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1

Flower choice copying in bumblebees  

PubMed Central

We tested a hypothesis originating with Darwin that bees outside the nest exhibit social learning in flower choices. Naive bumblebees, Bombus impatiens, were allowed to observe trained bees or artificial bees forage from orange or green flowers. Subsequently, observers of bees on green flowers landed more often on green flowers than non-observing controls or observers of models on orange flowers. These results demonstrate that bumblebees can change flower choice by observations of non-nest mates, a novel form of social learning in insects that could provide unique benefits to the colony.

Worden, Bradley D; Papaj, Daniel R

2005-01-01

2

The flavonoid pathway regulates the petal colors of cotton flower.  

PubMed

Although biochemists and geneticists have studied the cotton flower for more than one century, little is known about the molecular mechanisms underlying the dramatic color change that occurs during its short developmental life following blooming. Through the analysis of world cotton germplasms, we found that all of the flowers underwent color changes post-anthesis, but there is a diverse array of petal colors among cotton species, with cream, yellow and red colors dominating the color scheme. Genetic and biochemical analyses indicated that both the original cream and red colors and the color changes post-anthesis were related to flavonoid content. The anthocyanin content and the expression of biosynthesis genes were both increased from blooming to one day post-anthesis (DPA) when the flower was withering and undergoing abscission. Our results indicated that the color changes and flavonoid biosynthesis of cotton flowers were precisely controlled and genetically regulated. In addition, flavonol synthase (FLS) genes involved in flavonol biosynthesis showed specific expression at 11 am when the flowers were fully opened. The anthocyanidin reductase (ANR) genes, which are responsible for proanthocyanidins biosynthesis, showed the highest expression at 6 pm on 0 DPA, when the flowers were withered. Light showed primary, moderate and little effects on flavonol, anthocyanin and proanthocyanidin biosynthesis, respectively. Flavonol biosynthesis was in response to light exposure, while anthocyanin biosynthesis was involved in flower color changes. Further expression analysis of flavonoid genes in flowers of wild type and a flavanone 3-hydroxylase (F3H) silenced line showed that the development of cotton flower color was controlled by a complex interaction between genes and light. These results present novel information regarding flavonoids metabolism and flower development. PMID:23951318

Tan, Jiafu; Wang, Maojun; Tu, Lili; Nie, Yichun; Lin, Yongjun; Zhang, Xianlong

2013-01-01

3

The Flavonoid Pathway Regulates the Petal Colors of Cotton Flower  

PubMed Central

Although biochemists and geneticists have studied the cotton flower for more than one century, little is known about the molecular mechanisms underlying the dramatic color change that occurs during its short developmental life following blooming. Through the analysis of world cotton germplasms, we found that all of the flowers underwent color changes post-anthesis, but there is a diverse array of petal colors among cotton species, with cream, yellow and red colors dominating the color scheme. Genetic and biochemical analyses indicated that both the original cream and red colors and the color changes post-anthesis were related to flavonoid content. The anthocyanin content and the expression of biosynthesis genes were both increased from blooming to one day post-anthesis (DPA) when the flower was withering and undergoing abscission. Our results indicated that the color changes and flavonoid biosynthesis of cotton flowers were precisely controlled and genetically regulated. In addition, flavonol synthase (FLS) genes involved in flavonol biosynthesis showed specific expression at 11 am when the flowers were fully opened. The anthocyanidin reductase (ANR) genes, which are responsible for proanthocyanidins biosynthesis, showed the highest expression at 6 pm on 0 DPA, when the flowers were withered. Light showed primary, moderate and little effects on flavonol, anthocyanin and proanthocyanidin biosynthesis, respectively. Flavonol biosynthesis was in response to light exposure, while anthocyanin biosynthesis was involved in flower color changes. Further expression analysis of flavonoid genes in flowers of wild type and a flavanone 3-hydroxylase (F3H) silenced line showed that the development of cotton flower color was controlled by a complex interaction between genes and light. These results present novel information regarding flavonoids metabolism and flower development.

Tan, Jiafu; Wang, Maojun; Tu, Lili; Nie, Yichun; Lin, Yongjun; Zhang, Xianlong

2013-01-01

4

Color versus bioactivity in the flowers of Bougainvillea spectabilis (Nyctaginaceae).  

PubMed

The methanolic extracts of Bougainvillea spectabilis (Nyctaginaceae) flowers (five different colors) were screened biologically by performing four bioassays: antibacterial, antifungal, brine shrimp lethality and phytotoxicity. It was observed that the methanolic extract of white flowers was the most biologically active among all tested extracts. The extracts of white, orange and shocking pink flowers inhibit, while the extracts of red and violet flowers promote, the growth of Lemna plants. The extract of white flowers also exhibits toxicity against shrimp larvae with a LD50 value of 33.5627 microg/mL. However, none of the tested samples gave positive responses against any tested fungi. PMID:15700638

Ali, Muhammad Shaiq; Ibrahim, Syed Amir; Ahmed, Farman; Pervez, Muhammad Kashif

2005-01-01

5

A quantitative theory of human color choices.  

PubMed

The system for colorimetry adopted by the Commission Internationale de l'Eclairage (CIE) in 1931, along with its subsequent improvements, represents a family of light mixture models that has served well for many decades for stimulus specification and reproduction when highly controlled color standards are important. Still, with regard to color appearance many perceptual and cognitive factors are known to contribute to color similarity, and, in general, to all cognitive judgments of color. Using experimentally obtained odd-one-out triad similarity judgments from 52 observers, we demonstrate that CIE-based models can explain a good portion (but not all) of the color similarity data. Color difference quantified by CIELAB ?E explained behavior at levels of 81% (across all colors), 79% (across red colors), and 66% (across blue colors). We show that the unexplained variation cannot be ascribed to inter- or intra-individual variations among the observers, and points to the presence of additional factors shared by the majority of responders. Based on this, we create a quantitative model of a lexicographic semiorder type, which shows how different perceptual and cognitive influences can trade-off when making color similarity judgments. We show that by incorporating additional influences related to categorical and lightness and saturation factors, the model explains more of the triad similarity behavior, namely, 91% (all colors), 90% (reds), and 87% (blues). We conclude that distance in a CIE model is but the first of several layers in a hierarchy of higher-order cognitive influences that shape color triad choices. We further discuss additional mitigating influences outside the scope of CIE modeling, which can be incorporated in this framework, including well-known influences from language, stimulus set effects, and color preference bias. We also discuss universal and cultural aspects of the model as well as non-uniformity of the color space with respect to different cultural biases. PMID:23409103

Komarova, Natalia L; Jameson, Kimberly A

2013-01-01

6

Cytotoxic and bioactive properties of different color tulip flowers and degradation kinetic of tulip flower anthocyanins.  

PubMed

This study was conducted to determine the potential use of anthocyanin-based extracts (ABEs) of wasted tulip flowers as food/drug colorants. For this aim, wasted tulip flowers were samples and analyzed for their bioactive properties and cytotoxicity. Total phenolic contents of the extracts of the claret red (126.55 mg of gallic acid equivalent (GAE)/g dry extract) and orange-red (113.76 mg GAE/g dry extract) flowers were the higher than those of the other tulip flowers. Total anthocyanin levels of the violet, orange-red, claret red and pink tulip flower extracts were determined as 265.04, 236.49, 839.08 and 404.45 mg pelargonidin 3-glucoside/kg dry extract, respectively and these levels were higher than those of the other flowers. The extracts were more effective for the inhibition of Listeria monocytogenes, Staphylococcus aureus and Yersinia enterocolitica compared to other tested bacteria. Additionally, the cytotoxic effects of five different tulip flower extracts on human breast adenocarcinoma (MCF-7) cell line were investigated. The results showed that the orange red, pink and violet extracts had no cytotoxic activity against MCF-7 cell lines while yellow and claret red extracts appeared to be toxic for the cells. Overall, the extracts of tulip flowers with different colors possess remarkable bioactive and cytotoxic properties. PMID:23712096

Sagdic, Osman; Ekici, Lutfiye; Ozturk, Ismet; Tekinay, Turgay; Polat, Busra; Tastemur, Bilge; Bayram, Okan; Senturk, Berna

2013-08-01

7

A MYB transcription factor controls flower color in soybean.  

PubMed

Purple-blue flower of soybean (Glycine max [L.] Merr.) is controlled by the W2 locus. Previous studies revealed that a MYB transcription factor gene GmMYB-G20-1 was located at a position similar to the W2 gene and that a base substitution generated a stop codon in the MYB domains of 2 soybean lines with purple-blue flowers. This study was conducted to confirm the relationship between GmMYB-G20-1 and the W2 gene. Cleaved amplified polymorphic sequence analysis to detect the base substitution suggested that a similar mutation occurred in 2 other soybean lines having purple-blue flowers, 037-E-8, and Yogetsu 1-blue. Thus, all genotypes having purple-blue flowers had identical base substitutions. To verify the function of GmMYB-G20-1, apple latent spherical virus (ALSV) vectors were constructed to perform virus-induced gene silencing of GmMYB-G20-1. A cultivar Harosoy with purple flowers (W2W2) was infected by the empty ALSV vector (wtALSV) or the GmMYB-G20-1-ALSV vector containing a fragment (nucleotide position 685-885) of GmMYB-G20-1. Plants infected by empty vectors had only purple flowers. In contrast, most flowers of plants infected with GmMYB-G20-1-ALSV had irregular gray/blue sectors in flower petals and some of the flowers had almost gray/blue petals. These results strongly suggest that silencing of GmMYB-G20-1 can alter flower color and that it may correspond to the W2 gene. PMID:23048163

Takahashi, Ryoji; Yamagishi, Noriko; Yoshikawa, Nobuyuki

2013-01-01

8

Flower color–flower scent associations in polymorphic Hesperis matronalis (Brassicaceae)  

Microsoft Academic Search

Floral scent emission rate and composition of purple and white flower color morphs of Hesperis matronalis (Brassicaceae) were determined for two populations and, for each, at two times of day using dynamic headspace collection and GC–MS. The floral volatile compounds identified for this species fell into two main categories, terpenoids and aromatics. Principal component analysis of 30 compounds demonstrated that

Cassie J. Majetic; Robert A. Raguso; Stephen J. Tonsor; Tia-Lynn Ashman

2007-01-01

9

Pollinator-Mediated Selection on Flower Color, Flower Scent and Flower Morphology of Hemerocallis: Evidence from Genotyping Individual Pollen Grains On the Stigma  

PubMed Central

To trace the fate of individual pollen grains through pollination processes, we determined genotypes of single pollen grains deposited on Hemerocallis stigmas in an experimental mixed-species array. Hemerocallis fulva, pollinated by butterflies, has diurnal, reddish and unscented flowers, and H. citrina, pollinated by hawkmoths, has nocturnal, yellowish and sweet scent flowers. We observed pollinator visits to an experimental array of 24 H. fulva and 12 F2 hybrids between the two species (H. fulva and H. citrina) and collected stigmas after every trip bout of swallowtail butterflies or hawkmoths. We then measured selection by swallowtail butterflies or hawkmoths through male and female components of pollination success as determined by single pollen genotyping. As expected, swallowtail butterflies imposed selection on reddish color and weak scent: the number of outcross pollen grains acquired is a quadratic function of flower color with the maximum at reddish color, and the combined pollination success was maximal at weak scent (almost unrecognizable for human). This explains why H. fulva, with reddish flowers and no recognizable scent, is mainly pollinated by swallowtail butterflies. However, we found no evidence of hawkmoths-mediated selection on flower color or scent. Our findings do not support a hypothesis that yellow flower color and strong scent intensity, the distinctive floral characteristics of H. citrina, having evolved in adaptations to hawkmoths. We suggest that the key trait that triggers the evolution of nocturnal flowers is flowering time rather than flower color and scent.

Hirota, Shun K.; Nitta, Kozue; Suyama, Yoshihisa; Kawakubo, Nobumitsu; Yasumoto, Akiko A.; Yahara, Tetsukazu

2013-01-01

10

Effects of perceived danger on flower choice by bees  

Microsoft Academic Search

Studies on animal-flower interactions have mostly neglected the third trophic level of pollinators' predators, even though antipredatory behaviour of pollinators may affect patterns of pollinator visitation, pollen transfer and floral traits. In three experiments, it was found that honeybees showed sensitivity to perceived danger at flowers by preferring apparently safe flowers over equally rewarding alternatives harbouring either a dead bee

Reuven Dukas

2001-01-01

11

The antioxidant and Flavonoids contents of Althaea officinalis L. flowers based on their color  

PubMed Central

Objective: There has been a growing interest in finding plants with biological active ingredients for medicinal application. Materials and Methods: Three colors of petals of Althaea officinalis (A. officinalis) flowers, i.e., pink, reddish pink, and white were examined for total antioxidant activity and ?avonoids content. Results: The reddish pink flowers of A. officinalis have more antioxidant activity and the power of antioxidant activity was reddish pink > pink > white. Conclusion: Findings suggest that the dark color can serve as an indicator of antioxidant content of the plant. Flavonoid content was highest in white flower thus this result indicated that flowers with light color can be considered for medicinal uses.

Sadighara, Parisa; Gharibi, Soraya; Moghadam Jafari, Amir; Jahed Khaniki, Golamreza; Salari, Samira

2012-01-01

12

Allelic variation of soybean flower color gene W4 encoding dihydroflavonol 4-reductase 2  

PubMed Central

Background Flower color of soybean is primarily controlled by six genes, viz., W1, W2, W3, W4, Wm and Wp. This study was conducted to investigate the genetic and chemical basis of newly-identified flower color variants including two soybean mutant lines, 222-A-3 (near white flower) and E30-D-1 (light purple flower), a near-isogenic line (Clark-w4), flower color variants (T321 and T369) descended from the w4-mutable line and kw4 (near white flower, Glycine soja). Results Complementation tests revealed that the flower color of 222-A-3 and kw4 was controlled by the recessive allele (w4) of the W4 locus encoding dihydroflavonol 4-reductase 2 (DFR2). In 222-A-3, a single base was deleted in the first exon resulting in a truncated polypeptide consisting of 24 amino acids. In Clark-w4, base substitution of the first nucleotide of the fourth intron abolished the 5? splice site, resulting in the retention of the intron. The DFR2 gene of kw4 was not expressed. The above results suggest that complete loss-of-function of DFR2 gene leads to near white flowers. Light purple flower of E30-D-1 was controlled by a new allele at the W4 locus, w4-lp. The gene symbol was approved by the Soybean Genetics Committee. In E30-D-1, a single-base substitution changed an amino acid at position 39 from arginine to histidine. Pale flowers of T369 had higher expression levels of the DFR2 gene. These flower petals contained unique dihydroflavonols that have not yet been reported to occur in soybean and G. soja. Conclusions Complete loss-of-function of DFR2 gene leads to near white flowers. A new allele of the W4 locus, w4-lp regulates light purple flowers. Single amino acid substitution was associated with light purple flowers. Flower petals of T369 had higher levels of DFR2 gene expression and contained unique dihydroflavonols that are absent in soybean and G. soja. Thus, mutants of the DFR2 gene have unique flavonoid compositions and display a wide variety of flower color patterns in soybean, from near white, light purple, dilute purple to pale.

2014-01-01

13

Comparing Distributions of Color Words: Pitfalls and Metric Choices  

PubMed Central

Computational methods have started playing a significant role in semantic analysis. One particularly accessible area for developing good computational methods for linguistic semantics is in color naming, where perceptual dissimilarity measures provide a geometric setting for the analyses. This setting has been studied first by Berlin & Kay in 1969, and then later on by a large data collection effort: the World Color Survey (WCS). From the WCS, a dataset on color naming by 2 616 speakers of 110 different languages is made available for further research. In the analysis of color naming from WCS, however, the choice of analysis method is an important factor of the analysis. We demonstrate concrete problems with the choice of metrics made in recent analyses of WCS data, and offer approaches for dealing with the problems we can identify. Picking a metric for the space of color naming distributions that ignores perceptual distances between colors assumes a decorrelated system, where strong spatial correlations in fact exist. We can demonstrate that the corresponding issues are significantly improved when using Earth Mover's Distance, or Quadratic -square Distance, and we can approximate these solutions with a kernel-based analysis method.

Vejdemo-Johansson, Mikael; Vejdemo, Susanne; Ek, Carl-Henrik

2014-01-01

14

Flower color polymorphism in Iris lutescens (Iridaceae): biochemical analyses in light of plant-insect interactions.  

PubMed

We describe a flower color polymorphism in Iris lutescens, a species widespread in the Northern part of the Mediterranean basin. We studied the biochemical basis of the difference between purple and yellow flowers, and explored the ecological and evolutionary consequences of such difference, in particular visual discrimination by insects, a potential link with scent emitted and the association between color and scent. Anthocyanins were found to be present in much greater concentrations in purple flowers than in yellow ones, but the anthocyanin composition did not differ between color morphs. Likewise, no quantitative difference in anthocyanin content was found between vegetative tissues of the two morphs. Floral anthocyanins were dominated by delphinidin 3-O-(p-coumaroylrutinoside)-5-O-glucoside (also called delphanin) and its aliphatic derivatives. Small amounts of delphinidin 3-O-(p-caffeoylrutinoside)-5-O-glucoside and its aliphatic derivatives were also characterized. Based on a description of bumblebees' (one of the main pollinators of I. lutescens) color perception, purple and yellow flowers of I. lutescens could be visually discriminated as blue and blue-green, respectively, and likely by a wide variety of other insects. The overall chemical composition of the scent produced was not significantly different between morphs, being dominated by terpenoids, mainly myrcene, (E)-?-ocimene and limonene. A slight color-scent correlation was nevertheless detected, consistent with the shared biosynthetic origin of both pigments and volatile compounds. Therefore in this species, the difference in the amounts of pigments responsible for flower color difference seems to be the major difference between the two morphs. Pollinators are probably the main selective agent driving the evolution of flower color polymorphism in I. lutescens, which represents a suitable species for investigating how such polymorphism is maintained. PMID:23790644

Wang, Hui; Conchou, Lucie; Bessière, Jean-Marie; Cazals, Guillaume; Schatz, Bertrand; Imbert, Eric

2013-10-01

15

Flower color as a model system for studies of plant evo-devo  

PubMed Central

Even though pigmentation traits have had substantial impacts on the field of animal evolutionary developmental biology, they have played only relatively minor roles in plant evo-devo. This is surprising given the often direct connection between flower color and fitness variation mediated through the effects of pollinators. At the same time, ecological and evolutionary genetic studies have utilized the molecular resources available for the anthocyanin pathway to generate several examples of the molecular basis of putatively adaptive transitions in flower color. Despite this opportunity to synthesize experimental approaches in ecology, evolution, and developmental biology, the investigation of many fundamental questions in evo-devo using this powerful model is only at its earliest stages. For example, a long-standing question is whether predictable genetic changes accompany the repeated evolution of a trait. Due to the conserved nature of the biochemical and regulatory control of anthocyanin biosynthesis, it has become possible to determine whether, and under what circumstances, different types of mutations responsible for flower color variation are preferentially targeted by natural selection. In addition, because plants use anthocyanin and related compounds in vegetative tissue for other important physiological functions, the identification of naturally occurring transitions from unpigmented to pigmented flowers provides the opportunity to examine the mechanisms by which regulatory networks are co-opted into new developmental domains. Here, we review what is known about the ecological and molecular basis of anthocyanic flower color transitions in natural systems, focusing on the evolutionary and developmental features involved. In doing so, we provide suggestions for future work on this trait and suggest that there is still much to be learned from the evolutionary development of flower color transitions in nature.

Sobel, James M.; Streisfeld, Matthew A.

2013-01-01

16

Gene loss and parallel evolution contribute to species difference in flower color.  

PubMed

Although the importance of regulatory and functional sequence evolution in generating species differences has been studied to some extent, much less is known about the role of other types of genomic changes, such as fluctuation in gene copy number. Here, we apply analyses of gene function and expression of anthocyanin pigment pathway genes, as well as cosegregation analyses in backcross populations, to examine the genetic changes involved in the shift from blue to red flowers in Andean Iochroma (Solanaceae). We demonstrate that deletion of a gene coding for an anthocyanin pathway enzyme was necessary for the transition to red floral pigmentation. The downregulation of a second pathway gene was also necessary for the novel flower color, and this regulatory pattern parallels the genetic change in the two other red-flowered species in the sister family Convolvulaceae in which flower color change has been examined genetically. Finally, we document a shift in enzymatic function at a third locus, but the importance of this change in the transition to red flowers depends on the exact order with which the three changes occurred. This study shows that gene inactivation or loss can be involved in the origin of phenotypic differences between species, thereby restricting the possibility of reversion to the ancestral state. It also demonstrates that parallel evolution of red flowers in three different species occurs via a common developmental/regulatory change but by mutations in different genes. PMID:21551271

Smith, Stacey D; Rausher, Mark D

2011-10-01

17

Negative frequency-dependent selection maintains a dramatic flower color polymorphism in the rewardless orchid Dactylorhiza sambucina (L.) Soò  

Microsoft Academic Search

The orchid Dactylorhiza sambucina shows a stable and dramatic flower-color polymorphism, with both yellow- and purple-flowered individuals present in natural populations throughout the range of the species in Europe. The evolutionary significance of flower-color polymorphisms found in many rewardless orchid species has been discussed at length, but the mechanisms responsible for their maintenance remain unclear. Laboratory experiments have suggested that

Luc D. B. Gigord; Mark R. MacNair; Ann Smithson

2001-01-01

18

Arctic Mustard Flower Color Polymorphism Controlled by Petal-Specific Downregulation at the Threshold of the Anthocyanin Biosynthetic Pathway  

PubMed Central

Intra- and interspecific variation in flower color is a hallmark of angiosperm diversity. The evolutionary forces underlying the variety of flower colors can be nearly as diverse as the colors themselves. In addition to pollinator preferences, non-pollinator agents of selection can have a major influence on the evolution of flower color polymorphisms, especially when the pigments in question are also expressed in vegetative tissues. In such cases, identifying the target(s) of selection starts with determining the biochemical and molecular basis for the flower color variation and examining any pleiotropic effects manifested in vegetative tissues. Herein, we describe a widespread purple-white flower color polymorphism in the mustard Parrya nudicaulis spanning Alaska. The frequency of white-flowered individuals increases with increasing growing-season temperature, consistent with the role of anthocyanin pigments in stress tolerance. White petals fail to produce the stress responsive flavonoid intermediates in the anthocyanin biosynthetic pathway (ABP), suggesting an early pathway blockage. Petal cDNA sequences did not reveal blockages in any of the eight enzyme-coding genes in white-flowered individuals, nor any color differentiating SNPs. A qRT-PCR analysis of white petals identified a 24-fold reduction in chalcone synthase (CHS) at the threshold of the ABP, but no change in CHS expression in leaves and sepals. This arctic species has avoided the deleterious effects associated with the loss of flavonoid intermediates in vegetative tissues by decoupling CHS expression in petals and leaves, yet the correlation of flower color and climate suggests that the loss of flavonoids in the petals alone may affect the tolerance of white-flowered individuals to colder environments.

Dick, Cynthia A.; Buenrostro, Jason; Butler, Timothy; Carlson, Matthew L.; Kliebenstein, Daniel J.; Whittall, Justen B.

2011-01-01

19

Genetic analysis of genes controlling natural variation of seed coat and flower colors in soybean.  

PubMed

Soybean exhibits natural variation in flower and seed coat colors via the deposition of various anthocyanin pigments in the respective tissues. Although pigmentation in seeds or flowers has been well dissected at molecular level in several plant species, the genes controlling natural variation in anthocyanin traits in the soybean are not completely understood. To evaluate the genetic correlation between genetic loci and genes, 8 enzyme-encoding gene families and a transcription factor were localized in a soybean genome-wide genetic map. Among the seed coat color-controlling loci, the genetic location of the gene encoding for W1 was substantiated in the context of the current soybean molecular genetic map and O was postulated to correspond to anthocyanidin reductase. Among the genetic loci that regulate flower pigmentation, the genetic locations of the genes encoding for W1, W4, and Wp were identified, W3 was mapped on soybean linkage group B2 (chromosome 14), and W2 was postulated to correspond to an MYB transcription factor. Correlation studies between the developed markers and 3 color-controlling loci provided important empirical data that should prove useful in the design of marker-assisted breeding schemes as well as future association studies involving soybean. PMID:20584753

Yang, Kiwoung; Jeong, Namhee; Moon, Jung-Kyung; Lee, Yeong-Ho; Lee, Suk-Ha; Kim, Hwan Mook; Hwang, Cheol Ho; Back, Kyoungwhan; Palmer, Reid G; Jeong, Soon-Chun

2010-01-01

20

Negative frequency-dependent selection maintains a dramatic flower color polymorphism in the rewardless orchid Dactylorhiza sambucina (L.) Soo  

Microsoft Academic Search

The orchid Dactylorhiza sambucina shows a stable and dramatic flower-color polymorphism, with both yellow- and purple-flow- ered individuals present in natural populations throughout the range of the species in Europe. The evolutionary significance of flower-color polymorphisms found in many rewardless orchid species has been discussed at length, but the mechanisms respon- sible for their maintenance remain unclear. Laboratory experi- ments

Luc D. B. Gigord; Mark R. Macnair; Ann Smithson

2001-01-01

21

A single-base deletion in soybean flavonol synthase gene is associated with magenta flower color.  

PubMed

The Wm locus of soybean [Glycine max (L.) Merr.] controls flower color. Dominant Wm and recessive wm allele of the locus produce purple and magenta flower, respectively. A putative full-length cDNA of flavonol synthase (FLS), gmfls1 was isolated by 5' RACE and end-to-end PCR from a cultivar Harosoy with purple flower (WmWm). Sequence analysis revealed that gmfls1 consisted of 1,208 nucleotides encoding 334 amino acids. It had 59-72% homology with FLS proteins of other plant species. Conserved dioxygenase domains A and B were found in the deduced polypeptide. Sequence comparison between Harosoy and Harosoy-wm (magenta flower mutant of Harosoy; wmwm) revealed that they differed by a single G deletion in the coding region of Harosoy-wm. The deletion changed the subsequent reading frame resulting in a truncated polypeptide consisting of 37 amino acids that lacked the dioxygenase domains A and B. Extracts of E. coli cells expressing gmfls1 of Harosoy catalyzed the formation of quercetin from dihydroquercetin, whereas cell extracts expressing gmfls1 of Harosoy-wm had no FLS activity. Genomic Southern analysis suggested the existence of three to four copies of the FLS gene in the soybean genome. CAPS analysis was performed to detect the single-base deletion. Harosoy and Clark (WmWm) exhibited longer fragments, while Harosoy-wm had shorter fragments due to the single-base deletion. The CAPS marker co-segregated with genotypes at Wm locus in a F(2) population segregating for the locus. Linkage mapping using SSR markers revealed that the Wm and gmfls1 were mapped at similar position in the molecular linkage group F. The above results strongly suggest that gmfls1 represents the Wm gene and that the single-base deletion may be responsible for magenta flower color. PMID:17006592

Takahashi, Ryoji; Githiri, Stephen M; Hatayama, Kouta; Dubouzet, Emilyn G; Shimada, Norimoto; Aoki, Toshio; Ayabe, Shin-ichi; Iwashina, Tsukasa; Toda, Kyoko; Matsumura, Hisakazu

2007-01-01

22

Relationship between the Composition of Flavonoids and Flower Colors Variation in Tropical Water Lily (Nymphaea) Cultivars  

PubMed Central

Water lily, the member of the Nymphaeaceae family, is the symbol of Buddhism and Brahmanism in India. Despite its limited researches on flower color variations and formation mechanism, water lily has background of blue flowers and displays an exceptionally wide diversity of flower colors from purple, red, blue to yellow, in nature. In this study, 34 flavonoids were identified among 35 tropical cultivars by high-performance liquid chromatography (HPLC) with photodiode array detection (DAD) and electrospray ionization mass spectrometry (ESI-MS). Among them, four anthocyanins: delphinidin 3-O-rhamnosyl-5-O-galactoside (Dp3Rh5Ga), delphinidin 3-O-(2?-O-galloyl-6?-O-oxalyl-rhamnoside) (Dp3galloyl-oxalylRh), delphinidin 3-O-(6?-O-acetyl-?-glucopyranoside) (Dp3acetylG) and cyanidin 3- O-(2?-O-galloyl-galactopyranoside)-5-O-rhamnoside (Cy3galloylGa5Rh), one chalcone: chalcononaringenin 2?-O-galactoside (Chal2?Ga) and twelve flavonols: myricetin 7-O-rhamnosyl-(1?2)-rhamnoside (My7RhRh), quercetin 7-O-galactosyl-(1?2)-rhamnoside (Qu7GaRh), quercetin 7-O-galactoside (Qu7Ga), kaempferol 7-O-galactosyl-(1?2)-rhamnoside (Km7GaRh), myricetin 3-O-galactoside (My3Ga), kaempferol 7-O-galloylgalactosyl-(1?2)-rhamnoside (Km7galloylGaRh), myricetin 3-O-galloylrhamnoside (My3galloylRh), kaempferol 3-O-galactoside (Km3Ga), isorhamnetin 7-O-galactoside (Is7Ga), isorhamnetin 7-O-xyloside (Is7Xy), kaempferol 3-O-(3?-acetylrhamnoside) (Km3-3?acetylRh) and quercetin 3-O-acetylgalactoside (Qu3acetylGa) were identified in the petals of tropic water lily for the first time. Meanwhile a multivariate analysis was used to explore the relationship between pigments and flower color. By comparing, the cultivars which were detected delphinidin 3-galactoside (Dp3Ga) presented amaranth, and detected delphinidin 3?-galactoside (Dp3?Ga) presented blue. However, the derivatives of delphinidin and cyanidin were more complicated in red group. No anthocyanins were detected within white and yellow group. At the same time a possible flavonoid biosynthesis pathway of tropical water lily was presumed putatively. These studies will help to elucidate the evolution mechanism on the formation of flower colors and provide theoretical basis for outcross breeding and developing health care products from this plant.

Zhu, Manlan; Zheng, Xuchen; Shu, Qingyan; Li, Hui; Zhong, Peixing; Zhang, Huijin; Xu, Yanjun; Wang, Lijin; Wang, Liangsheng

2012-01-01

23

The Genetic Basis of a Rare Flower Color Polymorphism in Mimulus lewisii Provides Insight into the Repeatability of Evolution  

PubMed Central

A long-standing question in evolutionary biology asks whether the genetic changes contributing to phenotypic evolution are predictable. Here, we identify a genetic change associated with segregating variation in flower color within a population of Mimulus lewisii. To determine whether these types of changes are predictable, we combined this information with data from other species to investigate whether the spectrum of mutations affecting flower color transitions differs based on the evolutionary time-scale since divergence. We used classic genetic techniques, along with gene expression and population genetic approaches, to identify the putative, loss-of-function mutation that generates rare, white flowers instead of the common, pink color in M. lewisii. We found that a frameshift mutation in an anthocyanin pathway gene is responsible for the white-flowered polymorphism found in this population of M. lewisii. Comparison of our results with data from other species reveals a broader spectrum of flower color mutations segregating within populations relative to those that fix between populations. These results suggest that the genetic basis of fixed differences in flower color may be predictable, but that for segregating variation is not.

Nutter, Laura I.; Cross, Kaitlyn A.

2013-01-01

24

Negative frequency-dependent selection maintains a dramatic flower color polymorphism in the rewardless orchid Dactylorhiza sambucina (L.) So?  

PubMed Central

The orchid Dactylorhiza sambucina shows a stable and dramatic flower-color polymorphism, with both yellow- and purple-flowered individuals present in natural populations throughout the range of the species in Europe. The evolutionary significance of flower-color polymorphisms found in many rewardless orchid species has been discussed at length, but the mechanisms responsible for their maintenance remain unclear. Laboratory experiments have suggested that behavioral responses by pollinators to lack of reward availability might result in a reproductive advantage for rare-color morphs. Consequently, we performed an experiment varying the relative frequency of the two color morphs of D. sambucina to test whether rare morph advantage acted in the natural habitat of the species. We show here clear evidence from this manipulative experiment that rare-color morphs have reproductive advantage through male and female components. This is the first demonstration, to our knowledge, that negative frequency-dependent selection through pollinator preference for rare morphs can cause the maintenance of a flower-color polymorphism.

Gigord, Luc D. B.; Macnair, Mark R.; Smithson, Ann

2001-01-01

25

Negative frequency-dependent selection maintains a dramatic flower color polymorphism in the rewardless orchid Dactylorhiza sambucina (L.) Soo.  

PubMed

The orchid Dactylorhiza sambucina shows a stable and dramatic flower-color polymorphism, with both yellow- and purple-flowered individuals present in natural populations throughout the range of the species in Europe. The evolutionary significance of flower-color polymorphisms found in many rewardless orchid species has been discussed at length, but the mechanisms responsible for their maintenance remain unclear. Laboratory experiments have suggested that behavioral responses by pollinators to lack of reward availability might result in a reproductive advantage for rare-color morphs. Consequently, we performed an experiment varying the relative frequency of the two color morphs of D. sambucina to test whether rare morph advantage acted in the natural habitat of the species. We show here clear evidence from this manipulative experiment that rare-color morphs have reproductive advantage through male and female components. This is the first demonstration, to our knowledge, that negative frequency-dependent selection through pollinator preference for rare morphs can cause the maintenance of a flower-color polymorphism. PMID:11353863

Gigord, L D; Macnair, M R; Smithson, A

2001-05-22

26

Flower color diversity revealed by differential expression of flavonoid biosynthetic genes and flavonoid accumulation in herbaceous peony (Paeonia lactiflora Pall.).  

PubMed

Herbaceous peony (Paeonia lactiflora Pall.) is an important ornamental plant which contains different flower colors. In this paper, eight genes encoding phenylalanine ammonialyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), flavonoid 3'-hydroxylase (F3'H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS), UDP-glucose: flavonoid 3-o-glucosyltransferase (UF3GT) were isolated. Moreover, the expression patterns of these eight genes and UF5GT in the flowers were investigated in three cultivars, that is, 'Hongyanzhenghui', 'Yulouhongxing' and 'Huangjinlun' with purplish-red, white and yellow flower respectively. Furthermore, flavonoid accumulation in the flowers was also analyzed. The results showed that in different organs, most of genes expressed higher in flowers than in other organs. During the development of flowers, all genes could be divided into four groups. The first group (PlPAL) was highly expressed in S1 and S4. The second group (PlCHS and PlCHI) was at a high expression level throughout the whole developmental stages. The third group (PlF3H, PlF3'H, PlDFR, PlANS and PlUF5GT) gradually decreased with the development of flowers. The fourth group (PlUF3GT) gradually increased during the flower development. In addition, anthoxanthins and anthocyanins were detected in 'Hongyanzhenghui' and 'Yulouhongxing', chalcones and anthoxanthins were found in 'Huangjinlun'. When different color flowers were concerned, low expression level of PlCHI induced most of the substrate accumulation in the form of chalcones and displaying yellow, changing a small part of substrates to anthoxanthins, and there was no anthocyanin synthesis in 'Huangjinlun' because of low expression level of DFR. In 'Yulouhongxing', massive expressions of upstream genes and low expression of DFR caused synthesis of a great deal of anthoxanthins and a small amount of colorless anthocyanins. In 'Hongyanzhenghui', a large number of colored anthocyanins were changed from anthoxanthins because of PlDFR, PlANS and PlUF3GT high expressions. These results would provide us a theoretical basis to understand the formation of P. lactiflora flower colors. PMID:23054003

Zhao, Daqiu; Tao, Jun; Han, Chenxia; Ge, Jintao

2012-12-01

27

FLOWER COLOR AND PATTERNING IN THE GENUS HEMEROCALLIS AND ITS HYBRIDS: A MATHEMATICAL MODEL AND EXPERIMENTAL ANALYSIS  

Microsoft Academic Search

The development of patterns in flowers has been examined by many over the years. The seminal work of Alan Turing in 1952 laid out a method to model such coloration by looking at the process as a distributed communications between cells with feedback. This paper uses the Turing model combined with the current knowledge of gene expression and secondary pathways.

