cell wide) removed so that a bright point's intensity does not effect its own background. This smoothing function is applied to the full disk image. Then we divide the original image by the smoothed image to obtain our filtered image. A bright point is defined as any contiguous set of pixels (including diagonally) which have enhancements of 30% or more above the background; a micro bright point is any bright point 16 pixels or smaller in size. We then analyzed the bright points that were fully within quiet regions (0.6 x 0.6 solar radius) centered on disk center on six different days.

Leaf Colour as a Signal of Chemical Defence to Insect Herbivores in Wild Cabbage (Brassica oleracea).

PubMed

Green, Jonathan P; Foster, Rosie; Wilkins, Lucas; Osorio, Daniel; Hartley, Susan E

2015-01-01

Leaf colour has been proposed to signal levels of host defence to insect herbivores, but we lack data on herbivory, leaf colour and levels of defence for wild host populations necessary to test this hypothesis. Such a test requires measurements of leaf spectra as they would be sensed by herbivore visual systems, as well as simultaneous measurements of chemical defences and herbivore responses to leaf colour in natural host-herbivore populations. In a large-scale field survey of wild cabbage (Brassica oleracea) populations, we show that variation in leaf colour and brightness, measured according to herbivore spectral sensitivities, predicts both levels of chemical defences (glucosinolates) and abundance of specialist lepidopteran (Pieris rapae) and hemipteran (Brevicoryne brassicae) herbivores. In subsequent experiments, P. rapae larvae achieved faster growth and greater pupal mass when feeding on plants with bluer leaves, which contained lower levels of aliphatic glucosinolates. Glucosinolate-mediated effects on larval performance may thus contribute to the association between P. rapae herbivory and leaf colour observed in the field. However, preference tests found no evidence that adult butterflies selected host plants based on leaf coloration. In the field, B. brassicae abundance varied with leaf brightness but greenhouse experiments were unable to identify any effects of brightness on aphid preference or performance. Our findings suggest that although leaf colour reflects both levels of host defences and herbivore abundance in the field, the ability of herbivores to respond to colour signals may be limited, even in species where performance is correlated with leaf colour.

Leaf Colour as a Signal of Chemical Defence to Insect Herbivores in Wild Cabbage (Brassica oleracea)

PubMed Central

Wilkins, Lucas; Osorio, Daniel; Hartley, Susan E.

2015-01-01

Leaf colour has been proposed to signal levels of host defence to insect herbivores, but we lack data on herbivory, leaf colour and levels of defence for wild host populations necessary to test this hypothesis. Such a test requires measurements of leaf spectra as they would be sensed by herbivore visual systems, as well as simultaneous measurements of chemical defences and herbivore responses to leaf colour in natural host-herbivore populations. In a large-scale field survey of wild cabbage (Brassica oleracea) populations, we show that variation in leaf colour and brightness, measured according to herbivore spectral sensitivities, predicts both levels of chemical defences (glucosinolates) and abundance of specialist lepidopteran (Pieris rapae) and hemipteran (Brevicoryne brassicae) herbivores. In subsequent experiments, P. rapae larvae achieved faster growth and greater pupal mass when feeding on plants with bluer leaves, which contained lower levels of aliphatic glucosinolates. Glucosinolate-mediated effects on larval performance may thus contribute to the association between P. rapae herbivory and leaf colour observed in the field. However, preference tests found no evidence that adult butterflies selected host plants based on leaf coloration. In the field, B. brassicae abundance varied with leaf brightness but greenhouse experiments were unable to identify any effects of brightness on aphid preference or performance. Our findings suggest that although leaf colour reflects both levels of host defences and herbivore abundance in the field, the ability of herbivores to respond to colour signals may be limited, even in species where performance is correlated with leaf colour. PMID:26353086

Afternoon nap and bright light exposure improve cognitive flexibility post lunch.

PubMed

Slama, Hichem; Deliens, Gaétane; Schmitz, Rémy; Peigneux, Philippe; Leproult, Rachel

2015-01-01

Beneficial effects of napping or bright light exposure on cognitive performance have been reported in participants exposed to sleep loss. Nonetheless, few studies investigated the effect of these potential countermeasures against the temporary drop in performance observed in mid-afternoon, and even less so on cognitive flexibility, a crucial component of executive functions. This study investigated the impact of either an afternoon nap or bright light exposure on post-prandial alterations in task switching performance in well-rested participants. Twenty-five healthy adults participated in two randomized experimental conditions, either wake versus nap (n=15), or bright light versus placebo (n=10). Participants were tested on a switching task three times (morning, post-lunch and late afternoon sessions). The interventions occurred prior to the post-lunch session. In the nap/wake condition, participants either stayed awake watching a 30-minute documentary or had the opportunity to take a nap for 30 minutes. In the bright light/placebo condition, participants watched a documentary under either bright blue light or dim orange light (placebo) for 30 minutes. The switch cost estimates cognitive flexibility and measures task-switching efficiency. Increased switch cost scores indicate higher difficulties to switch between tasks. In both control conditions (wake or placebo), accuracy switch-cost score increased post lunch. Both interventions (nap or bright light) elicited a decrease in accuracy switch-cost score post lunch, which was associated with diminished fatigue and decreased variability in vigilance. Additionally, there was a trend for a post-lunch benefit of bright light with a decreased latency switch-cost score. In the nap group, improvements in accuracy switch-cost score were associated with more NREM sleep stage N1. Thus, exposure to bright light during the post-lunch dip, a countermeasure easily applicable in daily life, results in similar beneficial effects as a short nap on performance in the cognitive flexibility domain with possible additional benefits on latency switch-cost scores.

Afternoon Nap and Bright Light Exposure Improve Cognitive Flexibility Post Lunch

PubMed Central

Schmitz, Rémy; Peigneux, Philippe; Leproult, Rachel

2015-01-01

Beneficial effects of napping or bright light exposure on cognitive performance have been reported in participants exposed to sleep loss. Nonetheless, few studies investigated the effect of these potential countermeasures against the temporary drop in performance observed in mid-afternoon, and even less so on cognitive flexibility, a crucial component of executive functions. This study investigated the impact of either an afternoon nap or bright light exposure on post-prandial alterations in task switching performance in well-rested participants. Twenty-five healthy adults participated in two randomized experimental conditions, either wake versus nap (n=15), or bright light versus placebo (n=10). Participants were tested on a switching task three times (morning, post-lunch and late afternoon sessions). The interventions occurred prior to the post-lunch session. In the nap/wake condition, participants either stayed awake watching a 30-minute documentary or had the opportunity to take a nap for 30 minutes. In the bright light/placebo condition, participants watched a documentary under either bright blue light or dim orange light (placebo) for 30 minutes. The switch cost estimates cognitive flexibility and measures task-switching efficiency. Increased switch cost scores indicate higher difficulties to switch between tasks. In both control conditions (wake or placebo), accuracy switch-cost score increased post lunch. Both interventions (nap or bright light) elicited a decrease in accuracy switch-cost score post lunch, which was associated with diminished fatigue and decreased variability in vigilance. Additionally, there was a trend for a post-lunch benefit of bright light with a decreased latency switch-cost score. In the nap group, improvements in accuracy switch-cost score were associated with more NREM sleep stage N1. Thus, exposure to bright light during the post-lunch dip, a countermeasure easily applicable in daily life, results in similar beneficial effects as a short nap on performance in the cognitive flexibility domain with possible additional benefits on latency switch-cost scores. PMID:26016658

Landmarks selection in street map design

NASA Astrophysics Data System (ADS)

Kao, C. J.

