Misinterpreting Changes of Illuminant on Complex Mondrian Patterns

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 111-111
Author(s):  
S M C Nascimento ◽  
D H Foster
Keyword(s):  
Visual System ◽  
Temperature Change ◽  
Short Wavelength ◽  
Choice Experiment ◽  
The Other ◽  
Invariant Cone ◽  
Colour Temperature ◽  
Long Wavelength ◽  
Naturally Occurring ◽  
Colour Changes

Ratios of cone excitations from different surfaces of the same coloured scene are almost invariant under illuminance changes, and might provide the cue by which the visual system discriminates illuminant from non-illuminant changes in coloured scenes. Previous work with pairs of surfaces showed that observers were able to detect small, naturally occurring, violations in these ratios (Nascimento and Foster, 1995 Perception24 Supplement, 60 – 61). In the present study, sensitivity to violations was assessed with more complex, Mondrian patterns. In a two-interval forced-choice experiment, two colour transformations of the same Mondrian pattern were compared by observers. The patterns comprised 7 × 7 coloured patches. Each patch was a simulation of a Munsell surface, and the whole pattern was illuminated by a Planckian illuminant of variable colour temperature. In one of the intervals only the colour temperature of the illuminant changed; in the other, the same colour-temperature change was made, but, in addition, the spectral reflectances of the surfaces were adjusted such that all cone ratios were exactly preserved for the three classes of cone. The task was to identify which of the intervals contained the pure illuminant change. Observers could reliably discriminate the intervals but systematically interpreted colour changes with invariant cone-ratios as being illuminant changes, with a probability that increased as the degree of violation of invariance increased. Performance depended mainly on long-wavelength-sensitive cones, less on medium-wavelength-sensitive cones, and little or not at all on short-wavelength-sensitive cones or luminance signals. Cone-excitation ratios, although sometimes unreliable, appear to be the dominant cue for deciding on the nature of colour changes.

scholarly journals Röntgenspektroskopische Untersuchung der chemischen Bindung in Oxiden

1967 ◽  
Vol 22 (9) ◽  
pp. 1401-1407 ◽  
Author(s):  
Hans-Ulrich Chun ◽  
Dieter Hendel
Keyword(s):  
Fine Structure ◽  
Metal Atom ◽  
Short Wavelength ◽  
The Other ◽  
Main Line ◽  
Ionic Character ◽  
Long Wavelength ◽  
Short Wavelength Side ◽  
Oxygen Bond ◽  
Wavelength Side

This paper reports about the fine structure in the O—K-spectra of the oxides BeO, MgO, CaO, SrO, BaO, Sc2O5, Y2O3, La2O3, Sm2O3, Yb2O3, NiO and ZnO. The spectra show the satellite lines α3, α4, α5, α6 on the short wavelength side of the main line α1,2 and a shoulder β′ on its long wavelength side. The wavelengths of all lines depend on the nature of the oxide. For the positions of the lines Kα1.2 in the spectra no systematic relation to other data of the oxides is observed. On the other hand the distance of the a4-satellite from the α1,2-line decreases with increasing electronegativity of the metal atom in the oxide. This distance can be used as a measure for the ionic character of the metal-oxygen bond in these compounds.

Processing of S-cone signals in the inner plexiform layer of the mammalian retina

2013 ◽  
Vol 31 (2) ◽  
pp. 153-163 ◽  
Author(s):  
KIYOHARU J. MIYAGISHIMA ◽  
ULRIKE GRÜNERT ◽  
WEI LI
Keyword(s):  
Ganglion Cell ◽  
Short Wavelength ◽  
Plexiform Layer ◽  
The Other ◽  
Current Understanding ◽  
Inner Plexiform Layer ◽  
Color Information ◽  
Long Wavelength ◽  
Mammalian Retina ◽  
Cell Processes

AbstractColor information is encoded by two parallel pathways in the mammalian retina. One pathway compares signals from long- and middle-wavelength sensitive cones and generates red-green opponency. The other compares signals from short- and middle-/long-wavelength sensitive cones and generates blue-green (yellow) opponency. Whereas both pathways operate in trichromatic primates (including humans), the fundamental, phylogenetically ancient color mechanism shared among most mammals is blue-green opponency. In this review, we summarize the current understanding of how signals from short-wavelength sensitive cones are processed in the primate and nonprimate mammalian retina, with a focus on the inner plexiform layer where bipolar, amacrine, and ganglion cell processes interact to facilitate the generation of blue-green opponency.