TERRENCE P MCGARTY

2008-01-01

28

Engineering of flower color in forsythia by expression of two independently-transformed dihydroflavonol 4-reductase and anthocyanidin synthase genes of flavonoid pathway  

Microsoft Academic Search

Flower color was modified in forsythia (Forsythia x intermedia cv ‘Spring Glory’) by inducing anthocyanin synthesis in petals through sequential Agrobacterium-mediated transformation with dihydroflavonol 4-reductase from Antirrhinum majus (AmDFR) and anthocyanidin synthase from Matthiola incana (MiANS) genes. This is the second report of flower color modification of an ornamental shrub after rose, and the first time an ANS gene is

Carlo Rosati; Philippe Simoneau; Dieter Treutter; Pascal Poupard; Yves Cadot; Alain Cadic; Michel Duron

2003-01-01

29

Race-Conscious Adoption Choices, Multiraciality, and Color-Blind Racial Ideology  

ERIC Educational Resources Information Center

Analysis of interview data illustrates how White adoptive parents rationalize choices regarding adoptee race. Parents who were willing to adopt children of color stressed unwillingness to adopt Black children. The preference for adopting multiracial children goes against the prevalent method of racial classification, hypodescent, by defining…

Sweeney, Kathryn A.

2013-01-01

30

The evolution of wing color: male mate choice opposes adaptive wing color divergence in Colias butterflies  

Microsoft Academic Search

Correlated evolution of mate signals and mate preference may be constrained if selection pressures acting on mate preference differ from those acting on mate signals. In particular, opposing selection pressures may act on mate preference and signals when traits have sexual as well as nonsexual functions. In the butterfly Colias philodice eriphyle, divergent selection on wing color across an elevational

Jacintha Ellers; Carol L. Boggs

2003-01-01

31

Effect of salt stress in the regulation of anthocyanins and color of hibiscus flowers by digital image analysis.  

PubMed

The effect of salt stress (200 mM NaCl for 28 days) on physiological characteristics of Hibiscus rosa-sinensis, such as abscisic acid (ABA) content, electrolyte leakage, and photochemical efficiency in leaves, and its influence on biomass production, anthocyanin composition, and color expression of flowers were evaluated. Salinity significantly increased electrolyte leakage and ABA content in leaves and reduced the flower fresh weight. Chlorophyll fluorescence parameters were lower in salt stress condition, compared to control. Moreover, salt stress negatively affected the content of anthocyanins (mainly cyanidin-3-sophoroside), which resulted in a visually perceptible loss of color. The detailed anthocyanin composition monitored by HPLC-DAD-MS and the color variations by digital image analysis due to salt stress showed that the effect was more noticeable at the basal portion of petals. A forward stepwise multiple regression was performed for predicting the content of anthocyanins from appearance characteristics obtained by image analysis, reaching R-square values up to 0.90. PMID:25005605

Trivellini, Alice; Gordillo, Belén; Rodríguez-Pulido, Francisco J; Borghesi, Eva; Ferrante, Antonio; Vernieri, Paolo; Quijada-Morín, Natalia; González-Miret, M Lourdes; Heredia, Francisco J

2014-07-23

32

Female sticklebacks use male coloration in mate choice and hence avoid parasitized males  

NASA Astrophysics Data System (ADS)

AN important problem in evolutionary biology since the time of Darwin has been to understand why females preferentially mate with males handicapped by secondary sexual ornaments1-3. One hypothesis of sexual selection theory is that these ornaments reliably reveal the male's condition4-6, which can be affected for example by parasites4,7-13. Here we show that in the three-spined stickleback (Gasterosteus aculeatus) the intensity of male red breeding coloration positively correlates with physical condition. Gravid females base their active mate choice on the intensity of the male's red coloration. Choice experiments under green light prevent the use of red colour cues by females, and males that were previously preferred are now chosen no more than randomly, although the courtship behaviour of the males remains unchanged. Parasitieation causes a deterioration in the males' condition and a decrease in the intensity of their red coloration. Tests under both lighting conditions reveal that the females recognize the formerly parasitized males by the lower intensity of their breeding coloration. Female sticklebacks possibly select a male with a good capacity for paternal care14 but if there is additive genetic variation for parasite resistance, then they might also select for resistance genes, as proposed by Hamilton and Zuk4.

Milinski, Manfred; Bakker, Theo C. M.

1990-03-01

33

Flower Color and Means to Determine Causal Anthocyanins And Their Concentrations1  

Microsoft Academic Search

This paper looks at the issue of the coloration of plants and the ability to estimate the concentrations of certain colorants such as anthocyanins based upon commonly available spectrometer methods. The approach is to begin with classic color theory which has been employed extensively elsewhere and then to develop a model for reflectance using the Beer's model and in turn

Terrence P. McGarty

34

Nonsense mutation of an MYB transcription factor is associated with purple-blue flower color in soybean.  

PubMed

Previous studies revealed that the recessive allele of the W2 locus generated purple-blue color and high vacuolar pH of flower petals in soybean. The location of W2 gene was reportedly close to simple sequence repeat marker Satt318 in molecular linkage group B2. We used information from the soybean genome to clone a candidate gene for W2. An MYB transcription factor gene belonging to G20 group was found in the vicinity of Satt318. Full-length cDNAs were cloned from purple-flowered cultivar Harosoy (W2 allele) and purple-blue flowered cultivars, Nezumisaya and w2-20 (w2 allele), by reverse transcription-PCR and designated as GmMYB-G20-1. Its open reading frame was 1083 bp long that encoded 361 amino acids in Harosoy. GmMYB-G20-1 had 53.7% similarity in amino acid sequence with the PH4 gene of petunia controlling blueness and vacuolar pH of flower petals. GmMYB-G20-1 of Nezumisaya and w2-20 had 3 base substitutions compared with that of Harosoy. The first substitution generated a stop codon in the MYB domain, resulting in truncated polypeptides. Cleaved amplified polymorphic sequence (CAPS) marker was developed to detect the base substitution. The polymorphic CAPS marker co-segregated with alleles at the W2 locus in the F(2) population. These results suggest that GmMYB-G20-1 might correspond to the W2 gene. PMID:21566002

Takahashi, Ryoji; Benitez, Eduardo R; Oyoo, Maurice E; Khan, Nisar A; Komatsu, Setsuko

2011-01-01

35

Apis cerana japonica discriminates between floral color phases of the oriental orchid, Cymbidium floribundum.  

PubMed

Foragers of the Japanese honeybee (Apis cerana japonica) were attracted by flowers of an oriental orchid (Cymbidium floribundum) and were observed to carry the pollinia on their scutella. After the removal of pollinia from the flowers, their labial color changed from white to reddish brown. Both artificial removal of pollinia and ethrel treatment of the flowers also induced this labial color change. Labia in color-changed flowers showed a decreased reflectance of wavelengths less than 670 nm compared to control intact flower. Both reflectance irradiance spectra and ultraviolet photographs showed that only the nectar guide in white (unchanged) flowers reflected ultraviolet light, and that this reflectance decreased with labial color change. Dual choice experiments showed that the honeybee foragers preferentially visited flowers having white labia rather than reddish brown. We suggest that Japanese honeybees discriminate between the floral phases of C. floribundum using color vision. PMID:21110714

Sugahara, Michio; Minamoto, Toshifumi; Fuchikawa, Taro; Michinomae, Masanao; Shimizu, Isamu

2010-12-01

36

Color  

NSDL National Science Digital Library

Using this project will expose you to concepts of color, color wheels, color combinations, and techniques of using color. Use the following links, follow the directions to define color terms, create color schemes and explore the use of color in creating designs. Color Scheme Generator 2 This site identifiesbasic terms related to color, using acolor wheeland making color schemes. Color Theory This site explains terminology of color. Color Theory Tutorial This site gives excellent examples and information about ...

Dent, Mrs.

2010-03-23

37

Do Flower Color and Floral Scent of Silene Species affect Host Preference of Hadena bicruris, a Seed-Eating Pollinator, under Field Conditions?  

PubMed Central

Specialization in plant–insect interactions is an important driver of evolutionary divergence; yet, plant traits mediating such interactions are poorly understood. In this study, we investigated how flower color and floral scent are related to seed predation by a seed-eating pollinator. We used field-transplanted recombinant F2 hybrids between Silene latifolia and S. dioica that are the preferred and alternative hosts of the moth Hadena bicruris and crosses within these species for comparison. We scored seed predation and flower color and analyzed floral scent. Pinker S. dioica-like flowers and emission of ?-pinene decreased the odds of seed predation while emission of benzyl acetate and 6-methyl-5-hepten-2-one increased the odds of seed predation. Emission of these compounds did not differ significantly between the two Silene species. Our results suggest that flower color plays an important role in the specific interaction of H. bicruris with its preferred host S. latifolia. The compounds ?-pinene, benzyl acetate and 6-methyl-5-hepten-2-one could represent non-specific deterrents and attractants to ovipositing moths. Alternatively, emission of these compounds could be related to herbivory or pathogen attack and act as a signal for host quality. This would weaken the predictability of the plant's costs and benefits of the interaction and act to maintain an imperfect degree of specialization.

Page, Paul; Favre, Adrien; Schiestl, Florian P.; Karrenberg, Sophie

2014-01-01

38

Functional analysis of Antirrhinum kelloggii flavonoid 3'-hydroxylase and flavonoid 3',5'-hydroxylase genes; critical role in flower color and evolution in the genus Antirrhinum.  

PubMed

The enzymes flavonoid 3'-hydroxylase (F3'H) and flavonoid 3',5'-hydroxylase (F3'5'H) play an important role in flower color by determining the B-ring hydroxylation pattern of anthocyanins, the major floral pigments. F3'5'H is necessary for biosynthesis of the delphinidin-based anthocyanins that confer a violet or blue color to most plants. Antirrhinum majus does not produce delphinidin and lacks violet flower colour while A. kelloggii produces violet flowers containing delphinidin. To understand the cause of this inter-specific difference in the Antirrhinum genus, we isolated one F3'H and two F3'5'H homologues from the A. kelloggii petal cDNA library. Their amino acid sequences showed high identities to F3'Hs and F3'5'Hs of closely related species. Transgenic petunia expressing these genes had elevated amounts of cyanidin and delphinidin respectively, and flower color changes in the transgenics reflected the type of accumulated anthocyanidins. The results indicate that the homologs encode F3'H and F3'5'H, respectively, and that the ancestor of A. majus lost F3'5'H activity after its speciation from the ancestor of A. kelloggii. PMID:21959781

Ishiguro, Kanako; Taniguchi, Masumi; Tanaka, Yoshikazu

2012-05-01

39

The effect of male coloration on female mate choice in closely related Lake Victoria cichlids ( Haplochromis nyererei complex)  

Microsoft Academic Search

We studied the effect of male coloration on interspecific female mate choice in two closely related species of haplochromine\\u000a cichlids from Lake Victoria. The species differ primarily in male coloration. Males of one species are red, those of the other\\u000a are blue. We recorded the behavioral responses of females to males of both species in paired male trials under white

Ole Seehausen; Jacques J. M. van Alphen

1998-01-01

40

Multisensory integration of colors and scents: insights from bees and flowers.  

PubMed

Karl von Frisch's studies of bees' color vision and chemical senses opened a window into the perceptual world of a species other than our own. A century of subsequent research on bees' visual and olfactory systems has developed along two productive but independent trajectories, leaving the questions of how and why bees use these two senses in concert largely unexplored. Given current interest in multimodal communication and recently discovered interplay between olfaction and vision in humans and Drosophila, understanding multisensory integration in bees is an opportunity to advance knowledge across fields. Using a classic ethological framework, we formulate proximate and ultimate perspectives on bees' use of multisensory stimuli. We discuss interactions between scent and color in the context of bee cognition and perception, focusing on mechanistic and functional approaches, and we highlight opportunities to further explore the development and evolution of multisensory integration. We argue that although the visual and olfactory worlds of bees are perhaps the best-studied of any non-human species, research focusing on the interactions between these two sensory modalities is vitally needed. PMID:24710696

Leonard, Anne S; Masek, Pavel

2014-06-01

41

Wide variety of flower-color and -shape mutants regenerated from leaf cultures irradiated with ion beams  

NASA Astrophysics Data System (ADS)

The efficiency of ion-beam irradiation combined with tissue culture in obtaining floral mutants was investigated and compared with those of gamma rays and X-rays in carnation. Leaf segments of carnation plants in vitro were irradiated with the 220 MeV carbon ions, and cultured till the shoot regenerated. The carbon ion had the highest effect in reducing the regeneration frequency, and the RBE value with respect to gamma-rays was four. The higher mutation frequency and the wider mutation spectrum were obtained in plants irradiated with the carbon ions than low LET radiations. Three new carnation varieties developed by ion-beam irradiation were applied for the registration of the Japanese Ministry of Agriculture, Forestry and Fisheries. The results indicate that ion beam irradiation could induce wide variety of flower-color and -shape mutants, and that the combined method of ion-beam irradiation with tissue culture is useful to obtain the commercial varieties in a short time.

Okamura, M.; Yasuno, N.; Ohtsuka, M.; Tanaka, A.; Shikazono, N.; Hase, Y.

2003-05-01

42

Sexual dimorphism of staminate- and pistillate-phase flowers of Saponaria officinalis (bouncing bet) affects pollinator behavior and seed set.  

PubMed

The sequential separation of male and female function in flowers of dichogamous species allows for the evolution of differing morphologies that maximize fitness through seed siring and seed set. We examined staminate- and pistillate-phase flowers of protandrous Saponaria officinalis for dimorphism in floral traits and their effects on pollinator attraction and seed set. Pistillate-phase flowers have larger petals, greater mass, and are pinker in color, but due to a shape change, pistillate-phase flowers have smaller corolla diameters than staminate-phase flowers. There was no difference in nectar volume or sugar content one day after anthesis, and minimal evidence for UV nectar guide patterns in staminate- and pistillate-phase flowers. When presented with choice arrays, pollinators discriminated against pistillate-phase flowers based on their pink color. Finally, in an experimental garden, in 2012 there was a negative correlation between seed set of an open-pollinated, emasculated flower and pinkness (as measured by reflectance spectrometry) of a pistillate-phase flower on the same plant in plots covered with shade cloth. In 2013, clones of genotypes chosen from the 2012 plants that produced pinker flowers had lower seed set than those from genotypes with paler flowers. Lower seed set of pink genotypes was found in open-pollinated and hand-pollinated flowers, indicating the lower seed set might be due to other differences between pink and pale genotypes in addition to pollinator discrimination against pink flowers. In conclusion, staminate- and pistillate-phase flowers of S. officinalis are dimorphic in shape and color. Pollinators discriminate among flowers based on these differences, and individuals whose pistillate-phase flowers are most different in color from their staminate-phase flowers make fewer seeds. We suggest morphological studies of the two sex phases in dichogamous, hermaphroditic species can contribute to understanding the evolution of sexual dimorphism in plants without the confounding effects of genetic differences between separate male and female individuals. PMID:24690875

Davis, Sandra L; Dudle, Dana A; Nawrocki, Jenna R; Freestone, Leah M; Konieczny, Peter; Tobin, Michael B; Britton, Michael M

2014-01-01

43

Alternative expression of vacuolar iron transporter and ferritin genes leads to blue/purple coloration of flowers in tulip cv. 'Murasakizuisho'.  

PubMed

Flowers of tulip cv. 'Murasakizuisho' have a purple perianth except for the bottom region, which is blue in color even though it has the same anthocyanin, delphinidin 3-O-rutinoside, as the entire perianth. The development of the blue coloration in the perianth bottom is due to complexation by anthocyanin, flavonol and iron (Fe), as well as a vacuolar iron transporter, TgVit1. Although transient expression of TgVit1 in the purple cells led to a color change to light blue, the coloration of the transformed cells did not coincide with the dark blue color of the cells of the perianth bottom. We thought that another factor is required for the blue coloration of the cells of perianth bottom. To examine the effect of ferritin (FER), an Fe storage protein, on blue color development, we cloned an FER gene (TgFER1) and performed expression analyses. TgFER1 transcripts were found in the cells located in the upper region of the petals along with purple color development by anthocyanin and were not found in the blue cells of the perianth bottom. This gene expression is in contrast to that of TgVit1, expressed only in the cells of the perianth bottom. Co-expression of TgVIT1 and TgFER-RNAi, constructed for suppressing endogenous TgFER1 by RNA interference (RNAi), changed the purple petal cells to a dark blue color similar to that of the natural perianth bottom. These results strongly suggest that TgVit1 expression and TgFER1 suppression are critical for the development of blue color in the perianth bottom. PMID:20022978

Shoji, Kazuaki; Momonoi, Kazumi; Tsuji, Tosiaki

2010-02-01

44

Memory-Context Effects of Screen Color in Multiple-Choice and Fill-In Tests  

ERIC Educational Resources Information Center

In this experimental study, 44 undergraduates completed five computer-based instructional lessons and either two multiplechoice tests or two fill-in-the-blank tests. Color-coded borders were displayed during the lesson, adjacent to the screen text and illustrations. In the experimental condition, corresponding border colors were shown at posttest.…

Prestera, Gustavo E.; Clariana, Roy; Peck, Andrew

2005-01-01

45

Age Differences in the Associations between Felt Temperatures and Color Choices  

ERIC Educational Resources Information Center

The present study was designed to explore age differences in the association of temperatures with specific colors, using as stimuli actual felt temperatures rather than the 'imagined' or ambient temperatures used in other studies. (Author)

Morgan, George A.; And Others

1975-01-01

46

Seeing the light: illumination as a contextual cue to color choice behavior in bumblebees.  

PubMed

The principal challenge faced by any color vision system is to contend with the inherent ambiguity of stimulus information, which represents the interaction between multiple attributes of the world (e.g., object reflectance and illumination). How natural systems deal with this problem is not known, although traditional hypotheses are predicated on the idea that vision represents object reflectance accurately by discounting early in processing the conflating effects of illumination. Here, we test the merits of this general supposition by confronting bumblebees (Bombus terrestris) with a color discrimination task that can be solved only if information about the illuminant is not discounted but maintained in processing and thus available to higher-order learned behavior. We show that bees correctly use the intensity and chromaticity of illumination as a contextual cue to guide them to different target colors. In fact, we trained bees to choose opposite, rather than most similar, target colors after an illumination change. This performance cannot be explained with a simple color-constancy mechanism that discounts illumination. Further tests show that bees do not use a simple assessment of the overhead illumination, but that they assess the spectral relationships between a floral target and its background. These results demonstrate that bees can be color-constant without discounting the illuminant; that, in fact, they can use information about the illuminant itself as a salient source of information. PMID:15731346

Lotto, R Beau; Chittka, Lars

2005-03-01

47

The b Gene of Pea Encodes a Defective Flavonoid 3?,5?-Hydroxylase, and Confers Pink Flower Color1[W][OA  

PubMed Central

The inheritance of flower color in pea (Pisum sativum) has been studied for more than a century, but many of the genes corresponding to these classical loci remain unidentified. Anthocyanins are the main flower pigments in pea. These are generated via the flavonoid biosynthetic pathway, which has been studied in detail and is well conserved among higher plants. A previous proposal that the Clariroseus (B) gene of pea controls hydroxylation at the 5? position of the B ring of flavonoid precursors of the anthocyanins suggested to us that the gene encoding flavonoid 3?,5?-hydroxylase (F3?5?H), the enzyme that hydroxylates the 5? position of the B ring, was a good candidate for B. In order to test this hypothesis, we examined mutants generated by fast neutron bombardment. We found allelic pink-flowered b mutant lines that carried a variety of lesions in an F3?5?H gene, including complete gene deletions. The b mutants lacked glycosylated delphinidin and petunidin, the major pigments present in the progenitor purple-flowered wild-type pea. These results, combined with the finding that the F3?5?H gene cosegregates with b in a genetic mapping population, strongly support our hypothesis that the B gene of pea corresponds to a F3?5?H gene. The molecular characterization of genes involved in pigmentation in pea provides valuable anchor markers for comparative legume genomics and will help to identify differences in anthocyanin biosynthesis that lead to variation in pigmentation among legume species.

Moreau, Carol; Ambrose, Mike J.; Turner, Lynda; Hill, Lionel; Ellis, T.H. Noel; Hofer, Julie M.I.

2012-01-01

48

Flowers, Beautiful Flowers  

ERIC Educational Resources Information Center

In the lesson described, the middle school students had been studying the artist Georgia O'Keeffe and the history of her work. Students enhanced their flower portraits by adding a matching border and connecting the lesson to other subject areas. Students dissected a flower and drew a small diagram of the flower and labeled the parts. This is an…

School Arts: The Art Education Magazine for Teachers, 2005

2005-01-01

49

Design a Flower  

NSDL National Science Digital Library

In this activity, learners learn about the adaptations that flowers have developed which support pollination. Learners also list their personal preferences (i.e. favorite color, food) and a partner will create a "designer flower" to match their preferences. Learners can participate in a Take-Home challenge, in which they will draw a fictional pollinator-plant pair.

Pollack, Lydia

2010-01-01

50

COLORS!  

NSDL National Science Digital Library

In this project, students will learn about primary, secondary, and complementary colors. After exploring a few sites and participating in a few deep questions as a class, they will create an optical illusion using complimentary colors. Younger students who are learning this unit will need to do this activity with a parent or as a class with a teacher or aide. INTRODUCTION: Questions to discuss with the students: 1. What colors do you see in this room? 2. What are some jobs that use colors? An Artist? Decorator? ...

Sarah

2009-09-28

51

Color-Changing Carnations  

NSDL National Science Digital Library

Learners place cut flowers in colored water and observe how the flowers change. The flowers absorb the water through the stem and leaves. By watching the journey of harmless food coloring, learners can see all the places water goes in a plant.

Museum Of Science And Industry, Chicago

2012-01-01

52

Age differences in the associations between felt temperatures and color choices.  

PubMed

Thirty-six subjects, twelve each at 6, 12, and 18 years of age, were asked which of four colors (blue, green, yellow, or red) they were reminded of by each of four temperatures (containers at 4, 23, 35, or 45 deg C). More 18-year-olds than expected by chance made each of the conventional associations: hot/red, warm/yellow, cool/green, cold/blue. The 12-year-olds reliably made the hot/red association but none of the others. No more 6-year-olds than expected by chance made any of the conventional associations. The results suggest that the conventional associations are founded on a loosely held cultural norm rather than on an evolutionary or physiological basis. PMID:1236563

Morgan, G A; Goodson, F E; Jones, T

1975-03-01

53

'Le Rouge et le Noir': A decline in flavone formation correlates with the rare color of black dahlia (Dahlia variabilis hort.) flowers  

PubMed Central

Background More than 20,000 cultivars of garden dahlia (Dahlia variabilis hort.) are available showing flower colour from white, yellow and orange to every imaginable hue of red and purple tones. Thereof, only a handful of cultivars are so-called black dahlias showing distinct black-red tints. Flower colour in dahlia is a result of the accumulation of red anthocyanins, yellow anthochlors (6’-deoxychalcones and 4-deoxyaurones) and colourless flavones and flavonols, which act as copigments. White and yellow coloration occurs only if the pathway leading to anthocyanins is incomplete. Not in all cultivars the same step of the anthocyanin pathway is affected, but the lack of dihydroflavonol 4-reductase activity is frequently observed and this seems to be based on the suppression of the transcription factor DvIVS. The hitherto unknown molecular background for black colour in dahlia is here presented. Results Black cultivars accumulate high amounts of anthocyanins, but show drastically reduced flavone contents. High activities were observed for all enzymes from the anthocyanin pathway whereas FNS II activity could not be detected or only to a low extent in 13 of 14 cultivars. cDNA clones and genomic clones of FNS II were isolated. Independently from the colour type, heterologous expression of the cDNA clones resulted in functionally active enzymes. FNS II possesses one intron of varying length. Quantitative Real-time PCR showed that FNS II expression in black cultivars is low compared to other cultivars. No differences between black and red cultivars were observed in the expression of transcription factors IVS and possible regulatory genes WDR1, WDR2, MYB1, MYB2, 3RMYB and DEL or the structural genes of the flavonoid pathway. Despite the suppression of FHT expression, flavanone 3-hydroxylase (FHT, synonym F3H) enzyme activity was clearly present in the yellow and white cultivars. Conclusions An increased accumulation of anthocyanins establishes the black flowering phenotypes. In the majority of black cultivars this is due to decreased flavone accumulation and thus a lack of competition for flavanones as the common precursors of flavone formation and the anthocyanin pathway. The low FNS II activity is reflected by decreased FNS II expression.

2012-01-01

54

Flower Parts.  

ERIC Educational Resources Information Center

Presents ideas for spring flower displays. Has students constructing their own interactive flower displays as extra-credit assignments to reinforce vocabulary and scientific concepts, and modeling flowers with household items. (JRH)

Steinheimer, Margaret

1997-01-01

55

Hyperacidification of vacuoles by the combined action of two different P-ATPases in the tonoplast determines flower color.  

PubMed

The acidification of endomembrane compartments is essential for enzyme activities, sorting, trafficking, and trans-membrane transport of various compounds. Vacuoles are mildly acidic in most plant cells because of the action of V-ATPase and/or pyrophosphatase proton pumps but are hyperacidified in specific cells by mechanisms that remained unclear. Here, we show that the blue petal color of petunia ph mutants is due to a failure to hyperacidify vacuoles. We report that PH1 encodes a P3B-ATPase, hitherto known as Mg2(+) transporters in bacteria only, that resides in the vacuolar membrane (tonoplast). In vivo nuclear magnetic resonance and genetic data show that PH1 is required and, together with the tonoplast H(+) P3A-ATPase PH5, sufficient to hyperacidify vacuoles. PH1 has no H(+) transport activity on its own but can physically interact with PH5 and boost PH5 H(+) transport activity. Hence, the hyperacidification of vacuoles in petals, and possibly other tissues, relies on a heteromeric P-ATPase pump. PMID:24388746

Faraco, Marianna; Spelt, Cornelis; Bliek, Mattijs; Verweij, Walter; Hoshino, Atsushi; Espen, Luca; Prinsi, Bhakti; Jaarsma, Rinse; Tarhan, Eray; de Boer, Albertus H; Di Sansebastiano, Gian-Pietro; Koes, Ronald; Quattrocchio, Francesca M

2014-01-16

56

Discovering Flowers in a New Light  

NSDL National Science Digital Library

Although students may have made observations of plants and flowers, not many have looked closely at their various structures or seen the colorful designs of flowers that are only apparent when magnified. The 5E learning cycle described in this article engages students in scientific inquiry using digital microscopy to explore the various parts of a flower.

Bell, Randy L.; Mcnall, Rebecca L.

2004-01-01

57

Florivores prefer white versus pink petal color morphs in wild radish, Raphanus sativus.  

PubMed

Many hypotheses suggest that pollinators act to maintain or change floral color morph frequencies in nature, although pollinator preferences do not always match color morph frequencies in the field. Therefore, non-pollinating agents may also be responsible for color morph frequencies. To test this hypothesis, we examined whether Raphanus sativus plants with white flowers received different amounts of florivory than plants with pink flowers, and whether florivores preferred one floral color over the other. We found that white-flowered plants received significantly more floral damage than pink-flowered plants in eight populations over 4 years in northern California. Both generalists and specialists on Brassicaceae preferred white petals in choice and short-term no choice tests. In performance tests, generalists gained more weight on white versus pink petals whereas specialists gained similar amounts of weight on pink and white morphs. Because our results suggest that florivores prefer and perform better on white versus pink flowers, these insects may have the opportunity to affect the frequency of color morphs in the field. PMID:23080301

McCall, Andrew C; Murphy, Stephen J; Venner, Colin; Brown, Monique

2013-05-01

58

Colorful Collage: Visions of Flowers  

ERIC Educational Resources Information Center

The technique of what people today call "collage" is not new. In Victorian times, elaborate art was created from bristly horsehair as a type of collage. The modern collage dates to the early 1900s when Picasso pasted newspaper on a drawing. In 1919 Karl Schwitters, a German artist, developed collage into an art form that was as important as…

Skophammer, Karen

2011-01-01

59

Colors, Colors?  

NSDL National Science Digital Library

In this activity related to the famous "Stroop Effect," learners explore how words influence what we see and how the brain handles "mixed messages." Learners read colored words and are asked to say the color of the word, not what the word says. Learners use a data table to keep track of where they have trouble reading the colors. They analyze this data by answering questions and drawing conclusions. Learners can also take this test using the online version.

Songstad, Susan

2009-01-01

60

Flower Fisting  

Microsoft Academic Search

This essay asks about the fate of flowers in an age of colony collapse disorder and market-driven industrial agriculture. From human hand-pollination to the genetic selection of self-pollinating crops, contemporary responses to CCD bring to ironic conclusion certain tropes of flowers as figures of deceit, mortality, transience, and appearance without substance. Taking \\

Anne-Lise François

2011-01-01

61

Flower Development  

PubMed Central

Flowers are the most complex structures of plants. Studies of Arabidopsis thaliana, which has typical eudicot flowers, have been fundamental in advancing the structural and molecular understanding of flower development. The main processes and stages of Arabidopsis flower development are summarized to provide a framework in which to interpret the detailed molecular genetic studies of genes assigned functions during flower development and is extended to recent genomics studies uncovering the key regulatory modules involved. Computational models have been used to study the concerted action and dynamics of the gene regulatory module that underlies patterning of the Arabidopsis inflorescence meristem and specification of the primordial cell types during early stages of flower development. This includes the gene combinations that specify sepal, petal, stamen and carpel identity, and genes that interact with them. As a dynamic gene regulatory network this module has been shown to converge to stable multigenic profiles that depend upon the overall network topology and are thus robust, which can explain the canalization of flower organ determination and the overall conservation of the basic flower plan among eudicots. Comparative and evolutionary approaches derived from Arabidopsis studies pave the way to studying the molecular basis of diverse floral morphologies.

Alvarez-Buylla, Elena R.; Benitez, Mariana; Corvera-Poire, Adriana; Chaos Cador, Alvaro; de Folter, Stefan; Gamboa de Buen, Alicia; Garay-Arroyo, Adriana; Garcia-Ponce, Berenice; Jaimes-Miranda, Fabiola; Perez-Ruiz, Rigoberto V.; Pineyro-Nelson, Alma; Sanchez-Corrales, Yara E.

2010-01-01

62

Flower development.  

PubMed

Flowers are the most complex structures of plants. Studies of Arabidopsis thaliana, which has typical eudicot flowers, have been fundamental in advancing the structural and molecular understanding of flower development. The main processes and stages of Arabidopsis flower development are summarized to provide a framework in which to interpret the detailed molecular genetic studies of genes assigned functions during flower development and is extended to recent genomics studies uncovering the key regulatory modules involved. Computational models have been used to study the concerted action and dynamics of the gene regulatory module that underlies patterning of the Arabidopsis inflorescence meristem and specification of the primordial cell types during early stages of flower development. This includes the gene combinations that specify sepal, petal, stamen and carpel identity, and genes that interact with them. As a dynamic gene regulatory network this module has been shown to converge to stable multigenic profiles that depend upon the overall network topology and are thus robust, which can explain the canalization of flower organ determination and the overall conservation of the basic flower plan among eudicots. Comparative and evolutionary approaches derived from Arabidopsis studies pave the way to studying the molecular basis of diverse floral morphologies. PMID:22303253

Alvarez-Buylla, Elena R; Benítez, Mariana; Corvera-Poiré, Adriana; Chaos Cador, Alvaro; de Folter, Stefan; Gamboa de Buen, Alicia; Garay-Arroyo, Adriana; García-Ponce, Berenice; Jaimes-Miranda, Fabiola; Pérez-Ruiz, Rigoberto V; Piñeyro-Nelson, Alma; Sánchez-Corrales, Yara E

2010-01-01

63

Flowers & Weeds.  

ERIC Educational Resources Information Center

Describes the topics and teaching strategies employed in an Issues in Biology course. Discusses flowers, plant breeding, potatoes and tomatoes, the chocolate tree, weeds, Arabidopis, gene transfers, and plant genes/human genes. Contains 22 references. (JRH)

Flannery, Maura C.

1996-01-01

64

Genetic and linkage analysis of purple-blue flower in soybean.  

PubMed

Flower color of soybean is primarily controlled by genes W1, W3, W4, Wm, and Wp. In addition, the soybean gene symbol W2, w2 produces purple-blue flower in combination with W1. This study was conducted to determine the genetic control of purple-blue flower of cultivar (cv). Nezumisaya. F(1) plants derived from a cross between Nezumisaya and purple flower cv. Harosoy had purple flowers. Segregation of the F(2) plants fitted a ratio of 3 purple:1 purple-blue. F(3) lines derived from F(2) plants with purple-blue flowers were fixed for purple-blue flowers, whereas those from F(2) plants with purple flowers fitted a ratio of 1 fixed for purple flower:2 segregating for flower color. These results indicated that the flower color of Nezumisaya is controlled by a single gene whose recessive allele is responsible for purple-blue flower. Complementation analysis revealed that flower color of Nezumisaya is controlled by W2. Linkage mapping revealed that W2 is located in molecular linkage group B2. Sap obtained from banner petals of cvs. with purple flower had a pH value of 5.73-5.77, whereas that of cvs. with purple-blue flower had a value of 6.07-6.10. Our results suggested that W2 is responsible for vacuolar acidification of flower petals. PMID:18502733

Takahashi, Ryoji; Matsumura, Hisakazu; Oyoo, Maurice E; Khan, Nisar A

2008-01-01

65

Flowers in Their Variety.  

ERIC Educational Resources Information Center

Describes the diversity of flowers with regard to the flower paintings of Pierre-Joseph Redoute, books about flowers, and research in genetic studies. Discusses gardening flowers and flowering strategies and criticizes the fact that biology education has moved steadily away from plants. (KHR)

Flannery, Maura C.

2002-01-01

66

Seeing Color in School Choice  

ERIC Educational Resources Information Center

Research across states has consistently shown that African American parents tend to send their children to charter schools with higher concentrations of African American students as compared to the concentrations of the district-assigned schools their children would otherwise attend. However, little research has addressed why these parents choose…

Lewis, Wayne D.; Danzig, Arnold

2010-01-01

67

Flower diversity and angiosperm diversification.  

PubMed

The flower itself, which comprises most of the evolutionary innovations of flowering plants, bears special significance for understanding the origin and diversification of angiosperms. The sudden origin of angiosperms in the fossil record poses unanswered questions on both the origins of flowering plants and their rapid spread and diversification. Central to these questions is the role that the flower, and floral diversity, played. Recent clarifications of angiosperm phylogeny provide the foundation for investigating evolutionary transitions in floral features and the underlying genetic mechanisms of stasis and change. The general features of floral diversity can best be addressed by considering key patterns of variation: an undifferentiated versus a differentiated perianth; elaboration of perianth organs in size and color; merosity of the flower; and phyllotaxy of floral organs. Various models of gene expression now explain the regulation of floral organization and floral organ identity; the best understood are the ABC(E) model and its modifications, but other gene systems are important in specific clades and require further study. Furthermore, the propensity for gene and genome duplications in angiosperms provides abundant raw material for novel floral features--emphasizing the importance of understanding the conservation and diversification of gene lineages and functions in studies of macroevolution. PMID:24395253

Soltis, Pamela S; Soltis, Douglas E

2014-01-01

68

Infants' Recognition of Objects Using Canonical Color  

ERIC Educational Resources Information Center

We explored infants' ability to recognize the canonical colors of daily objects, including two color-specific objects (human face and fruit) and a non-color-specific object (flower), by using a preferential looking technique. A total of 58 infants between 5 and 8 months of age were tested with a stimulus composed of two color pictures of an object…

Kimura, Atsushi; Wada, Yuji; Yang, Jiale; Otsuka, Yumiko; Dan, Ippeita; Masuda, Tomohiro; Kanazawa, So; Yamaguchi, Masami K.

2010-01-01

69

The regulation of carotenoid pigmentation in flowers.  