2014-02-01

In Taiwan many electrical maps present their landmarks according to the category of the feature, a designer short of knowledge about mental representation of space, can cause the map to lose its communication effects. To resolve this map design problem, in this research through long-term memory recall, navigation and observation, and short-term memory processing 111 participants were asked to select the proper landmark from study area. The results reveal that in Taiwan convenience stores are the most popular local landmark in rural and urban areas. Their commercial signs have a unique design and bright color. Contrasted to their background, this makes the convenience store a salient feature. This study also developed a rule to assess the priority of the landmarks to design them in different scale maps.

A Systematic Review of Bright Light Therapy for Eating Disorders.

PubMed

Beauchamp, Marshall T; Lundgren, Jennifer D

2016-10-27

Bright light therapy is a noninvasive biological intervention for disorders with nonnormative circadian features. Eating disorders, particularly those with binge-eating and night-eating features, have documented nonnormative circadian eating and mood patterns, suggesting that bright light therapy may be an efficacious stand-alone or adjunctive intervention. The purpose of this systematic literature review, using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, was (1) to evaluate the state of the empirical treatment outcome literature on bright light therapy for eating disorders and (2) to explore the timing of eating behavior, mood, and sleep-related symptom change so as to understand potential mechanisms of bright light therapy action in the context of eating disorder treatment. A comprehensive literature search using PsycInfo and PubMed/MEDLINE was conducted in April 2016 with no date restrictions to identify studies published using bright light therapy as a treatment for eating disorders. Keywords included combinations of terms describing disordered eating (eating disorder, anorexia nervosa, bulimia nervosa, binge eating, binge, eating behavior, eating, and night eating) and the use of bright light therapy (bright light therapy, light therapy, phototherapy). After excluding duplicates, 34 articles were reviewed for inclusion. 14 published studies of bright light therapy for eating disorders met inclusion criteria (included participants with an eating disorder/disordered-eating behaviors; presented as a case study, case series, open-label clinical trial, or randomized/nonrandomized controlled trial; written in English; and published and available by the time of manuscript review). Results suggest that bright light therapy is potentially effective at improving both disordered-eating behavior and mood acutely, although the timing of symptom response and the duration of treatment effects remain unknown. Future research should systematically control for placebo response, assess symptom change frequently and across a broad range of systems, and evaluate the longer-term efficacy of bright light therapy for eating disorders. © Copyright 2016 Physicians Postgraduate Press, Inc.

Correlations among the properties of galaxies found in a blind HI survey, which also have SDSS optical data

NASA Astrophysics Data System (ADS)

Garcia-Appadoo, D. A.; West, A. A.; Dalcanton, J. J.; Cortese, L.; Disney, M. J.

2009-03-01

We have used the Parkes Multibeam system and the Sloan Digital Sky Survey to assemble a sample of 195 galaxies selected originally from their HI signature to avoid biases against unevolved or low surface brightness objects. For each source nine intrinsic properties are measured homogeneously, as well as inclination and an optical spectrum. The sample, which should be almost entirely free of either misidentification or confusion, includes a wide diversity of galaxies ranging from inchoate, low surface brightness dwarfs to giant spirals. Despite this diversity there are five clear correlations among their properties. They include a common dynamical mass-to-light ratio within their optical radii, a correlation between surface brightness and luminosity and a common HI surface density. Such correlation should provide strong constrains on models of galaxy formation and evolution.

Assessment of mesoscale convective systems using IR brightness temperature in the southwest of Iran

NASA Astrophysics Data System (ADS)

Rafati, Somayeh; Karimi, Mostafa

2017-07-01

In this research, the spatial and temporal distribution of Mesoscale Convective Systems was assessed in the southwest of Iran using Global merged satellite IR brightness temperature (acquired from Meteosat, GOES, and GMS geostationary satellites) and synoptic station data. Event days were selected using a set of storm reports and precipitation criteria. The following criteria are used to determine the days with occurrence of convective systems: (1) at least one station reported 6-h precipitation exceeding 10 mm and (2) at least three stations reported phenomena related to convection (thunderstorm, lightning, and shower). MCSs were detected based on brightness temperature, maximum areal extent, and duration thresholds (228 K, 10,000 km2, and 3 h, respectively). An MCS occurrence classification system is developed based on mean sea level, 850 and 500 hPa pressure patterns.

Spectral and spatial selectivity of luminance vision in reef fish

PubMed Central

Siebeck, Ulrike E.; Wallis, Guy Michael; Litherland, Lenore; Ganeshina, Olga; Vorobyev, Misha

2014-01-01

Luminance vision has high spatial resolution and is used for form vision and texture discrimination. In humans, birds and bees luminance channel is spectrally selective—it depends on the signals of the long-wavelength sensitive photoreceptors (bees) or on the sum of long- and middle-wavelength sensitive cones (humans), but not on the signal of the short-wavelength sensitive (blue) photoreceptors. The reasons of such selectivity are not fully understood. The aim of this study is to reveal the inputs of cone signals to high resolution luminance vision in reef fish. Sixteen freshly caught damselfish, Pomacentrus amboinensis, were trained to discriminate stimuli differing either in their color or in their fine patterns (stripes vs. cheques). Three colors (“bright green”, “dark green” and “blue”) were used to create two sets of color and two sets of pattern stimuli. The “bright green” and “dark green” were similar in their chromatic properties for fish, but differed in their lightness; the “dark green” differed from “blue” in the signal for the blue cone, but yielded similar signals in the long-wavelength and middle-wavelength cones. Fish easily learned to discriminate “bright green” from “dark green” and “dark green” from “blue” stimuli. Fish also could discriminate the fine patterns created from “dark green” and “bright green”. However, fish failed to discriminate fine patterns created from “blue” and “dark green” colors, i.e., the colors that provided contrast for the blue-sensitive photoreceptor, but not for the long-wavelength sensitive one. High resolution luminance vision in damselfish, Pomacentrus amboinensis, does not have input from the blue-sensitive cone, which may indicate that the spectral selectivity of luminance channel is a general feature of visual processing in both aquatic and terrestrial animals. PMID:25324727

A multifrequency evaluation of active and passive microwave sensors for oil spill detection and assessment

NASA Technical Reports Server (NTRS)

Fenner, R. G.; Reid, S. C.; Solie, C. H.

1980-01-01

An evaluation is given of how active and passive microwave sensors can best be used in oil spill detection and assessment. Radar backscatter curves taken over oil spills are presented and their effect on synthetic aperture radar (SAR) imagery are discussed. Plots of microwave radiometric brightness variations over oil spills are presented and discussed. Recommendations as to how to select the best combination of frequency, viewing angle, and sensor type for evaluation of various aspects of oil spills are also discussed.

Optical Selection Rule of Excitons in Gapped Chiral Fermion Systems

NASA Astrophysics Data System (ADS)

Zhang, Xiaoou; Shan, Wen-Yu; Xiao, Di

2018-02-01

We show that the exciton optical selection rule in gapped chiral fermion systems is governed by their winding number w , a topological quantity of the Bloch bands. Specifically, in a CN-invariant chiral fermion system, the angular momentum of bright exciton states is given by w ±1 +n N with n being an integer. We demonstrate our theory by proposing two chiral fermion systems capable of hosting dark s -like excitons: gapped surface states of a topological crystalline insulator with C4 rotational symmetry and biased 3 R -stacked MoS2 bilayers. In the latter case, we show that gating can be used to tune the s -like excitons from bright to dark by changing the winding number. Our theory thus provides a pathway to electrical control of optical transitions in two-dimensional material.