Assimilation of various organic carbon sources by Haematococcus strains

2009 ◽  
Vol 57 (2) ◽  
pp. 231-237
Author(s):  
M. Zych ◽  
A. Stolarczyk ◽  
K. Maca ◽  
A. Banaś ◽  
K. Termińska-Pabis ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Organic Compounds ◽  
Present Experiment ◽  
Carbon Sources ◽  
Growth Conditions ◽  
Mixotrophic Growth ◽  
Naturally Occurring ◽  
Organic Carbon Sources ◽  
Secondary Carotenoids ◽  
Colour Changes

Differences in the assimilation of individual organic compounds (5 mM sugars and L-asparagine) under mixotrophic growth conditions were described for three naturally occurring Haematococcus strains.The effects of assimilation were measured by the growth intensity and size of algal cells, and the effect of colour changes in the cultures was observed. Some compounds caused the cell colouration to change from green to yellow, being the result of chlorophyll disappearance and the accumulation of yellow secondary carotenoids. In the present experiment none of the cultures turned red, thus excluding the intense accumulation of the commercially interesting carotenoid, astaxanthin.

Comparison of Stratification in a Water Tank and a PCM-Water Tank

2007 ◽  
Author(s):  
A. Castell ◽  
C. Sole´ ◽  
M. Medrano ◽  
M. Nogue´s ◽  
L. F. Cabeza
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Temperature Change ◽  
High Energy ◽  
Hot Water ◽  
The Other ◽  
High Energy Density ◽  
Water Tank ◽  
Charging And Discharging Processes ◽  
Change Material

Most of the storage systems available on the market use water as storage medium. Enhancing the storage performance is necessary to increase the performance of most systems. The stratification phenomenon is employed to improve the efficiency of storage tanks. Heat at an intermediate temperature, not high enough to heat up the top layer, can still be used to heat the lower, colder layers. There are a lot of parameters to study the stratification in a water tank such as the Mix Number and the Richardson Number among others. The idea studied here was to use these stratification parameters to compare two tanks with the same dimensions during charging and discharging processes. One of them is a traditional water tank and the other is a PCM-water (a water tank with a Phase Change Material). A PCM is good because it has high energy density if there is a small temperature change, since then the latent heat is much larger than the sensible heat. On the other hand, the temperature change in the top layer of a hot water store with stratification is usually small as it is held as close as possible at or above the temperature for usage. In the system studied the Phase Change Material is placed at the top of the tank, therefore the advantages of the stratification still remain. The aim of this work is to demonstrate that the use of PCM in the upper part of a water tank holds or improves the benefit of the stratification phenomenon.

Interactions between DNA-bound trimers of the yeast heat shock factor

1994 ◽  
Vol 14 (1) ◽  
pp. 501-508
Author(s):  
J J Bonner ◽  
C Ballou ◽  
D L Fackenthal
Keyword(s):  
Heat Shock ◽  
Protein Complexes ◽  
Consensus Sequence ◽  
The Other ◽  
Inverted Repeats ◽  
Electrophoretic Mobilities ◽  
Naturally Occurring ◽  
Initial Identification ◽  
Dyad Symmetry ◽  
Chemical Cross Linking

The heat shock transcription factor (HSF) is a trimer that binds to DNA containing inverted repeats of the sequence nGAAn. HSF can bind DNA with the sequence nGAAnnTTCn or with the sequence nTTCnnGAAn, with little preference for either sequence over the other. However, (nGAAnnTTCn)2 is considerably less active as a heat shock response element (HSE) than is (nTTCnnGAAn)2. The electrophoretic mobilities of DNA-protein complexes and chemical cross-linking between protein monomers indicate that the sequence (nGAAnnTTCn)2 is capable of binding a single HSF trimer. In contrast, the sequence with higher biological activity, (nTTCnnGAAn)2, is capable of binding two trimers. Thus, the ability of four-nGAAn-element HSEs to bind one or two trimers depends on the permutation with which the elements are presented. A survey of naturally occurring HSEs shows the sequence (nTTCnnGAAn)2 to be the more prevalent. We suggest that the greater ability of one permutation over the other to bind two HSF trimers accounts for the initial identification of the naturally occurring heat shock consensus sequence as a region of dyad symmetry.