PubMed

Carotenoids fulfill many processes that are essential for normal growth and development in plants, but they are also responsible for the breathtaking variety of red-to-yellow colors we see in flowers and fruits. Although such visual diversity helps to attract pollinators and encourages herbivores to distribute seeds, humans also benefit from the aesthetic properties of flowers and an entire floriculture industry has developed on the basis that new and attractive varieties can be produced. Over the last decade, much has been learned about the impact of carotenoid metabolism on flower color development and the molecular basis of flower color. A number of different regulatory mechanisms have been described ranging from the transcriptional regulation of genes involved in carotenoid synthesis to the control of carotenoid storage in sink organs. This means we can now explain many of the natural colorful varieties we see around us and also engineer plants to produce flowers with novel and exciting varieties that are not provided by nature. PMID:20688043

Zhu, Changfu; Bai, Chao; Sanahuja, Georgina; Yuan, Dawei; Farré, Gemma; Naqvi, Shaista; Shi, Lianxuan; Capell, Teresa; Christou, Paul

2010-12-01

70

Color Constant Color Indexing  

Microsoft Academic Search

Objects can be recognized on the basis of their color alone by color indexing, a technique developed by Swain-Ballard (1991) which involves matching color-space histograms. Color indexing fails, however, when the incident illumination varies either spatially or spectrally. Although this limitation might be overcome by preprocessing with a color constancy algorithm, we instead propose histogramming color ratios. Since the ratios

Brian V. Funt; Graham D. Finlayson

1995-01-01

71

I Can Count the Petals of a Flower. Second Edition.  

ERIC Educational Resources Information Center

This book introduces children to the numbers 1 through 16 (and some basic mathematical concepts) using the petals of a variety of flowers. The first part of the book contains 16 full-color photographs, each photograph showing a flower with 1 to 16 petals, with the number printed below the photograph. These pages can be used to introduce or…

Wahl, John; Wahl, Stacey

72

Sepal phenolic profile during Helleborus niger flower development.  

PubMed

Morphological changes and phenolic patterns of developing hellebore sepals and the effects of pistil removal on these parameters were studied by comparing six flower stages of Helleborus niger. Color changes were evaluated colorimetrically, chlorophyll content was measured spectrophotometrically, and anthocyanins and flavonols were identified and quantified with HPLC-MS. Pistil removal not only altered the morphological development of hellebore flower resulting in smaller flower and significant color changes but also lead to several biochemical modifications. Five cyanidin glycosides have been identified from the group of anthocyanins in hellebore. Individual and total anthocyanin content increased from bud to subsequent developmental stages. Moreover, significantly higher content levels of individual and total anthocyanins have been measured in non-pollinated flower sepals compared to sepals of pollinated flowers. From the group of flavonols eight quercetin and kaempferol compounds have been quantified in hellebore sepals. Flavonol content significantly decreased during flower development with lowest levels recorded in sepals of non-pollinated and senescent pollinated hellebore flowers. Sepals of pollinated flowers contained highest levels of chlorophyll and significantly lower amounts of chlorophyll were measured in non-pollinated flowers and in sepals of senescent stage. PMID:23796521

Schmitzer, Valentina; Mikulic-Petkovsek, Maja; Stampar, Franci

2013-11-01

73

Design a Hummingbird Flower.  

ERIC Educational Resources Information Center

Presents an activity that engages students in designing and making an artificial flower adapted for pollination by hummingbirds. Students work in teams to design flowers that maximize the benefit from attracting hummingbirds. Examines characteristics of real flowers adapted to pollination by hummingbirds. (DLH)

Bailey, Kim

2002-01-01

74

Ancient Bisexual Flowers  

Microsoft Academic Search

Fossil flowers discovered in 94-million-year-old clays of the Dakota Formation in Nebraska are among the earliest known demonstrably bisexual flowers. The flowers are of medium size and have pentamerous whorls of clearly differentiated floral parts, petals alternate with the sepals, short stamens are borne opposite the petals, the carpels are fused, and a receptacular disk is present. The pollen is

James F. Basinger; David L. Dilcher

1984-01-01

75

Color Sensor.  

National Technical Information Service (NTIS)

A color sensor for generating color information defining colors of an image includes an input section, a color processing section, a color comparison section, a color boundary processing section and a memory processing section. The input section includes ...

R. L. Woodall

2001-01-01

76

'Who's who' in two different flower types of Calluna vulgaris (Ericaceae): morphological and molecular analyses of flower organ identity  

PubMed Central

Background The ornamental crop Calluna vulgaris is of increasing importance to the horticultural industry in the northern hemisphere due to a flower organ mutation: the flowers of the 'bud-flowering' phenotype remain closed i.e. as buds throughout the total flowering period and thereby maintain more colorful flowers for a longer period of time than the wild-type. This feature is accompanied and presumably caused by the complete lack of stamens. Descriptions of this botanical particularity are inconsistent and partially conflicting. In order to clarify basic questions of flower organ identity in general and stamen loss in detail, a study of the wild-type and the 'bud-flowering' flower type of C. vulgaris was initiated. Results Flowers were examined by macro- and microscopic techniques. Organ development was investigated comparatively in both the wild-type and the 'bud-flowering' type by histological analyses. Analysis of epidermal cell surface structure of vegetative tissues and perianth organs using scanning electron microscopy revealed that in wild-type flowers the outer whorls of colored organs may be identified as sepals, while the inner ones may be identified as petals. In the 'bud-flowering' type, two whorls of sepals are directly followed by the gynoecium. Both, petals and stamens, are completely missing in this flower type. The uppermost whorl of green leaves represents bracts in both flower types. In addition, two MADS-box genes (homologs of AP3/DEF and SEP1/2) were identified in C. vulgaris using RACE-PCR. Expression analysis by qRT-PCR was conducted for both genes in leaves, bracts, sepals and petals. These experiments revealed an expression pattern supporting the organ classification based on morphological characteristics. Conclusions Organ identity in both wild-type and 'bud-flowering' C. vulgaris was clarified using a combination of microscopic and molecular methods. Our results for bract, sepal and petal organ identity are supported by the 'ABCDE model'. However, loss of stamens in the 'bud-flowering' phenotype is an exceptional flower organ modification that cannot be explained by modified spatial expression of known organ identity genes.

2009-01-01

77

Enriching tortoises: assessing color preference.  

PubMed

Environmental enrichment is a principle that is used to enhance the quality of care for nonhuman animals in captivity. To achieve this, it is necessary to understand the animal's needs. This study focused on color preference to provide food stimuli as a source of environmental enrichment for the tortoise, Chelonoidis denticulata. During this study, the stimuli green-, blue-, yellow-, and red-colored bananas and plaster blocks were randomly offered to the tortoises. Analysis of the data showed that the tortoises had a preference for the stimuli dyed with colors red and yellow over the other presented colors. It was possible to conclude that presenting food in different colors stimulated the animals to evaluate their environment and make choices in relation to their color preference. Thus, this experiment introduced an element of choice into their lives, beyond identifying color food preferences for the tortoises. The element of choice is known to be important to animal welfare. PMID:24911428

Passos, Luiza F; Mello, Humberto Espirito Santo; Young, Robert John

2014-01-01

78

Iridescent flowers? Contribution of surface structures to optical signaling.  

PubMed

The color of natural objects depends on how they are structured and pigmented. In flowers, both the surface structure of the petals and the pigments they contain determine coloration. The aim of the present study was to assess the contribution of structural coloration, including iridescence, to overall floral coloration. We studied the reflection characteristics of flower petals of various plant species with an imaging scatterometer, which allows direct visualization of the angle dependence of the reflected light in the hemisphere above the petal. To separate the light reflected by the flower surface from the light backscattered by the components inside (e.g. the vacuoles), we also investigated surface casts. A survey among angiosperms revealed three different types of floral surface structure, each with distinct reflections. Petals with a smooth and very flat surface had mirror-like reflections and petal surfaces with cones yielded diffuse reflections. Petals with striations yielded diffraction patterns when single cells were illuminated. The iridescent signal, however, vanished when illumination similar to that found in natural conditions was applied. Pigmentary rather than structural coloration determines the optical appearance of flowers. Therefore, the hypothesized signaling by flowers with striated surfaces to attract potential pollinators presently seems untenable. PMID:24713039

van der Kooi, Casper J; Wilts, Bodo D; Leertouwer, Hein L; Staal, Marten; Elzenga, J Theo M; Stavenga, Doekele G

2014-07-01

79

Utilization of Temple waste flower -Tagetus erecta for Dyeing of Cotton, Wool and Silk on Industrial scale  

Microsoft Academic Search

Huge amounts of Tagetus erecta (marigold) flowers are offered in temples in India, creating a very large waste. These waste flowers were collected and used for industrial dyeing. Tagetus belongs to the family Asteraceae. It produces natural dye from its flowers (petals) consisting mainly of carotenoid-lutein and flavonoid- patuletin, these colorants have been isolated and identified. The crude extract has

Padma S. Vankar; Rakhi Shanker

2009-01-01

80

Occurrence of nudicaulin structural variants in flowers of papaveraceous species.  

PubMed

The intense color of yellow Papaver nudicaule flowers is conferred by the presence of nudicaulins, a group of alkaloids with a unique pentacyclic skeleton composed of an indole ring and a polyphenolic moiety. Petals from eight different Papaveraceae species composed of different color varieties were probed for the presence of nudicaulins. In addition to their occurrence in yellow P. nudicaule flowers, nudicaulins I-VIII were detected and quantified in orange flowers of P. nudicaule, and in yellow and orange Papaver alpinum flowers. Meconopsis cambrica petals showed a divergent nudicaulin spectrum, with compounds having an attached 3-hydroxy-3-methyl-glutaryl group (HMG) instead of a malonyl unit at one of the glucose units. Flavonols and anthocyanins that accompany nudicaulins were identified. The taxonomical significance of the occurrence of nudicaulins is briefly discussed. PMID:23684236

Tatsis, Evangelos C; Böhm, Hartmut; Schneider, Bernd

2013-08-01

81

Computer color reproduction  

NASA Astrophysics Data System (ADS)

Computer based color imaging is rapidly moving from the realm of the specialist to the general public. To enable users the greatest benefit from advances in color image reproduction technology, the computer systems have to modify to incorporate this new technology. Two possible approaches are described - by the adoption of color management system software, and by the adoption of device independent color variables. Although both systems are likely to perform equally well when properly configured, the later is likely to be the long term choice as it will yield the most robust, lower cost and transparent system.

Motta, Ricardo J.

1995-04-01

82

Identification of Mendel's White Flower Character  

Microsoft Academic Search

BackgroundThe genetic regulation of flower color has been widely studied, notably as a character used by Mendel and his predecessors in the study of inheritance in pea.Methodology\\/Principal FindingsWe used the genome sequence of model legumes, together with their known synteny to the pea genome to identify candidate genes for the A and A2 loci in pea. We then used a

Roger P. Hellens; Carol Moreau; Kui Lin-Wang; Kathy E. Schwinn; Susan J. Thomson; Mark W. E. J. Fiers; Tonya J. Frew; Sarah R. Murray; Julie M. I. Hofer; Jeanne M. E. Jacobs; Kevin M. Davies; Andrew C. Allan; Abdelhafid Bendahmane; Clarice J. Coyne; Gail M. Timmerman-Vaughan; T. H. Noel Ellis

2010-01-01

83

Optimum harvesting time of herbaceous peony buds for cutting flowers  

Microsoft Academic Search

The herbaceous peony is one of the cut flowers that has become increasingly popular in the international market in recent\\u000a years. In the study, 11 cultivars of herbaceous peonies suitable for cutting flowers were selected; different harvesting stages\\u000a (three or four stages) were identified according to bud development observation (bud firmness, bud diameter, sepal angle,\\u000a petal angle, and color showing).

Xiao-nan Yu; Peng-peng Guo; Guang-pei Lu; Qi-xiang Zhang

2011-01-01

84

Heat-producing flowers  

Microsoft Academic Search

The flowers of some plants produce enough heat to raise their temperatures as much as 35°C above air temperature. Three species have been shown to regulate flower temperature within a narrow range by an unknown physiological mechanism that increases the rate of heat production as air temperature decreases. Thermogenic plants occur only in ancient families of seed plants, and have

Roger S. Seymour; Paul Schultze-Motel

1997-01-01

85

Grass flower development.  

PubMed

Grasses bear unique flowers lacking obvious petals and sepals in special inflorescence units, the florets and the spikelet. Despite this, grass floral organs such as stamens and lodicules (petal homologs) are specified by ABC homeotic genes encoding MADS domain transcription factors, suggesting that the ABC model of eudicot flower development is largely applicable to grass flowers. However, some modifications need to be made for the model to fit grasses well: for example, a YABBY gene plays an important role in carpel specification. In addition, a number of genes are involved in the development of the lateral organs that constitute the spikelet. In this review, we discuss recent progress in elucidating the genes required for flower and spikelet development in grasses, together with those involved in fate determination of the spikelet and flower meristems. PMID:24395252

Hirano, Hiro-Yuki; Tanaka, Wakana; Toriba, Taiyo

2014-01-01

86

Skin Segmentation Using Color Pixel Classification: Analysis and Comparison  

Microsoft Academic Search

This work presents a study of three important issues of the color pixel classification approach to skin segmentation: color representation, color quantization, and classification algorithm. Our analysis of several representative color spaces using the Bayesian classifier with the histogram technique shows that skin segmentation based on color pixel classification is largely unaffected by the choice of the color space. However,

Son Lam Phung; Abdesselam Bouzerdoum; Douglas Chai

2005-01-01

87

The breath of a flower  

PubMed Central

In this article I comment on our findings that floral carbon dioxide (CO2) can be used by Manduca sexta hawkmoths in a scale- and context-dependent fashion. We firstly found, in wind tunnel assays, that diffusing floral CO2 is used as long-distance cue (e.g., meters). Moths track CO2 plumes up-wind in the same manner they track floral odors. Nevertheless, CO2 did not appear to function as a local stimulus for flower probing, evidencing a scale-dependent role in nectar foraging. These results were further enriched by a second finding. In dual choice assays, where moths were offered two scented artificial flowers of which only one emitted above-ambient CO2-levels, female Manduca sexta chose to feed on the CO2 emitting flower only when host-plant volatiles were added to the background. We discuss this apparent measurement of oviposition obligations during foraging in the context of the life histories of both insect and plant species. These findings seem to pinpoint the usually artificial nature of compartmentalizing herbivory and pollination as different, isolated aspects of insect-plant interactions. Insects do not seem to have a defined response to a certain stimulus; instead, motor programs appear to be in response to composite arrangements of external stimuli and inner states. If animal-plant interactions have evolved under these premises, I believe it may prove beneficial to include a non-linear, integrative view of plant multi-signaling and life history aspects into the study of pollination biology.

2008-01-01

88

Color Me Safe Coloring Book  

MedlinePLUS

... to... Añadir en... Favorites Delicious Digg Google Bookmarks Color Me Safe Color Me Safe is a coloring book designed for ... the pictures and reading about the Safe Family. Color Me Safe can help parents talk with their ...

89

Flower Constancy, Insect Psychology, and Plant Evolution  

NASA Astrophysics Data System (ADS)

Individuals of some species of pollinating insects tend to restrict their visits to only a few of the available plant species, in the process bypassing valuable food sources. The question of why this flower constancy exists is a rich and important one with implications for the organization of natural communities of plants, floral evolution, and our understanding of the learning processes involved in finding food. Some scientists have assumed that flower constancy is adaptive per se. Others argued that constancy occurs because memory capacity for floral features in insects is limited, but attempts to identify the limitations often remained rather simplistic. We elucidate now different sensory and motor memories from natural foraging tasks are stored and retrieved, using concepts from modern learning science and visual search, and conclude that flower constancy is likely to have multiple causes. Possible constraints favoring constancy are interference sensitivity of short-term memory, and temporal limitations on retrieving information from long-term memory as rapidly as from short-term memory, but further empirical evidence is needed to substantiate these possibilities. In addition, retrieving memories may be slower and more prone to errors when there are several options than when an insect copes with only a single task. In addition to memory limitations, we also point out alternative explanations for flower constancy. We then consider the way in which floral parameters, such as interplant distances, nectar rewards, flower morphology, and floral color (as seen through bees' eyes) affect constancy. Finally, we discuss the implications of pollinator constancy for plant evolution. To date there is no evidence that flowers have diverged to favor constancy, although the appropriate tests may not have yet been conducted. However, there is good evidence against the notion that pollinator constancy is involved in speciation or maintenance of plant species integrity.

Chittka, Lars; Thomson, James D.; Waser, Nickolas M.

90

Stars and Flowers, Flowers and Stars  

NASA Astrophysics Data System (ADS)

The author, a graduated from the Bucharest University (1964), actually living and working in Israel, concerns his book to variable stars and flowers, two domains of his interest. The analogies includes double stars, eclipsing double stars, eclipses, Big Bang. The book contains 34 chapters, each of which concerns various relations between astronomy and other sciences and pseudosciences such as Psychology, Religion, Geology, Computers and Astrology (to which the author is not an adherent). A special part of the book is dedicated to archeoastronomy and ethnoastronomy, as well as to history of astronomy. Between the main points of interest of these parts: ancient sanctuaries in Sarmizegetusa (Dacia), Stone Henge(UK) and other. The last chapter of the book is dedicated to flowers. The book is richly illustrated. It is designed for a wide circle of readers.

Minti, Hari

2012-12-01

91

Caught between Parasitoids and Predators - Survival of a Specialist Herbivore on Leaves and Flowers of Mustard Plants.  

PubMed

The survival of insect herbivores typically is constrained by food choice and predation risk. Here, we explored whether movement from leaves to flowers increases survival of herbivores that prefer to feed on floral tissues. Combining field and greenhouse experiments, we investigated whether flowering influences the behavior of Pieris brassicae butterflies and caterpillars and, consequently, herbivore survival in the field. In this context, we investigated also if flowers of Brassica nigra can provide caterpillars refuge from the specialist parasitoid Cotesia glomerata and from predatory social wasps. By moving to flowers, caterpillars escaped from the parasitoid. Flowers are nutritionally superior when compared with leaves, and caterpillars develop faster when feeding on flowers. However, late-stage caterpillars can be preyed upon intensively by social wasps, irrespective of whether they feed on leaves or flowers. We conclude that flower preference by P. brassicae is more likely driven by nutritional advantages and reduced parasitism on flowers, than by risks of being killed by generalist predators. PMID:24888744

Lucas-Barbosa, Dani; Poelman, Erik H; Aartsma, Yavanna; Snoeren, Tjeerd A L; van Loon, Joop J A; Dicke, Marcel

2014-06-01

92

Colored Shadows  

NSDL National Science Digital Library

In this optics activity, learners discover that not all shadows are black. Learners explore human color perception by using colored lights to make additive color mixtures. With three colored lights, learners can make shadows of seven different colors. They can also explore how to make shadows of individual colors, including black. Use this activity demonstrate how receptors in the retina of the eye work to see color.

Exploratorium, The

2011-10-31

93

77 FR 12103 - Culturally Significant Objects Imported for Exhibition Determinations: “Colorful Realm: Japanese...  

Federal Register 2010, 2011, 2012, 2013

...Culturally Significant Objects Imported for Exhibition Determinations: ``Colorful Realm...that the objects to be included in the exhibition ``Colorful Realm: Japanese Bird-and-Flower...imported from abroad for temporary exhibition within the United States, are of...

2012-02-28

94

Color Thieves  

NSDL National Science Digital Library

This story poses a challenge to its readers to solve the mystery of light, color, and how we see color. It also asks the question, "What is color?" After investigating the phenomena of color and color filters, students should realize that light is made up

Konicek-Moran, Richard

2009-04-01

95

Flower Tessellation Patterning and a Genetic Pathway Explanation1  

Microsoft Academic Search

The development of patterns in flowers has been examined by many over the years. The seminal work of Alan Turing in 1952 laid out a method to model such coloration by looking at the process as a distributed communications between cells with feedback. This paper uses the Turing model combined with the current knowledge of gene expression and secondary pathways.

Terrence P. McGarty

96

Map Coloring  

NSDL National Science Digital Library

Is there any math in coloring maps. Believe it or not there is alot of math involoved in coloring a map. The cool people at MEGA MATH have created activities for you to experiment with map coloring and see just how fun it is. Mega Math Workbook open the activity called The Most Colorful Math of All Some other fun activities can be found at Coloring Penrose Tiles Colorful mathematics Jeff Week&s Geometry Software Games ...

Hadley, Mrs.

2005-06-18

97

8.G Flower Vases  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: My sisterâs birthday is in a few weeks and I would like to buy her a new vase to keep fresh flowers in her house. She often forgets to water her flower...

98

Tough Choice.  

ERIC Educational Resources Information Center

To help public schools experience free-market competition, Secretary of Education Lamar Alexander and President Bush propose parental choice among private, parochial, and public schools, supported by public financing for program design and tuition grants. Sidebars highlight church/state separation concerns and school choice experiments in…

Shapiro, Walter

1991-01-01

99

Bach flower remedies.  

PubMed

Bach remedies were identified by Dr Edward Bach, a physician and homoeopath. Bach flower remedies consist of 38 remedies which are designed as a system of emotional healing. Remedies are dispensed in homoeopathic dosages, are safe and do not appear to interfere with any other medication. Nurses may find the remedies a useful adjunct to their nursing care. PMID:9432436

Mantle, F

1997-10-01

100

Preferred Color Spaces for White Balancing  

Microsoft Academic Search

When rendering photographs, it is important to preserve the gray tones despite variations in the ambient illumination. When the illuminant is known, white balancing that preserves gray tones can be performed in many different color spaces; the choice of color space influences the renderings of other colors. In this behavioral study, we ask whether users have a preference for the

Feng Xiao; Joyce E. Farrell; Jeffrey M. Dicarlo; Brian A. Wandell

2003-01-01

101

Preferred Color Spaces for White Balancing  

Microsoft Academic Search

When rendering photographs, it is important to preserve the gray tones despite variations in the ambient illumination. When the illuminant is known, white balancing that preserves gray tones can be performed in many different color spaces; the choice of color space influences the renderings of other colors. In this behavioral study, we ask whether users have a preference for the

Feng Xiao; Joyce E. Farrell; Jeffrey M. DiCarlo; Brian A. Wandell

102

Color Mixing  

NSDL National Science Digital Library

This is an online activity where learners can virtually mix different colors of light or paint (you can switch between them) and see how the colors combine. It demonstrates how millions of colors are created on computer monitors and TVs, and in art and printing. Learners can try to match a given target color ("Mix to Match"), or simply play around with mixtures ("Mix for Fun"). Background information explains how light is additive (more colors tends towards white), whereas paint absorbs color and is subtractive (more colors tends towards black). There's also information about how the human eye works.

Industry, Oregon M.

2002-01-01

103

Consumer preferences for color combinations: An empirical analysis of similarity-based color relationships  

Microsoft Academic Search

In this paper, we examine aesthetic color combinations in a realistic product self-design task using the NIKEiD online configurator. We develop a similarity-based model of color relationships and empirically model the choice likelihoods of color pairs as a function of the distances between colors in the CIELAB color space. Our empirical analysis reveals three key findings. First, people de-emphasize lightness

Xiaoyan Deng; Sam K. Hui; J. Wesley Hutchinson

2010-01-01

104

Integrated Signaling in Flower Senescence  

PubMed Central

Flower senescence is the terminal phase of developmental processes that lead to the death of flower, which include, flower wilting, shedding of flower parts and fading of blossoms. Since it is a rapid process as compared to the senescence of other parts of the plant it therefore provides excellent model system for the study of senescence. During flower senescence, developmental and environmental stimuli enhance the upregulation of catabolic processes causing breakdown and remobilization of cellular constituents. Ethylene is well known to play regulatory role in ethylene-sensitive flowers while in ethylene-insensitive flowers abscisic acid (ABA) is thought to be primary regulator. Subsequent to perception of flower senescence signal, death of petals is accompanied by the loss of membrane permeability, increase in oxidative and decreased level of protective enzymes. The last stages of senescence involve the loss of of nucleic acids (DNA and RNA), proteins and organelles, which is achieved by activation of several nucleases, proteases and wall modifiers. Environmental stimuli such as pollination, drought and other stresses also affect senescence by hormonal imbalance. In this article we have covered the following: perception mechanism and specificity of flower senescence, flower senescence-associated events, like degradation of cell membranes, proteins and nucleic acids, environmental/external factors affecting senescence, like pollination and abiotic stress, hormonal and non-hormonal regulation of flower/petal senescence and finally the senescence associated genes (SAGs) have also been described.

Tripathi, Siddharth Kaushal

2007-01-01

105

Chemical composition of the essential oils from flowers, stems, and roots of Salvia multicaulis growing wild in Iran  

Microsoft Academic Search

In this work, hydrodistilled essen tial oils from crushed dry flowers, stems, and roots of Salvia multicaulis Vahl. (Lamiaceae) from Semnan province (Iran) were studied by GC and GC\\/MS [9]. The air-dried flowers, stems, and roots of the plant yielded 0.38, 0.29, and 0.18% (w\\/w) yellowish colored oil, respectively. The percentage composition of the flower, stem, and root oil of

M. Mohammadhosseini; A. Pazoki; H. Akhlaghi

2008-01-01

106

Flowering and Pollination  

NSDL National Science Digital Library

This pdf includes background information and an activity for engaging students in the processes that occur during pollination, fertilization and seed development in Fast Plants. Pollination is explained and illustrated and an activity for students to pollinate Fast Plants and observe reproductive development is described.In participating in this activity students will: understand flowering as the sexually mature stage of plant development; understand where and how ovules and pollen originate (male and female gamete formation); explore the parts of the flower and the role that each part plays in reproduction; observe the reproductive tissues of plants, including pollen and stigma, under magnification; understand the interdependent coevolutionary relationship of bees and brassicas; and begin the process of reproduction in their Fast Plants by performing a pollination using a beestick, setting the stage for future developmental events.

Program, The W.

107

Fish and Flowers  

NSDL National Science Digital Library

We all know rain makes the flowers grow but sometimes fish help too. Thats according to University of Florida ecologist Robert Holt. He and his colleagues studied eight freshwater ponds. There, bees pollinate nearby flowers, while dragonflies prey on the bees. But fish control the dragonfly population by eating their larvae. Holts team compared the flora around ponds with fish to ponds without. Ponds that had fish in them tended to have fewer larval dragonflies, and fewer adult dragonflies which meant more bees, and more frequent pollinations. Plants around fishless ponds, on the other hand, were more likely to be pollen starved. The study suggests one way that the effects of overfishing may ripple onto land. A more complete description of the research and a transcript of the audio file is included. In addition, links to additional resources are included for further inquiry.

American Association for the Advancement of Science (;)

2005-12-05

108

Choice of hunting site as a consequence of experience in late-instar crab spiders  

Microsoft Academic Search

Earlier experiences may play an important role in the choice of hunting sites, but their effects on the foraging repertoire\\u000a of most animals remain poorly understood. I tested the role of previous flower choices (hunting sites) by penultimate-instar\\u000a female crab spiders Misumena vatia in making subsequent patch-choice decisions. M. vatia is a sit-and-wait predator, and the two flower species used,

Douglass H. Morse

1999-01-01

109

Conservatory of Flowers  

NSDL National Science Digital Library

San Francisco's Conservatory of Flowers at Golden Gate Park has recently reopened to the public after a year of renovation to repair damage from a devastating windstorm in 1995. The Conservatory's attractive Web site offers a virtual tour, highlighting the Conservatory's "dramatic new exhibits and horticultural displays." Visitors can also learn more about featured plants (palms, at the moment), check out an online photo gallery, and learn all about the restoration of Conservatory buildings and displays.

110

Evidence for an evolutionarily conserved interaction between cell wall biosynthesis and flowering in maize and sorghum  

PubMed Central

Background Factors that affect flowering vary among different plant species, and in the grasses in particular the exact mechanism behind this transition is not fully understood. The brown midrib (bm) mutants of maize (Zea mays L.), which have altered cell wall composition, have different flowering dynamics compared to their wild-type counterparts. This is indicative of a link between cell wall biogenesis and flowering. In order to test whether this relationship also exists in other grasses, the flowering dynamics in sorghum (Sorghum bicolor (L.) Moench) were investigated. Sorghum is evolutionarily closely related to maize, and a set of brown midrib (bmr) mutants similar to the maize bm mutants is available, making sorghum a suitable choice for study in this context. Results We compared the flowering time (time to half-bloom) of several different bmr sorghum lines and their wild-type counterparts. This revealed that the relationship between cell wall composition and flowering was conserved in sorghum. Specifically, the mutant bmr7 flowered significantly earlier than the corresponding wild-type control, whereas the mutants bmr2, bmr4, bmr6, bmr12, and bmr19 flowered later than their wild-type controls. Conclusion The change in flowering dynamics in several of the brown midrib sorghum lines provides evidence for an evolutionarily conserved mechanism that links cell wall biosynthesis to flowering dynamics. The availability of the sorghum bmr mutants expands the germplasm available to investigate this relationship in further detail.

Vermerris, Wilfred; Thompson, Karen J; McIntyre, Lauren M; Axtell, John D

2002-01-01

111

Flowering in time: genes controlling photoperiodic flowering in Arabidopsis.  

PubMed Central

Successful sexual reproduction in plants relies upon the strict coordination of flowering time with favourable seasons of the year. One of the most important seasonal cues for the model plant Arabidopsis thaliana (Arabidopsis) is day length. Genes influencing flowering time in Arabidopsis have been isolated, some of which are involved in the perception and signalling of day length. This review discusses recent progress that has been made in understanding how Arabidopsis integrates environmental and internal signals to ensure a sharp transition to flowering and new insights on the role of the circadian clock in controlling the expression of genes that promote flowering in response to day length.

Putterill, J

2001-01-01

112

Seeing Color  

ERIC Educational Resources Information Center

Colors are powerful tools for engaging children, from the youngest years onward. We hang brightly patterned mobiles above their cribs and help them learn the names of colors as they begin to record their own ideas in pictures and words. Colors can also open the door to an invisible world of electromagnetism, even when children can barely imagine…

Texley, Juliana

2005-01-01

113

Light-colored fluorineless titanium-based enamels for steel  

Microsoft Academic Search

The aim of the present work is to obtain titanium-based enamel containing coatings posessing thermally stable coloration for domestic articles, in particular, for steel vessels. When developing colored coatings, the choice of the enamel base is of paramount importance since the color of the coating and the color stability depend to a considerable extent on the enamel matrix composition. The

L. D. Antonova; D. F. Ushakov; M. S. Zakharov

1985-01-01

114

Project Choice.  

ERIC Educational Resources Information Center

Project Choice was begun with the goal of increasing the number of inner-city students who graduate on time. Ewing M. Kauffman and his business and foundation associates designed and elected to test a model that used the promise of postsecondary education or training as the incentive to stay in school. This report details the evolution of Project…

Ewing Marion Kauffman Foundation, Kansas City, MO.

115

Angelina's choice.  

PubMed

This is an opinion piece on how a celebrity's personal choice to undergo prophylactic mastectomy on discovery of an aberrant gene, when publicly promoted, carries in itself the power to influence and impact healthcare trends and decisions. When celebrities advocate causes that are universally and uniformly acceptable and indisputable as the best in the realm of healthcare and cure (e.g. no smoking), it creates well-being and awareness in society at large. But those which are personal choices made out of a repertoire of other available and effective options may, because of celebrity preference, don the mantle of a norm. They thus run the danger of being blindly replicated by others without proper awareness and knowledge of the true potential of disease, risk factors, and other existing remedial or risk-reducing measures. Society should thus be encouraged to question, debate, and understand the validity, authenticity, and reason of the choices, especially those with a medical basis. This tempering of information with intelligence and rationale and making informed choices based on facts will serve humanity as a whole. PMID:24455660

Goel, Nishu Singh

2013-10-01

116

Flower scents from the Pacific.  

PubMed

For a long time, exotic scents from the islands of the South Pacific have universally been appreciated. Most frequently, fragrant flowers (e.g., frangipani, jasmine sambac, tiaré, pua kenikeni) are used locally for ornamental purposes such as flower garlands (leis). Despite their powerful and delightful fragrance, very few of these flowers have been commercially employed in this part of the world for perfume manufacturing. Creative perfumers are nevertheless strongly interested to better understand these fragrances and to use them, either genuine or artificially reconstituted. Analytical results on the fragrance of these flowers are reported, together with some economical considerations. PMID:18618387

Joulain, Daniel

2008-06-01

117

Flower senescence: some molecular aspects.  

PubMed

Some molecular aspects of flower senescence have been reviewed. The isolation, identification and characterization of different genes from various flowers (mainly from petals) associated with senescence have been discussed. The isolated genes were divided into different groups. A large proportion of genes have been found to be upregulated during flower senescence while some genes were also found to be downregulated indicating that there exists a complex interplay between the expression patterns of various genes. The genes involved in petal expansion are found to be upregulated during normal flower development from anthesis to open flower stage, but XTH (Xyloglucan endotransglucosylase hydrolase) is found to be involved in petal expansion as well as abscission. Cysteine proteases or the genes encoding cysteine proteases (assigned a central role in protein degradation) have been identified from various flower systems, but no cysteine protease has been identified from senescing Mirabilis jalapa flowers. In addition to proteases, the genes encoding ubiquitin (exhibiting proteasomal degradation by 26S proteasomes) have also been identified suggesting the two alternate pathways for protein degradation. Genes encoding specific nucleases have also been identified, but they displayed an early increase in transcript abundance before the senescence symptoms become evident and characterize the involvement of PCD during flower senescence. A range of transcription factors are described and their possible role in flower senescence has been discussed. A detailed description of genes involved in ethylene synthesis and the components involved in ethylene signaling have been presented. PMID:24178586

Shahri, Waseem; Tahir, Inayatullah

2014-02-01

118

Color Terms and Color Concepts  

ERIC Educational Resources Information Center

In their lead articles, both Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) declare a general relation between color term knowledge and the ability to conceptually represent color. Kowalski and Zimiles, in particular, argue for a priority for the conceptual representation in color term acquisition. The complexities of the interaction…

Davidoff, Jules

2006-01-01

119

Color terms and color concepts  

Microsoft Academic Search

In their lead articles, both Kowalski and Zimiles (2006) and O’Hanlon and Roberson (2006) declare a general relation between color term knowledge and the ability to conceptually represent color. Kowalski and Zimiles, in particular, argue for a priority for the conceptual representation in color term acquisition. The complexities of the interaction are taken up in the current commentary, especially with

Jules Davidoff

2006-01-01

120

Focal colors are universal after all  

PubMed Central

It is widely held that named color categories in the world's languages are organized around universal focal colors and that these focal colors tend to be chosen as the best examples of color terms across languages. However, this notion has been supported primarily by data from languages of industrialized societies. In contrast, recent research on a language from a nonindustrialized society has called this idea into question. We examine color-naming data from languages of 110 nonindustrialized societies and show that (i) best-example choices for color terms in these languages cluster near the prototypes for English white, black, red, green, yellow, and blue, and (ii) best-example choices cluster more tightly across languages than do the centers of category extensions, suggesting that universal best examples (foci) may be the source of universal tendencies in color naming.

Regier, Terry; Kay, Paul; Cook, Richard S.

2005-01-01

121

Color Analysis  

NASA Astrophysics Data System (ADS)

Color, flavor, and texture are the three principal quality attributes that determine food acceptance, and color has a far greater influence on our judgment than most of us appreciate. We use color to determine if a banana is at our preferred ripeness level, and a discolored meat product can warn us that the product may be spoiled. The marketing departments of our food corporations know that, for their customers, the color must be "right." The University of California Davis scorecard for wine quality designates four points out of 20, or 20% of the total score, for color and appearance (1). Food scientists who establish quality control specifications for their product are very aware of the importance of color and appearance. While subjective visual assessment and use of visual color standards are still used in the food industry, instrumental color measurements are extensively employed. Objective measurement of color is desirable for both research and industrial applications, and the ruggedness, stability, and ease of use of today's color measurement instruments have resulted in their widespread adoption.

Wrolstad, Ronald E.; Smith, Daniel E.