Photometric redshifts and clustering of emission line galaxies selected jointly by DES and eBOSS

DOE PAGES

Jouvel, S.; Delubac, T.; Comparat, J.; ...

2017-03-24

We present the results of the first test plates of the extended Baryon Oscillation Spectroscopic Survey. This paper focuses on the emission line galaxies (ELG) population targetted from the Dark Energy Survey (DES) photometry. We analyse the success rate, efficiency, redshift distribution, and clustering properties of the targets. From the 9000 spectroscopic redshifts targetted, 4600 have been selected from the DES photometry. The total success rate for redshifts between 0.6 and 1.2 is 71\\% and 68\\% respectively for a bright and faint, on average more distant, samples including redshifts measured from a single strong emission line. We find a meanmore » redshift of 0.8 and 0.87, with 15 and 13\\% of unknown redshifts respectively for the bright and faint samples. In the redshift range 0.6« less

Photometric redshifts and clustering of emission line galaxies selected jointly by DES and eBOSS

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

Jouvel, S.; Delubac, T.; Comparat, J.

We present the results of the first test plates of the extended Baryon Oscillation Spectroscopic Survey. This paper focuses on the emission line galaxies (ELG) population targetted from the Dark Energy Survey (DES) photometry. We analyse the success rate, efficiency, redshift distribution, and clustering properties of the targets. From the 9000 spectroscopic redshifts targetted, 4600 have been selected from the DES photometry. The total success rate for redshifts between 0.6 and 1.2 is 71\\% and 68\\% respectively for a bright and faint, on average more distant, samples including redshifts measured from a single strong emission line. We find a meanmore » redshift of 0.8 and 0.87, with 15 and 13\\% of unknown redshifts respectively for the bright and faint samples. In the redshift range 0.6« less

H{sub 2}O Megamasers toward Radio-bright Seyfert 2 Nuclei

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

Zhang, J. S.; Liu, Z. W.; Henkel, C.

2017-02-20

Using the Effelsberg-100 m telescope, we perform a successful pilot survey on H{sub 2}O maser emission toward a small sample of radio-bright Seyfert 2 galaxies with a redshift larger than 0.04. The targets were selected from a large Seyfert 2 sample derived from the spectroscopic Sloan Digital Sky Survey Data Release 7 (SDSS-DR7). One source, SDSS J102802.9+104630.4 ( z ∼ 0.0448), was detected four times during our observations, with a typical maser flux density of ∼30 mJy and a corresponding (very large) luminosity of ∼1135 L {sub ⊙}. The successful detection of this radio-bright Seyfert 2 and an additional tentativemore » detection support our previous statistical results that H{sub 2}O megamasers tend to arise from Seyfert 2 galaxies with large radio luminosity. The finding provides further motivation for an upcoming larger H{sub 2}O megamaser survey toward Seyfert 2s with particularly radio-bright nuclei with the basic goal to improve our understanding of the nuclear environment of active megamaser host galaxies.« less

Assessment of using digital manipulation tools for diagnosing mandibular radiolucent lesions

PubMed Central

Raitz, R; Assunção Junior, JNR; Fenyo-Pereira, M; Correa, L; de Lima, LP

2012-01-01

Objective The purpose of this study was to analyse the use of digital tools for image enhancement of mandibular radiolucent lesions and the effects of this manipulation on the percentage of correct radiographic diagnoses. Methods 24 panoramic radiographs exhibiting radiolucent lesions were selected, digitized and evaluated by non-experts (undergraduate and newly graduated practitioners) and by professional experts in oral diagnosis. The percentages of correct and incorrect diagnoses, according to the use of brightness/contrast, sharpness, inversion, highlight and zoom tools, were compared. All dental professionals made their evaluations without (T1) and with (T2) a list of radiographic diagnostic parameters. Results Digital tools were used with low frequency mainly in T2. The most preferred tool was sharpness (45.2%). In the expert group, the percentage of correct diagnoses did not change when any of the digital tools were used. For the non-expert group, there was an increase in the frequency of correct diagnoses when brightness/contrast was used in T2 (p=0.008) and when brightness/contrast and sharpness were not used in T1 (p=0.027). The use or non-use of brightness/contrast, zoom and sharpness showed moderate agreement in the group of experts [kappa agreement coefficient (κ)=0.514, 0.425 and 0.335, respectively]. For the non-expert group there was slight agreement for all the tools used (κ≤0.237). Conclusions Consulting the list of radiographic parameters before image manipulation reduced the frequency of tool use in both groups of examiners. Consulting the radiographic parameters with the use of some digital tools was important for improving correct diagnosis only in the group of non-expert examiners. PMID:22116126

Assessment of using digital manipulation tools for diagnosing mandibular radiolucent lesions.

PubMed

Raitz, R; Assunção Junior, J N R; Fenyo-Pereira, M; Correa, L; de Lima, L P

2012-03-01

The purpose of this study was to analyse the use of digital tools for image enhancement of mandibular radiolucent lesions and the effects of this manipulation on the percentage of correct radiographic diagnoses. 24 panoramic radiographs exhibiting radiolucent lesions were selected, digitized and evaluated by non-experts (undergraduate and newly graduated practitioners) and by professional experts in oral diagnosis. The percentages of correct and incorrect diagnoses, according to the use of brightness/contrast, sharpness, inversion, highlight and zoom tools, were compared. All dental professionals made their evaluations without (T₁) and with (T₂) a list of radiographic diagnostic parameters. Digital tools were used with low frequency mainly in T₂. The most preferred tool was sharpness (45.2%). In the expert group, the percentage of correct diagnoses did not change when any of the digital tools were used. For the non-expert group, there was an increase in the frequency of correct diagnoses when brightness/contrast was used in T₂ (p=0.008) and when brightness/contrast and sharpness were not used in T₁ (p=0.027). The use or non-use of brightness/contrast, zoom and sharpness showed moderate agreement in the group of experts [kappa agreement coefficient (κ) = 0.514, 0.425 and 0.335, respectively]. For the non-expert group there was slight agreement for all the tools used (κ ≤ 0.237). Consulting the list of radiographic parameters before image manipulation reduced the frequency of tool use in both groups of examiners. Consulting the radiographic parameters with the use of some digital tools was important for improving correct diagnosis only in the group of non-expert examiners.

Interferon-γ production by tubulointerstitial human CD56bright natural killer cells contributes to renal fibrosis and chronic kidney disease progression.