scholarly journals The Glucosamine Controversy; A Pharmacokinetic Issue

2011 ◽  
Vol 14 (2) ◽  
pp. 264 ◽  
Author(s):  
Ali Aghazadeh-Habashi ◽  
Fakhreddin Jamali
Keyword(s):  
Clinical Trial ◽  
Animal Studies ◽  
The Other ◽  
Naturally Occurring ◽  
Assessment Metrics ◽  
Disease Modifying ◽  
Clinical Trial Results ◽  
Higher Doses ◽  
Positive Results ◽  
Rule Out

Glucosamine (GlcN) is a naturally occurring aminosugar that is widely used to treat osteoarthritis despite controversial clinical trial results. Animal studies, on the other hand, unequivocally suggest anti-inflammatory and disease modifying effects for GlcN. Many explanations have been offered as to the root of the controversy. They include superiority of a crystalline sulphate salt over HCl, industry bias, insensitive assessment metrics and poor methodology. Herein, we rule out a difference in bioequivalence between GlcN salts and that of chemically equivalent doses and suggest additional factors; i.e., inconsistency in the chemical potency of some products used, under-dosing of patients as well as variable and erratic bioavailability indices for the lack of GlcN efficacy observed in some studies. Clinical trials using higher doses of pharmaceutical grade GlcN or formulations with greater bioavailability should yield positive results. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Municipal Representatives’ Accounts of Decision-Making Practices during Geriatric Case Conferences

2017 ◽  
Vol 23 (45) ◽  
pp. 129
Author(s):  
Søren Beck Nielsen
Keyword(s):  
Senior Citizens ◽  
General Characteristic ◽  
The Other ◽  
Residential Home ◽  
Residential Homes ◽  
Social Actors ◽  
Naturally Occurring ◽  
Case Conferences ◽  
The Relationship ◽  
Elderly Citizen

This article addresses questions of elucidation in talk-in-interaction. How do social actors give accounts of what they are doing? To what degree do actors sustain a taken-for-granted level of reasoning? The analysis is based upon naturally occurring data consisting of a corpus of audio recorded case conferences at various geriatric wards in Danish hospitals. The article elaborates one of the important insights of Harold Garfinkel regarding the relationship between discourse and social interaction: as a general characteristic, people tend to treat their fellow interlocutors’ conversational contributions as adequate for-all-practical-purposes. Specifically, the article investigates how Danish municipal representatives account for their decisions about whether or not senior citizens are to be referred to residential homes. This practice, I demonstrate, is characterized by non-explicitness with regards to rules and regulations. Instead, municipal representatives make use of developmental discourse: a worsened condition is used to justify a referral to a residential home. On the other hand, an improved condition is used to justify that an elderly citizen is not referred to a residential home.

scholarly journals Optical axes of catadioptric systems including visual, Purkinje and other nonvisual systems of a heterocentric astigmatic eye

2010 ◽  
Vol 69 (3) ◽  
Author(s):  
W. F. Harris
Keyword(s):  
Visual System ◽  
Optical Axis ◽  
The Other ◽  
Optical Systems ◽  
Numerical Examples ◽  
Straight Line ◽  
Optical Axes ◽  
Catadioptric Systems ◽  
Reflecting Surfaces ◽  
Special Case

For a dioptric system with elements which may be heterocentric and astigmatic an optical axis has been defined to be a straight line along which a ray both enters and emerges from the system.  Previous work shows that the dioptric system may or may not have an optical axis and that, if it does have one, then that optical axis may or may not be unique.  Formulae were derived for the locations of any optical axes.  The purpose of this paper is to extend those results to allow for reflecting surfaces in the system in addition to refracting elements.  Thus the paper locates any optical axes in catadioptric systems (including dioptric systems as a special case).  The reflecting surfaces may be astigmatic and decentred or tilted.  The theory is illustrated by means of numerical examples.  The locations of the optical axes are calculated for seven optical systems associated with a particular heterocentric astigmatic model eye.  The optical systems are the visual system, the four Purkinje systems and two other nonvisual systems of the eye.  The Purkinje systems each have an infinity of optical axes whereas the other nonvisual systems, and the visual system, each have a unique optical axis. (S Afr Optom 2010 69(3) 152-160)

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