122

Color categories and color appearance  

PubMed Central

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue–green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses.

Webster, Michael A.; Kay, Paul

2011-01-01

123

Flowers: More Than Just Pretty  

NSDL National Science Digital Library

Children love to look at flowers but few are inclined to become familiar with the structure and function of the flower. This story is aimed at providing some motivation for children to learn about one of the most important evolutionary developments in the

Konicek-Moran, Richard

2009-04-01

124

The influence of pigmentation patterning on bumblebee foraging from flowers of Antirrhinum majus  

NASA Astrophysics Data System (ADS)

Patterns of pigmentation overlying the petal vasculature are common in flowering plants and have been postulated to play a role in pollinator attraction. Previous studies report that such venation patterning is significantly more attractive to bee foragers in the field than ivory or white flowers without veins. To dissect the ways in which venation patterning of pigment can influence bumblebee behaviour, we investigated the response of flower-naïve individuals of Bombus terrestris to veined, ivory and red near-isogenic lines of Antirrhinum majus. We find that red venation shifts flower colour slightly, although the ivory background is the dominant colour. Bees were readily able to discriminate between ivory and veined flowers under differential conditioning but showed no innate preference when presented with a free choice of rewarding ivory and veined flowers. In contrast, both ivory and veined flowers were selected significantly more often than were red flowers. We conclude that advantages conferred by venation patterning might stem from bees learning of their use as nectar guides, rather than from any innate preference for striped flowers.

Whitney, Heather M.; Milne, Georgina; Rands, Sean A.; Vignolini, Silvia; Martin, Cathie; Glover, Beverley J.

2013-03-01

125

Insect odour perception: recognition of odour components by flower foraging moths  

PubMed Central

Odours emitted by flowers are complex blends of volatile compounds. These odours are learnt by flower-visiting insect species, improving their recognition of rewarding flowers and thus foraging efficiency. We investigated the flexibility of floral odour learning by testing whether adult moths recognize single compounds common to flowers on which they forage. Dual choice preference tests on Helicoverpa armigera moths allowed free flying moths to forage on one of three flower species; Argyranthemum frutescens (federation daisy), Cajanus cajan (pigeonpea) or Nicotiana tabacum (tobacco). Results showed that, (i) a benzenoid (phenylacetaldehyde) and a monoterpene (linalool) were subsequently recognized after visits to flowers that emitted these volatile constituents, (ii) in a preference test, other monoterpenes in the flowers' odour did not affect the moths' ability to recognize the monoterpene linalool and (iii) relative preferences for two volatiles changed after foraging experience on a single flower species that emitted both volatiles. The importance of using free flying insects and real flowers to understand the mechanisms involved in floral odour learning in nature are discussed in the context of our findings.

Cunningham, John Paul; Moore, Chris J; Zalucki, Myron P; Cribb, Bronwen W

2006-01-01

126

Carpet choices for healthcare facilities.  

PubMed

Carpet as a floorcovering choice in healthcare facilities is increasing in popularity. Technological advances have made carpet an appropriate choice not only for common areas and offices, but also for patient rooms. Color options are diverse, and can serve patient care concerns, such as orientation for patients with Alzheimer's disease. Carpet performance is related to its density, construction and fiber/yarn type. Many carpet types have antimicrobial treatments to aid in reducing the propagation and spread of microorganisms. Carpet is also tested for emissions of volatile organic compounds based on industry criteria. Proper maintenance is essential to maintaining carpet appearance and useful life. PMID:10134936

Wise, K O

1994-07-01

127

Coloring Remainders in Pascal's Triangle  

NSDL National Science Digital Library

This Java applet activity allows students to visually identify more number patterns in Pascal's Triangle by coloring numbers that have the same remainder when divided by the number rolled, thereby practicing division and remainders. A learner rolls a random number, which can be from 1 to the number of rows of the triangle, or enters his/her own choice. There is an auto-color button that will automatically color the correct entries and the number of rows of Pascal's triangle can be increased or decreased. Separate tabs to access information for the learner, the instructor and to seek help are provided.

2004-01-01

128

Color Metric.  

ERIC Educational Resources Information Center

This booklet was designed to convey metric information in pictoral form. The use of pictures in the coloring book enables the more mature person to grasp the metric message instantly, whereas the younger person, while coloring the picture, will be exposed to the metric information long enough to make the proper associations. Sheets of the booklet…

Illinois State Office of Education, Springfield.

129

Color Lines.  

ERIC Educational Resources Information Center

Teaching about color and value scales emphasizes a systematic approach to the effects of color and may reinforce assumptions rooted in racism. Describes how an 8th grade art class challenged the symbolism of black as evil and white as good. By showing that this is a culturally constructed meaning, art teachers model that such meaning can also be…

Gude, Olivia

2001-01-01

130

Light and Color Research Continues in Arkansas.  

ERIC Educational Resources Information Center

Describes a research project that will measure whether student achievement, blood pressure, height, and weight gain are influenced by the choice of color and/or the source of artificial light in the classroom. Four third-grade classrooms will be the treatment groups involving two colors and three different artificial light sources. (MLF)

Sydoriak, Diane

1984-01-01

131

An experimental comparison of RGB, YIQ, LAB, HSV, and opponent color models  

Microsoft Academic Search

The increasing availability of affordable color raster graphics displays has made it important to develop a better understanding of how color can be used effectively in an interactive environment. Most contemporary graphics displays offer a choice of some 16 million colors; the user's problem is to find the right color.Folklore has it that the RGB color space arising naturally from

Michael W. Schwarz; William B. Cowan; John C. Beatty

1987-01-01

132

Innate colour preferences of flower visitors  

Microsoft Academic Search

Freshly emerged flower visitors exhibit colour preferences prior to individual experience with flowers. The understanding of innate colour preferences in flower visitors requires a detailed analysis, as, on the one hand, colour is a multiple-signal stimulus, and, on the other hand, flower visits include a sequence of behavioural reactions each of which can be driven by a preferential behaviour. Behavioural

K. Lunau; E. J. Maier

1995-01-01

133

Changing Colors  

NSDL National Science Digital Library

In this challenge, learners have to figure out in what order to combine five solutions to change the color from clear, to yellow, to blue, and back to clear. The five chemicals are potassium iodide, sodium thiosulfate, sodium hypochlorite (Clorox bleach), soluble starch (Niagara spray starch), and water. The color changes indicate chemical reactions, and the lesson includes some background information about the reactions that create different colors. Suggestions are given for guiding learners through systematic approaches to making the different combinations and observing the results, and for explaining to different age groups what happens when the solutions are combined.

Sciencenter

2012-06-26

134

Color Theory  

NSDL National Science Digital Library

This Web site, developed by the Exploratories Project at Brown University, provides a series of applets to help users understand the various concepts in Color Theory. In the combined Color Mixing applet, undergraduate and high school students can discover how lights, paints, and filters interact. Users can learn about the properties of incoming light, frequency, and reflectance. The site also provides activities for metamers, Triple Cell Response, and much more. Anyone seeking help with color concepts will benefit from this educational, interactive Web site.

135

Farming and Gardening: Flower Garden  

NSDL National Science Digital Library

In this activity, students will Explore the relationships between fractions and percents while creating a grid of different flowers in a garden. Then the students will combine this grid with others to apply the concepts to a larger set.

Math, Pbs T.

2010-01-01

136

Spirit Has Flower Power  

NASA Technical Reports Server (NTRS)

The Mars Exploration Rover Spirit took this image with its hazard-avoidance camera on sol 86 (March 31, 2004), after the rover's rock abrasion tool had brushed for three minutes on each of six locations on the rock named 'Mazatzal' to create a flower-shaped mosaic.

The goal for this operation was to create a brushed area big enough for the miniature thermal emission spectrometer to capture within one of its pixels, which are 11 centimeters (4.3 inches) in diameter at the distance between the rock and the instrument. Because the rock abrasion tool creates individual brushed areas only about 5 centimeters (2 inches) in diameter, the team designed this six-location series of tool placements in order to brush 92 percent to 95 percent of the spectrometer's pixel size.

This operation was only the second time the rock abrasion tool has created a brushing mosaic. The first time was a three-spot brushing on the rock called 'Humphrey.' The brush was originally designed to be used as an aide during full grinding operations, however it has been very effective in brushing the top layer off of dusty martian rocks to allow scientists a multi-depth look into the rocks on Mars.

2004-01-01

137

Color appearance in stereoscopy  

NASA Astrophysics Data System (ADS)

The relationship between color and lightness appearance and the perception of depth has been studied since a while in the field of perceptual psychology and psycho-physiology. It has been found that depth perception affects the final object color and lightness appearance. In the stereoscopy research field, many studies have been proposed on human physiological effects, considering e.g. geometry, motion sickness, etc., but few has been done considering lightness and color information. Goal of this paper is to realize some preliminar experiments in Virtual Reality in order to determine the effects of depth perception on object color and lightness appearance. We have created a virtual test scene with a simple 3D simultaneous contrast configuration. We have created three different versions of this scene, each with different choices of relative positions and apparent size of the objects. We have collected the perceptual responses of several users after the observation of the test scene in the Virtual Theater of the University of Milan, a VR immersive installation characterized by a semi-cylindrical screen that covers 120° of horizontal field of view from an observation distance of 3.5 m. We present a description of the experiments setup and procedure, and we discuss the obtained results.

Gadia, Davide; Rizzi, Alessandro; Bonanomi, Cristian; Marini, Daniele; Galmonte, Alessandra; Agostini, Tiziano

2011-02-01

138

Colored floral organs influence pollinator behavior and pollen transfer in Commelina communis (Commelinaceae)  

Microsoft Academic Search

Visual floral guides such as colored anthers, lines, dots, and UV-absorption patterns on petals are commonly observed in insect- pollinated angiosperms. Floral guides that are known to enhance foraging efficiency of visitors on flowers thus promote return visits (foraging facilitation hypothesis, which predicts that visitors will discriminate against flowers with inferior floral guides). In this study, we experimentally examined the

ATUSHI USHIMARU; TAKESHI WATANABE; KENSUKE NAKATA

2007-01-01

139

Color Facsimile.  

National Technical Information Service (NTIS)

The purpose of this project was to continue the color facsimile work started under a previous task, including the evaluation of the use of default Huffman tables, optimized (Custom) Huffman tables, default quantization tables, and scaled quantization tabl...

S. Perschau

1995-01-01

140

Colorful Electrophoresis  

NSDL National Science Digital Library

In this activity, learners follow step-by-step instructions to build a gel electrophoresis chamber using inexpensive materials from local hardware and electronic stores. Then, learners follow instructions to simulate DNA electrophoresis using food colors from the kitchen pantry.

Utah, University O.

2012-01-01

141

Finding Colors  

NSDL National Science Digital Library

In this chemistry challenge, learners combine acids and bases in a universal indicator to create five different colors. Using vinegar, washing soda, and Bogen universal indicator, the goal is to find combinations that create red, orange, yellow, green, and blue solutions. Background information explains a little about how acids and bases interact to affect the pH of a solution, and how the indicator changes color based on the pH. Safety notes are included.

Sciencenter

2011-08-20

142

Colored Shadows  

NSDL National Science Digital Library

This activity demonstrates the additive properties of light. Different-colored lights are shown on the same spot on a screen so that the reflecting light is white. Colored shadows, however, can be made by holding an object between the light sources and the screen. The site provides an explanation for how this occurs along with extension activities and information about the eyeâs retina. Materials needed and assembly instructions are also included. This activity is part of Exploratorium's Science Snacks series.

2006-07-22

143

Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides  

PubMed Central

ABSTRACT Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dogma indicates that flower color serves as an important long-range visual signal allowing pollinators to detect the flowers, while floral guides function as close-range signals that direct pollinators to a reward. We initiated the work presented here by first assessing the population level variation in UV absorbent floral guides for conspecific flowers. We assessed two species, Rudbeckia hirta and R. fulgida. We then used several petal cut-and-paste experiments to test whether UV floral guides can also function to attract visitors. We manipulated floral guide size and evaluated visitation frequency. In all experiments, pollinator visitation rates were clearly associated with floral guide size. Diminished floral guides recruited relatively few insect visitors. Exaggerated floral guides recruited more visitors than smaller or average sized guides. Thus, UV floral guides play an important role in pollinator recruitment and in determining the relative attractiveness of conspecific flower heads. Consideration of floral guides is therefore important when evaluating the overall conspicuousness of flower heads relative to background coloration. This work raises the issue of whether floral guides serve as honest indicators of reward, since guide size varies in nature for conspecific flowers at the same developmental stage and since preferences for larger guides were found. To our knowledge, these are the first cut-and-paste experiments conducted to examine whether UV absorbent floral guides affect visitation rates and pollinator preference.

Horth, Lisa; Campbell, Laura; Bray, Rebecca

2014-01-01

144

Colorful Waves  

NSDL National Science Digital Library

You're probably really upset that all you have so far is a simple little ray model of light. When do we get to the good stuff, you say? How about now? As a bonus, you get to look at lots of pretty colors. This chapter addresses how light can be modeled as a series of waves. These waves consist of changing electric and magnetic fields that can travel through empty space, as well as through other mediums. Different frequencies of light waves correspond to different colors of light. White light is composed of all the colors of visible light. Visible light is just a small portion of the entire spectrum of electromagnetic waves.

Robertson, William C.

2003-01-01

145

Sequence variation of chalcone synthase gene in a spontaneous white-flower mutant of Chinese cabbage-pak-choi  

Microsoft Academic Search

A spontaneous white-flower mutant of Chinese cabbage-pak-choi (Brassica campestris ssp. chinenesis, syn. B. rapa ssp. chinenesis) was found in our test fields, and all the plant characters except flower color were identical with wild type ones. We hypothesized\\u000a that a mutational event had occurred in the gene coding for chalcone synthase (CHS), the key enzyme of flavonoid biosynthesis\\u000a pathway. Two

Ming Jiang; Jiashu Cao

2008-01-01

146

Harmonious colors: from alchemy to science  

NASA Astrophysics Data System (ADS)

There is a very long tradition in designing color palettes for various applications, going back to at least the Upanishad. Although color palettes have been influenced by the available colorants, starting with the advent of aniline dyes in the late 1850s there have been few physical limits on the choice of individual colors. This abundance of choices exacerbates the problem of limiting the number of colors in a palette, i.e., in keeping them into a manageable quantity. For example, it is not practical for a car company to offer each model in hundreds of colors. Instead, for each model year a small number of color palettes is offered, each containing the colors for the body, trim, interior, etc. Another example is the fashion industry, where in addition to solid colors there are also patterns, leading to a huge variety of combinations that would be impossible to stock. The traditional solution is that of "color forecasting." Color consultants assess the sentiment or affective state of a target customer class and compare it with new colorants offered by the industry. They assemble a limited color palette, name the colors according to the sentiment, and publish their result. Textile manufacturers will produce fabrics in these colors and fashion designers will design clothes, accessories, and furniture based on these fabrics. Eventually, the media will communicate these forecasts to the consumers, who will be admired by their cohorts when they choose colors from the forecast palette, which by then is widely diffused. The color forecasting business is very labor intensive and difficult, thus for years computer engineers have tried to come up with algorithms to design harmonious color palettes, alas with little commercial success. For example, Johannes Itten's color theory has been implemented many times, but despite Itten's success in the Bauhaus artifacts, the computer tools have been of little utility. Indeed, contrary to the auditory sense, there is no known physiological mechanism sustaining harmony and the term "harmonious" just has the informal meaning of "going well together." We argue that the intellectual flaw resides in the belief that a masterful individual can devise a "perfect methodology" that the engineer can then reduce to practice in a computer program. We suggest that the correct approach is to consider color forecasting as an act of distillation, where a palette is digested from the sentiment of a very large number of people. We describe how this approach can be reduced to an algorithm by replacing the subjective process with a data analytic process.

Beretta, Giordano B.; Moroney, Nathan M.

2012-01-01

147

Cross-Cultural Color-Odor Associations  

PubMed Central

Colors and odors are associated; for instance, people typically match the smell of strawberries to the color pink or red. These associations are forms of crossmodal correspondences. Recently, there has been discussion about the extent to which these correspondences arise for structural reasons (i.e., an inherent mapping between color and odor), statistical reasons (i.e., covariance in experience), and/or semantically-mediated reasons (i.e., stemming from language). The present study probed this question by testing color-odor correspondences in 6 different cultural groups (Dutch, Netherlands-residing-Chinese, German, Malay, Malaysian-Chinese, and US residents), using the same set of 14 odors and asking participants to make congruent and incongruent color choices for each odor. We found consistent patterns in color choices for each odor within each culture, showing that participants were making non-random color-odor matches. We used representational dissimilarity analysis to probe for variations in the patterns of color-odor associations across cultures; we found that US and German participants had the most similar patterns of associations, followed by German and Malay participants. The largest group differences were between Malay and Netherlands-resident Chinese participants and between Dutch and Malaysian-Chinese participants. We conclude that culture plays a role in color-odor crossmodal associations, which likely arise, at least in part, through experience.

Levitan, Carmel A.; Ren, Jiana; Woods, Andy T.; Boesveldt, Sanne; Chan, Jason S.; McKenzie, Kirsten J.; Dodson, Michael; Levin, Jai A.; Leong, Christine X. R.; van den Bosch, Jasper J. F.

2014-01-01

148

The Role of Mate Choice in Biocomputation: Sexual Selection as a Process of Search, Optimization and Diversification  

Microsoft Academic Search

The most successful, complex, and numerous species on earth are composed of sexually- reproducing animals and flowering plants. Both groups typically undergo a form of sexual selection through mate choice: animals are selected by conspecifics and flowering plants are selected by heterospecific pollinators. This suggests that the evolution of phenotypic complexity and diversity may be driven not simply by natural-selective

Geoffrey F. Miller; Peter M. Todd

1995-01-01

149

Antimicrobial activity of Leucas aspera flowers  

Microsoft Academic Search

The methanol extract of Leucas aspera flowers, its fractions, the alkaloidal residue and the expressed flower juice, tested for antimicrobial activity, showed good antibacterial activity for methanol extract and methanol fraction with maximum activity for the alkaloidal residue.

K. Mangathayaru; J. Lakshmikant; N. Shyam Sundar; R. Swapna; X. Fatima Grace; J. Vasantha

2005-01-01

150

[Control of flower formation (author's transl)].  

PubMed

The flower formation, i. e., the change of vegetative to generative development is a far-reaching turning-point for the higher plant. Accompanied by basic transformation of metabolism, flower formation leads to development of stamen and carpel, i.e. the fundamental structure for propagation. For plants that die after fructification flower formation therefore means the 'beginning of the end'. The determination of flower formation is a problem highly recognized by plant physiologists: The most important partial process in this physiological development is the transformation of the vegetative point which usually produces foliage leaves. As a consequence of this transformation the primordia are formed (morphogenesis). The change in information is controlled by a flower-hormone which is produced in the leaves and transported to the vegetative point where it activates the so-called 'flowering-genes'. There is no positive information on the chemical structure of flower hormones. Other factors of flower formation control will be discussed. PMID:7194049

Schwemmle, B

1980-01-01

151

How Bumblebees First Find Flowers: Habituation of Visual Pattern Preferences, Spontaneous Recovery, and Dishabituation  

ERIC Educational Resources Information Center

Two experiments examined the exploratory behaviour of flower-naive bumblebees. Bees were tested four times in a 12-arm radial arm maze in which they never received reward. Patterned and unpatterned stimuli were presented at the end of each corridor and the choices of the bees were recorded. We examined the effects of two variables, time and the…

Plowright, C. M. S.; Simonds, V. M.; Butler, M. A.

2006-01-01

152

Pyrethrum flowers and pyrethroid insecticides.  

PubMed Central

The natural pyrethrins from the daisy-like flower, Tanacetum or Chrysanthemum cinerariifolium, are nonpersistent insecticides of low toxicity to mammals. Synthetic analogs or pyrethroids, evolved from the natural compounds by successive isosteric modifications, are more potent and stable and are the newest important class of crop protection chemicals. They retain many of the favorable properties of the pyrethrins.

Casida, J E

1980-01-01

153

Molecular Biology of Orchid Flowers  

Microsoft Academic Search

Orchidaceae constitutes one of the largest families in angiosperms. The versatility and specialization in orchid floral morphology, scent and colour patterns endear orchidologists and plant biologists to orchid plants. Moreover, the co-evolution of the sophisticated orchid floral presentation and pollinators leads to the ingenious device of the orchid flower. Because of market needs and the current level of breeding technologies,

Wen-Chieh Tsai; Yu-Yun Hsiao; Zhao-Jun Pan; Chia-Chi Hsu; Ya-Ping Yang; Wen-Huei Chen; Hong-Hwa Chen

2008-01-01

154

Flower Development: The Antirrhinum Perspective  

Microsoft Academic Search

Research with the snapdragon, Antirrhinum majus, has a long history with many highlights, making this species a significant model system for comparative genetic, molecular, and ecological studies. In this chapter, we focus interest on flower development, in particular the genetic control of floral organ identity, floral asymmetry, and petal cell?type specification, where results obtained with Antirrhinum provided the first insights

Brendan Davies; Maria Cartolano

2006-01-01

155

Rufous hummingbirds' memory for flower location  

Microsoft Academic Search

We used an open-field analogue of the eight-arm radial maze to investigate the role of memory during foraging by rufous hummingbirds, Selasphorus rufus. In experiment 1 we attempted to determine whether birds were able to differentiate between flowers of the same type that they had emptied, flowers they had seen but not visited and new flowers. They were tested with

Jonathan Henderson; T. Andrew Hurly; Susan D. Healy

2001-01-01

156

Spring Flowers: Harvest of a Sensitive Eye  

ERIC Educational Resources Information Center

Defining and describing a number of spring flowers, this article includes illustrations and explanations that demonstrate "art and science are born of the same parents". The flowers discussed are skunk cabbage, bellwort, spring beauty, jack-in-the-pulpit, Solomon's seal, wild geranium, showy orchids, moccasin flower, bluets, apple, and Indian…

Clark, Eloise; Levin, Ted

1978-01-01

157

Ability of Bumblebees to Discriminate Differences in the Shape of Artificial Flowers of Primula sieboldii (Primulaceae)  

PubMed Central

Background and Aims Flower shapes are important visual cues for pollinators. However, the ability of pollinators to discriminate between flower shapes under natural conditions is poorly understood. This study focused on the diversity of flower shape in Primula sieboldii and investigated the ability of bumblebees to discriminate between flowers by combining computer graphics with a traditional behavioural experiment. Methods Elliptic Fourier descriptors described shapes by transforming coordinate information for the contours into coefficients, and principal components analysis summarized these coefficients. Using these methods, artificial flowers were created based on the natural diversity of petal shape in P. sieboldii. Dual-choice tests were then performed to investigate the ability of the bumblebees to detect differences in the aspect ratio of petals and the depth of their head notch. Key Results The insects showed no significant ability to detect differences in the aspect ratio of the petals under natural conditions unless the morphological distance increased to an unrealistic level. These results suggest the existence of a perception threshold for distances in this parameter. The bumblebees showed a significant preference for narrow petals even after training using flowers with wide petals. The bumblebees showed a significant ability to discriminate based on the depth of the petal head notch after training using artificial flowers with a deep head notch. However, they showed no discrimination in tests with training using extreme distances between flowers in this parameter. Conclusions A new type of behavioural experiment was demonstrated using real variation in flower corolla shape in P. sieboldii. If the range in aspect ratios of petals expands much further, bumblebees may learn to exhibit selective behaviour. However, because discrimination by bumblebees under natural conditions was low, there may be no strong selective behaviour based on innate or learned preferences under natural conditions.

Yoshioka, Yosuke; Ohashi, Kazuharu; Konuma, Akihiro; Iwata, Hiroyoshi; Ohsawa, Ryo; Ninomiya, Seishi

2007-01-01

158

Floral affinity and benefits of dietary mixing with flowers for a polyphagous scarab, Popillia japonica Newman.  

PubMed

Many generalist herbivores, especially adult beetles, are facultative florivores, feeding on leaves but readily accepting floral tissues when available. We speculated that day-flying beetles with high energetic requirements would benefit from dietary mixing with nutrient-rich flower tissues and favor them during foraging. We tested that "Floral Affinity Hypothesis" with Popillia japonica, a day-active ruteline scarab that feeds intermittently throughout its adult life on multiple plant species. In field tests with six species of flowering hosts, far more landings occurred on flowers than on foliage for all plants except Hibiscus syriacus which bears flowers along the main stem rather than terminally. Trials with elevated plants showed that height of the floral display contributes to beetles' landing on flowers. Flower petals generally were preferred over leaves in laboratory choice tests. Nitrogen and water content were comparable or higher in foliage than in petals, but plant sugars were much higher in petals. Longevity and fecundity of beetles provided single-plant diets of Hibiscus, Rosa x hybrida, or Trifolium flowers for 3 weeks were as high, or higher, than for beetles fed foliage of Tilia cordata, a highly suitable resource. As expected, rotating flowers or Tilia foliage with marginally suitable Quercus palustris foliage enhanced those parameters relative to a diet of Quercus alone, but beetles provided high-quality Tilia foliage also benefitted from dietary mixing with flowers. Nearly all past dietary mixing studies concerned immature insects, for which growth rate is paramount. Opportunistic florivory by adult beetles represents a type of dietary mixing wherein the premium may be calorie-rich food for fueling flight muscles, with ensuing reproductive benefits. PMID:15146324

Held, David W; Potter, Daniel A

2004-07-01

159

Floral color changes in Boswellia sacra Flueck. (Burseraceae): A dialogue between plant and pollinator  

Microsoft Academic Search

The present study provides new information about the reproductive biology of Boswellia sacra (Burseraceae), focusing on the nectary and its attractiveness for pollinators. The nectary disc changes its color from yellow to orange and red during the flower development. The colors are related to the main period of the stigmatic receptivity, to the dehiscence of anthers with pollen presentation and

Marta Mariotti Lippi; Claudia Giuliani; Tiziana Gonnelli; Laura Maleci Bini

2011-01-01

160

Color Television and Colorimetry  

Microsoft Academic Search

The high lights of the history of color measurement and of color photography are reviewed. Following this introduction, the principles of modern 3-color colorimetry are developed from a hypothetical experiment in color matching. The conventional theory of \\

W. T. Wintringham

1951-01-01

161

Effects of shade on plant growth and flower quality in the herbaceous peony (Paeonia lactiflora Pall.).  

PubMed

Herbaceous peony (Paeonia lactiflora Pall.) is an important ornamental plant used in urban green spaces, but little is known about whether it can grow in a shaded environment or understory. In this study, effects of shade on plant growth and flower quality in the herbaceous peony were investigated. The results showed that P. lactiflora morphology parameters, including plant height, leaf number, stem diameter, branch number, node number and plant crown width, were higher in plants grown with sun exposure compared to those grown in shade; however, opposite trends were observed for the top and middle leaf areas of the plant. Compared with sun exposure, shade decreased P. lactiflora photosynthetic capacity, light saturation point (LSP) and light compensation point (LCP) and increased the apparent quantum yield (AQY), mainly due to declined stomatal conduction (Gs). These decreases caused the soluble sugar, soluble protein and malondialdehyde (MDA) contents to decline, which led to delayed initial flowering date, prolonged flowering time, reduced flower fresh weight, increased flower diameter and faded flower color. Through cloning and expression analysis of anthocyanin biosynthetic genes, we determined that the fading of flower color was the result of reduced anthocyanin content, which was caused by the combined activity of anthocyanin biosynthesis genes and, in particular, of the upstream phenylalanine ammonialyase gene (PlPAL) and chalcone synthase gene (PlCHS). These results could provide us with a theoretical basis for further application of P. lactiflora in the greening of urban spaces and an understanding of the mechanisms behind the changes induced by shade. PMID:23141672

Zhao, Daqiu; Hao, Zhaojun; Tao, Jun

2012-12-01

162

ODORANT1 regulates fragrance biosynthesis in petunia flowers.  

PubMed

Floral scent is important to plant reproduction because it attracts pollinators to the sexual organs. Therefore, volatile emission is usually tuned to the foraging activity of the pollinators. In Petunia hybrida, volatile benzenoids determine the floral aroma. Although the pathways for benzenoid biosynthesis have been characterized, the enzymes involved are less well understood. How production and emission are regulated is unknown. By targeted transcriptome analyses, we identified ODORANT1 (ODO1), a member of the R2R3-type MYB family, as a candidate for the regulation of volatile benzenoids in Petunia hybrida cv W115 (Mitchell) flowers. These flowers are only fragrant in the evening and at night. Transcript levels of ODO1 increased before the onset of volatile emission and decreased when volatile emission declined. Downregulation of ODO1 in transgenic P. hybrida Mitchell plants strongly reduced volatile benzenoid levels through decreased synthesis of precursors from the shikimate pathway. The transcript levels of several genes in this pathway were reduced by suppression of ODO1 expression. Moreover, ODO1 could activate the promoter of the 5-enol-pyruvylshikimate-3-phosphate synthase gene. Flower pigmentation, which is furnished from the same shikimate precursors, was not influenced because color and scent biosynthesis occur at different developmental stages. Our studies identify ODO1 as a key regulator of floral scent biosynthesis. PMID:15805488

Verdonk, Julian C; Haring, Michel A; van Tunen, Arjen J; Schuurink, Robert C

2005-05-01

163

Is School Choice Working?  

ERIC Educational Resources Information Center

A coauthor of "Who Chooses, Who Loses?" (1996) argues that choice does little to desegregate schools or break down ethnic family enclaves. Choice schools are usually founded on publicly financed organizations. Choice appears to increase parental involvement without substantially improving student achievement. Choice schools need clear plans for…

Fuller, Bruce

1996-01-01

164

[Color science in shade determination for ceramometal].  

PubMed

The authors in this study analyse some elements of color science, necessary to an adequate shade choice for ceramo-metal systems. Some light's physical properties, such as reflection, refraction and metamerism, light sources, contrast's effects can determine a change of real color shade. Adoption of some practice devices allows an appropriate porcelain shade selection for give to final crowns a naturalness' character in armony with patient's dentition. PMID:2639525

Cassaro, A; Pitini, A; Romano, B

1989-01-01

165

Spectral Sensitivities and Color Signals in a Polymorphic Damselfly  

PubMed Central

Animal communication relies on conspicuous signals and compatible signal perception abilities. Good signal perception abilities are particularly important for polymorphic animals where mate choice can be a challenge. Behavioral studies suggest that polymorphic damselflies use their varying body colorations and/or color patterns as communication signal for mate choice and to control mating frequencies. However, solid evidence for this hypothesis combining physiological with spectral and behavioral data is scarce. We investigated this question in the Australian common blue tail damselfly, Ischnura heterosticta, which has pronounced female-limited polymorphism: andromorphs have a male-like blue coloration and gynomorphs display green/grey colors. We measured body color reflectance and investigated the visual capacities of each morph, showing that I. heterosticta have at least three types of photoreceptors sensitive to UV, blue, and green wavelength, and that this visual perception ability enables them to detect the spectral properties of the color signals emitted from the various color morphs in both males and females. We further demonstrate that different color morphs can be discriminated against each other and the vegetation based on color contrast. Finally, these findings were supported by field observations of natural mating pairs showing that mating partners are indeed chosen based on their body coloration. Our study provides the first comprehensive evidence for the function of body coloration on mate choice in polymorphic damselflies.

Huang, Shao-chang; Chiou, Tsyr-huei; Marshall, Justin; Reinhard, Judith

2014-01-01

166

Anthocyanins as Functional Food Colors  

NASA Astrophysics Data System (ADS)

Anthocyanins, a proanthocyanidin-type of flavonoid, contain an abundance of functional phytochemicals and occur in fruits such as cranberry, blueberry, orange, apple and in vegetables such as tomato, sweet pepper, spinach, and radishes. Functional and essential diets have been ingested in daily life since the primitive era of history. When anthocyanins are coupled with some water-soluble sugar molecules, their color becomes red, yellow, violet, or blue. It is very intriguing that anthocyanins provide the colorful variety of pigments for pansies, petunias, plums, and other diverse flowers. Chlorophyll in various fruits and vegetables is the main green phyto-component, while anthocyanins are probably the most important visible plant pigments in the natural kingdom having specific colors. Anthocyanins have been clinically used in many folklore medicines worldwide. Anthocyanins could provide health benefits for age-related diseases as well as other diseases. Anthocyanins have higher antioxidant capacity against oxidative stress induced by excess reactive oxygen species (ROS) such as superoxide radicals, hydrogen peroxide, and thus the human body might be protected from oxidative injury by anthocyanins. On the basis of these facts, we review the synthesis of plant flavonoids and their ability to scavenge oxidants, inhibit or activate enzymes, and the safety of proanthocyanidins and anthocyanidins present in common foods.

Motohashi, Noboru; Sakagami, Hiroshi

167

Color-Range Bodies in Color Photography.  

National Technical Information Service (NTIS)

Described is a method for constructing the color body of the color-photographic process. Constructed are color bodies for six processes on multilayer film and for a hydrotypic process using zonal matrix film. The basis for constructing the color body of t...

D. K. Balabukha M. M. Mirfazieva

1970-01-01

168

Choosing Choice: School Choice in International Perspective.  

ERIC Educational Resources Information Center

The chapters in this book originated as papers for a conference, School Choice and Educational Change, held in March 2000 at Michigan State University. An introductory chapter provides a comparative analysis of the lessons learned from international experience with school-choice policies, based on a review of case studies in several countries. The…

Plank, David N., Ed.; Sykes, Gary, Ed.

169

Active anthocyanin degradation in Brunfelsia calycina (yesterday--today--tomorrow) flowers.  

PubMed

Anthocyanins are the largest group of plant pigments responsible for colors ranging from red to violet and blue. The biosynthesis of anthocyanins, as part of the larger phenylpropanoid pathway, has been characterized in great detail. In contrast to the detailed molecular knowledge available on anthocyanin synthesis, very little is known about the stability and catabolism of anthocyanins in plants. In this study we present a preliminary characterization of active in planta degradation of anthocyanins, requiring novel mRNA and protein synthesis, in Brunfelsia calycina flowers. Brunfelsia is a unique system for this study, since the decrease in pigment concentration in its flowers (from dark purple to white) is extreme and rapid, and occurs at a specific and well-defined stage of flower development. Treatment of detached flowers with protein and mRNA synthesis inhibitors, at specific stages of flower development, prevented degradation. In addition, treatment of detached flowers with cytokinins delayed senescence without changing the rate of anthocyanin degradation, suggesting that degradation of anthocyanins is not part of the general senescence process of the flowers but rather a distinctive and specific pathway. Based on studies on anthocyanin degradation in wine and juices, peroxidases are reasonable candidates for the in vivo degradation. A significant increase in peroxidase activity was shown to correlate in time with the rate of anthocyanin degradation. An additional indication that oxidative enzymes are involved in the process is the fact that treatment of flowers with reducing agents, such as DTT and glutathione, caused inhibition of degradation. This study represents the first step in the elucidation of the molecular mechanism behind in vivo anthocyanin degradation in plants. PMID:15918029

Vaknin, Hila; Bar-Akiva, Ayelet; Ovadia, Rinat; Nissim-Levi, Ada; Forer, Izhak; Weiss, David; Oren-Shamir, Michal

2005-09-01

170

Flower tracking in hawkmoths: behavior and energetics.  

PubMed

As hovering feeders, hawkmoths cope with flower motions by tracking those motions to maintain contact with the nectary. This study examined the tracking, feeding and energetic performance of Manduca sexta feeding from flowers moving at varied frequencies and in different directions. In general we found that tracking performance decreased as frequency increased; M. sexta tracked flowers moving at 1 Hz best. While feeding rates were highest for stationary flowers, they remained relatively constant for all tested frequencies of flower motion. Calculations of net energy gain showed that energy expenditure to track flowers is minimal compared to energy intake; therefore, patterns of net energy gain mimicked patterns of feeding rate. The direction effects of flower motion were greater than the frequency effects. While M. sexta appeared equally capable of tracking flowers moving in the horizontal and vertical motion axes, they demonstrated poor ability to track flowers moving in the looming axis. Additionally, both feeding rates and net energy gain were lower for looming axis flower motions. PMID:17170146

Sprayberry, Jordanna D H; Daniel, Thomas L

2007-01-01

171

Advanced Ocean Color Monitor (OCM) Feasibility Study. Executive Summary.  