PubMed

Law, Becker M P; Wilkinson, Ray; Wang, Xiangju; Kildey, Katrina; Lindner, Mae; Rist, Melissa J; Beagley, Kenneth; Healy, Helen; Kassianos, Andrew J

2017-07-01

Natural killer (NK) cells are a population of lymphoid cells that play a significant role in mediating innate immune responses. Studies in mice suggest a pathological role for NK cells in models of kidney disease. In this study, we characterized the NK cell subsets present in native kidneys of patients with tubulointerstitial fibrosis, the pathological hallmark of chronic kidney disease. Significantly higher numbers of total NK cells (CD3 - CD56 + ) were detected in renal biopsies with tubulointerstitial fibrosis compared with diseased biopsies without fibrosis and healthy kidney tissue using multi-color flow cytometry. At a subset level, both the CD56 dim NK cell subset and particularly the CD56 bright NK cell subset were elevated in fibrotic kidney tissue. However, only CD56 bright NK cells significantly correlated with the loss of kidney function. Expression of the tissue-retention and -activation molecule CD69 on CD56 bright NK cells was significantly increased in fibrotic biopsy specimens compared with non-fibrotic kidney tissue, indicative of a pathogenic phenotype. Further flow cytometric phenotyping revealed selective co-expression of activating receptor CD335 (NKp46) and differentiation marker CD117 (c-kit) on CD56 bright NK cells. Multi-color immunofluorescent staining of fibrotic kidney tissue localized the accumulation of NK cells within the tubulointerstitium, with CD56 bright NK cells (NKp46 + CD117 + ) identified as the source of pro-inflammatory cytokine interferon-γ within the NK cell compartment. Thus, activated interferon-γ-producing CD56 bright NK cells are positioned to play a key role in the fibrotic process and progression to chronic kidney disease. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

The large bright quasar survey. 6: Quasar catalog and survey parameters

NASA Astrophysics Data System (ADS)

Hewett, Paul C.; Foltz, Craig B.; Chaffee, Frederic H.

1995-04-01

Positions, redshifts, and magnitudes for the 1055 quasars in the Large Bright Quasar Survey (LBQS) are presented in a single catalog. Celestial positions have been derived using the PPM catalog to provide an improved reference frame. J2000.0 coordinates are given together with improved b1950.0 positions. Redshifts calculated via cross correlation with a high signal-to-noise ratio composite quasar spectrum are included and the small number of typographic and redshift misidentifications in the discovery papers are corrected. Spectra of the 12 quasars added to the sample since the publication of the discovery papers are included. Discriptions of the plate material, magnitude calibration, quasar candidate selection procedures, and the identification spectroscopy are given. Calculation of the effective area of the survey for the 1055 quasars comprising the well-defined LBQS sample specified in detail. Number-redshift and number-magnitude relations for the quasars are derived and the strengths and limitastions of the LBSQ sample summarized. Comparison with existing surveys is made and a qualitative assessment of the effectiveness of the LBQS undertaken. Positions, magnitudes, and optical spectra of the eight objects (less than 1%) in the survey that remain unidentified are also presented.

Advancing Leadership in Sport: Time to Take Off the Blinkers?

PubMed

Cruickshank, Andrew; Collins, Dave

2016-09-01

While leadership is one of the most significant factors in sport, most research has focused on who effective leaders are and what they overtly do rather than why and how they lead in a certain way at a certain time. Presumably shaped by social norms, the bulk of this work has also overstated the role of bright (or socially desirable) leadership intentions and behaviours; or at least overlooked how this style fits with the 'darker' (or socially undesirable) intentions and behaviours that are prevalent and effective in applied practice. Contextualising this situation against the origins and dominant paradigms of sport-specific study, we therefore highlight the need for greater emphasis on both the cognitive and dark sides of leadership. Regarding the former, we argue that expert leadership requires cognitive excellence given that optimal and consistent impact requires the conscious selection, combination and deployment of leadership behaviours. Regarding the latter, we also argue that bright intentions and behaviours can often only be a part of an effective leadership repertoire and can beneficially operate in tandem with inherently dark alternatives. To advance knowledge and practice, we therefore call for a more pragmatic approach to research that considers both the cognitive mechanisms-namely professional judgement and decision making-and the full spectrum of intentions and behaviours that underpin real world leadership.

Bright-light mask treatment of delayed sleep phase syndrome.

PubMed

Cole, Roger J; Smith, Julian S; Alcalá, Yvonne C; Elliott, Jeffrey A; Kripke, Daniel F

2002-02-01

We treated delayed sleep phase syndrome (DSPS) with an illuminated mask that provides light through closed eyelids during sleep. Volunteers received either bright white light (2,700 lux, n = 28) or dim red light placebo (0.1 lux, n = 26) for 26 days at home. Mask lights were turned on (< 0.01 lux) 4 h before arising, ramped up for 1 h, and remained on at full brightness until arising. Volunteers also attempted to systematically advance sleep time, avoid naps, and avoid evening bright light. The light mask was well tolerated and produced little sleep disturbance. The acrophase of urinary 6-sulphatoxymelatonin (6-SMT) excretion advanced significantly from baseline in the bright group (p < 0.0006) and not in the dim group, but final phases were not significantly earlier in the bright group (ANCOVA ns). Bright treatment did produce significantly earlier phases, however, among volunteers whose baseline 6-SMT acrophase was later than the median of 0602 h (bright shift: 0732-0554 h, p < 0.0009; dim shift: 0746-0717 h, ns; ANCOVA p = 0.03). In this subgroup, sleep onset advanced significantly only with bright but not dim treatment (sleep onset shift: bright 0306-0145 h, p < 0.0002; dim 0229-0211 h, ns; ANCOVA p < .05). Despite equal expectations at baseline, participants rated bright treatment as more effective than dim treatment (p < 0.04). We conclude that bright-light mask treatment advances circadian phase and provides clinical benefit in DSPS individuals whose initial circadian delay is relatively severe.

Building detection in SAR imagery

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

Steinbach, Ryan Matthew

Current techniques for building detection in Synthetic Aperture Radar (SAR) imagery can be computationally expensive and/or enforce stringent requirements for data acquisition. I present two techniques that are effective and efficient at determining an approximate building location. This approximate location can be used to extract a portion of the SAR image to then perform a more robust detection. The proposed techniques assume that for the desired image, bright lines and shadows, SAR artifact effects, are approximately labeled. These labels are enhanced and utilized to locate buildings, only if the related bright lines and shadows can be grouped. In order tomore » find which of the bright lines and shadows are related, all of the bright lines are connected to all of the shadows. This allows the problem to be solved from a connected graph viewpoint, where the nodes are the bright lines and shadows and the arcs are the connections between bright lines and shadows. For the first technique, constraints based on angle of depression and the relationship between connected bright lines and shadows are applied to remove unrelated arcs. The second technique calculates weights for the connections and then performs a series of increasingly relaxed hard and soft thresholds. This results in groups of various levels on their validity. Once the related bright lines and shadows are grouped, their locations are combined to provide an approximate building location. Experimental results demonstrate the outcome of the two techniques. The two techniques are compared and discussed.« less

C57 mice increase wheel-running behavior following stress: preliminary findings.

PubMed

Sibold, Jeremy S; Hammack, Sayamwong E; Falls, William A

2011-10-01

Exercise has been shown to reduce anxiety in both humans and animals. To date, there are few, if any studies that examine the effect of stress on self-selected exercise using an animal model. This study examined the effect of acute stress on wheel-running distance in mice. Forty 8-week-old, male C57BL/6J mice were randomly assigned to one of three groups: no stress + wheel-running experience, stress + wheel-running experience, or stress with no wheel-running experience. Stressed mice were exposed to foot shock in a brightly lit environment. Following treatment, wheel-running distances were observed for three hours. Stress significantly increased voluntary wheel-running in mice with wheel-running experience as compared to nonstressed controls and stressed mice with no wheel-running experience. These results suggest that mice familiar with wheel-running may self-select this exercise as a modality for the mitigation of accumulated anxiety.

The Evolution of the Galaxy Rest-Frame Ultraviolet Luminosity Function Over the First Two Billion Years

NASA Technical Reports Server (NTRS)

Finkelstein, Steven L.; Ryan, Russell E., Jr.; Papovich, Casey; Dickinson, Mark; Song, Mimi; Somerville, Rachel; Ferguson, Henry C.; Salmon, Brett; Giavalisco, Mauro; Koekomoer, Anton M.;

Bright, Light and Energy Efficient.