National Technical Information Service (NTIS)

After a theoretical analysis of the radiometric and geometric performances of the ocean color monitor instrument and a comparative study of the different configurations, a choice is made to select the instrument characteristics better adjusted to the Euro...

G. Cerutti-maori

1983-01-01

172

Color Theory for Design  

NSDL National Science Digital Library

This lesson will introduce students to color theory with a focus on the use of color in digital design. Students will discover the color wheel, and color harmonies. Color is a very powerful tool in design. It can, enhance a message, give an object visual weight and emphasis, and add richness and depth to a design. We can use color to signify data, to draw attention to a particular object, or to set a mood. Color ...

Jensen, Mr.

2009-10-04

173

Male flowers are better fathers than hermaphroditic flowers in andromonoecious Passiflora incarnata.  

PubMed

• The diversity of plant breeding systems provides the opportunity to study a range of potential reproductive adaptations. Many mechanisms remain poorly understood, among them the evolution and maintenance of male flowers in andromonoecy. Here, we studied the role of morphologically male flowers ('male morph') in andromonoecious Passiflora incarnata. • We measured morphological differences between hermaphroditic and male morph flowers in P. incarnata and explored the fruiting and siring ability of both flower types. • Male morph flowers in P. incarnata were of similar size to hermaphroditic flowers, and there was little evidence of different resource allocation to the two flower types. Male morph flowers were less capable of producing fruit, even under ample pollen and resource conditions. By contrast, male morph flowers were more successful in siring seeds. On average, male morph flowers sired twice as many seeds as hermaphroditic flowers. This difference in male fitness was driven by higher pollen export from male morph flowers as a result of greater pollen production and less self-pollen deposition. • The production of male morph flowers in P. incarnata appears to be a flexible adaptive mechanism to enhance male fitness, which might be especially beneficial when plants face temporary resource shortages for nurturing additional fruits. PMID:22122433

Dai, Can; Galloway, Laura F

2012-02-01

174

Disruptive Coloration  

NSDL National Science Digital Library

Most animals are patterned. While some markings may serve as an advertisement, many appear to function in concealment. Because of the principal way in which they seem to function, such markings are often termed disruptive coloration . Although there are a number of characteristics that may influence the effectiveness of markings in disruption; this study will only focus on two aspects: (1) the effectiveness of the position of markings in blurring or enhancing outline, and (2) the degree to which strongly contrasting markings may interfere with or aid recognition. In regard to the former, it must be kept in mind that the profile changes with change in viewing angle. Thus the pattern seen in relation to the profile most commonly presented to predator (or prey) is of most interest to us here.

Ipsen, David; Gillfillan, Gretchen L.; Judy Diamond (Revised New Edition); Judy Scotchmoor (Revised New Edition); Stebbins, Robert

2009-04-01

175

COLORS Magazine  

NSDL National Science Digital Library

COLORS Magazine was willed into existence in 1991 by photographer Oliviero Toscani and art director Tibor Kalman. Its goal was simple: "to show the world to the world.â The publication looks at social issues around the world through thoughtful prose and meaningful visuals. Visitors can click on the Stories tab to click through a visual field of photos that lead to such stories as military service in South Korea and cuts to public spending in the United Kingdom. The Notebooks area brings together commentaries from all over the world as part of a collaboration with Reporters sans Frontieres. The Projects area contains links to special issues and projects, such as the News Machine that "churns your tweets through different media filters.â Interested users can learn about obtaining a print subscription or explore the corresponding blog.

176

Fluorescence detection of tyrosinase activity on dopamine-betaxanthin purified from Portulaca oleracea (common purslane) flowers.  

PubMed

Tyrosinase or polyphenol oxidase (EC 1.14.18.1) is one of the key enzymes for the biosynthesis of natural pigment betalains. These are an important class of water-soluble pigments, characteristic of plants belonging to the order Caryophyllales. In this work, dopamine-betaxanthin (also known as miraxanthin V) is reported as the pigment responsible for the bright coloration in yellow flowers of Portulaca oleracea (common purslane). The natural pigment is purified, and used as a substrate for the catecholase (diphenolase) activity of the enzyme tyrosinase. A new, continuous method to follow the activity is developed based on the fluorescent properties of the betaxanthin. Fluorescence of the enzyme activity derived products is reported for the first time. Relevance of the fluorescent phenomenon is discussed based on fluorescence images and the description of a physiological inner filter effect present in flowers of P. oleracea. The first description of the betalain content in flower pistils is also provided. PMID:19227976

Gandía-Herrero, Fernando; Jiménez-Atiénzar, Mercedes; Cabanes, Juana; Escribano, Josefa; García-Carmona, Francisco

2009-03-25

177

Using color management in color document processing  

NASA Astrophysics Data System (ADS)

Color Management Systems have been used for several years in Desktop Publishing (DTP) environments. While this development hasn't matured yet, we are already experiencing the next generation of the color imaging revolution-Device Independent Color for the small office/home office (SOHO) environment. Though there are still open technical issues with device independent color matching, they are not the focal point of this paper. This paper discusses two new and crucial aspects in using color management in color document processing: the management of color objects and their associated color rendering methods; a proposal for a precedence order and handshaking protocol among the various software components involved in color document processing. As color peripherals become affordable to the SOHO market, color management also becomes a prerequisite for common document authoring applications such as word processors. The first color management solutions were oriented towards DTP environments whose requirements were largely different. For example, DTP documents are image-centric, as opposed to SOHO documents that are text and charts centric. To achieve optimal reproduction on low-cost SOHO peripherals, it is critical that different color rendering methods are used for the different document object types. The first challenge in using color management of color document processing is the association of rendering methods with object types. As a result of an evolutionary process, color matching solutions are now available as application software, as driver embedded software and as operating system extensions. Consequently, document processing faces a new challenge, the correct selection of the color matching solution while avoiding duplicate color corrections.

Nehab, Smadar

1995-04-01

178

In vitro flowering of bitter melon  

Microsoft Academic Search

Flowers were formed from shoot tips of bitter melon (Momordica charantia L.) cultured on Murashige and Skoog medium supplemented with 90 mM sucrose, 0.05 mM Fe2+ and 4 µM N6-benzyladenine (BA). The addition of 0.05 mM Fe2+ to the medium prevented chlorosis of the explant and promoted normal flowering. Increasing the ratio of carbon to nitrogen promoted male flower formation

S. Wang; L. Tang; F. Chen

2001-01-01

179

Female flowers and inflorescences of Didymelaceae  

Microsoft Academic Search

.  ?In molecular analyses Didymelaceae together with Buxaceae form a fairly well-supported clade among families near the base\\u000a of eudicots. Only little is known, however, about the flowers and inflorescences of Didymelaceae. In this study, the structure\\u000a of the female flowers and inflorescences of Didymeles integrifolia was studied. Flowers are unicarpellate and orientation of the carpel is slightly deflected abaxially as

M. von Balthazar; G. E. Schatz; P. K. Endress

2003-01-01

180

Quaternion color texture segmentation  

Microsoft Academic Search

The quaternion representation of color is shown here to be effective in the context of segmenting color images into regions of similar color texture. The advantage of using quaternion arithmetic is that a color can be represented and analyzed as a single entity. A low-dimensional basis for the color textures found in a given image is derived via quaternion principal

Lilong Shi; Brian Funt

2007-01-01

181

Similarity of Color Images  

Microsoft Academic Search

We describe two new color indexing techniques. The first one is a more robust version of thecommonly used color histogram indexing. In the index we store the cumulative color histograms.The L 1 -, L 2 -, or L1 -distance between two cumulative color histograms can be used to define asimilarity measure of these two color distributions. We show that while

Markus A. Stricker; Markus Orengo

1995-01-01

182

Colors and Shapes  

NSDL National Science Digital Library

How do you name things by color and shape? Lets learn about shapes and colors! 1. Watch this Color Video 2. Play this Color Game 3. Complete this Color Page 4. Watch this Shape Video 5. Watch this Shape Video2 6. Play this Shape Game 7. ...

Ms.campbell

2012-04-04

183

Hu Yinglin's ‘Connoisseurs of Flowers’: translation and commentary  

Microsoft Academic Search

People who love flowers are rare enough, but people who are connoisseurs of flowers are even rarer — not that anyone who is a connoisseur of flowers is not a lover of flowers. Nowadays, it is not just the case that vulgar people fail to cultivate flowers at home; even enthusiasts who do cultivate them are ignorant of their names.

Alison Hardie

1999-01-01

184

Privatization and Educational Choice.  

ERIC Educational Resources Information Center

This book describes how and why educational choice movements will affect public education. It uses a public-choice approach to argue that both the supporters and opponents of private and school choice have failed to address several critical issues. Following an introductory chapter, chapter 2 is devoted to the rationale for contracting out…

Lieberman, Myron

185

Public Choice III  

Microsoft Academic Search

This book represents a considerable revision and expansion of Public Choice II (1989). Six new chapters have been added, and several chapters from the previous edition have been extensively revised. The discussion of empirical work in public choice has been greatly expanded. As in the previous editions, all of the major topics of public choice are covered. These include: why

Dennis C. Mueller

2003-01-01

186

Choice with Responsibility  

ERIC Educational Resources Information Center

Argues that choice with responsibility belongs to the child, there must be a gradual continuous assumption of responsibility, and the choice with responsibility is a learning process. It is important to avoid offering choices that are not authentic. Adults also have responsibilities in fostering children's growth along these lines. (BF/JH)

Veach, Davia M.

1977-01-01

187

Savage Misunderstandings about Choice.  

ERIC Educational Resources Information Center

Although Jonathan Kozol is well-informed about choice program imperfections, schools of choice are superior to traditional schools. In places like East Harlem, school choice is helping transform youngsters from captive, disenfranchised malcontents to true students involved in their education. The challenge is to make every district school worthy…

Gura, Mark

1993-01-01

188

SOCIOLOGICAL RATIONAL CHOICE THEORY  

Microsoft Academic Search

Although rational choice theory has made considerable advances in other social sciences, its progress in sociology has been limited. Some sociologists' reser- vations about rational choice arise from a misunderstanding of the theory. The first part of this essay therefore introduces rational choice as a general theoretical perspective, or family of theories, which explains social outcomes by construct- ing models

Michael Hechter; Satoshi Kanazawa

1997-01-01

189

Music-color associations are mediated by emotion  

PubMed Central

Experimental evidence demonstrates robust cross-modal matches between music and colors that are mediated by emotional associations. US and Mexican participants chose colors that were most/least consistent with 18 selections of classical orchestral music by Bach, Mozart, and Brahms. In both cultures, faster music in the major mode produced color choices that were more saturated, lighter, and yellower whereas slower, minor music produced the opposite pattern (choices that were desaturated, darker, and bluer). There were strong correlations (0.89 < r < 0.99) between the emotional associations of the music and those of the colors chosen to go with the music, supporting an emotional mediation hypothesis in both cultures. Additional experiments showed similarly robust cross-modal matches from emotionally expressive faces to colors and from music to emotionally expressive faces. These results provide further support that music-to-color associations are mediated by common emotional associations.

Palmer, Stephen E.; Schloss, Karen B.; Xu, Zoe; Prado-Leon, Lilia R.

2013-01-01

190

Display Device Color Management and Visual Surveillance of Vehicles  

ERIC Educational Resources Information Center

Digital imaging has seen an enormous growth in the last decade. Today users have numerous choices in creating, accessing, and viewing digital image/video content. Color management is important to ensure consistent visual experience across imaging systems. This is typically achieved using color profiles. In this thesis we identify the limitations…

Srivastava, Satyam

2011-01-01

191

Information content of colored motifs in complex networks.  

PubMed

We study complex networks in which the nodes are tagged with different colors depending on their function (colored graphs), using information theory applied to the distribution of motifs in such networks. We find that colored motifs can be viewed as the building blocks of the networks (much more than the uncolored structural motifs can be) and that the relative frequency with which these motifs appear in the network can be used to define its information content. This information is defined in such a way that a network with random coloration (but keeping the relative number of nodes with different colors the same) has zero color information content. Thus, colored motif information captures the exceptionality of coloring in the motifs that is maintained via selection. We study the motif information content of the C. elegans brain as well as the evolution of colored motif information in networks that reflect the interaction between instructions in genomes of digital life organisms. While we find that colored motif information appears to capture essential functionality in the C. elegans brain (where the color assignment of nodes is straightforward), it is not obvious whether the colored motif information content always increases during evolution, as would be expected from a measure that captures network complexity. For a single choice of color assignment of instructions in the digital life form Avida, we find rather that colored motif information content increases or decreases during evolution, depending on how the genomes are organized, and therefore could be an interesting tool to dissect genomic rearrangements. PMID:21762026

Adami, Christoph; Qian, Jifeng; Rupp, Matthew; Hintze, Arend

2011-01-01

192

Tooth - abnormal colors  

MedlinePLUS

Abnormal tooth color is any color other than the white to yellowish-white of normal teeth. ... things can cause tooth discoloration. The change in color may affect the entire tooth, or just appear ...

193

Skin color - patchy  

MedlinePLUS

Patchy skin color is areas where the skin color is irregular. Mottling or mottled skin refers to blood vessel changes in ... in the skin cells that gives skin its color Growth of bacteria or other organisms on the ...

194

Comparative Genomic Analysis of Soybean Flowering Genes  

PubMed Central

Flowering is an important agronomic trait that determines crop yield. Soybean is a major oilseed legume crop used for human and animal feed. Legumes have unique vegetative and floral complexities. Our understanding of the molecular basis of flower initiation and development in legumes is limited. Here, we address this by using a computational approach to examine flowering regulatory genes in the soybean genome in comparison to the most studied model plant, Arabidopsis. For this comparison, a genome-wide analysis of orthologue groups was performed, followed by an in silico gene expression analysis of the identified soybean flowering genes. Phylogenetic analyses of the gene families highlighted the evolutionary relationships among these candidates. Our study identified key flowering genes in soybean and indicates that the vernalisation and the ambient-temperature pathways seem to be the most variant in soybean. A comparison of the orthologue groups containing flowering genes indicated that, on average, each Arabidopsis flowering gene has 2-3 orthologous copies in soybean. Our analysis highlighted that the CDF3, VRN1, SVP, AP3 and PIF3 genes are paralogue-rich genes in soybean. Furthermore, the genome mapping of the soybean flowering genes showed that these genes are scattered randomly across the genome. A paralogue comparison indicated that the soybean genes comprising the largest orthologue group are clustered in a 1.4 Mb region on chromosome 16 of soybean. Furthermore, a comparison with the undomesticated soybean (Glycine soja) revealed that there are hundreds of SNPs that are associated with putative soybean flowering genes and that there are structural variants that may affect the genes of the light-signalling and ambient-temperature pathways in soybean. Our study provides a framework for the soybean flowering pathway and insights into the relationship and evolution of flowering genes between a short-day soybean and the long-day plant, Arabidopsis.

Jung, Chol-Hee; Wong, Chui E.; Singh, Mohan B.; Bhalla, Prem L.

2012-01-01

195

Colored Shadows Investigation  

NSDL National Science Digital Library

This activity (located on page 3 of the PDF) is a full inquiry investigation into mixing colors with light. Groups of learners will set up colored lights in a darkened room and record the color of shadows cast by each color. They will continue to collect data as they experiment with combinations of multiple colored lights and produce a data table to organize their findings. Relates to linked video, DragonflyTV GPS: Light and Color.

Twin Cities Public Television, Inc.

2006-01-01

196

Delayed flowering and global warming  

NASA Astrophysics Data System (ADS)

Within general trends toward earlier spring, observed cases of species and ecosystems that have not advanced their phenology, or have even delayed it, appear paradoxical, especially when made in temperate regions experiencing significant warming. The typical interpretation of this pattern has been that non-responders are insensitive to relatively small levels of warming over the past 40 years, while species showing delays are often viewed as statistical noise or evidence for unknown confounding factors at play. However, plant physiology studies suggest that when winter chilling (vernalization) is required to initiate spring development, winter warming may retard spring events, masking expected advances caused by spring warming. Here, we analyzed long-term data on phenology and seasonal temperatures from 490 species on two continents and demonstrate that 1) apparent non-responders are indeed responding to warming, but their responses to winter and spring warming are opposite in sign, 2) observed trends in first flowering date depend strongly on the magnitude of a given species' response to autumn/winter versus spring warming, and 3) inclusion of these effects strongly improves hindcast predictions of long-term flowering trends. With a few notable exceptions, climate change research has focused on the overall mean trend towards phenological advance, minimizing discussion of apparently non-responding species. Our results illuminate an under-studied source of complexity in wild species responses and support the need for models incorporating diverse environmental cues in order to improve predictability of species responses to anthropogenic climate change.

Cook, B. I.; Wolkovich, E. M.; Parmesan, C.

2011-12-01

197

Scent glands in legume flowers.  

PubMed

Scent glands, or osmophores, are predominantly floral secretory structures that secrete volatile substances during anthesis, and therefore act in interactions with pollinators. The Leguminosae family, despite being the third largest angiosperm family, with a wide geographical distribution and diversity of habits, morphology and pollinators, has been ignored with respect to these glands. Thus, we localised and characterised the sites of fragrance production and release in flowers of legumes, in which scent plays an important role in pollination, and also tested whether there are relationships between the structure of the scent gland and the pollinator habit: diurnal or nocturnal. Flowers in pre-anthesis and anthesis of 12 legume species were collected and analysed using immersion in neutral red, olfactory tests and anatomical studies (light and scanning electron microscopy). The main production site of floral scent is the perianth, especially the petals. The scent glands are distributed in a restricted way in Caesalpinia pulcherrima, Anadenanthera peregrina, Inga edulis and Parkia pendula, constituting mesophilic osmophores, and in a diffuse way in Bauhinia rufa, Hymenaea courbaril, Erythrostemon gilliesii, Poincianella pluviosa, Pterodon pubescens, Platycyamus regnellii, Mucuna urens and Tipuana tipu. The glands are comprised of cells of the epidermis and mesophyll that secrete mainly terpenes, nitrogen compounds and phenols. Relationships between the presence of osmophores and type of anthesis (diurnal and nocturnal) and the pollinator were not found. Our data on scent glands in Leguminosae are original and detail the type of diffuse release, which has been very poorly studied. PMID:23574349

Marinho, C R; Souza, C D; Barros, T C; Teixeira, S P

2013-04-10

198

Color constrasts in advertising: facade colors of food and drink consumption venues  

NASA Astrophysics Data System (ADS)

The building facade has a visually defined impact and there are numerous forces driving the choice of colors used. Commercial premises such as pubs, restaurants and bars are normally but not always clearly marked as such. Although we human beings can have the option of free choice in the colors we use around the home there are numerous positive driving forces dictating those we use in business life. Many of these factors have been identified. They depend on the type of population these venues serve, their geography and their traditions.

Hutchings, John

2002-06-01

199

Moth using proboscis to get food from flower  

NSDL National Science Digital Library

Not only bees pollinate flowers. Moths have a specialized mouth structure called a proboscis that is used to extract nectar and pollinate the flower. The moth benefits by getting food and the flower benefits by being pollinated.

Katie Hale (California State University, Fullerton;Student, Biological Sciences)

2006-12-30

200

Bee covered in pollen inside a flower  

NSDL National Science Digital Library

Unlike animals, plants are unable to move and find other plants to mate with. Thus, plants rely on insects and other animals to transfer pollen (male sperm) from one flower to the female sex organ (carpels) on another flower. This is called pollination.

Katie Hale (CSUF;Biological Sciences)

2007-06-19

201

Ancient asymmetries in the evolution of flowers  

Microsoft Academic Search

Dorsoventral asymmetry in flowers is thought to have evolved many times independently as a specialized adaptation to animal pollinators [1, 2]. To understand how such a complex trait could have arisen repeatedly, we have compared the expression of a gene controlling dorsoventral asymmetry in Antirrhinum with its counterpart in Arabidopsis, a distantly related species with radially symmetrical flowers. We found

Pilar Cubas; Enrico Coen; José Miguel Mart??nez Zapater

2001-01-01

202

The Purpose and Power of Color in Industrial Design: Encouraging the Meaningful Use of Color in Design Education  

Microsoft Academic Search

Color may be the most influential factor in the decision to buy, or not to buy. In Malcolm Gladwell's book, Blink: The Power of Thinking without Thinking, he suggests that when presented with a choice, the subconscious mind makes a decision within just a few seconds. Even before one rationalizes and investigates the choices, through rapid cognition, the mind has

Jason A. Morris

203

Synchronization of the flowering transition by the tomato TERMINATING FLOWER gene.  

PubMed

The transition to flowering is a major determinant of plant architecture, and variation in the timing of flowering can have profound effects on inflorescence architecture, flower production and yield. Here, we show that the tomato mutant terminating flower (tmf) flowers early and converts the multiflowered inflorescence into a solitary flower as a result of precocious activation of a conserved floral specification complex encoded by ANANTHA (AN) and FALSIFLORA (FA). Without TMF, the coordinated flowering process is disrupted, causing floral identity genes, such as AN and members of the SEPALLATA (SEP) family, to activate precociously, while the expression of flowering transition genes, such as FRUITFULL (FUL), is delayed. Indeed, driving AN expression precociously is sufficient to cause early flowering, and this expression transforms multiflowered inflorescences into normal solitary flowers resembling those of the Solanaceae species petunia and tobacco. Thus, by timing AN activation, TMF synchronizes flower formation with the gradual reproductive transition, which, in turn, has a key role in determining simple versus complex inflorescences. PMID:23143603

MacAlister, Cora A; Park, Soon Ju; Jiang, Ke; Marcel, Fabien; Bendahmane, Abdelhafid; Izkovich, Yinon; Eshed, Yuval; Lippman, Zachary B

2012-12-01

204

Identification and characterization of flowering genes in kiwifruit: sequence conservation and role in kiwifruit flower development  

PubMed Central

Background Flower development in kiwifruit (Actinidia spp.) is initiated in the first growing season, when undifferentiated primordia are established in latent shoot buds. These primordia can differentiate into flowers in the second growing season, after the winter dormancy period and upon accumulation of adequate winter chilling. Kiwifruit is an important horticultural crop, yet little is known about the molecular regulation of flower development. Results To study kiwifruit flower development, nine MADS-box genes were identified and functionally characterized. Protein sequence alignment, phenotypes obtained upon overexpression in Arabidopsis and expression patterns suggest that the identified genes are required for floral meristem and floral organ specification. Their role during budbreak and flower development was studied. A spontaneous kiwifruit mutant was utilized to correlate the extended expression domains of these flowering genes with abnormal floral development. Conclusions This study provides a description of flower development in kiwifruit at the molecular level. It has identified markers for flower development, and candidates for manipulation of kiwifruit growth, phase change and time of flowering. The expression in normal and aberrant flowers provided a model for kiwifruit flower development.

2011-01-01

205

PHYTOCHROME-DEPENDENT LATE-FLOWERING accelerates flowering through physical interactions with phytochrome B and CONSTANS  

PubMed Central

In flowering plants, light is one of the major environmental stimuli that determine the timing of the transition from the vegetative to reproductive phase. In Arabidopsis, phytochrome B (phyB); phyA; cryptochrome 2; and FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 are major photoreceptors that regulate flowering. Unlike phyA; cryptochrome 2; and FLAVIN-BINDING, KELCH REPEAT, F-BOX 1, phyB delays flowering mainly by destabilizing the CONSTANS (CO) protein, whose reduction leads to decreased expression of a florigen gene, FLOWERING LOCUS T. However, it remains unclear how the phyB-mediated CO destabilization is mechanistically regulated. Here, we identify a unique PHYTOCHROME-DEPENDENT LATE-FLOWERING (PHL) gene, which is mainly involved in the phyB-dependent regulation of flowering. Plants with mutant phl exhibited a late-flowering phenotype, especially under long-day conditions. The late-flowering phenotype of the phl mutant was completely overridden by a phyB mutation, indicating that PHL normally accelerates flowering by countering the inhibitory effect of phyB on flowering. Accordingly, PHL physically interacted with phyB both in vitro and in vivo in a red light-dependent manner. Furthermore, in the presence of phyB under red light, PHL interacted with CO as well. Taken together, we propose that PHL regulates photoperiodic flowering by forming a phyB–PHL–CO tripartite complex.

Endo, Motomu; Tanigawa, Yoshiyasu; Murakami, Tadashi; Araki, Takashi; Nagatani, Akira

2013-01-01

206

California Policy Choices. Volume 1.  

National Technical Information Service (NTIS)

California Policy Choices is an annual, edited volume seeking to improve public policy choices made in California political systems. It does so not by advocating particular policy choices, but by analyzing the consequences of choices already made, by incr...

J. J. Kirlin D. R. Winkler

1984-01-01

207

The Families of Flowering Plants  

NSDL National Science Digital Library

Australian authors L. Watson and M. J. Dallwitz have updated this magnificent resource of detailed character descriptions, taxonomic information, references, and line illustrations of "all the Angiosperm families" from Acanthaceae to Zygophyllaceae. Users will find extensive data on plant and flower morphology, "seedling germination type, embryology, anther ontogeny, pollen cytology and morphology, stigma type, sieve-tube plastids, leaf, stem, nodal and wood anatomy, and phytochemistry (phenolics, alkaloids, cyanogenesis, etc.)." Watson and Dallwitz also include detailed taxonomic information on family synonyms, "numbers of species and genera in each family, and complete lists or (in the case of the largest families only) examples of the genera in each." A character list and an 'implicit attributes' section accompany the resource; information for downloading is available at the site. For teachers and graduate students alike, this online resource will be hard to beat.

208

Organizing color in dentistry.  

PubMed

Although esthetic dentistry techniques have grown more sophisticated, the fabrication and control of color in dentistry can be improved. An organized and precise system is necessary to combine artistic and scientific approaches. For this, a color order system, based on Munsell's notations and spectrophotometric research on the color space of natural teeth, would provide restorations of excellent color. PMID:2447140

Miller, L

1987-12-01

209

Color identification testing device  

NASA Technical Reports Server (NTRS)

Testing device, which determines ability of a technician to identify color-coded electric wires, is superior to standard color blindness tests. It tests speed of wire selection, detects partial color blindness, allows rapid testing, and may be administered by a color blind person.

Brawner, E. L.; Martin, R.; Pate, W.

1970-01-01

210

Approximate Hypergraph Coloring  

Microsoft Academic Search

A coloring of a hypergraph is a mapping of vertices to colors such that no hyperedge is monochromatic. We are interested in the problem of coloring 2-colorable hypergraphs. For the special case of graphs (hypergraphs of dimension 2) this can easily be done in linear time. The problem for general hypergraphs is much more dicult since a result of Lov

Pierre Kelsen; Sanjeev Mahajan; Ramesh Hariharan

1996-01-01

211

Color quantization of images  

Microsoft Academic Search

The authors develop algorithms for the design of hierarchical tree structured color palettes incorporating performance criteria which reflect subjective evaluations of image quality. Tree structured color palettes greatly reduce the computational requirements of the palette design and pixel mapping tasks, while allowing colors to be properly allocated to densely populated areas of the color space. The algorithms produce higher-quality displayed

Michael T. Orchard; Charles A. Bouman

1991-01-01

212

Color Transfer between Images  

Microsoft Academic Search

Often this means removing a dominant and undesirable color cast, such as the yellow in photos taken under incandescent illumination. This article describes a method for a more general form of color correction that borrows one image's color characteristics from anoth-er. Figure 1 shows an example of this process, where we applied the colors of a sunset photograph to a

Erik Reinhard; Michael Ashikhmin; Bruce Gooch; Peter Shirley

2001-01-01

213

Standard RGB Color Spaces  

Microsoft Academic Search

This paper describes the specifications and usage of standard RGB color spaces promoted today by standard bodies and\\/or the imaging industry. As in the past, most of the new standard RGB color spaces were developed for specific imaging workflow and applications. They are used as interchange spaces to communicate color and\\/or as working spaces in imaging applications. Standard color spaces

Sabine Süsstrunk; Robert Buckley; Steve Swen

1999-01-01

214

Color Me Understood.  

ERIC Educational Resources Information Center

Describes the "color system" as a way of grouping children into different personality types based on a certain color: orange, blue, green, and gold. Lists stress producers for specific color people. Asserts that, through making groups of different colors, children begin to see the various specialties others can bring to the group and learn to…

Harris, Judy J.

2000-01-01

215

Balanced edge colorings  

Microsoft Academic Search

This paper contains two principal results. The first proves that any graph G can be given a balanced proper edge coloring by k colors for any k???(G). Here balanced means that the number of vertices incident with any set of d colors is essentially fixed for each d, that is, for two different d-sets of colors the number of vertices

Paul N. Balister; Alexandr V. Kostochka; Hao Li; Richard H. Schelp

2004-01-01

216

Adaptive Skin Color Classificator  

Microsoft Academic Search

Skin color is an important feature of faces. Various ap- plications benefit from robust skin color detection. Skin color may look quite different, depending on camera set- tings, illumination, shadows, people's tans, ethnic groups. That variation is a challenging aspect of skin color classi- fication. In this paper, we present an approach that uses a high level vision module to

Matthias Wimmer; Bernd Radig; Informatik IX

2005-01-01

217

Urine - abnormal color  

MedlinePLUS

The usual color of urine is straw-yellow. Abnormally colored urine may be cloudy, dark, or blood-colored. ... Abnormal urine color may be caused by infection, disease, medicines, or food you eat. Cloudy or milky urine is a sign ...

218

A Regulatory Network for Coordinated Flower Maturation  

PubMed Central

For self-pollinating plants to reproduce, male and female organ development must be coordinated as flowers mature. The Arabidopsis transcription factors AUXIN RESPONSE FACTOR 6 (ARF6) and ARF8 regulate this complex process by promoting petal expansion, stamen filament elongation, anther dehiscence, and gynoecium maturation, thereby ensuring that pollen released from the anthers is deposited on the stigma of a receptive gynoecium. ARF6 and ARF8 induce jasmonate production, which in turn triggers expression of MYB21 and MYB24, encoding R2R3 MYB transcription factors that promote petal and stamen growth. To understand the dynamics of this flower maturation regulatory network, we have characterized morphological, chemical, and global gene expression phenotypes of arf, myb, and jasmonate pathway mutant flowers. We found that MYB21 and MYB24 promoted not only petal and stamen development but also gynoecium growth. As well as regulating reproductive competence, both the ARF and MYB factors promoted nectary development or function and volatile sesquiterpene production, which may attract insect pollinators and/or repel pathogens. Mutants lacking jasmonate synthesis or response had decreased MYB21 expression and stamen and petal growth at the stage when flowers normally open, but had increased MYB21 expression in petals of older flowers, resulting in renewed and persistent petal expansion at later stages. Both auxin response and jasmonate synthesis promoted positive feedbacks that may ensure rapid petal and stamen growth as flowers open. MYB21 also fed back negatively on expression of jasmonate biosynthesis pathway genes to decrease flower jasmonate level, which correlated with termination of growth after flowers have opened. These dynamic feedbacks may promote timely, coordinated, and transient growth of flower organs.

Ploense, Sara E.; Wu, Miin-Feng; Yadav, Vandana; Tholl, Dorothea; Chetelat, Aurore; Haupt, Ina; Kennerley, Brian J.; Hodgens, Charles; Farmer, Edward E.; Nagpal, Punita; Reed, Jason W.

2012-01-01

219

A regulatory network for coordinated flower maturation.  

PubMed

For self-pollinating plants to reproduce, male and female organ development must be coordinated as flowers mature. The Arabidopsis transcription factors AUXIN RESPONSE FACTOR 6 (ARF6) and ARF8 regulate this complex process by promoting petal expansion, stamen filament elongation, anther dehiscence, and gynoecium maturation, thereby ensuring that pollen released from the anthers is deposited on the stigma of a receptive gynoecium. ARF6 and ARF8 induce jasmonate production, which in turn triggers expression of MYB21 and MYB24, encoding R2R3 MYB transcription factors that promote petal and stamen growth. To understand the dynamics of this flower maturation regulatory network, we have characterized morphological, chemical, and global gene expression phenotypes of arf, myb, and jasmonate pathway mutant flowers. We found that MYB21 and MYB24 promoted not only petal and stamen development but also gynoecium growth. As well as regulating reproductive competence, both the ARF and MYB factors promoted nectary development or function and volatile sesquiterpene production, which may attract insect pollinators and/or repel pathogens. Mutants lacking jasmonate synthesis or response had decreased MYB21 expression and stamen and petal growth at the stage when flowers normally open, but had increased MYB21 expression in petals of older flowers, resulting in renewed and persistent petal expansion at later stages. Both auxin response and jasmonate synthesis promoted positive feedbacks that may ensure rapid petal and stamen growth as flowers open. MYB21 also fed back negatively on expression of jasmonate biosynthesis pathway genes to decrease flower jasmonate level, which correlated with termination of growth after flowers have opened. These dynamic feedbacks may promote timely, coordinated, and transient growth of flower organs. PMID:22346763

Reeves, Paul H; Ellis, Christine M; Ploense, Sara E; Wu, Miin-Feng; Yadav, Vandana; Tholl, Dorothea; Chételat, Aurore; Haupt, Ina; Kennerley, Brian J; Hodgens, Charles; Farmer, Edward E; Nagpal, Punita; Reed, Jason W

2012-02-01

220

Sweet memories: epigenetic control in flowering  

PubMed Central

Many plants respond to winter with epigenetic factors that gradually dampen repression of flowering so that they can flower in spring. The study of this process was important for the identification of the plant Polycomb group (PcG) of proteins and their role in the epigenetic control of plant gene expression. Fittingly, these studies continue to illuminate our understanding of PcG function. We discuss recent advances, particularly the role of noncoding RNA in the recruitment of PcG to target genes, and the role of the PcG in regulating the stem cell pool in flowers.

Muller, Ralf

2011-01-01

221

Latinos and School Choice  

ERIC Educational Resources Information Center

The authors describe how Latino students are underrepresented in public schools of choice. They provide evidence to refute the claim that Latino students who choose to leave assigned public schools enroll in religious schools instead. Charter schools stand out as the type of public schools of choice where Latino students are well represented.…

Gastic, Billie; Coronado, Diana Salas

2011-01-01

222

More Choice, Less Crime  

ERIC Educational Resources Information Center

Previous research debates whether public school choice improves students' academic outcomes, but there is little examination of its effects on their nonacademic outcomes. We use data from a nationally representative sample of high school students, a previously developed Tiebout choice measure, and metropolitan-level data on teenage arrest rates to…

Dills, Angela K.; Hernandez-Julian, Rey

2011-01-01

223

Children's Choices for 2008  

ERIC Educational Resources Information Center

Each year 12,500 school children from different regions of the United States read and vote on the newly published children's and young adults' trade books that they like best. The Children's Choices for 2008 list is the 34th in a series that first appeared as "Classroom Choices" in the November 1975 issue of "The Reading Teacher" (RT), a…

Reading Teacher, 2008

2008-01-01

224

Tense Choices in Citations.  