ERIC Educational Resources Information Center

American School and University, 1981

1981-01-01

The new Sharon Elementary School in Newburgh (Indiana) has a three-fuel plan that will allow selection of the most economical energy source for each heating season with an energy-efficient lighting system that includes skylights. (Author/MLF)

On correct evaluation techniques of brightness enhancement effect measurement data

NASA Astrophysics Data System (ADS)

Kukačka, Leoš; Dupuis, Pascal; Motomura, Hideki; Rozkovec, Jiří; Kolář, Milan; Zissis, Georges; Jinno, Masafumi

2017-11-01

This paper aims to establish confidence intervals of the quantification of brightness enhancement effects resulting from the use of pulsing bright light. It is found that the methods used so far may yield significant bias in the published results, overestimating or underestimating the enhancement effect. The authors propose to use a linear algebra method called the total least squares. Upon an example dataset, it is shown that this method does not yield biased results. The statistical significance of the results is also computed. It is concluded over an observation set that the currently used linear algebra methods present many patterns of noise sensitivity. Changing algorithm details leads to inconsistent results. It is thus recommended to use the method with the lowest noise sensitivity. Moreover, it is shown that this method also permits one to obtain an estimate of the confidence interval. This paper neither aims to publish results about a particular experiment nor to draw any particular conclusion about existence or nonexistence of the brightness enhancement effect.

Intuitive parameter-free visualization of tumor vascularization using rotating connectivity projections

NASA Astrophysics Data System (ADS)

Wiemker, Rafael; Bülow, Thomas; Opfer, Roland; Kabus, Sven; Dharaiya, Ekta

2008-03-01

We present an effective and intuitive visualization of the macro-vasculature of a selected nodule or tumor in three-dimensional image data (e.g. CT, MR, US). For the differential diagnosis of nodules the possible distortion of adjacent vessels is one important clinical criterion. Surface renderings of vessel- and tumor-segmentations depend critically on the chosen parameter- and threshold-values for the underlying segmentation. Therefore we use rotating Maximum Intensity Projections (MIPs) of a volume of interests (VOI) around the selected tumor. The MIP does not require specific parameters, and allows much quicker visual inspection in comparison to slicewise navigation, while the rotation gives depth cues to the viewer. Of the vessel network within the VOI, however, not all vessels are connected to the selected tumor, and it is tedious to sort out which adjacent vessels are in fact connected and which are overlaid only by projection. Therefore we suggest a simple transformation of the original image values into connectivity values. In the derived connectedness-image each voxel value corresponds to the lowest image value encountered on the highest possible pathway from the tumor to the voxel. The advantage of the visualization is that no implicit binary decision is made whether a certain vessel is connected to the tumor or not, but rather the degree of connectedness is visualized as the brightness of the vessel. Non-connected structures disappear, feebly connected structures appear faint, and strongly connected structures remain in their original brightness. The visualization does not depend on delicate threshold values. Promising results have been achieved for pulmonary nodules in CT.

Surface plasmon resonance based selective and sensitive colorimetric determination of azithromycin using unmodified silver nanoparticles in pharmaceuticals and human plasma

NASA Astrophysics Data System (ADS)

Chavada, Vijay D.; Bhatt, Nejal M.; Sanyal, Mallika; Shrivastav, Pranav S.

2017-01-01

In this article we report a novel method for colorimetric sensing and selective determination of a non-chromophoric drug-azithromycin, which lacks native absorbance in the UV-Visible region using unmodified silver nanoparticles (AgNPs). The citrate-capped AgNps dispersed in water afforded a bright yellow colour owing to the electrostatic repulsion between the particles due to the presence of negatively charged surface and showed surface plasmon resonance (SPR) band at 394 nm. Addition of positively charged azithromycin at a concentration as low as 0.2 μM induced rapid aggregation of AgNPs by neutralizing the negative charge on the particle surface. This phenomenon resulted in the colour change from bright yellow to purple which could be easily observed by the naked eye. This provided a simple platform for rapid determination of azithromycin based on colorimetric measurements. The factors affecting the colorimetric response like pH, volume of AgNPs suspension and incubation time were suitably optimized. The validated method was found to work efficiently in the established concentration range of 0.2-100.0 μM using two different calibration models. The selectivity of the method was also evaluated by analysis of nanoparticles-aggregation response upon addition of several anions, cations and some commonly prescribed antibiotics. The method was successfully applied for the analysis of azithromycin in pharmaceuticals and spiked human plasma samples with good accuracy and precision. The simplicity, efficiency and cost-effectiveness of the method hold tremendous potential for the analysis of such non-chromophoric pharmaceuticals.

Effect of bleaching agent and topical fluoride application on color and gloss of dental ceramics.

PubMed

Pires-de-Souza, Fernanda de Carvalho Panzeri; Contente, Marta Maria Martins Giamatei; Alandia-Román, Carla Cecilia; Vicente, Sergio Augusto de Freitas; Tonani, Rafaella

2016-01-01

The aim of this study was to evaluate the effect of 16% carbamide peroxide and 1.23% acidulated phosphate fluoride application and their association with a change in color (ΔE*) and brightness of dental ceramic submitted to different finishing procedures. A total of 120 test specimens were fabricated and randomly divided into 3 groups (n = 40) according to the type of finishing: glazing; polishing; or polishing and glazing. Initial color and brightness readouts were taken, and the finished specimens were divided into groups (n = 10) according to the treatment to which they were submitted: fluoride; bleaching; bleaching and fluoride; or control. After this, final color and brightness readouts were taken. The type of polishing had no influence on ΔE* or brightness (P > 0.05). Regardless of which solution was used, a decrease in brightness occurred only for the group treated with bleach and fluoride (P < 0.05). The results showed the use of fluoride after bleaching may interfere with the esthetics of a restoration.

Traveling wave and soliton solutions of coupled nonlinear Schrödinger equations with harmonic potential and variable coefficients.

PubMed

Zhong, Wei-Ping; Belić, Milivoj

2010-10-01

Exact traveling wave and soliton solutions, including the bright-bright and dark-dark soliton pairs, are found for the system of two coupled nonlinear Schrödinger equations with harmonic potential and variable coefficients, by employing the homogeneous balance principle and the F-expansion technique. A kind of shape-changing soliton collision is identified in the system. The collision is essentially elastic between the two solitons with opposite velocities. Our results demonstrate that the dynamics of solitons can be controlled by selecting the diffraction, nonlinearity, and gain coefficients.

There Are (super)Giants in the Sky: Searching for Misidentified Massive Stars in Algorithmically-Selected Quasar Catalogs

NASA Astrophysics Data System (ADS)

Dorn-Wallenstein, Trevor Z.; Levesque, Emily

2017-11-01

Thanks to incredible advances in instrumentation, surveys like the Sloan Digital Sky Survey have been able to find and catalog billions of objects, ranging from local M dwarfs to distant quasars. Machine learning algorithms have greatly aided in the effort to classify these objects; however, there are regimes where these algorithms fail, where interesting oddities may be found. We present here an X-ray bright quasar misidentified as a red supergiant/X-ray binary, and a subsequent search of the SDSS quasar catalog for X-ray bright stars misidentified as quasars.

Put on that colour, it fits your emotion: Colour appropriateness as a function of expressed emotion.