ERIC Educational Resources Information Center

Examines tense, aspect, and voice choices in the reporting verbs in a corpus of research articles from the "Journal of Psychosomatic Medicine." Investigates how such choices correlate with other syntactic elements in the citations, as well as with the discourse functions of the citations in their contexts. (TB)

Hawes, Thomas; Thomas, Sarah

1997-01-01

225

The Illusion of Choice  

ERIC Educational Resources Information Center

Both New Labour and the Conservatives are keen to emphasise choice and diversity in crucial areas of public provision--and particularly with regard to education and health. In this article, "FORUM" co-Editor Clyde Chitty concentrates on recent proposals by the two main parties for promoting greater choice in secondary schooling in England. This…

Chitty, Clyde

2004-01-01

226

School Choice Marches forward  

ERIC Educational Resources Information Center

One year ago, the "Wall Street Journal" dubbed 2011 "the year of school choice," opining that "this year is shaping up as the best for reformers in a very long time." School-choice laws took great strides in 2011, both in the number of programs that succeeded across states and also in the size and scope of the adopted programs. Yet education…

Butcher, Jonathan

2013-01-01

227

Memory for color reactivates color processing region  

Microsoft Academic Search

and gray abstract shapes. During retrieval, old and new shapes,were,presented,in gray and participants responded ‘old-colored’, ‘old-gray’, or ‘new’. Within color perception regions, color memory related activity was observed in the left fusiform gyrus, adjacent to the collateral sulcus. A retinotopic mapping,analysis,indicated,this activity occurred,within color processing,region,V8. The present,feature specific evidence,provides,compelling support,for a constructive,view of memory.,NeuroReport 00:000–000 ,,2009 Wolters Kluwer Health |

Scott D. Slotnick

228

Salicylic acid and the flowering gene FLOWERING LOCUS T homolog are involved in poor-nutrition stress-induced flowering of Pharbitis nil.  

PubMed

The short-day plants Pharbitis nil (synonym Ipomoea nil), var. Violet and Tendan were grown in a diluted nutrient solution or tap water for 20 days under long-day conditions. Violet plants were induced to flower and vegetative growth was inhibited, whereas Tendan plants were not induced to flower, although vegetative growth was inhibited under these conditions. The Violet plants induced to flower by poor-nutrition stress produced fertile seeds and their progeny developed normally. Defoliated Violet scions grafted onto the rootstocks of Violet or Tendan were induced to flower under poor-nutrition stress conditions, but Tendan scions grafted onto the Violet rootstocks were not induced to flower. These results indicate that a transmissible flowering stimulus is involved in the induction of flowering by poor-nutrition stress. The poor-nutrition stress-induced flowering was inhibited by aminooxyacetic acid, a phenylalanine ammonia-lyase inhibitor, and this inhibition was almost completely reversed by salicylic acid (SA). However, exogenously applied SA did not induce flowering under non-stress conditions, suggesting that SA may be necessary but not sufficient to induce flowering. PnFT2, a P. nil ortholog of the flowering gene FLOWERING LOCUS T (FT) of Arabidopsis thaliana, was expressed when the Violet plants were induced to flower by growing in tap water, but expression of PnFT1, another ortholog of FT, was not induced, suggesting the specific involvement of PnFT2 in stress-induced flowering. PMID:19906461

Wada, Kaede C; Yamada, Mizuki; Shiraya, Takeshi; Takeno, Kiyotoshi

2010-04-15

229

Gibberellins Promote Flowering of Arabidopsis by Activating the LEAFY Promoter  

Microsoft Academic Search

The gibberellin class of plant hormones has been implicated in the control of flowering in several species. In Arabidop- sis, severe reduction of endogenous gibberellins delays flowering in long days and prevents flowering in short days. We have investigated how the differential effects of gibberellins on flowering correlate with expression of LEAFY , a floral meristem identity gene. We have

Miguel A. Blázquez; Roland Green; Ove Nilsson; Michael R. Sussman; Detlef Weigel

1998-01-01

230

What color is it?  

NASA Astrophysics Data System (ADS)

Color management allows the deterministic handling of color data from input to output. This, of course, assumes that the first digital representation of our data is the "correct" color. It assumes that we did not make any errors in the input definitions, did not use wrong color input profiles, captured the user's intent, or fell prey to a host of other potential problems. After we have made those assumptions, we now can deterministically transfer the color from one place to another. Note that there is a big difference between "reproducing" one color at a different location and "deterministically transferring one set of color data to another location". The deterministic transfer is limited to the small set of physical metrics we decided to call "color". All other components of color are ignored.

Eschbach, Reiner; Sharma, Gaurav; Unal, Gozde B.

2004-12-01

231

Recent Advances of Flowering Locus T Gene in Higher Plants  

PubMed Central

Flowering Locus T (FT) can promote flowering in the plant photoperiod pathway and also facilitates vernalization flowering pathways and other ways to promote flowering. The expression of products of the FT gene is recognized as important parts of the flowering hormone and can induce flowering by long-distance transportation. In the present study, many FT-like genes were isolated, and the transgenic results show that FT gene can promote flowering in plants. This paper reviews the progress of the FT gene and its expression products to provide meaningful information for further studies of the functions of FT genes.

Xu, Feng; Rong, Xiaofeng; Huang, Xiaohua; Cheng, Shuiyuan

2012-01-01

232

Exploiting Mate Choice in Evolutionary Computation: Sexual Selection as a Process of Search, Optimization, And Diversification  

Microsoft Academic Search

Sexual selection through mate choice is a powerful evolutionary process that has been important in the success of sexually-reproducing animals and flowering plants. Over the short term, mate preferences evolve because they improve the outcome of sexual recombination. Over the long term, assortative mate preferences can help maintain genetic diversity, promote speciation, and facilitate evolutionary search through optimal outbreeding; selective

Geoffrey F. Miller

1994-01-01

233

Radiation coloration resistant glass  

DOEpatents

A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10.sup.7 rad, the coloration resistant glass does not lose transparency.

Tomozawa, Minoru (Troy, NY); Watson, E. Bruce (Troy, NY); Acocella, John (Troy, NY)

1986-01-01

234

Effects of Volatiles from Maruca vitrata Larvae and Caterpillar-Infested Flowers of Their Host Plant Vigna unguiculata on the Foraging Behavior of the Parasitoid Apanteles taragamae  

PubMed Central

The parasitoid wasp Apanteles taragamae is a promising candidate for the biological control of the legume pod borer Maruca vitrata, which recently has been introduced into Benin. The effects of volatiles from cowpea and peabush flowers and Maruca vitrata larvae on host selection behavior of the parasitoid Apanteles taragamae were investigated under laboratory conditions by using a Y-tube olfactometer. Naïve and oviposition-experienced female wasps were given a choice between several odor sources that included (1) uninfested, (2) Maruca vitrata-infested, and (3) mechanically damaged cowpea flowers, as well as (4) stem portions of peabush plants carrying leaves and flowers, (5) healthy M. vitrata larvae, and moribund (6), and live (7) virus-infected M. vitrata larvae. Responses of naïve and oviposition-experienced female wasps did not differ for any of the odor source combinations. Wasps were significantly attracted to floral volatiles produced by cowpea flowers that had been infested with M. vitrata larvae and from which the larvae had been removed. Apanteles taragamae females also were attracted to Maruca vitrata-infested flowers after removal of both the larvae and their feces. Female wasps discriminated between volatiles from previously infested flowers and mechanically damaged flowers. Uninfested cowpea flowers attracted only oviposition-experienced wasps that had received a rewarding experience (i.e. the parasitization of two M. vitrata larvae feeding on cowpea flowers) before the olfactometer test. Wasps also were attracted to uninfested leaves and flowers of peabush. Moreover, they were also attracted to healthy and live virus-infected M. vitrata larvae, but not when the latter were moribund. Our data show that, similarly to what has been extensively been reported for foliar volatiles, flowers of plants also emit parasitoid-attracting volatiles in response to being infested with an herbivore.

Dannon, Elie A.; Tamo, Manuele; Van Huis, Arnold

2010-01-01

235

Classification and geography of the flowering plants  

Microsoft Academic Search

Thome, Robert F. (Rancho Santa Ana Botanic Garden, Claremont, CA 91711). Classification and geography of the flowering plants.\\u000a Bot. Rev.58(3): 225–348. 1992.—This treatment of the flowering plants is the latest revision of my classification of the Class Angiospermae\\u000a and replaces my 1983 and more recent 1992 synopses. An update is necessary because so much new information has been published\\u000a in

Robert F. Thorne

1992-01-01

236

Antigenotoxic spinasterol from Cucurbita maxima flowers  

Microsoft Academic Search

The antigenotoxic constituent of squash flowers was isolated by solvent partitioning and repeated vacuum liquid chromatography. The micronucleus test, an in vivo method, was used to monitor the antigenotoxicity of the various fractions during the isolation process. Isolate SQFwB2D from the chloroform extract of squash flowers is the most antigenotoxic isolate. It decreased the mutagenicity of tetracycline by 64.7% at

Irene M. Villaseñor; Pauline Lemon; Allan Palileo; John B. Bremner

1996-01-01

237

Argania spinosa (L.) Skeels flowering phenology  

Microsoft Academic Search

Argan (Argania spinosa (L.)Skeels) flowering was observed at Ait Melloul, Ait Baha andArgana, three sites in the south-west of Morocco during twoseasons, 1994–95 and 1995–96. Glomerule count wasmonitored on first-year and on last-year growth shootevery twenty days. Season was the primary source of variation ofglomerule count on argan first-year and last-yeargrowth shoots. The first season was very dry when flowering

Fouzia Bani-Aameur

2002-01-01

238

Why Is a Flower Five-Petaled?  

ERIC Educational Resources Information Center

This paper examines why many flowers are five-petaled through the use of a five-petaled model that draws insights from the location of cell clusters at a shoot apex, rather than by way of the Fibonacci sequence or the golden ratio as in the past. The conclusion drawn is that flowers are most likely to be five-petaled, followed by six-petaled;…

Nishiyama, Yutaka

2004-01-01

239

Sex determination in flowering plants.  

PubMed Central

In many ways, plants offer unique systems through which to study sex determination. Because the production of unisexual flowers has evolved independently in many plant species, different and novel mechanisms may be operational. Hence, there is probably not one unifying mechanism that explains sex determination in plants. Advances in our understanding of sex determination will come from the analysis of the genetics, molecular biology, and biochemistry of genes controlling sexual determination in plants. Several excellent model systems for bisexual floral development (Arabidopsis and Antirrhinum), monoecy (maize), and dioecy (Silene, asparagus, and mercury) are available for such analyses. The important questions that remain concern the mechanism of action of sex determination genes and their interrelationship, if any, with homeotic genes that determine the sexual identity of floral organ primordia. At the physiological level, the connection between hormone signaling and sexuality is not well understood, although significant correlations have been discovered. Finally, once the genes that regulate these processes are identified, cloned, and studied, new strategies for the manipulation of sexuality in plants should be forthcoming.

Dellaporta, S L; Calderon-Urrea, A

1993-01-01

240

Ring Beholds a Delicate Flower  

NASA Technical Reports Server (NTRS)

NASA's Spitzer Space Telescope finds a delicate flower in the Ring Nebula, as shown in this image. The outer shell of this planetary nebula looks surprisingly similar to the delicate petals of a camellia blossom. A planetary nebula is a shell of material ejected from a dying star. Located about 2,000 light years from Earth in the constellation Lyra, the Ring Nebula is also known as Messier Object 57 and NGC 6720. It is one of the best examples of a planetary nebula and a favorite target of amateur astronomers.

The 'ring' is a thick cylinder of glowing gas and dust around the doomed star. As the star begins to run out of fuel, its core becomes smaller and hotter, boiling off its outer layers. The telescope's infrared array camera detected this material expelled from the withering star. Previous images of the Ring Nebula taken by visible-light telescopes usually showed just the inner glowing loop of gas around the star. The outer regions are especially prominent in this new image because Spitzer sees the infrared light from hydrogen molecules. The molecules emit infrared light because they have absorbed ultraviolet radiation from the star or have been heated by the wind from the star.

Download the QuickTime movie for the animated version of this Ring Nebula image.

2005-01-01

241

Color visualization of cyclic magnitudes  

NASA Astrophysics Data System (ADS)

We exploit the perceptual, circular ordering of the hues in a technique for the visualization of cyclic variables. The hue is thus meaningfully used for the indication of variables such as the azimuth and the units of the measurement of time. The cyclic (or circular) variables may be both of the continuous type or the discrete type; among the first there is azimuth and among the last you find the musical notes and the days of the week. A correspondence between the values of a cyclic variable and the chromatic hues, where the natural circular ordering of the variable is respected, is called a color code for the variable. We base such a choice of hues on an assignment of of the unique hues red, yellow, green and blue, or one of the 8 even permutations of this ordered list, to 4 cardinal values of the cyclic variable, suitably ordered; color codes based on only 3 cardinal points are also possible. Color codes, being intuitive, are easy to remember. A possible low accuracy when reading instruments that use this technique is compensated by fast, ludic and intuitive readings; also, the use of a referential frame makes readings precise. An achromatic version of the technique, that can be used by dichromatic people, is proposed.

Restrepo, Alfredo; Estupiñán, Viviana

2014-02-01

242

Synchrony in the phenology of a culturally iconic spring flower.  

PubMed

We examine the flowering phenology of the cultural iconic Spring Snowflake Leucojum vernum, a considerable tourist attraction, recorded from two sites in western Poland. Flowering dates at the two sites were closely correlated but about 6 days later at the more natural area. The end of flowering was associated with the start of canopy leafing. Early flowering was related to a longer flowering season which may benefit ecotourism under future climate warming. PMID:21547445

Sparks, Tim H; Mizera, Tadeusz; Wójtowicz, Wanda; Tryjanowski, Piotr

2012-03-01

243

Synchrony in the phenology of a culturally iconic spring flower  

NASA Astrophysics Data System (ADS)

We examine the flowering phenology of the cultural iconic Spring Snowflake Leucojum vernum, a considerable tourist attraction, recorded from two sites in western Poland. Flowering dates at the two sites were closely correlated but about 6 days later at the more natural area. The end of flowering was associated with the start of canopy leafing. Early flowering was related to a longer flowering season which may benefit ecotourism under future climate warming.

Sparks, Tim H.; Mizera, Tadeusz; Wójtowicz, Wanda; Tryjanowski, Piotr

2012-03-01

244

Color and Streptomycetes1  

PubMed Central

A report summarizing the results of an international workshop on determination of color of streptomycetes is presented. The results suggest that the color systems which seem most practically appealing and effective to specialists on actinomycetes are those embracing a limited number of color names and groups. The broad groupings allow placement of isolates into reasonably well-defined categories based on color of aerial mycelium. Attempts to expand such systems (more color groups) lead to difficulties. It is common knowledge that many, if not all, of the individual groups would in these broad systems contain strains that differ in many other respects, e.g., spore-wall ornamentation, color of vegetative (substratal) mycelium, morphology of chains of spores, and numerous physiological criteria. Also, cultures of intermediate color can be found, which makes placement difficult. As it now stands, color as a criterion for characterization of streptomycetes and streptoverticillia is in questionable status. Although much useful color information can be obtained by an individual, the application of this information to that in the literature or its use in communication with other individuals leaves much to be desired. More objective methods of color determination are needed. At present, the most effective method that could be used internationally is the color-wheel system of Tresner and Backus. Furthermore, the significance of color in speciation of these organisms is an open question. Obviously, more critical work on the color problem is needed.

Pridham, Thomas G.

1965-01-01

245

Why are fruits colorful? The relative importance of achromatic and chromatic contrasts for detection by birds  

Microsoft Academic Search

The colors of fruits and flowers are traditionally viewed as an adaptation to increase the detectability of plant organs to\\u000a animal vectors. The detectability of visual signals increases with increasing contrasts between target and background. Contrasts\\u000a consist of a chromatic aspect (color) and an achromatic aspect (light intensity), which are perceived separately by animals.\\u000a To evaluate the relative importance of

Eliana Cazetta; Hinrich Martin Schaefer; Mauro Galetti

2009-01-01

246

Introducing the patient's choice.  

PubMed

Susan Lovett, a sister on an oncology ward in a Shropshire hospital, has won the Patient's Choice Award. She was nominated for the 'unbelievably kind and empathetic' care she provided to a patient and his family. PMID:24823568

Pearce, Lynne

2014-05-20

247

Color for Safety.  

National Technical Information Service (NTIS)

Emphasizes the importance of color in preventing accidents in the mineral industries. The correct color coding and labeling of fuel, gas and chemical pipes, and cylinders to prevent misuse of contents is pointed out.

1994-01-01

248

Developments in Color Micrographics.  

ERIC Educational Resources Information Center

Summarizes recent progress in color micrographics, which has centered about the corporate development of new microfilms whose capacities for reproducing and sustaining color image far exceed those of their predecessors. (Author/EJS)

Hourdajian, Ara

1983-01-01

249

Colored Contact Lens Dangers  

MedlinePLUS

... the Sun Eye Health News Consumer Alerts Colored Contact Lens Dangers Tweet Eye Health Lifestyle Topics Preventing ... Halloween Hazard: The Hidden Dangers of Buying Colored Contact Lenses Without a Prescription It started as an ...

250

Skin color enhancement based on favorite skin color in HSV color space  

Microsoft Academic Search

Skin color enhancement based on favorite skin color is proposed to make skin color displayed on large screen flat panel TVs agree with human favorite skin color. A robust skin detection method in different intensity is obtained after analyzing the distribution of skin color in HSV color space. The favorite skin color region is found via a psychological experiment too.

Xiao-Ning Zhang; Jue Jiang; Zhi-Hu Liang; Chun-Liang Liu

2010-01-01

251

Color ordering in QCD  

NASA Astrophysics Data System (ADS)

We derive color decompositions of arbitrary tree and one-loop QCD amplitudes into color-ordered objects called primitive amplitudes. Furthermore, we derive general fermion flip and reversion identities spanning the null space among the primitive amplitudes and use them to prove that all color-ordered tree amplitudes of massless QCD can be written as linear combinations of color-ordered tree amplitudes of N=4 super Yang-Mills theory.

Schuster, Theodor

2014-05-01

252

Quantum Dots and Colors  

NSDL National Science Digital Library

Students are introduced to the physical concept of the colors of rainbows as light energy in the form of waves with distinct wavelengths, but in a different manner than traditional kaleidoscopes. Looking at different quantum dot solutions, they make observations and measurements, and graph their data. They come to understand how nanoparticles interact with absorbing photons to produce colors. They learn the dependence of particle size and color wavelength and learn about real-world applications for using these colorful liquids.

University Of Houston

253

Color rendition engine.  

PubMed

A source of white light with continuously tuned color rendition properties, such as color fidelity, as well as color saturating and color dulling ability has been developed. The source, which is composed of red (R), amber (A), green (G), and blue (B) light-emitting diodes, has a spectral power distribution varied as a weighted sum of "white" RGB and AGB blends. At the RGB and AGB end-points, the source has a highest color saturating and color dulling ability, respectively, as follows from the statistical analysis of the color-shift vectors for 1269 Munsell samples. The variation of the weight parameter allows for continuously traversing all possible metameric RAGB blends, including that with the highest color fidelity. The source was used in a psychophysical experiment on the estimation of the color appearance of familiar objects, such as vegetables, fruits, and soft-drink cans of common brands, at correlated color temperatures of 3000 K, 4500 K, and 6500 K. By continuously tuning the weight parameter, each of 100 subjects selected RAGB blends that, to their opinion, matched lighting characterized as "most saturating," "most dulling," "most natural," and "preferential". The end-point RGB and AGB blends have been almost unambiguously attributed to "most saturating" and "most dulling" lighting, respectively. RAGB blends that render a highest number of colors with high fidelity have, on average, been attributed to "most natural" lighting. The "preferential" color quality of lighting has, on average, been matched to RAGB blends that provide color rendition with fidelity somewhat reduced in favor of a higher saturation. Our results infer that tunable "color rendition engines" can validate color rendition metrics and provide lighting meeting specific needs and preferences to color quality. PMID:22418343

Zukauskas, Art?ras; Vaicekauskas, Rimantas; Vitta, Pranciškus; Tuzikas, Ar?nas; Petrulis, Andrius; Shur, Michael

2012-02-27

254

Coloring Local Feature Extraction  

Microsoft Academic Search

\\u000a Although color is commonly experienced as an indispensable quality in describing the world around us, state-of-the art local feature-based representations are mostly based on shape description, and ignore color information. The description of color\\u000a is hampered by the large amount of variations which causes the measured color values to vary significantly. In this paper\\u000a we aim to extend the description

Joost Van De Weijer; Cordelia Schmid

2006-01-01

255

Fruits and Vegetables: Color Your Plate  

NSDL National Science Digital Library

In this activity, learners explore healthy choices related to the foods they eat. The importance of a variety of fruits and vegetables to a healthy diet is the focus of the experience. Learners read a story book about fruits and vegetables, repeat a helpful riddle, and draw pictures of fruits/vegetables. These drawings are then cut out and taped to "color" a Healthy Choice bulletin board plate. Learners can also taste-test different fruits and vegetables at snack or lunch time. Learners are encouraged to try one new color each day. This activity is featured on pp. 12-13 of the "Health House: Food, Fitness, & Fun 24/7!" unit of study for K-2 learners.

Reitsma, Beverly A.; Indianapolis, The C.

2012-06-26

256

Fruits and Vegetables: Color Your Plate  

NSDL National Science Digital Library

In this activity, learners explore healthy choices related to the foods they eat. The importance of a variety of fruits and vegetables to a healthy diet is the focus of the experience. Learners read a story book about fruits and vegetables, repeat a helpful riddle, and draw pictures of fruits/vegetables. These drawings are then cut out and taped to "color" a Healthy Choice bulletin board plate. Learners can also taste-test different fruits and vegetables at snack or lunch time. Learners are encouraged to try one new color each day. This activity is featured on pp. 12-13 of the "Health House: Food, Fitness, & Fun 24/7!" unit of study for K-2 learners.

Reitsma, Beverly A.; Indianapolis, The C.

2014-04-30

257

No female mate choice in Mallee dragon lizards, Ctenophorus fordi  

Microsoft Academic Search

Aspects of sexual selection were studied in a sexually monomorphic Australian agamid lizard (Ctenophorus fordi), in particular with respect to the sensory exploitation hypothesis. In enclosure trials, females were offered the choice between 'large' vs. 'small' males and, in a different experiment, males with 'blue' vs. 'normal' head color. The rationale for these experiments was: firstly, to establish if females

MATS OLSSON

2001-01-01

258

No female mate choice in Mallee dragon lizards, Ctenophorus fordi  

Microsoft Academic Search

Aspects of sexual selection were studied in a sexually monomorphic Australian agamid lizard (Ctenophorus fordi), in particular with respect to the sensory exploitation hypothesis. In enclosure trials, females were offered the choice between ‘large’ vs. ‘small’ males and, in a different experiment, males with ‘blue’ vs. ‘normal’ head color. The rationale for these experiments was: firstly, to establish if females

Mats Olsson

2001-01-01

259

Biology of Skin Color.  

ERIC Educational Resources Information Center

Information from scientific journals on the biology of skin color is discussed. Major areas addressed include: (1) biology of melanin, melanocytes, and melanosomes; (2) melanosome and human diversity; (3) genetics of skin color; and (4) skin color, geography, and natural selection. (JN)

Corcos, Alain

1983-01-01

260

Ocean Color Climate Records  

Microsoft Academic Search

Individual ocean color missions have finite lifetimes, so it is critical to produce a consistent time series across ocean color missions if we are to address fundamental questions of Earth science importance, especially how the ocean biogeochemical system is changing. Developing Ocean Color Climate Records (OCCR's), which meet the definitions of the National Research Council has been a challenge. Consistent

W. Gregg

2007-01-01

261

Competitive image colorization  

Microsoft Academic Search

This paper presents a new method for image colorization based on manually added scribbles. We determine color propagation paths in the image by minimizing the geodesic distance from the scribbles using Dijkstra algorithm. After that, chrominance blending is performed to colorize the image. Our contribution lies in proposing the competitive approach for selecting an appropriate type of the path cost.

Michal Kawulok; Bogdan Smolka

2010-01-01

262

Requirements for color technology  

Microsoft Academic Search

The requirements for color technology in the general office are reviewed. The two most salient factors driving the requirements for color are the information explosion and the virtually negligible growth in white collar productivity in the recent past. Accordingly, the business requirement upon color technology is that it be utilized in an effective and efficient manner to increase office productivity.

Ronald B. Campbell

1993-01-01

263

Color based skin classification  

Microsoft Academic Search

Skin detection is used in applications ranging from face detection, tracking body parts and hand gesture analysis, to retrieval and blocking objectionable content. In this paper, we investigate and evaluate (1) the effect of color space transformation on skin detection performance and finding the appropriate color space for skin detection, (2) the role of the illuminance component of a color

Rehanullah Khan; Allan Hanbury; Julian Stöttinger; Abdul Bais

264

Color and Psychological Functioning  

Microsoft Academic Search

Color is a ubiquitous perceptual experience, yet little scientific information about the influence of color on affect, cognition, and behavior is available. Accordingly, we have developed a general model of color and psychological functioning, which we present in this article. We also describe a hypothesis derived from this model regarding the influence of red in achievement contexts. In addition, we

Andrew J. Elliot; Markus A. Maier

2007-01-01

265

Color and Psychological  

Microsoft Academic Search

Color is a ubiquitous perceptual experience, yet little scientific information about the influence of color on affect, cognition, and behavior is available. Accord- ingly, we have developed a general model of color and psychologicalfunctioning,whichwepresentinthisarticle. We also describe a hypothesis derived from this model re- garding the influence of red in achievement contexts. In addition, we report a series of experiments

Andrew J. Elliot; Markus A. Maier

266

Color vision deficiencies  

NASA Astrophysics Data System (ADS)

Congenital and acquired color vision defects are described in the context of physiological data. Light sources, photometry, color systems and test methods are described. A list of medicines is also presented. The practical social consequences of color vision deficiencies are discussed.

Vannorren, D.

1982-04-01

267

Spinning Your (Color) Wheels  

NSDL National Science Digital Library

In this optics activity, learners use everyday materials to make a color wheel. When learners spin the wheel like a top, they will be surprised to see all the colors mixing together to appear white. Use this activity to introduce learners to color and the visible spectrum.

America, Optical S.

2008-01-01

268

Four Color Theorem  

NSDL National Science Digital Library

Suppose we have a map in which no single territory is made up of disconnected regions. How many colors are needed to color the territories of this map, if all the territories that share a border segment must be of different colors?

269

Reimagining the Color Wheel  

ERIC Educational Resources Information Center

Color wheels are a traditional project for many teachers. The author has used them in art appreciation classes for many years, but one problem she found when her pre-service art education students created colored wheels was that they were boring: simple circles, with pie-shaped pieces, which students either painted or colored in. This article…

Snyder, Jennifer

2011-01-01

270

First flowering dates and flowering periods of prairie plants at Woodworth, North Dakota  

USGS Publications Warehouse

We recorded flowering events for 97 species of prairie plants for 2-6 years near Woodworth, ND. Earliest and latest flower initiation dates varied by year. Temperature seemed much more important than precipitation in influencing phenology of species that bloom from late March through May, but no strong climatic effect was evident for plants that bloom later in the growing season.

Callow, J. M.; Kantrud, H. A.; Higgins, K. F.

1992-01-01

271

A stochastic flowering model describing an asynchronically flowering set of trees.  

PubMed

A general stochastic model is presented that simulates the time course of flowering of individual trees and populations, integrating the synchronization of flowering both between and within trees. Making some hypotheses, a simplified expression of the model, called the 'shoot' model, is proposed, in which the synchronization of flowering both between and within trees is characterized by specific parameters. Two derived models, the 'tree' model and the 'population' model, are presented. They neglect the asynchrony of flowering, respectively, within trees, and between and within trees. Models were fitted and tested using data on flowering of Psidium cattleianum observed at study sites at elevations of 200, 520 and 890 m in Reunion Island. The 'shoot' model fitted the data best and reproduced the strong irregularities in flowering shown by empirical data. The asynchrony of flowering in P. cattleianum was more pronounced within than between trees. Simulations showed that various flowering patterns can be reproduced by the 'shoot' model. The use of different levels of organization of the general model is discussed. PMID:12234153

Normand, F; Habib, R; Chadoeuf, J

2002-09-01

272

Effect of flower structure and flower colour on intrafloral warming and pollen germination and pollen-tube growth in winter flowering Crocus L. (Iridaceae)  

Microsoft Academic Search

The internal temperature of the flowers of three colour variants of winter floweringCrocus chrysanthusand ofC. tommasinianuswere compared with ambient in the dark, and when subject to artificial horizontal illumination with daylight spectra. Illuminated flowers warmed up to 3°C above ambient. In the dark, flowers also showed slight warming. In all varieties, pollen germinated more freely at 15°C compared to 6°C,

JUNO MCKEE; A. J. RICHARDS

1998-01-01

273

Color associations for days and letters across different languages  

PubMed Central

While colors are commonplace in everyday metaphors, relatively little is known about implicit color associations to linguistic or semantic concepts in a general population. In this study, we test color associations for ordered linguistic concepts (letters and days). The culture and language specificity of these effects was examined in a large group (457) of Dutch-speaking participants, 92 English-speaking participants, and 49 Hindi-speaking participants. Non-random distributions of color choices were revealed; consistencies were found across the three language groups in color preferences for both days and letters. Interestingly, while the Hindi-speaking participants were presented with letter stimuli matched on phonology, their pattern of letter-to-color preferences still showed similarities with Dutch- and English-speaking participants. Furthermore, we found that that the color preferences corresponded between participants indicating to have conscious color experiences with letters or days (putative synesthetes) and participants who do not (non-synesthetes). We also explored possible mechanisms underlying the color preferences. There were a few specific associations, including red for “A,” red for “Monday,” and white for “Sunday.” We also explored more general mechanisms, such as overall color preferences as shown by Simner et al. (2005). While certainly not all variation can be explained or predicted, the results show that regularities are present in color-to-letter or color-to-day preferences in both putative synesthetes and non-synesthetes across languages. Both letter-to-color and day-to-color preferences were influenced by multiple factors. The findings support a notion of abstract concepts (such as days and letters) that are not represented in isolation, but are connected to perceptual representational systems. Interestingly, at least some of these connections to color representations are shared across different language/cultural groups.

Rouw, Romke; Case, Laura; Gosavi, Radhika; Ramachandran, Vilayanur

2014-01-01

274

Pyrethrins protect pyrethrum leaves against attack by western flower thrips, Frankliniella occidentalis.  

PubMed

Pyrethrins are active ingredients extracted from pyrethrum flowers (Tanacetum cinerariifolium), and are the most widely used botanical insecticide. However, several thrips species are commonly found on pyrethrum flowers in the field, and are the dominant insects found inside the flowers. Up to 80% of western flower thrips (WFT, Frankliniella occidentalis) adults died within 3 days of initiating feeding on leaves of pyrethrum, leading us to evaluate the role of pyrethrins in the defense of pyrethrum leaves against WFT. The effects of pyrethrins on WFT survival, feeding behavior, and reproduction were measured both in vitro and in planta (infiltrated leaves). The lethal concentration value (LC50) for pyrethrins against WFT adults was 12.9 mg/ml, and pyrethrins at 0.1% (w/v) and 1% (w/v) had significantly negative effects on feeding, embryo development, and oviposition. About 20-70% of WFT were killed within 2 days when they were fed chrysanthemum leaves containing 0.01-1% pyrethrins. Chrysanthemum leaves containing 0.1% or 1% pyrethrins were significantly deterrent to WFT. In a no-choice assay, the reproduction of WFT was reduced significantly when the insects were fed leaves containing 0.1% pyrethrins, and no eggs were found in leaves containing 1% pyrethrins. Our results suggest that the natural concentrations of pyrethrins in the leaves may be responsible for the observed high mortality of WFT on pyrethrum. PMID:22456949

Yang, Ting; Stoopen, Geert; Wiegers, Gerrie; Mao, Jing; Wang, Caiyun; Dicke, Marcel; Jongsma, Maarten A

2012-04-01

275

Color preference, seasonality, spatial distribution and species composition of thrips (Thysanoptera: Thripidae) in northern highbush blueberries  

Microsoft Academic Search

We investigated color preference, seasonal abundance, spatial distribution and species composition of thrips in northern highbush blueberries, Vaccinium corymbosum L., in New Jersey (USA). White sticky traps were more attractive to thrips compared with yellow or blue traps. Thrips captures using white sticky traps showed that their flight activity begins 20–30 d after the onset of flowering, with 10, 50 and

C. R. Rodriguez-Saona; S. Polavarapu; J. D. Barry; D. Polk; R. Jörnsten; P. V. Oudemans; O. E. Liburd

2010-01-01

276

Specific color sensitivities of prey and predator explain camouflage in different visual systems  

Microsoft Academic Search

In situations of aggressive mimicry, predators adapt their color to that of the substrate on which they sit for hunting, a behavior that is presumed to hide them from prey as well as from their own predators. Females of few crab-spider species encounter such situations when lying on flowers to ambush pollinators. To evaluate the efficiency of spider camouflage on

Marc Théry; Martine Debut; Doris Gomez; Jérôme Casas

2005-01-01

277

Resistor Color-Code  

NSDL National Science Digital Library

"Resistor manufactures implement the standard EIA color-code using three, four and five color bands to identify nominal resistor values. It is imperative that engineers and technicians know how to interpret the color markings on resistors in order to perform analysis and repairs on electronic products." On this page, visitors will find a key to the code for three, four, and five band resistors and exercises to check for understanding. A Resistor Color-Code chart can also be downloaded and printed from this site, as well as a Resistor Color-Code Converter.

2011-07-19

278

Molecular Expressions: Color Separation  

NSDL National Science Digital Library

This item is an interactive Java simulation for introductory physics students on the topic of color. It explores how individual subtractive primary colors can be separated from a full-color photograph and then be reassembled to create the original scene. The mouse cursor may be used to superimpose color separations over one another. As additional separations are added, the resulting image exhibits the realism of a color photograph. This item is part of a larger collection of materials on optics and microscopy developed by the National High Magnetic Field Laboratory and Florida State University.

Davidson, Michael; Parry-Hill, Matthew J.; Sutter, Robert

2008-08-21

279

Multifactorial optimization of the decolorisation parameters of wastewaters resulting from dyeing flowers.  

PubMed

This work deals with the treatment of the wastewaters resulting from the process of dyeing flowers. In some local cases for growing flowers near to Medellín (Colombia), wastewater color was found to be one of the main problems in meeting local effluent standards. Wastewaters were treated by photodegradation process (which includes photocatalysis) to achieve the degradation of dyes mixture and organic matter in the wastewater. A multifactorial experimental design was proposed, including as experimental factors the following variables: pH, and the concentration of both catalyst (TiO(2)) and hydrogen peroxide (H(2)O(2)). According to the obtained results, at the optimized variables values, it is possible to reach a 99% reduction of dyes, a 76.9% of mineralization (TOC) and a final biodegradability of 0.834. Kinetic analysis allows proposing a pseudo first order reaction for the reduction, the mineralization, and the biodegradation processes. PMID:19381002

Pavas, Edison Gil; Gómez-García, Miguel Angel

2009-01-01

280

Color Classification of Coordination Compounds.  

ERIC Educational Resources Information Center

Proposes that colored compounds be classified by reference to a standard color-order system incorporating a color dictionary. Argues that the colors of new compounds could be incorporated into the characterization process and into computer storage systems. (TW)

Poncini, Laurence; Wimmer, Franz L.

1987-01-01

281

Flower development in the asterid lineage.  

PubMed

A complete understanding of the genetic control of flower development requires a comparative approach, involving species from across the angiosperm lineage. Using the accessible model plant Arabidopsis thaliana many of the genetic pathways that control development of the reproductive growth phase have been delineated. Research in other species has added to this knowledge base, revealing that, despite the myriad of floral forms found in nature, the genetic blueprint of flower development is largely conserved. However, these same studies have also highlighted differences in the way flowering is controlled in evolutionarily diverse species. Here, we review flower development in the eudicot asterid lineage, a group of plants that diverged from the rosid family, which includes Arabidopsis, 120 million years ago. Work on model species such as Antirrhinum majus, Petunia hybrida, and Gerbera hybrida has prompted a reexamination of textbook models of flower development; revealed novel mechanisms controlling floral gene expression; provided a means to trace evolution of key regulatory genes; and stimulated discussion about genetic redundancy and the fate of duplicated genes. PMID:24395251

Causier, Barry; Davies, Brendan

2014-01-01

282

Attention mediates the effect of nutrition label information on consumers' choice. Evidence from a choice experiment involving eye-tracking.  