PubMed

Dael, Nele; Perseguers, Marie-Noëlle; Marchand, Cynthia; Antonietti, Jean-Philippe; Mohr, Christine

2016-01-01

People associate affective meaning with colour, and this may influence decisions about colours. Hue is traditionally considered the most salient descriptor of colour and colour-affect associations, although colour brightness and saturation seem to have particularly strong affective connotations. To test whether colour choices can be driven by emotion, we investigated whether and how colour hue, brightness, and saturation are systematically associated with bodily expressions of positive (joy) and negative (fear) emotions. Twenty-five non-colour-blind participants viewed videos of these expressions and selected for each video the most appropriate colour using colour sliders providing values for hue, brightness, and saturation. The overall colour choices were congruent with the expressed emotion--that is, participants selected brighter and more saturated colours for joy expressions than for fear expressions. Also, colours along the red-yellow spectrum were deemed more appropriate for joy expressions and cyan-bluish hues for fear expressions. The current study adds further support to the role of emotion in colour choices by (a) showing that emotional information is spontaneously used in an unconstrained choice setting, (b) extending to ecologically valid stimuli occurring in everyday encounters (dressed bodies), and (c) suggesting that all colour parameters are likely to be important when processing affective nonverbal person information, though not independently from each other.

High-efficiency, 154  W CW, diode-pumped Raman fiber laser with brightness enhancement.

PubMed

Glick, Yaakov; Fromzel, Viktor; Zhang, Jun; Ter-Gabrielyan, Nikolay; Dubinskii, Mark

2017-01-20

We demonstrate a high-power, high-efficiency Raman fiber laser pumped directly by laser diode modules at 978 nm. 154 W of CW power were obtained at a wavelength of 1023 nm with an optical to optical efficiency of 65%. A commercial graded-index (GRIN) core fiber acts as the Raman fiber in a power oscillator configuration, which includes spectral selection to prevent generation of the second Stokes. In addition, brightness enhancement of the pump beam by a factor of 8.4 is attained due to the Raman gain distribution profile in the GRIN fiber. To the best of our knowledge this is the highest power and highest efficiency Raman fiber laser demonstrated in any configuration allowing brightness enhancement (i.e., in either cladding-pumped configuration or with GRIN fibers, excluding step-index core pumped), regardless of pumping scheme (i.e., either diode pumped or fiber laser pumped).

Mechanical design and fabrication of the VHF-gun, the Berkeley normal-conducting continuous-wave high-brightness electron source

NASA Astrophysics Data System (ADS)

Wells, R. P.; Ghiorso, W.; Staples, J.; Huang, T. M.; Sannibale, F.; Kramasz, T. D.

2016-02-01

A high repetition rate, MHz-class, high-brightness electron source is a key element in future high-repetition-rate x-ray free electron laser-based light sources. The VHF-gun, a novel low frequency radio-frequency gun, is the Lawrence Berkeley National Laboratory (LBNL) response to that need. The gun design is based on a normal conducting, single cell cavity resonating at 186 MHz in the VHF band and capable of continuous wave operation while still delivering the high accelerating fields at the cathode required for the high brightness performance. The VHF-gun was fabricated and successfully commissioned in the framework of the Advanced Photo-injector EXperiment, an injector built at LBNL to demonstrate the capability of the gun to deliver the required beam quality. The basis for the selection of the VHF-gun technology, novel design features, and fabrication techniques are described.

Mechanical design and fabrication of the VHF-gun, the Berkeley normal-conducting continuous-wave high-brightness electron source.

PubMed

Wells, R P; Ghiorso, W; Staples, J; Huang, T M; Sannibale, F; Kramasz, T D

2016-02-01

A high repetition rate, MHz-class, high-brightness electron source is a key element in future high-repetition-rate x-ray free electron laser-based light sources. The VHF-gun, a novel low frequency radio-frequency gun, is the Lawrence Berkeley National Laboratory (LBNL) response to that need. The gun design is based on a normal conducting, single cell cavity resonating at 186 MHz in the VHF band and capable of continuous wave operation while still delivering the high accelerating fields at the cathode required for the high brightness performance. The VHF-gun was fabricated and successfully commissioned in the framework of the Advanced Photo-injector EXperiment, an injector built at LBNL to demonstrate the capability of the gun to deliver the required beam quality. The basis for the selection of the VHF-gun technology, novel design features, and fabrication techniques are described.

Bright Single InAsP Quantum Dots at Telecom Wavelengths in Position-Controlled InP Nanowires: The Role of the Photonic Waveguide

NASA Astrophysics Data System (ADS)

Haffouz, Sofiane; Zeuner, Katharina D.; Dalacu, Dan; Poole, Philip J.; Lapointe, Jean; Poitras, Daniel; Mnaymneh, Khaled; Wu, Xiaohua; Couillard, Martin; Korkusinski, Marek; Schöll, Eva; Jöns, Klaus D.; Zwiller, Valery; Williams, Robin L.

2018-05-01

We report on the site-selected growth of bright single InAsP quantum dots embedded within InP photonic nanowire waveguides emitting at telecom wavelengths. We demonstrate a dramatic dependence of the emission rate on both the emission wavelength and the nanowire diameter. With an appropriately designed waveguide, tailored to the emission wavelength of the dot, an increase in count rate by nearly two orders of magnitude (0.4kcps to 35kcps) is obtained for quantum dots emitting in the telecom O-band. Using emission-wavelength-optimised waveguides, we demonstrate bright, narrow linewidth emission from single InAsP quantum dots with an unprecedented tuning range from 880nm to 1550nm. These results pave the way towards efficient single photon sources at telecom wavelengths using deterministically grown InAsP/InP nanowire quantum dots.

A complex multi-notch astronomical filter to suppress the bright infrared sky.

PubMed

Bland-Hawthorn, J; Ellis, S C; Leon-Saval, S G; Haynes, R; Roth, M M; Löhmannsröben, H-G; Horton, A J; Cuby, J-G; Birks, T A; Lawrence, J S; Gillingham, P; Ryder, S D; Trinh, C

2011-12-06

A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe, as redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1,000 and 1,800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between them. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8 m telescopes and future 30 m telescopes will open up many new research avenues in the years to come.

To Be or not to Be: Simultaneous Spectroscopy and Photometry of Be Stars

NASA Astrophysics Data System (ADS)

Martin, John C.; O'Brien, J.; Cranford, K.; Gorski, L.; Hubbell-Thomas, J.; Lord, J.; McLain, D.; McLain, J.; Schlaf, E.; Schweighauser, C.

2008-05-01

After decades of study, aspects of the Be phenomenon still defy explanation. It is not clear how some stars are able to change from Be to Be-shell stars when the differences in the models of each type rely on differences in disk inclination with respect to the observer. It is also unclear what mechanism causes some Be stars to periodically cease showing emission in their spectra: thereby, entering a "normal" B star phase. The Barber Observatory at University of Illinois Springfield has embarked on a project to monitor simultaneously the photometry and spectra of selected bright Be and Be-shell stars and identify patterns in the variability of their brightness and line profiles that could provide insight into the Be mechanism. Our pilot study of Be-shell star Psi Per has identified sudden changes in the spectral line profiles that correlate with equally fast changes in V band brightness.

The Feasibility of Using the BrightHearts Biofeedback-Assisted Relaxation Application for the Management of Pediatric Procedural Pain: A Pilot Study.

PubMed

Burton, Karen L O; Morrow, Angela M; Beswick, Brooke V; Khut, George P

2018-04-17

The objective of this pilot study was to assess the acceptability and feasibility of using BrightHearts, a biofeedback-assisted relaxation application (app), in children undergoing painful procedures. Thirty children 7 to 18 years of age undergoing a medical procedure (peripheral blood collection, botulinum toxin injection, or intravenous cannula insertion) participated. Participants used BrightHearts, a heart rate-controlled biofeedback-assisted relaxation training app delivered via an iPad with heart rate measured through a pulse oximeter worn on the ear or thumb. Feasibility was assessed through observations and patient, parent/carer, and healthcare professional feedback. Patient, parent/carer, and healthcare professional satisfaction with BrightHearts was rated using investigator-developed surveys. Eighty-three percent of child participants reported that they found BrightHearts helpful during the procedure and that they would use BrightHearts again. All parents and 96% of healthcare professionals indicated they would use BrightHearts again. Sixty-four percent of healthcare providers perceived that BrightHearts assisted with the ease of performing the procedure. Qualitative analyses found 2 themes: (1) BrightHearts calms through providing distraction and biofeedback and (2) the impact of BrightHearts on the procedure. This pilot study demonstrates the feasibility of using biofeedback-assisted relaxation delivered via the BrightHearts app in children undergoing peripheral blood collection and cannulation. Future studies are required to evaluate BrightHearts' efficacy in reducing pain and anxiety during painful procedures and distinguish the effects of a biofeedback-mediated app from distraction. © 2018 World Institute of Pain.

Sensitivity and Bias in Searches of Cockpit Display of Traffic Information Utilizing Highlighting/Lowlighting

NASA Technical Reports Server (NTRS)

Johnson, Walter W.; Jordan, Kevin; Liao, Min-Ju; Granada, Stacy

2003-01-01

A previous investigation showed that when bright and dim traffic symbols were mixed together on a cockpit display of traffic information, dim targets required longer search times than bright targets. The current experiment utilized Signal Detection methodology to determine the cause of this effect. Two factors were manipulated, Intensity and Mixture. The Intensity manipulation varied whether targets were bright or dim. The Mixture manipulation varied whether the brightness of all aircraft symbols was the same, or if half were bright and half dim. Participants were given 1.25 s to search a display of eight aircraft and determine whether a target was present or absent (50% of the time a target was present) and then rated their confidence in the accuracy of their decision. A Mixture by Intensity repeated-measures ANOVA on the signal detectability measure, A (a non- parametric variant of d ), revealed that targets presented at the dim intensity in the mixed condition yielded significantly lower sensitivity than either of the pure (homogenous) conditions or the bright targets in the mixed condition. There was not a significant difference in False Alarm rates between any conditions, indicating no change in decision criterion. Findings are discussed in terms of possible masking effects evoked by bright aircraft over the dim aircraft. Funding for this work was provided by the Advanced Air Transportation Technologies Project of NASA s Airspace Operation Systems Program.

FluoroMyelin™ Red is a bright, photostable and non-toxic fluorescent stain for live imaging of myelin

PubMed Central

Monsma, Paula C.; Brown, Anthony

2012-01-01

FluoroMyelin™ Red is a commercially available water-soluble fluorescent dye that has selectivity for myelin. This dye is marketed for the visualization of myelin in brain cryosections, though it is also used widely to stain myelin in chemically fixed tissue. Here we have investigated the suitability of FluoroMyelin™ Red as a vital stain for live imaging of myelin in myelinating co-cultures of Schwann cells and dorsal root ganglion neurons. We show that addition of FluoroMyelin™ Red to the culture medium results in selective staining of myelin sheaths, with an optimal staining time of 2 hours, and has no apparent adverse effect on the neurons, their axons, or the myelinating cells at the light microscopic level. The fluorescence is bright and photostable, permitting long-term time-lapse imaging. After rinsing the cultures with medium lacking FluoroMyelin™ Red, the dye diffuses out of the myelin with a half life of about 130 minutes resulting in negligible fluorescence remaining after 18–24 hours. In addition, the large Stokes shift exhibited by FluoroMyelin™ Red makes it possible to readily distinguish it from popular and widely used green and red fluorescent probes such as GFP and mCherry. Thus FluoroMyelin™ Red is a useful reagent for live fluorescence imaging studies on myelinated axons. PMID:22743799

Energy-Saving Tunnel Illumination System Based on LED's Intelligent Control

NASA Astrophysics Data System (ADS)

Guo, Shanshan; Gu, Hanting; Wu, Lan; Jiang, Shuixiu

2011-02-01

At present there is a lot of electric energy wastage in tunnel illumination, whose design is based on the maximum brightness outside and the maximum vehicle speed all year round. LED's energy consumption is low, and the control of its brightness is simple and effective. It can be quickly adjusted between 0-100% of its maximum brightness, and will not affect the service life. Therefore, using LED as tunnel's illumination source, we can achieve a good energy saving effect. According to real-time data acquisition of vehicle speed, traffic flow and brightness outside the tunnel, the auto real-time control of tunnel illumination can be achieved. And the system regulated the LED luminance by means of combination of LED power module and intelligent control module. The tunnel information was detected by inspection equipments, which included luminometer, vehicle detector, and received by RTU(Remote Terminal Unit), then synchronously transmitted to PC. After data processing, RTU emitted the dimming signal to the LED driver to adjust the brightness of LED. Despite the relatively high cost of high-power LED lights, the enormous energy-saving effect and the well-behaved controllability is beyond compare to other lighting devices.

A simple approach to spectrally resolved fluorescence and bright field microscopy over select regions of interest

NASA Astrophysics Data System (ADS)

Dahlberg, Peter D.; Boughter, Christopher T.; Faruk, Nabil F.; Hong, Lu; Koh, Young Hoon; Reyer, Matthew A.; Shaiber, Alon; Sherani, Aiman; Zhang, Jiacheng; Jureller, Justin E.; Hammond, Adam T.

2016-11-01

A standard wide field inverted microscope was converted to a spatially selective spectrally resolved microscope through the addition of a polarizing beam splitter, a pair of polarizers, an amplitude-mode liquid crystal-spatial light modulator, and a USB spectrometer. The instrument is capable of simultaneously imaging and acquiring spectra over user defined regions of interest. The microscope can also be operated in a bright-field mode to acquire absorption spectra of micron scale objects. The utility of the instrument is demonstrated on three different samples. First, the instrument is used to resolve three differently labeled fluorescent beads in vitro. Second, the instrument is used to recover time dependent bleaching dynamics that have distinct spectral changes in the cyanobacteria, Synechococcus leopoliensis UTEX 625. Lastly, the technique is used to acquire the absorption spectra of CH3NH3PbBr3 perovskites and measure differences between nanocrystal films and micron scale crystals.

Artificial light at night confounds broad-scale habitat use by migrating birds

USGS Publications Warehouse

McLaren, James D.; Buler, Jeffrey J.; Schreckengost, Tim; Smolinsky, Jaclyn A.; Boone, Matthew; van Loon, E. Emiel; Dawson, Deanna K.; Walters, Eric L.

2018-01-01

With many of the world's migratory bird populations in alarming decline, broad-scale assessments of responses to migratory hazards may prove crucial to successful conservation efforts. Most birds migrate at night through increasingly light-polluted skies. Bright light sources can attract airborne migrants and lead to collisions with structures, but might also influence selection of migratory stopover habitat and thereby acquisition of food resources. We demonstrate, using multi-year weather radar measurements of nocturnal migrants across the northeastern U.S., that autumnal migrant stopover density increased at regional scales with proximity to the brightest areas, but decreased within a few kilometers of brightly-lit sources. This finding implies broad-scale attraction to artificial light while airborne, impeding selection for extensive forest habitat. Given that high-quality stopover habitat is critical to successful migration, and hindrances during migration can decrease fitness, artificial lights present a potentially heightened conservation concern for migratory bird populations.