PubMed

In two eye-tracking studies, we explored whether and how attention to nutrition information mediates consumers' choice. Consumers had to select either the healthiest option or a product of their preference within an assortment. On each product a particular label (Choices logo, monochrome GDA label, or color-coded GDA label) communicated the product's nutrient profile. In study 1, participants had to select from 4 products differentiated, in addition to the nutrition information, by flavor (strawberry, muesli, apple, chocolate; varied within participants) and brand (local vs. global, varied between participants). Study 2 further explored brand effect within-participants, and thus only 2 flavors (strawberry, chocolate) were presented within an assortment. Actual choice made, response time and eye movements were recorded. Respondents fixated longer and more often on products with color-coded GDAs label than on products with monochrome GDAs or Choices logo. A health goal resulted in longer and more frequent fixations in comparison to a preference goal. Products with color-coded and monochrome GDAs had the highest likelihood of being chosen, and this effect was related to the attention-getting property of the label (irrespective of brand and flavor effects). The product fixated most had the highest likelihood of being chosen. These results suggest that attention mediates the effect of nutrition labels on choice. PMID:24503332

Bialkova, Svetlana; Grunert, Klaus G; Juhl, Hans Jørn; Wasowicz-Kirylo, Grazyna; Stysko-Kunkowska, Malgorzata; van Trijp, Hans C M

2014-05-01

283

Energy Choices Game  

NSDL National Science Digital Library

Use this board game to introduce the concepts of energy use in our lives and the very real impact that personal choices can have on our energy consumption, energy bills and fuel supply. The game begins as students select cards that define their modes of transportation and home design. The players roll dice and move around the board, landing on "choice" or "situation" blocks and selecting cards that describe consumer choices and real-life events that impact their energy consumption and annual energy bills. As the players pass gasoline stations or energy bill gates, they must pay annual expenses as defined by their original cards, with amounts altered by the choices they've made along the way. Gasoline cards are collected to represent total consumption. Too many gas-guzzling vehicles can result in total depletion of their gasoline supply â at which point everyone must walk or ride the bus. At the end of the game, the players count their remaining dollars to determine the winner. Discussion questions probe the students to interpret what choices they made and which situations they encountered had the most impact on their energy consumption and energy bills. All game board, card and money files are available online free of charge.

Office Of Educational Partnerships

284

Homology modeling and dynamics study of aureusidin synthase--an important enzyme in aurone biosynthesis of snapdragon flower.  

PubMed

Aurones, a class of plant flavonoids, provide bright yellow color on some important ornamental flowers, such as cosmos, coreopsis, and snapdragon (Antirrhinum majus). Recently, it has been elucidated that aureusidin synthase (AUS), a homolog of plant polyphenol oxidase (PPO), plays a key role in the yellow coloration of snapdragon flowers. In addition, it has been shown that AUS is a chalcone-specific PPO specialized for aurone biosynthesis. AUS gene has been successfully demonstrated as an attractive tool to engineer yellow flowers in blue flowers. Despite these biological studies, the structural basis for the specificity of substrate interactions of AUS remains elusive. In this study, we performed homology modeling of AUS using Grenache PPO and Sweet potato catechol oxidase (CO). An AUS-inhibitor was then developed from the initial homology model based on the CO and subsequently validated. We performed a thorough study between AUS and PTU inhibitor by means of interaction energy, which indicated the most important residues in the active site that are highly conserved. Analysis of the molecular dynamics simulations of the apo enzyme and ligand-bound complex showed that complex is relatively stable than apo and the active sites of both systems are flexible. The results from this study provide very helpful information to understand the structure-function relationships of AUS. PMID:21470561

Elumalai, Pavadai; Liu, Hsuan-Liang

2011-08-01

285

Color Reproduction with a Smartphone  

ERIC Educational Resources Information Center

The world is full of colors. Most of the colors we see around us can be created on common digital displays simply by superposing light with three different wavelengths. However, no mixture of colors can produce a fully pure color identical to a spectral color. Using a smartphone, students can investigate the main features of primary color addition…

Thoms, Lars-Jochen; Colicchia, Giuseppe; Girwidz, Raimund

2013-01-01

286

White-point independent RGB Primaries for Color Image Encoding  

Microsoft Academic Search

We present a method to calculate sets of RGB primariesthat are white-point independent and have suitable gamutproperties when evaluated with regards to surface colors.These primaries can be used as a basis for defining anoutput-referred color encoding intended for printapplications. The resulting RGB sensors are sharp, i.e. decorrelated,emphasizing again that for imagingapplications, the choice of a chromatic adaptationtransform based on sharp

Sabine Süsstrunk; Clement Fredembach; Jack Holm; Graham D. Finlayson

287

Tropism in azalea and lily flowers  

NASA Astrophysics Data System (ADS)

Tropic responses were examined in azalea Rhododendrom pulchrum and lily Lilium cv. 'Casablanca' flowers. Orientation of the flowers in these two species depicts several up/down characteristics, such as angle of the corolla opening, alignment or configuration of a specific petal at the top, plus direction in the curved tip of the pistil and stamen. Gravity was found to be the prime factor, with light as a secondary signal that determines gravitropism in the pistil of the azalea. Within the azalea, sedimented amyloplasts were observed throughout the cells along the inner layers below the epidermis. In lily flowers, no sedimented amyloplasts were found in style cells, and phototropic responses caused upward bending of the pistil. Responses of lily pistils to monochromatic light were consistent with the action spectrum for phototropism in the shoots of monocotyledonous plants. We discuss how these features may increase the fitness for pollination in these two species.

Shimizu, M.; Tomita-Yokotani, K.; Nakamura, T.; Yamashita, M.

288

Orchid flowers tolerance to gamma-radiation  

NASA Astrophysics Data System (ADS)

Cut flowers are fresh goods that may be treated with fumigants such as methyl bromide to meet the needs of the quarantine requirements of importing countries. Irradiation is a non-chemical alternative to substitute the methyl bromide treatment of fresh products. In this research, different cut orchids were irradiated to examine their tolerance to gamma-rays. A 200 Gy dose did inhibit the Dendrobium palenopsis buds from opening, but did not cause visible damage to opened flowers. Doses of 800 and 1000 Gy were damaging because they provoked the flowers to drop from the stem. Cattleya irradiated with 750 Gy did not show any damage, and were therefore eligible for the radiation treatment. Cymbidium tolerated up to 300 Gy and above this dose dropped prematurely. On the other hand, Oncydium did not tolerate doses above 150 Gy.

Kikuchi, Olivia Kimiko

2000-03-01

289

Bilabiate Flowers: The Ultimate Response to Bees?  

PubMed Central

Background and Aims Bilabiate flowers have evolved in many lineages of the angiosperms, thus representing a convincing example of parallel evolution. Similar to keel blossoms, they have obviously evolved in order to protect pollen against pollen-collecting bees. Although many examples are known, a comprehensive survey on floral diversity and functional constraints of bilabiate flowers is lacking. Here, the concept is widened and described as a general pattern. Methods The present paper is a conceptional review including personal observations of the authors. To form a survey on the diversity of bilabiate blossoms, a search was made for examples across the angiosperms and these were combined with personal observations collected during the last 25 years, coupled with knowledge from the literature. New functional terms are introduced that are independent of morphological and taxonomic associations. Key Results Bilabiate constructions occur in at least 38 angiosperm families. They are characterized by dorsiventral organization and dorsal pollen transfer. They are most often realised on the level of a single flower, but may also be present in an inflorescence or as part of a so-called ‘walk-around flower’. Interestingly, in functional terms all nototribic blossoms represent bilabiate constructions. The great majority of specialized bee-flowers can thus be included under bilabiate and keel blossoms. The syndrome introduced here, however, also paves the way for the inclusion of larger animals such as birds and bats. The most important evolutionary trends appear to be in the saving of pollen and the precision of its transfer. With special reference to the Lamiales, selected examples of bilabiate flowers are presented and their functional significance is discussed. Conclusions Bilabiate blossoms protect their pollen against pollen-collecting bees and at the same time render their pollination more precisely. The huge diversity of realised forms indicate the high selection pressure towards the bilabiate syndrome. As bees are very inventive, however, bilabiate constructions will not represent the ultimate response to bees.

Westerkamp, Christian; Classen-Bockhoff, Regine

2007-01-01

290

Shorter flowering seasons and declining abundance of flower visitors in a warmer Arctic  

NASA Astrophysics Data System (ADS)

Advancing phenology in response to global warming has been reported across biomes, raising concerns about the temporal uncoupling of trophic interactions. Concurrently, widely reported flower visitor declines have been linked to resource limitations. Phenological responses in the Arctic have been shown to outpace responses from lower latitudes and recent studies suggest that differences between such responses for plants and their flower visitors could be particularly pronounced in the Arctic. The evidence for phenological uncoupling is scant because relevant data sets are lacking or not available at a relevant spatial scale. Here, we present evidence of a climate-associated shortening of the flowering season and a concomitant decline in flower visitor abundance based on a long-term, spatially replicated (1996-2009) data set from high-Arctic Greenland. A unique feature of the data set is the spatial and temporal overlap of independent observations of plant and insect phenology. The shortening of the flowering season arose through spatial variation in phenological responses to warming. The shorter flowering seasons may have played a role in the observed decline in flower visitor abundance. Our results demonstrate that the dramatic climatic changes currently taking place in the Arctic are strongly affecting individual species and ecological communities, with implications for trophic interactions.

Høye, Toke T.; Post, Eric; Schmidt, Niels M.; Trøjelsgaard, Kristian; Forchhammer, Mads C.

2013-08-01

291

The nature of colors  

NASA Astrophysics Data System (ADS)

Color is a visible aspect of objects and lights, and as such is an objective characteristic of our phenomenal world. Correspondingly also objects and lights are objective, although their subjectivity cannot be disregarded since they belong to our phenomenal world. The distinction between perception and sensation deals with colors seen either in complex displays or in isolation. Reality of colors is apparently challenged by virtual reality, while virtual reality is a good example of what colors are. It seems difficult to combine that aspect of reality colors have in our experience and the concept that colors represent something in the external environment: the distinction between stimulation and perceived object is crucial for understanding the relationships between phenomenal world and physical reality. A modern concept of isomorphism seems useful in interpreting the role of colors. The relationship between the psychological structure of colors and the physical stimulation is enlightened by the analysis of pseudocolors. The perceptual, subjective characteristics of colors go along with the subjectivity of scientific concepts. Colors, emotions, and concepts are all in some people's mind: none of them is independent of the subject mind. Nevertheless they can be communicated from person to person by an appropriate scientific terminology.

da Pos, Osvaldo

2002-06-01

292

The size-color illusion.  

PubMed

Slides were made from Munsell color chips in three sizes, four hues, and two chromas; all had the same intensity. A direct-comparisons, forced-choice procedure was used with 100 male and female volunteers from psychology courses. When pairs of slides had the same size and chroma, the order of decreasing apparent size was red-purple, yellow-red, purple-blue, and green. At chroma/8, all comparisons were significant except yellow-red over purple-blue. At chroma/4, the same order was found, but the effect was not pronounced. When pairs were made up of identical hues but different chromas, the square with chroma/4 (less saturation) appeared significantly larger. PMID:886307

Tedford, W H; Bergquist, S L; Flynn, W E

1977-07-01

293

Constitutional biases in early perceptual learning: I. Preferences between colors, patterns, and composite stimuli of colors and patterns in genetically manipulated and imprinted quail chicks (C. coturnix japonica)  

Microsoft Academic Search

Bidirectional genetic selection of quail for early color preferences, for 18 generations, resulted in nearly perfect choices of blue over red in one and red over blue in the other selected line. It also enhanced the preference of a grated over a dotted black-and-white pattern. Color and pattern preferences in hybrids of selected and control lines fell back to about

Joseph K. Kovach

1983-01-01

294

Moral responsibility and economic choice  

Microsoft Academic Search

Presents a normative model of responsible choice which is consistent with the main psychological theories of human choice behaviour. Identifies different aspects of complex economic choices, namely a deontological aspect, a goal achievement aspect, and a stakeholder aspect. Defines responsible choice as choosing the least worst alternative in the multidimensional space of deontological, instrumental, and external values. Demonstrates that the

Lászlo Zsolnai

1997-01-01

295

Special Issue Topic: School Choice.  

ERIC Educational Resources Information Center

Includes "The Choice Movement" (Brogan); "Choice in American Education" (Witte); "Role of Parents in Education" (Mawdsley); "As Arrows in the Hand" (Coons); "Vouchers in Wisconsin" (Underwood); "Milwaukee Parental Choice Program (MPCP)" (Grover); "Civil Liberties and the MPCP" (Bolick); "Comments on School Choice" (Jauch); "Two Classes of…

Brogan, Bernard R.; And Others

1991-01-01

296

Color and scent: how single genes influence pollinator attraction.  

PubMed

A major function of angiosperm flowers is the recruitment of animal pollinators that serve to transfer pollen among conspecific plants. Distinct sets of floral characteristics, called pollination syndromes, are correlated with visitation by specific groups of pollinators. Switches among pollination syndromes have occurred in many plant families. Such switches must have involved coordinated changes in multiple traits and multiple genes. Two well-studied floral traits affecting pollinator attraction are petal color and scent production. We review current knowledge about the biosynthetic pathways for floral color and scent production and their interaction at the genetic and biochemical levels. A key question in the field concerns the genes that underlie natural variation in color and scent and how such genes affect pollinator preference, reproductive isolation, and ultimately speciation. PMID:23467550

Sheehan, H; Hermann, K; Kuhlemeier, C

2012-01-01

297

School Choice in Milwaukee.  

ERIC Educational Resources Information Center

Uses Milwaukee's school choice/voucher initiative to illustrate how politically motivated evaluation and compromise legislation can dilute potentially beneficial educational innovations. The initiative's success despite counterproductive legislative tampering and biased evaluation is addressed, along with a discussion of the evaluation's…

Peterson, Paul E.; And Others

1996-01-01

298

Choice of Living Arrangements  

ERIC Educational Resources Information Center

Background: The rights to choose where and with whom to live are widely endorsed but commonly denied to adults with intellectual disabilities (ID). The current study provides a contemporary benchmark on the degree of choice exercised by adult service users in the USA. Method: Data came from the National Core Indicators programme. Participants were…

Stancliffe, R. J.; Lakin, K. C.; Larson, S.; Engler, J.; Taub, S.; Fortune, J.

2011-01-01

299

Commuters route choice behaviour  

Microsoft Academic Search

The paper reports laboratory experiments with a two route choice scenario. In each session 18 subjects had to choose between a main road M and a side road S. The capacity of M was larger. Feedback was given in treatment I only on the subjects' own travel time and in treatment II on travel time for M and S. The

R. Selten; T. Chmura; T. Pitz; S. Kube; M. Schreckenberg

2007-01-01

300

Project Choice: Lessons Learned.  

ERIC Educational Resources Information Center

Project Choice began with a simple goal: to increase the number of inner-city students who graduate from high school on time and become productive members of society. To that end, Ewing M. Kauffman, his Foundation, and associates designed and implemented a program that promised postsecondary education or training to some students in the Kansas…

Ewing Marion Kauffman Foundation, Kansas City, MO.

301

Learning from School Choice.  

ERIC Educational Resources Information Center

This volume contains revised versions of 16 essays presented at a conference, "Rethinking School Governance," hosted by Harvard's Program on Education Policy and Governance in June 1997. Part 1, "Introduction," contains two chapters: (1) "School Choice: A Report Card" (Paul E. Peterson); and (2) "The Case for Charter Schools" (Bryan C. Hassel).…

Peterson, Paul E., Ed.; Hassel, Bryan C., Ed.

302

Reason-based choice  

Microsoft Academic Search

This paper considers the role of reasons and arguments in the making of decisions. It is proposed that, when faced with the need to choose, decision makers often seek and construct reasons in order to resolve the conflict and fustify their choice, to themselves and to others. Experiments that explore and manipulate the role of reasons are reviewed, and other

Eldar Shafir; Itamar Simonson; Amos Tversky

1993-01-01

303

Mate choice turns cognitive  

Microsoft Academic Search

Evolutionary psychology has revolutionized research on human mate choice and sexual attraction in recent years, combining a rigorous Darwinian framework based on sexual selection theory with a loosely cognitivist orientation to task analysis and mechanism modelling. This hard Darwinian, soft computational approach has been most successful at revealing the adaptive logic behind physical beauty, demonstrating that many sexual cues computed

Geoffrey F. Miller; Peter M. Todd

1998-01-01

304

Digital color representation  

DOEpatents

An image population having a large number of attributes is processed to form a display population with a predetermined smaller number of attributes which represent the larger number of attributes. In a particular application, the color values in an image are compressed for storage in a discrete lookup table (LUT) where an 8-bit data signal is enabled to form a display of 24-bit color values. The LUT is formed in a sampling and averaging process from the image color values with no requirement to define discrete Voronoi regions for color compression. Image color values are assigned 8-bit pointers to their closest LUT value whereby data processing requires only the 8-bit pointer value to provide 24-bit color values from the LUT.

White, James M. (Los Alamos, NM); Faber, Vance (Los Alamos, NM); Saltzman, Jeffrey S. (Los Alamos, NM)

1992-01-01

305

New color anaglyph method  

NASA Astrophysics Data System (ADS)

Anagliphs generally means a stereoscopic method using 2 principal color filters and is impossible to perceive the full-color stereo-pair for the viewers as above. A new anagliph method using 3 principal color filters (RGB) is presented in this paper. The method enables the complete full- color stereoscopic image taking and output technique. We produced the prototype system which composed of an ordinal TV camera with RGB color optical filters positioned at the pupil or the iris as a function of a single lens stereoscopic image taking device and using a special electrical circuit for a stereoscopic image output devices. Time-parallel full-color stereo pair was delivered to the several viewers by a prototype system with an ordinal our stereoscopic liquid crystal display (STEREVIQ) which permits the observation of a stereo pair by several persons simultaneously without the use of special glasses. Especially the system's cost performance is excellent except STEREVIQ.

Hattori, Tomohiko; Arita, Eiji; Nakamura, Toshihisa; Kurio, Masaru; Sakuma, Sadayuki

1997-05-01

306

Simultaneous color constancy.  

PubMed

Observers matched patches (simulated Munsell papers) in two simultaneously presented computer-controlled displays, a standard array presented under 6500-K illumination and a test array under 4000 or 10,000 K. Adaptation to the test illuminants was limited. The adjusted patch was surrounded by a single color (annulus display) or by many colors (Mondrian display). Observers either matched hue and saturation or made surface-color (paper) matches in which the subject was asked to make the test patch look as if it were cut from the same piece of paper as the standard patch. For two of the three subjects, the paper matches were approximately color constant. The hue-saturation matches showed little color constancy. Moreover, the illumination difference between the two displays was always visible. Our data show that simultaneous mechanisms alone (e.g., simultaneous color contrast) alter hues and saturations too little to produce hue constancy. PMID:3772637

Arend, L; Reeves, A

1986-10-01

307

Michigan Monkey-Flower ('Mimulus glabratus var. michiganensis') Recovery Plan.  

National Technical Information Service (NTIS)

Mirnulus glabratus var. michiganensis (Pennell) Fassett, (Michigan monkey-flower), a member of the Scrophulariaceae (snapdragon family), is an endemic variety of a widespread and diverse complex of yellow monkey-flowers. The taxon is known from only 15 ex...

M. R. Penskar

1997-01-01

308

Mutation in TERMINAL FLOWER1 Reverses the Photoperiodic Requirement for Flowering in the Wild Strawberry Fragaria vesca1[W  

PubMed Central

Photoperiodic flowering has been extensively studied in the annual short-day and long-day plants rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana), whereas less is known about the control of flowering in perennials. In the perennial wild strawberry, Fragaria vesca (Rosaceae), short-day and perpetual flowering long-day accessions occur. Genetic analyses showed that differences in their flowering responses are caused by a single gene, SEASONAL FLOWERING LOCUS, which may encode the F. vesca homolog of TERMINAL FLOWER1 (FvTFL1). We show through high-resolution mapping and transgenic approaches that FvTFL1 is the basis of this change in flowering behavior and demonstrate that FvTFL1 acts as a photoperiodically regulated repressor. In short-day F. vesca, long photoperiods activate FvTFL1 mRNA expression and short days suppress it, promoting flower induction. These seasonal cycles in FvTFL1 mRNA level confer seasonal cycling of vegetative and reproductive development. Mutations in FvTFL1 prevent long-day suppression of flowering, and the early flowering that then occurs under long days is dependent on the F. vesca homolog of FLOWERING LOCUS T. This photoperiodic response mechanism differs from those described in model annual plants. We suggest that this mechanism controls flowering within the perennial growth cycle in F. vesca and demonstrate that a change in a single gene reverses the photoperiodic requirements for flowering.

Koskela, Elli A.; Mouhu, Katriina; Albani, Maria C.; Kurokura, Takeshi; Rantanen, Marja; Sargent, Daniel J.; Battey, Nicholas H.; Coupland, George; Elomaa, Paula; Hytonen, Timo

2012-01-01

309

RNA silencing in white petunia flowers creates pigmentation patterns invisible to the human eye.  

PubMed

Modern commercial petunias exhibit a wide range of flower colors, which can be observed in gardens. In this study, we present a petunia cultivar that exhibits a floral pattern that is invisible to humans but is possibly visible to pollinating insects. We show that this hidden pattern is established by differentially localized accumulation of flavonols and cinnamic acid derivatives in the corolla limb. This accumulation is caused by a combination of two distinct mechanisms that inhibit anthocyanin biosynthesis: a loss-of-function mutation in the ANTHOCYANIN2, and localized RNA-silencing of CHALCONE SYNTHASE-A. PMID:22498238

Matsubara, Kiyoshi; Kei, Satoko; Koizumi, Mayuko; Kodama, Hiroaki; Ando, Toshio

2012-06-15

310

Color recognition in Prolog  

NASA Astrophysics Data System (ADS)

Hardware capable of recognizing the `named' colors (e.g., `red,' `yellow,' orange, etc.,) is available now at modest cost. This has been interfaced to a standard computer, running Prolog. The result is a powerful combination, capable of intelligently interpreting colored images, such as those on simple product packaging. The structure and applications of such a system are described. Prolog programs are presented which are capable of recognizing bananas, flags, and dragons. Learning color patterns is also discussed.

Batchelor, Bruce G.

1992-11-01

311

Color gamut transform pairs  

Microsoft Academic Search

Digital control of color television monitors—in particular, via frame buffers—has added precise control of a large subset of human colorspace to the capabilities of computer graphics. This subset is the gamut of colors spanned by the red, green, and blue (RGB) electron guns exciting their respective phosphors. It is called the RGB monitor gamut. Full-blown color theory is a quite

Alvy Ray Smith

1978-01-01

312

Resolution and Color Depth  

NSDL National Science Digital Library

This computer interactive lets you explore the effect of changing the number of colors and resolution of a picture. You can see the picture in high quality (72 dots per inch), low quality (10 dpi), or in-between (30 dpi). You also can change the color depth from two colors to millions. Background information and extensions are provided, including connections to paintings by artists George Seurat and Roy Lichtenstein.

Omsi

2004-01-01

313

Anthocyanins as Food Colorants  

Microsoft Academic Search

\\u000a The interest of the food industry in natural colorants replacing synthetic dyes has increased significantly over the last\\u000a years, mainly due to safety issues. This chapter deals with the interest of using natural anthocyanins and their derivatives\\u000a as food colorants. The importance of color for the acceptability of food products and the need for satisfying and attracting\\u000a more consumers to

Nuno Mateus; Victor de Freitas

314

Structures in color space  

NASA Astrophysics Data System (ADS)

Classic colorimetry and the traditionally used color space do not represent all perceived colors (for example, browns look dark yellow in colorimetric conditions of observation) so, the specific goal of this work is to suggest another concept of color and to prove that the corresponding set of colors is complete. The idea of our approach attributing color to surface patches (not to the light) immediately ties all the problems of color perception and vision geometry. The equivalence relation in the linear space of light fluxes F established by a procedure of colorimetry gives us a 3D color space H. By definition we introduce a sample (sigma) (surface patch) as a linear mapping (sigma) : L yields H, where L is a subspace of F called the illumination space. A Dedekind structure of partial order can be defined in the set of the samples: two samples (alpha) and (Beta) belong to one chromatic class if ker(alpha) equals ker(Beta) and (alpha) > (Beta) if ker(alpha) ker(Beta) . The maximal elements of this chain create the chromatic class BLACK. There can be given geometrical arguments for L to be 3D and it can be proved that in this case the minimal element of the above Dedekind structure is unique and the corresponding chromatic class is called WHITE containing the samples (omega) such that ker(omega) equals {0} L. Color is defined as mapping C: H yields H and assuming color constancy the complete set of perceived colors is proved to be isomorphic to a subset C of 3 X 3 matrices. This subset is convex, limited and symmetrical with E/2 as the center of symmetry. The problem of metrization of the color space C is discussed and a color metric related to shape, i.e., to vision geometry, is suggested.

Petrov, Alexander P.

1996-09-01

315

NCI Color Palette  

Cancer.gov

NCI's official colors are red and gray. To create a strong, cohesive NCI presence and an intuitive website experience, the main NCI website was designed in light of this color scheme. NCI's official colors are used consistently throughout the main NCI website to help create a uniform look for the site and to reinforce the tie between the site's home page and its constituent pages.

316

Primary Colors of Pigment  

NSDL National Science Digital Library

In this laboratory activity, students create secondary colors by mixing primary colors. Food coloring, test tubes, and a test tube stand are used. The activity is composed of a student handout with directions and a data sheet. The resource is part of the teacher's guide accompanying the video, NASA Why Files: The Case of the Mysterious Red Light. Lesson objectives supported by the video, additional resources, teaching tips and an answer sheet are included in the teacher's guide.

317

Colors Collide or Combine  

NSDL National Science Digital Library

Learners place multiple M&M's in a plate of water to watch what happens as the candies dissolve. Often learners expect the colors from each M&M to blend when they come together, but instead the colors remain separate along a defined border. Learners will explore how the areas of color change shape as M&Mâs are placed in different positions in the plate.

Kessler, James H.; Galvan, Patricia M.

2007-01-01

318

Ghostscript color management  

NASA Astrophysics Data System (ADS)

This document introduces an updated color architecture that has been designed for Ghostscript. Ghostscript is a well known open source document rendering and conversion engine. Prior to this update, the handling of color in Ghostscript was based primarily upon PostScript color management. The new design results in a flexible ICC-based architecture that works well in Ghostscript's multi-threaded rendering environment.

Vrhel, Michael J.; Johnston, Raymond

2011-01-01

319

Natural Variation in Petal Color in Lycoris longituba Revealed by Anthocyanin Components  

PubMed Central

Lycoris longituba is one of the species belonging to the Amaryllidaceae family. Despite its limited distribution, endemic to central eastern China, this species displays an exceptionally wide diversity of flower colors from purple, red, orange, to yellow, in nature. We study the natural variation of floral color in L. longituba by testing the components of water-soluble vacuolar pigments – anthocyanins – in its petals using high-performance liquid chromatography coupled with photodiode array detection and electrospray ionization mass spectrometry. Four anthocyanins were identified, cyanidin-3-sophoroside (Cy3So), cyanidin-3-xylosylglucoside (Cy3XyGlc), cyanidin-3-sambubioside (Cy3Sa), and pelargonidin-3-xylosylglucoside (Pg3XyGlc), which occur at various amounts in L. longituba petals of different colors. A multivariate analysis was used to explore the relationship between pigments and flower color. Anthocyanins have been thought to play a major role in acting as a UV screen that protects the plant's DNA from sunlight damage and attracting insects for the purpose of pollination. Thus, knowledge about the content and type of anthocyanins determining the petal coloration of Lycoris longituba will help to study the adaptive evolution of flowers and provide useful information for the ornamental breeding of this species.

He, Qiuling; Shen, Ye; Wang, Mingxiu; Huang, Minren; Yang, Ruizhen; Zhu, Shuijin; Wang, Liangsheng; Xu, Yanjun; Wu, Rongling

2011-01-01

320

Color reproduction with a smartphone  

NASA Astrophysics Data System (ADS)

The world is full of colors. Most of the colors we see around us can be created on common digital displays simply by superposing light with three different wavelengths. However, no mixture of colors can produce a fully pure color identical to a spectral color. Using a smartphone, students can investigate the main features of primary color addition and understand how colors are made on digital displays.

Thoms, Lars-Jochen; Colicchia, Giuseppe; Girwidz, Raimund

2013-10-01

321

Flowers of the Primrose destroyed by Birds  

Microsoft Academic Search

I HOPE that you will permit me to make a few final remarks on the destruction of primrose flowers by birds. But first I must return my best thanks to your correspondents, as well as to some gentlemen who have written direct to me, and to whom I have not had time to send separate answers. Secondly, I must plead

Charles Darwin

1874-01-01

322

The fruit of the golden flower  

Microsoft Academic Search

As a pioneer in psychologically exploring Eastern religions and philosophies, Jung has been accused of psychologism and fashioning spiritual traditions to confirm his own theories. The author looks at Jung's engagement with the Taoist text, The secret of the golden flower; exploring Jung's writing of a commentary, in the context of his life and interests at the time. In noting

Malcolm Davy-Barnes

2009-01-01

323

Essential oil composition of Salvia miltiorrhiza flower  

Microsoft Academic Search

Hydrodistillation of the flower of seven populations of Salvia miltiorrhiza Bge. collected in different locations in China afforded a pale yellowish oil in a yield of approximately 0.2%. A total of 82 compounds were identified across all the samples, accounting for 98–100% of the total compositions of each sample. Components were mainly monoterpenes, sesquiterpenes, fatty acids and alkanes. GC and

Qian Liang; Zong-Suo Liang; Jun-Ru Wang; Wen-Hui Xu

2009-01-01

324

Colour preferences of flower-naive honeybees  

Microsoft Academic Search

Flower-naive honeybees Apis mellifera L. flying in an enclosure were tested for their colour preferences. Bees were rewarded once on an achromatic (grey, aluminium or hardboard), or on a chromatic (ultraviolet) disk. Since naive bees never alighted on colour stimuli alone, a scent was given in combination with colour. Their landings on twelve colour stimuli were recorded. Results after one

M. Giurfa; J. Núñez; L. Chittka; R. Menzel

1995-01-01

325

White-flowered Form of Syringa vulgaris  

NSDL National Science Digital Library

White-flowered form of Syringa vulgaris from the Arnold Arboretum of harvard University. Several hundred cultivars of lilacs were developed from 22 wild species through extensive hybridizatino and artificial selection. The parentage of several of these hybrids was confirmed using restriction site analysis of both chloroplast and nuclear ribosomal DNA.

Ki-Joong Kim (Yeungnam University;Department of Biology ADR;POSTAL)

2004-03-09

326

Hearts and flowers: Bryophyllum poisoning of cattle.  

PubMed

Findings from natural cases and experiments with cattle emphasise that flowering plants are the most important form of Bryophyllum (Kalanchoe) spp in poisonings in Australia. The main life-threatening lesion is myocardial. The effects on the alimentary tract are less important than was believed previously. B. tubiflorum, B. daigremontianum x B. tubiflorum, B. pinnatum and B. proliferum caused 41 recorded poisoning incidents affecting 379 cattle in Queensland between 1960 and 1984. Poisoning occurred between May and October--the flowering season of these plants. Experimental B. tubiflorum poisoning and natural poisonings produced anorexia, depression, ruminal atony, diarrhoea, heart rate and rhythm abnormalities, dyspnoea and death. Increased plasma concentrations of urea, creatinine and glucose and decreased chloride were measured experimentally. Both natural and experimental cases had myocardial degeneration and necrosis with haemorrhages of the heart and alimentary tract. Cattle with severe dyspnoea had atelectasis and emphysema of the lungs. Some cattle had mild nephrosis. The median lethal doses of B. tubiflorum flowers, roots and leaf plus stem were 0.7, 2.3 and 5.0 g dry matter/kg liveweight respectively (7, 7 and 40 g wet weight/kg). Bufadienolides have been isolated recently from B. tubiflorum flowers and the syndrome is consistent with cardiac glycoside poisoning. PMID:3778371

McKenzie, R A; Dunster, P J

1986-07-01

327

Nauriaq Aglagvinmi (The Flower in the Classroom).  

ERIC Educational Resources Information Center

This elementary language text is designed for children in bilingual Inupiat-English programs in the Alaskan villages of Ambler, Kobuk, Kiana, Noorvik, and Shungnak. It contains a story about a flower that begins to grow in a rug in a classroom. Each page of text is illustrated with a black-and-white drawing. The English equivalent is given at the…

Pope, Mary L.; And Others

328

Forecasting flowering phenology under climate warming by modelling the regulatory dynamics of flowering-time genes.  

PubMed

Understanding how climate warming has an impact on the life cycle schedule of terrestrial organisms is critical to evaluate ecosystem vulnerability to environmental change. Despite recent advances identifying the molecular basis of temperature responses, few studies have incorporated this knowledge into predictive models. Here we develop a method to forecast flowering phenology by modelling regulatory dynamics of key flowering-time genes in perennial life cycles. The model, parameterized by controlled laboratory experiments, accurately reproduces the seasonal changes in gene expression, the corresponding timing of floral initiation and return to vegetative growth after a period of flowering in complex natural environments. A striking scenario forecast by the model under climate warming is that the shift in the return time to vegetative growth is greater than that in floral initiation, which results in a significant reduction of the flowering period. Our study demonstrates the usefulness of gene expression assessment to predict unexplored risks of climate change. PMID:23941973

Satake, Akiko; Kawagoe, Tetsuhiro; Saburi, Yukari; Chiba, Yukako; Sakurai, Gen; Kudoh, Hiroshi

2013-01-01

329

Using a Mousy, Little Flower to Understand the Flamboyant Ones.  

ERIC Educational Resources Information Center

Discusses major leaps in knowledge about the production of flowers that have come from studying genes that regulate the flowers of mouse ear cress (Arabidopsis thaliana). Examines the ABC model of flower morphogenesis, commonality of genes, evolution of angiosperms, and agricultural and horticultural potential. (LZ)

Gillis, Anna Maria

1995-01-01

330

Flowering and Seed Production in Seven Hardwood Species.  

National Technical Information Service (NTIS)

Flowering and seed production of selected trees in northwestern Pennsylvania and southwestern New York were rated visually for several years. The seed crops of white ash and sugar maple were closely related to the amount of flowering, and flowering can be...

T. J. Grisez

1975-01-01

331

The control of flowering in time and space  

Microsoft Academic Search

The transition to flowering is one of the most important developmental decisions made by plants. Classical studies have highlighted the importance of photoperiod in controlling flowering time. More recently, the identification of mutants specifically affected in the photoperiod pathway in the model system Arabidopsis thaliana has enabled the flowering time pathways to be placed in a molecular context. This review

Katja E. Jaeger; Alexander Graf; Philip A. Wigge

2006-01-01

332

Pollinator experience, neophobia and the evolution of flowering time  

PubMed Central

Environmental changes, such as current climate warming, can exert directional selection on reproductive phenology. In plants, evolution of earlier flowering requires that the individuals bearing genes for early flowering successfully reproduce; for non-selfing, zoophilous species, this means that early flowering individuals must be visited by pollinators. In a laboratory experiment with artificial flowers, we presented captive bumble-bees (Bombus impatiens) with flower arrays representing stages in the phenological progression of a two-species plant community: Bees that had been foraging on flowers of one colour were confronted with increasing numbers of flowers of a second colour. Early flowering individuals of the second ‘species’ were significantly under-visited, because bees avoided unfamiliar flowers, particularly when these were rare. We incorporated these aspects of bee foraging behaviour (neophobia and positive frequency dependence) in a simulation model of flowering-time evolution for a plant population experiencing selection against late flowering. Unlike simple frequency dependence, a lag in pollinator visitation prevented the plant population from responding to selection and led to declines in population size. Pollinator behaviour thus has the potential to constrain evolutionary adjustments of flowering phenology.

Forrest, Jessica; Thomson, James D.

2008-01-01

333

Pollinator experience, neophobia and the evolution of flowering time.  