A simple approach to spectrally resolved fluorescence and bright field microscopy over select regions of interest.

PubMed

Dahlberg, Peter D; Boughter, Christopher T; Faruk, Nabil F; Hong, Lu; Koh, Young Hoon; Reyer, Matthew A; Shaiber, Alon; Sherani, Aiman; Zhang, Jiacheng; Jureller, Justin E; Hammond, Adam T

2016-11-01

A standard wide field inverted microscope was converted to a spatially selective spectrally resolved microscope through the addition of a polarizing beam splitter, a pair of polarizers, an amplitude-mode liquid crystal-spatial light modulator, and a USB spectrometer. The instrument is capable of simultaneously imaging and acquiring spectra over user defined regions of interest. The microscope can also be operated in a bright-field mode to acquire absorption spectra of micron scale objects. The utility of the instrument is demonstrated on three different samples. First, the instrument is used to resolve three differently labeled fluorescent beads in vitro. Second, the instrument is used to recover time dependent bleaching dynamics that have distinct spectral changes in the cyanobacteria, Synechococcus leopoliensis UTEX 625. Lastly, the technique is used to acquire the absorption spectra of CH 3 NH 3 PbBr 3 perovskites and measure differences between nanocrystal films and micron scale crystals.

A 20 GHz bright sample for δ > 72° - II. Multifrequency follow-up

NASA Astrophysics Data System (ADS)

Ricci, R.; Righini, S.; Verma, R.; Prandoni, I.; Carretti, E.; Mack, K.-H.; Massardi, M.; Procopio, P.; Zanichelli, A.; Gregorini, L.; Mantovani, F.; Gawroński, M. P.; Peel, M. W.

2013-11-01

We present follow-up observations at 5, 8 and 30 GHz of the K-band Northern Wide Survey (KNoWS) 20 GHz Bright Sample, performed with the 32-m Medicina radio telescope and the 32-m Toruń radio telescope. The KNoWS sources were selected in the Northern Polar Cap (δ > 72°) and have a flux density limit S20 GHz = 115 mJy. We include NRAO-VLA Sky Survey 1.4 GHz measurements to derive the source radio spectra between 1.4 and 30 GHz. Based on optical identifications, 68 per cent of the sources are quasars and 27 per cent are radio galaxies. A redshift measurement is available for 58 per cent of the sources. The radio spectral properties of the different source populations are found to be in agreement with those of other high-frequency-selected samples.

Effects of rotation on the nighttime brightness of overhead highway signs utilizing high intensity sheeting.

DOT National Transportation Integrated Search

1974-01-01

As an initial step in the establishment of guidelines for the use of high intensity sheeting on overhead signs, a pilot study was made to investigate the effect of rotation on the average nighttime brightness of signs utilizing this material. Rotatio...

Automatic brightness control of laser spot vision inspection system

NASA Astrophysics Data System (ADS)

Han, Yang; Zhang, Zhaoxia; Chen, Xiaodong; Yu, Daoyin

2009-10-01

The laser spot detection system aims to locate the center of the laser spot after long-distance transmission. The accuracy of positioning laser spot center depends very much on the system's ability to control brightness. In this paper, an automatic brightness control system with high-performance is designed using the device of FPGA. The brightness is controlled by combination of auto aperture (video driver) and adaptive exposure algorithm, and clear images with proper exposure are obtained under different conditions of illumination. Automatic brightness control system creates favorable conditions for positioning of the laser spot center later, and experiment results illuminate the measurement accuracy of the system has been effectively guaranteed. The average error of the spot center is within 0.5mm.

Reduced Phase-Advance of Plasma Melatonin after Bright Morning Light in the Luteal, but not Follicular, Menstrual Cycle Phase in Premenstrual Dysphoric Disorder: An Extended Study

PubMed Central

Parry, Barbara L.; Meliska, Charles J.; Sorenson, Diane L.; Martínez, L. Fernando; López, Ana M.; Elliott, Jeffrey A.; Hauger, Richard L.

2011-01-01

We previously observed blunted phase-shift responses to morning bright light in women with Premenstrual Dysphoric Disorder (PMDD). The aim of this study was to determine if we could replicate these findings using a higher intensity, shorter duration light pulse and to compare these results with the effects of an evening bright light pulse. In 17 PMDD patients and 14 normal control (NC) subjects, we measured plasma melatonin at 30 minute intervals from 18:00–10:00 h in dim (< 30 lux) or dark conditions the night before (night 1) and after (night 3) a bright light pulse (administered on night 2) in both follicular and luteal menstrual cycle phases. The bright light (either 3,000 lux for 6 h or 6,000 lux for 3 h) was given either in the AM, 7 h after the Dim Light Melatonin Onset (DLMO) measured the previous month, or in the PM, 3 h after the DLMO. In the luteal, but not in the follicular, phase, AM light advanced melatonin offset between night 1 and night 3 significantly less in PMDD than in NC subjects. The effects of PM light were not significant, nor were there significant effects of the light pulse on melatonin measures of onset, duration, peak or area under the curve. These findings replicated our previous finding of a blunted phase-shift response to morning bright light in the luteal, but not the follicular, menstrual cycle phase in PMDD compared with NC women, using a brighter (6,000 vs. 3,000 lux) light pulse for a shorter duration (3 vs. 6 h). As the effect of PM bright light on melatonin phase-shift responses did not differ between groups or significantly alter other melatonin measures, these results suggest that in PMDD there is a luteal phase subsensitivity or an increased resistance to morning bright light cues which are critical in synchronizing human biological rhythms. The resulting circadian rhythm malsynchonization may contribute to the occurrence of luteal phase depressive symptoms in women with PMDD. PMID:21721857

Experimental characterization of the effects induced by passive plasma lens on high brightness electron bunches

NASA Astrophysics Data System (ADS)

Marocchino, A.; Anania, M. P.; Bellaveglia, M.; Biagioni, A.; Bini, S.; Bisesto, F.; Brentegani, E.; Chiadroni, E.; Cianchi, A.; Croia, M.; Di Giovenale, D.; Ferrario, M.; Filippi, F.; Giribono, A.; Lollo, V.; Marongiu, M.; Mostacci, A.; Di Pirro, G.; Pompili, R.; Romeo, S.; Rossi, A. R.; Scifo, J.; Shpakov, V.; Vaccarezza, C.; Villa, F.; Zigler, A.

2017-10-01

We report on the experimental characterization of the effect that a passive plasma lens in the overdense regime has on high-brightness bunch quality by means of 6D phase-space analysis. The passive lens is generated by confining hydrogen gas with a capillary tube pre-ionized with a high-voltage discharge. We observed that the optimum condition is retrieved at the end of the overdense regime with almost no effect on bunch brightness. The presence of gas jets, leaking from the hollow capillary end-points, extends the lens effects also outside of the capillary, resulting in longer focusing channels. Experimental results are supported with numerical simulations of the complete accelerator line together with the plasma channel section.

Influence of interplanetary magnetic field and solar wind on auroral brightness in different regions

NASA Astrophysics Data System (ADS)

Yang, Y. F.; Lu, J. Y.; Wang, J.-S.; Peng, Z.; Zhou, L.

2013-01-01