PubMed

Environmental changes, such as current climate warming, can exert directional selection on reproductive phenology. In plants, evolution of earlier flowering requires that the individuals bearing genes for early flowering successfully reproduce; for non-selfing, zoophilous species, this means that early flowering individuals must be visited by pollinators. In a laboratory experiment with artificial flowers, we presented captive bumble-bees (Bombus impatiens) with flower arrays representing stages in the phenological progression of a two-species plant community: Bees that had been foraging on flowers of one colour were confronted with increasing numbers of flowers of a second colour. Early flowering individuals of the second 'species' were significantly under-visited, because bees avoided unfamiliar flowers, particularly when these were rare. We incorporated these aspects of bee foraging behaviour (neophobia and positive frequency dependence) in a simulation model of flowering-time evolution for a plant population experiencing selection against late flowering. Unlike simple frequency dependence, a lag in pollinator visitation prevented the plant population from responding to selection and led to declines in population size. Pollinator behaviour thus has the potential to constrain evolutionary adjustments of flowering phenology. PMID:19129131

Forrest, Jessica; Thomson, James D

2009-03-01

334

Photoreceptors and the photoperiodic response controlling flowering of Arabidopsis  

Microsoft Academic Search

At least three photoreceptors act directly or indirectly on photoperiodic flowering responses ofArabidopsis thaliana. Photosynthetic effects of growth conditions or genotype may limit the supply of sugars to the shoot apex, so causing a delay in flowering. Blue wavelengths are also important as shown by thehy4mutant which lacks a flavoprotein and is late to flower if the available light is

Rod King; David Bagnall

1996-01-01

335

Do consecutive flower visits within a crown diminish fruit set in mass-flowering Hancornia speciosa (Apocynaceae)?  

PubMed

Hancornia speciosa is a self-incompatible, mass-flowering, sphingophilous fruit crop (mangaba) of northeast and central Brazil. The flowers have a precise pollination apparatus, which optimizes pollen transfer between flower and pollinator. While the pollination mechanism avoids self-pollination, mass-flowering promotes geitonogamy. During a flower visit, almost half of the exogenous pollen grains adhering to the proboscis are deposited on the stigma surface. A pollination experiment with a nylon thread simulating six consecutive flower visits within a crown revealed that only the first two flowers visited (positions 1 and 2) are highly likely to set fruit. Super-production of flowers, and consequently obligate low fruit set, seem to be part of the reproductive strategy of the obligate outcrossing plant, Hancornia speciosa. PMID:18426489

Pinto, C E; Oliveira, R; Schlindwein, C

2008-05-01

336

A method of skin color identification based on color classification  

Microsoft Academic Search

This paper describes a method to identify human skin region in an image on a color classification result. The method classifies the colors of all pixels in the image into several classes through K-means algorithm and segments the image into several parts according to the color class that each pixel belongs. Each class of color is represented by a color

Xiaoying Fang; Wenquan Gu; Chang Huang

2011-01-01

337

On the Hardness of 4Coloring a 3-Colorable Graph  

Microsoft Academic Search

We give a new proof showing that it is NP-hard to color a 3-colorable graph using just four colors. This result is already known (18), but our proof is novel as it does not rely on the PCP theorem, while the one in (18) does. This highlights a qualitative differ- ence between the known hardness result for coloring -colorable graphs

Venkatesan Guruswami; Sanjeev Khanna

2000-01-01

338

Color categories affect pre-attentive color perception  

Microsoft Academic Search

Categorical perception (CP) of color is the faster and\\/or more accurate discrimination of colors from different categories than equivalently spaced colors from the same category. Here, we investigate whether color CP at early stages of chromatic processing is independent of top–down modulation from attention. A visual oddball task was employed where frequent and infrequent colored stimuli were either same- or

Alexandra Clifford; Amanda Holmes; Ian R. L. Davies; Anna Franklin

2010-01-01

339

Psychology of Color: Similarities Between Abstract and Clothing Color Preferences  

Microsoft Academic Search

Two studies, one of university students and one of non-students, of the similarities between color preferences as an abstract concept and color preferences for clothing are reported. Using Munsell color standards in a controlled viewing setting, subjects ranked preferences for 10 hues, the color of a favorite garment, and dominant colors in their wardrobe. Chi Square, Kendall Coefficient of Concordance

Charlene Lind

1993-01-01

340

DEVELOPMENT OF FLOWER ORGANS IN COMMON LILAC (SYRINGA VULGARIS L.) CV. MME FLORENT STEPMAN  

Microsoft Academic Search

Studies on the development of common lilac cv. Mme Florent Stepman inflorescence buds and flowers were carried out in 2001-2002 in order to observe the development of flower organs before and after winter dormancy during the following phenological phases: inflorescence bud swelling, inflorescence elongation, flower bud whitening, flower bud swelling and flowering anthesis. The hypogynous, actinomorphic and perfect flower conforms

AGATA JE þDRZEJUK

2005-01-01

341

Possible contributions of TERMINAL FLOWER 1 to the evolution of rosette flowering in Leavenworthia (Brassicaceae)  

PubMed Central

Summary Leavenworthia crassa is a rosette flowering species that differs from inflorescence flowering species, such as Arabidopsis thaliana, in having elongated pedicels and shortened interfloral internodes on the main axis. Based on previous experiments, we hypothesized that changes to the L. crassa TFL1 ortholog, LcrTFL1, were important in the evolution of rosette flowering.We isolated LcrTFL1 and introduced a genomic construct into tfl1 mutant A. thaliana plants. We also generated and analyzed EGFP-LcrTFL1 reporter-fusion lines, and LcrTFL1/LcrLFY doubly transgenic lines.The transgene rescued the mutant defects, but manifested gain-of-function phenotypes. However, LcrTFL1 lines differed from 35S:TFL1 lines in several regards. Defects in floral meristem identity establishment were observed, as was the production of flowers with extra petals. We also noted features that resemble rosette flowering: LcrTFL1 lines produced significantly shorter interfloral internodes and significantly longer pedicels than either wild-type or 35S:TFL1 plants.Our data show that there are substantive differences in the regulation and/or function of TFL1 orthologs between A. thaliana and L. crassa. These may reflect changes that occurred during the evolution of rosette flowering in Leavenworthia, but, if so, our results show that additional, as-yet-unidentified genes were involved in this instance of architectural evolution.

Liu, Ning; Sliwinski, Marek K.; Correa, Raul; Baum, David A.

2011-01-01

342

Emission of volatile chemicals from flowering dogwood (cornus Florida L.) flowers.  

PubMed

Reproduction of flowering dogwood trees occurs via obligate out-crossing, and U.S. native bees have been suggested to be primary pollinators of this ecologically and economically important deciduous tree. Whether floral volatiles play a role in reproduction of the dogwood remains unclear. Objectives of this study were to identify principal volatile chemicals emitted from dogwood flowers and to assess a temporal volatile emission profile and volatile consistency across four cultivars. Inflorescences with intact bracts and 5 cm flower pedicel were removed from dogwood trees and subjected to headspace volatile collection. Six principal volatile compounds were detected from the flowers of the cultivar 'World's Fair' with 3-formylpyridine as the most abundant constituent. Subsequent headspace analyses performed using inflorescences without bracts or floral pedicels alone indicated that 3-formylpyridine, E-beta-ocimene, S-linalool, and ketoisophorone were mainly emitted from inflorescences. Experiments were also conducted to determine whether volatile emissions differed across time and between different cultivars of flowering dogwood. When volatile emission was analyzed for 48 h using 12 h light/dark cycles, the emission of several volatile compounds displayed diurnal patterns. Finally, whereas florets in inflorescences of four different dogwood cultivars emitted similar levels of the six principal floral volatile chemicals, 'Cherokee Brave' flowers alone yielded 4-methoxybenzaldehyde and germacrene-D. The implications of the findings of this study to dogwood breeding programs are discussed. PMID:18811168

Zhuang, Xiaofeng; Klingeman, William E; Hu, Jun; Chen, Feng

2008-10-22

343

Color preference and familiarity in performance on brand logo recall.  

PubMed

Two experiments assessed effects of color preference and brand-logo familiarity on recall performance. Exp. 1 explored the color preferences, using a forced-choice technique, of 189 women and 63 men, Taiwanese college students ages 18 to 20 years (M = 19.4, SD = 1.5). The sequence of the three most preferred colors was white, light blue, and black and of the three least preferred colors was light orange, dark violet, and dark brown. Exp. 2 investigated the effects of color preference based on the results of Exp. 1 and brand-logo familiarity on recall. A total of 27 women and 21 men, Taiwanese college students ages 18 to 20 years (M = 19.2, SD = 1.2) participated. They memorized a list of 24 logos (four logos shown in six colors) and then performed sequential recall. Analyses showed color preference significantly affected recall accuracy. Accuracy for high color preference was significantly greater than that for low preferences. Results showed no significant effects of brand-logo familiarity or sex on accuracy. In addition, the interactive effect of color preference and brand-logo familiarity on accuracy was significant. These results have implications for the design of brand logos to create and sustain memory of brand images. PMID:19093619

Huang, Kuo-Chen; Lin, Chin-Chiuan; Chiang, Shu-Ying

2008-10-01

344

Pragmatic choice in conversation.  

PubMed

How do people decide what to say in context? Many theories of pragmatics assume that people have specialized knowledge that drives them to utter certain words in different situations. But these theories are mostly unable to explain both the regularity and variability in people's speech behaviors. Our purpose in this article is to advance a view of pragmatics based on complexity theory, which specifically explains the pragmatic choices speakers make in conversations. The concept of self-organized criticality sheds light on how a history of utterances and subtle details of a situation surrounding a conversation may directly specify language behavior. Under this view, pragmatic choice in discourse does not reflect the output of any dedicated pragmatic module but arises from a complex coordination or coupling between speakers and their varying communicative tasks. PMID:22253174

Gibbs, Raymond W; Van Orden, Guy

2012-01-01

345

CropChoice  

NSDL National Science Digital Library

CropChoice is an alternative news and information source for American farmers and consumers about genetically modified crops, corporate agribusiness concentration, farm and trade policy, sustainable agriculture, wind farming and alternative energy, and rural economic and social issues. Users can explore the site's resources by topic, search past headlines and view press releases. Links are provided to sites that involve similar issues and information.

2007-04-16

346

Color recognition in Prolog  

Microsoft Academic Search

Hardware capable of recognizing the `named' colors (e.g., `red,' `yellow,' orange, etc.,) is available now at modest cost. This has been interfaced to a standard computer, running Prolog. The result is a powerful combination, capable of intelligently interpreting colored images, such as those on simple product packaging. The structure and applications of such a system are described. Prolog programs are

Bruce G. Batchelor

1992-01-01

347

Science Shorts: Seeing Color  

NSDL National Science Digital Library

Colors can open the door to an invisible world of electromagnetism, even when children can barely imagine things they cannot see. This article looks at color as a powerful tool for engaging children of all ages. A corresponding activity is included.

Texley, Juliana

2005-09-01

348

Color quality scale  

NASA Astrophysics Data System (ADS)

The color rendering index (CRI) has been shown to have deficiencies when applied to white light-emitting-diode-based sources. Furthermore, evidence suggests that the restricted scope of the CRI unnecessarily penalizes some light sources with desirable color qualities. To solve the problems of the CRI and include other dimensions of color quality, the color quality scale (CQS) has been developed. Although the CQS uses many of elements of the CRI, there are a number of fundamental differences. Like the CRI, the CQS is a test-samples method that compares the appearance of a set of reflective samples when illuminated by the test lamp to their appearance under a reference illuminant. The CQS uses a larger set of reflective samples, all of high chroma, and combines the color differences of the samples with a root mean square. Additionally, the CQS does not penalize light sources for causing increases in the chroma of object colors but does penalize sources with smaller rendered color gamut areas. The scale of the CQS is converted to span 0-100, and the uniform object color space and chromatic adaptation transform used in the calculations are updated. Supplementary scales have also been developed for expert users.

Davis, Wendy; Ohno, Yoshi

2010-03-01

349

Colors of Stars  

NSDL National Science Digital Library

In this activity, learners observe colors in the flame of a burning candle to explore connections between matter, light, color and temperature -- basic concepts of matter and energy. Then, learners elaborate on these basic concepts in a new context of astronomy by drawing scale models of stars. This activity involves an open flame; adult supervision is recommended.

Hemenway, Mary K.

2011-01-01

350

Colorful Underwater Sea Creatures  

ERIC Educational Resources Information Center

In this article, the author describes a project wherein students created colorful underwater sea creatures. This project began with a discussion about underwater sea creatures and how they live. The first step was making the multi-colored tissue paper that would become sea creatures and seaweed. Once students had the shapes of their sea creatures…

McCutcheon, Heather

2011-01-01

351

Requirements for color technology  

NASA Astrophysics Data System (ADS)

The requirements for color technology in the general office are reviewed. The two most salient factors driving the requirements for color are the information explosion and the virtually negligible growth in white collar productivity in the recent past. Accordingly, the business requirement upon color technology is that it be utilized in an effective and efficient manner to increase office productivity. Recent research on productivity and growth has moved beyond the classical two factor productivity model of labor and capital to explicitly include knowledge as a third and vital factor. Documents are agents of knowledge in the general office. Documents articulate, express, disseminate, and communicate knowledge. The central question addressed here is how can color, in conjunction with other techniques such as graphics and document design, improve the growth of knowledge? The central thesis is that the effective use of color to convert information into knowledge is one of the most powerful ways to increase office productivity. Material on the value of color is reviewed. This material is related to the role of documents. Document services are the way in which users access and utilize color technology. The requirements for color technology are then defined against the services taxonomy.

Campbell, Ronald B.

1993-06-01

352

Measurements of ocean color  

NASA Technical Reports Server (NTRS)

Phytoplankton density is determined by ocean color measurements. Phytoplankton is detected by remote sensing systems, because they contain chlorophyll. Chlorophyll has two strong absorption bands in the visible spectrum. The algae Chlorella shows the strongest absorptions at 450 and 675 nm. The measured spectrum of ocean color at low and high altitudes is shown.

Hovis, W. A.

1972-01-01

353

3-D Color Wheels  

ERIC Educational Resources Information Center

The blending of information from an academic class with projects from art class can do nothing but strengthen the learning power of the student. Creating three-dimensional color wheels provides the perfect opportunity to combine basic geometry knowledge with color theory. In this article, the author describes how her seventh-grade painting…

DuBois, Ann

2010-01-01

354

Choice Flowers and Well-Ordered Tables: Struggling Over Gender in a Nineteenth-Century Household  

Microsoft Academic Search

Historical archaeologists have generally considered households as isolated,bounded entities, and not as sets of social relations. Consequently, the household has gone unrecognized as an arena of struggle. Analysis of documents associated with the household of nineteenth-century reformer Gerrit Smith challenges this approach. At his Peterboro, New York estate, a struggle ensued between family members because of conflicting ideologies of self-presentation,

Hadley Kruczek-Aaron

2002-01-01

355

Origin choice and petal loss in the flower garden of spiral wave tip trajectories  

PubMed Central

Rotating spiral waves have been observed in numerous biological and physical systems. These spiral waves can be stationary, meander, or even degenerate into multiple unstable rotating waves. The spatiotemporal behavior of spiral waves has been extensively quantified by tracking spiral wave tip trajectories. However, the precise methodology of identifying the spiral wave tip and its influence on the specific patterns of behavior remains a largely unexplored topic of research. Here we use a two-state variable FitzHugh–Nagumo model to simulate stationary and meandering spiral waves and examine the spatiotemporal representation of the system’s state variables in both the real (i.e., physical) and state spaces. We show that mapping between these two spaces provides a method to demarcate the spiral wave tip as the center of rotation of the solution to the underlying nonlinear partial differential equations. This approach leads to the simplest tip trajectories by eliminating portions resulting from the rotational component of the spiral wave.

Gray, Richard A.; Wikswo, John P.; Otani, Niels F.

2009-01-01

356

Color evaluation of computer-generated color rainbow holography  

NASA Astrophysics Data System (ADS)

A color evaluation approach for computer-generated color rainbow holography (CGCRH) is presented. Firstly, the relationship between color quantities of a computer display and a color computer-generated holography (CCGH) colorimetric system is discussed based on color matching theory. An isochromatic transfer relationship of color quantity and amplitude of object light field is proposed. Secondly, the color reproduction mechanism and factors leading to the color difference between the color object and the holographic image that is reconstructed by CGCRH are analyzed in detail. A quantitative color calculation method for the holographic image reconstructed by CGCRH is given. Finally, general color samples are selected as numerical calculation test targets and the color differences between holographic images and test targets are calculated based on our proposed method.

Shi, Yile; Wang, Hui; Wu, Qiong

2013-02-01

357

Effect of ethylene on flower abscission: a survey.  

PubMed

The effect of ethylene on flower abscission was investigated in monocotyledons and eudicotyledons, in about 300 species from 50 families. In all species studied except Cymbidium, flower abscission was highly sensitive to ethylene. Flower fall was not consistent among the species in any family studied. It also showed no relationship with petal senescence or abscission, nor with petal colour changes or flower closure. Results suggest that flower abscission is generally mediated by endogenous ethylene, but that some exceptional ethylene-insensitive abscission occurs in the Orchidaceae. PMID:12102524

van Doorn, Wouter G

2002-06-01

358

Coefficient Color Constancy  

NASA Astrophysics Data System (ADS)

The goal of color constancy is to take the color responses (for example camera rgb triplets) of surfaces viewed under nn unknown illuminant and map them to illuminant independent descriptors. In existing theories this mapping is either a general linear 3 times 3 matrix or a simple diagonal matrix of scaling coefficients. The general theories have the advantage that the illuminant can be accurately discounted but have the disadvantage that nine parameters must be recovered. Conversely while the coefficient theories have only three unknowns, a diagonal matrix may only partially discount the illuminant. My starting point in this thesis is to generalize the coefficient approach; the goal is to retain its inherent simplicity while at the same time increasing its expressive power. Under the generalized coefficient scheme, I propose that a visual system transforms responses to a new sensor basis before applying the scaling coefficients. I present methods for choosing the best coefficient basis for a variety of statistical models of color responses. These models are rich enough that the generalized coefficient approach suffices for almost all possible sensor sets. To achieve color constancy the correct coefficients must be recovered. Existing algorithms can do so only when strong constraints are satisfied. For example it is often assumed that there is a white reflectance in every scene. In the second part of any thesis, I develop a new coefficient algorithm, which I call color in perspective, based on very weak (and very reasonable) assumptions about the world. I assume only that the range of color responses induced by different reflectances varies with a change in illumination and that illumination itself can vary only within certain bounds. I tested the algorithm on real images taken with a color video camera--extremely good constancy is delivered. Indeed the degree of constancy compares favorably with the best which is theoretically possible. The methods developed in this thesis can be applied to a variety of other areas: including color graphics, color reproduction and color appearance models.

Finlayson, Graham David

1995-01-01

359

Flowering cycles of woody bamboos native to southern South America.  

PubMed

Neotropical woody bamboos range from northern Mexico to southern Argentina and Chile. The most interesting aspect of bamboo biology is their flowering habit. The species that are the most intriguing are those that manifest a cyclic pattern of gregarious flowering after long vegetative periods. The flowering cycle has been described in very few species. The goal was to identify mass flowering events of woody bamboo species native to Argentina and neighboring areas, and to estimate the flowering cycle of each species. Sixteen species were surveyed: Chusquea culeou, C. deficiens, C. lorentziana, C. montana, C. quila, C. ramosissima, C. tenella, C. valdiviensis; Colanthelia rhizantha; Guadua chacoensis, G. paraguayana, G. trinii; Merostachys clausenii, M. multiramea, Rhipidocladum neumannii and R. racemiflorum. To reconstruct flowering dates, information from literature and herbarium collections was consulted and more than 990 records were gathered. Flowering cycles were estimated by recording the intervals between reported flowering events. Evidence of regular flowering cycles of ca. 30 years was found for most of the species considered. There is a remarkable concentration of flowering cycles about multiples of 15-16 years. Flowering synchrony among different species of woody bamboos was recorded for the first time in South America. PMID:24162620

Guerreiro, Carolina

2014-03-01

360

Large and abundant flowers increase indirect costs of corollas: a study of coflowering sympatric Mediterranean species of contrasting flower size.  

PubMed

Large floral displays receive more pollinator visits but involve higher production and maintenance costs. This can result in indirect costs which may negatively affect functions like reproductive output. In this study, we explored the relationship between floral display and indirect costs in two pairs of coflowering sympatric Mediterranean Cistus of contrasting flower size. We hypothesized that: (1) corolla production entails direct costs in dry mass, N and P, (2) corollas entail significant indirect costs in terms of fruit set and seed production, (3) indirect costs increase with floral display, (4) indirect costs are greater in larger-flowered sympatric species, and (5) local climatic conditions influence indirect costs. We compared fruit set and seed production of petal-removed flowers and unmanipulated control flowers and evaluated the influence of mean flower number and mean flower size on relative fruit and seed gain of petal-removed and control flowers. Fruit set and seed production were significantly higher in petal-removed flowers in all the studied species. A positive relationship was found between relative fruit gain and mean individual flower size within species. In one pair of species, fruit gain was higher in the large-flowered species, as was the correlation between fruit gain and mean number of open flowers. In the other pair, the correlation between fruit gain and mean flower size was also higher in the large-flowered species. These results reveal that Mediterranean environments impose significant constraints on floral display, counteracting advantages of large flowers from the pollination point of view with increased indirect costs of such flowers. PMID:23404071

Teixido, Alberto L; Valladares, Fernando

2013-09-01

361

"The American Way": Resisting the Empire of Force and Color-Blind Racism  

ERIC Educational Resources Information Center

Students of color (in particular, those who are first-generation Chicano/a as well as first-generation college students), form a discourse community with a tendency to rely on dominant color-blind ideology concerning freedom of choice and equal opportunity to explain their positions within the academy. In this article, the author analyzes the…

Martinez, Aja Y.

2009-01-01

362

Tropism in azalea and lily flowers  

NASA Astrophysics Data System (ADS)

Flowers have coevolved with pollinator animals. Some flowers have the up-down directional features in their form and orientation, which results the higher success of pollination under the influence of gravity. Azalea, Rhododendron pulchrum, flower responds against gravity, and orients the specific petal at its top. This petal with honey mark guides pollinator animals to nectary of the flower. Pistil and stamen bend upward by sensing gravity, and increase probability of their contact with pollinator. There was large sediment amyloplast found in sectioned tissue of style. In addition to this action of gravity, phototropic response was also observed at lesser degree, while the gravitational cue was removed by the 3D-clinorotation of the plant. In contrast to azalea, pistil of lily flower senses light in order to determine the direction of bending. Lily, Lilium cv. 'Casablanca', tepals open horizontally or slightly inclined downward. After its anthesis, pistil and stamen start to bend upward by light. Gravity induced no tropic response at all, evidenced by the experiment conducted under dark. Sediment amyloplast was not found in lily style. Phototropic response of pistil and stamen in lily was activated by blue light even at lower energy density. On the other hand, red light was not effective to induce the tropic response even with substantial energy density. This action spectrum of light agreed with those for the phototropism shown in coleoptile of monocotyledonous plants. Because the tropism of style was not hindered at removal of stigma, reception site for incident light is neither restricted to stigma nor its close vicinity, but distributes through style. The process of lily pistil elongation was analyzed in details to identify the site of its initiation and propagation of bending movement through the anthesis period. Elongation started at basal part of pistil and propagated towards its top after opening of perianth. Steep bending occurred at the basal zone of pistil as long as differential incidence of light was given at its part. Elongation and bending of filament of stamen in lily differed from those of style in several points. After perianth opened, filaments deployed and spread out from the central axis of flower. Distinctive elongation of filament developed at a zone close to anther. It will be discussed how such regulation made by either gravity or light improves the degree of adaptation for those plants during entomophilous pollination.

Shimizu, M.; Tomita-Yokotani, K.; Nakamura, T.; Yamashita, M.

363

Natural Variation of the RICE FLOWERING LOCUS T 1 Contributes to Flowering Time Divergence in Rice  

PubMed Central

In rice (Oryza sativa L.), there is a diversity in flowering time that is strictly genetically regulated. Some indica cultivars show extremely late flowering under long-day conditions, but little is known about the gene(s) involved. Here, we demonstrate that functional defects in the florigen gene RFT1 are the main cause of late flowering in an indica cultivar, Nona Bokra. Mapping and complementation studies revealed that sequence polymorphisms in the RFT1 regulatory and coding regions are likely to cause late flowering under long-day conditions. We detected polymorphisms in the promoter region that lead to reduced expression levels of RFT1. We also identified an amino acid substitution (E105K) that leads to a functional defect in Nona Bokra RFT1. Sequencing of the RFT1 region in rice accessions from a global collection showed that the E105K mutation is found only in indica, and indicated a strong association between the RFT1 haplotype and extremely late flowering in a functional Hd1 background. Furthermore, SNPs in the regulatory region of RFT1 and the E105K substitution in 1,397 accessions show strong linkage disequilibrium with a flowering time–associated SNP. Although the defective E105K allele of RFT1 (but not of another florigen gene, Hd3a) is found in many cultivars, relative rate tests revealed no evidence for differential rate of evolution of these genes. The ratios of nonsynonymous to synonymous substitutions suggest that the E105K mutation resulting in the defect in RFT1 occurred relatively recently. These findings indicate that natural mutations in RFT1 provide flowering time divergence under long-day conditions.

Ogiso-Tanaka, Eri; Matsubara, Kazuki; Yamamoto, Shin-ichi; Nonoue, Yasunori; Wu, Jianzhong; Fujisawa, Hiroko; Ishikubo, Harumi; Tanaka, Tsuyoshi; Ando, Tsuyu; Matsumoto, Takashi; Yano, Masahiro

2013-01-01

364

Interference Colors in Thin Films.  

ERIC Educational Resources Information Center

Explains interference colors in thin films as being due to the removal, or considerable reduction, of a certain color by destructive inteference that results in the complementary color being seen. (GA)

Armstrong, H. L.

1979-01-01

365

The effect of body coloration and group size on social partner preferences in female fighting fish (Betta splendens).  

PubMed

Females of the fighting fish Betta splendens have been shown to associate with other B. splendens females in a manner reminiscent of shoaling behavior. Since body coloration varies dramatically in this species, and since body coloration has been shown to affect shoalmate choice in other species of fish, we examined the influence of body coloration on association preferences in female B. splendens. In dichotomous choice tests, B. splendens females spent more time swimming near groups of females (regardless of coloration) than swimming near an empty chamber, and chose to swim near fish of similar coloration to their own when choosing between two distinctly colored groups of females. When examining the interplay between body coloration and group size, focal fish spent more time swimming near larger groups (N=5) of similarly colored fish than swimming near an individual female of similar coloration. However, focal fish showed no preference when presented with an individual female of similar coloration and a larger group of females of dissimilar coloration. These results suggest that association choices in B. splendens females are strongly affected by both body coloration and by group size. PMID:19059314

Blakeslee, C; McRobert, S P; Brown, A C; Clotfelter, E D

2009-02-01

366

Evolution of sexual dichromatism: contribution of carotenoid- versus melanin-based coloration  

Microsoft Academic Search

In birds, carotenoid-based plumage coloration is more dependent on physical condition and foraging abilities and less constrained developmentally than is melanin-based coloration. Thus, female mate choice for honest signals should result in more intense sexual selection on carotenoid- than on melanin-based plumage coloration. Using variation in sexual dimorphism as an indirect measure of the intensity of sexual selection, we tested

ALEXANDER V. BADYAEV; GEOFFREY E. HILL

2000-01-01

367

Quantized CIELab* space and encoded spatial structure for scalable indexing of large color image archives  

Microsoft Academic Search

This paper presents a scalable approach for content-based searching and browsing of color image archives using segmented color-layout and spatial structure information. The segmented color layout is computed using quantized CIE-Lab* space, and encoded quadtrees have been used to preserve and represent the structural information. Our careful choice of feature space and associated indexing provides a scalable content-based indexing and

Elif Albuz; Erturk D. Kocalar; Ashfaq A. Khokhar

2000-01-01

368

Mate Choice Copying in Humans  

Microsoft Academic Search

There is substantial evidence that in human mate choice, females directly select males based on male display of both physical\\u000a and behavioral traits. In non-humans, there is additionally a growing literature on indirect mate choice, such as choice through\\u000a observing and subsequently copying the mating preferences of conspecifics (mate choice copying). Given that humans are a social\\u000a species with a

D. Waynforth

2007-01-01

369

The Primary Colors of Light  

NSDL National Science Digital Library

In this activity, learners work in groups of four to explore light. Learners create new colors from the primary colors of light from flashlights covered in theatrical gels or cellophane. Then, learners demonstrate their new knowledge of the primary colors of light by coloring a venn diagram. Learners will also distinguish between primary colors of light and primary colors of pigment (like paint or crayon). This lesson guide includes an explanation section as well as tips for teachers and educators.

To, Josephine; Butcher, Ginger

2007-01-01

370

Bamboo-dominated forests of the southwest Amazon: detection, spatial extent, life cycle length and flowering waves.  

PubMed

We map the extent, infer the life-cycle length and describe spatial and temporal patterns of flowering of sarmentose bamboos (Guadua spp) in upland forests of the southwest Amazon. We first examine the spectra and the spectral separation of forests with different bamboo life stages. False-color composites from orbital sensors going back to 1975 are capable of distinguishing life stages. These woody bamboos flower produce massive quantities of seeds and then die. Life stage is synchronized, forming a single cohort within each population. Bamboo dominates at least 161,500 km(2) of forest, coincident with an area of recent or ongoing tectonic uplift, rapid mechanical erosion and poorly drained soils rich in exchangeable cations. Each bamboo population is confined to a single spatially continuous patch or to a core patch with small outliers. Using spatial congruence between pairs of mature-stage maps from different years, we estimate an average life cycle of 27-28 y. It is now possible to predict exactly where and approximately when new bamboo mortality events will occur. We also map 74 bamboo populations that flowered between 2001 and 2008 over the entire domain of bamboo-dominated forest. Population size averaged 330 km(2). Flowering events of these populations are temporally and/or spatially separated, restricting or preventing gene exchange. Nonetheless, adjacent populations flower closer in time than expected by chance, forming flowering waves. This may be a consequence of allochronic divergence from fewer ancestral populations and suggests a long history of widespread bamboo in the southwest Amazon. PMID:23359438

de Carvalho, Anelena L; Nelson, Bruce W; Bianchini, Milton C; Plagnol, Daniela; Kuplich, Tatiana M; Daly, Douglas C

2013-01-01

371

School Choice. Trends and Issues.  

ERIC Educational Resources Information Center

This document examines many of the issues surrounding school choice. It summarizes the prevalence of school choice and touches on elements of the debate, such as the dilemma in finding the right balance between individual/family freedom and the interests of the community. In looking at school-choice options, the paper divides them into…

Hadderman, Margaret, Comp.

372

Empirical research on accounting choice  

Microsoft Academic Search

We review research from the 1990s that examines the determinants and consequences of accounting choice, structuring our analysis around the three types of market imperfections that influence managers’ choices: agency costs, information asymmetries, and externalities affecting non-contracting parties. We conclude that research in the 1990s made limited progress in expanding our understanding of accounting choice because of limitations in research

Thomas D Fields; Thomas Z Lys; Linda Vincent

2001-01-01

373

Dynamics of Choice: A Tutorial  

ERIC Educational Resources Information Center

Choice may be defined as the allocation of behavior among activities. Since all activities take up time, choice is conveniently thought of as the allocation of time among activities, even if activities like pecking are most easily measured by counting. Since dynamics refers to change through time, the dynamics of choice refers to change of…

Baum, William M.

2010-01-01

374

Understanding Career Choices in Context.  

ERIC Educational Resources Information Center

Over several years, challenges have been made to traditional theories of career choice. One of these challenges has been to consider the contexts in which individuals live and how this can influence career choices. The purpose of this model is to create a framework to explain the influences on career choices over the lifespan. The term "career…

Minor, Carole W.; Vermeulen, Mary E.; Coy, Doris Rhea

375

Mass flowering of the tropical tree Shorea beccariana was preceded by expression changes in flowering and drought-responsive genes  

PubMed Central

Community-level mass flowering, known as general flowering, which occurs in South-East Asia at supra-annual irregular intervals, is considered a particularly spectacular phenomenon in tropical ecology. Recent studies have proposed several proximate factors inducing general flowering, such as drought and falls in minimum temperature. However, limited empirical data on the developmental and physiological processes have been available to test the significance of such factors. To overcome this limitation and test the hypotheses that general flowering is triggered by the proposed factors, we conducted an ‘ecological transcriptome’ study of a mass flowering species, Shorea beccariana, comparing meteorological data with genome-wide expression patterns obtained using next-generation sequencing. Among the 98 flowering-related genes identified, the homologs of a floral pathway integrator, SbFT, and a floral repressor, SbSVP, showed dramatic transcriptional changes before flowering, and their flowering functions were confirmed using transgenic Arabidopsis thaliana. Expression in drought-responsive and sucrose-induced genes also changed before flowering. All these expression changes occurred when the flowering-inducing level of drought was reached, as estimated using data from the preceding 10 years. These genome-wide expression data support the hypothesis that drought is a trigger for general flowering.

Kobayashi, Masaki J; Takeuchi, Yayoi; Kenta, Tanaka; Kume, Tomonori; Diway, Bibian; Shimizu, Kentaro K

2013-01-01

376

Mass flowering of the tropical tree Shorea beccariana was preceded by expression changes in flowering and drought-responsive genes.  

PubMed

Community-level mass flowering, known as general flowering, which occurs in South-East Asia at supra-annual irregular intervals, is considered a particularly spectacular phenomenon in tropical ecology. Recent studies have proposed several proximate factors inducing general flowering, such as drought and falls in minimum temperature. However, limited empirical data on the developmental and physiological processes have been available to test the significance of such factors. To overcome this limitation and test the hypotheses that general flowering is triggered by the proposed factors, we conducted an 'ecological transcriptome' study of a mass flowering species, Shorea beccariana, comparing meteorological data with genome-wide expression patterns obtained using next-generation sequencing. Among the 98 flowering-related genes identified, the homologs of a floral pathway integrator, SbFT, and a floral repressor, SbSVP, showed dramatic transcriptional changes before flowering, and their flowering functions were confirmed using transgenic Arabidopsis thaliana. Expression in drought-responsive and sucrose-induced genes also changed before flowering. All these expression changes occurred when the flowering-inducing level of drought was reached, as estimated using data from the preceding 10 years. These genome-wide expression data support the hypothesis that drought is a trigger for general flowering. PMID:23651119

Kobayashi, Masaki J; Takeuchi, Yayoi; Kenta, Tanaka; Kume, Tomonori; Diway, Bibian; Shimizu, Kentaro K

2013-09-01

377

Constructing Food Choice Decisions  

Microsoft Academic Search

Background  Food choice decisions are frequent, multifaceted, situational, dynamic, and complex and lead to food behaviors where people\\u000a acquire, prepare, serve, give away, store, eat, and clean up. Many disciplines and fields examine decision making.\\u000a \\u000a \\u000a \\u000a Purpose  Several classes of theories are applicable to food decision making, including social behavior, social facts, and social definition\\u000a perspectives. Each offers some insights but also makes

Jeffery Sobal; Carole A. Bisogni

2009-01-01

378

How choice modifies preference: neural correlates of choice justification.  

PubMed

When making a difficult choice, people often justify the choice by increasing their liking for the chosen object and decreasing their liking for the rejected object. To uncover the neural signatures of choice justification, we used functional magnetic resonance imaging to monitor neural activity when subjects rated their preference for chosen and rejected musical CDs before and after they made their choices. We observed that the trial-by-trial attitude change (i.e., increase of preference for chosen items and decrease of preference for rejected items) was predicted by post-choice activity in the ventral medial prefrontal cortex (MPFC), right temporal-parietal junction, anterior insula, and bilateral cerebellum. Furthermore, individual difference in choice justification (i.e., increased preference for chosen items minus decreased preference for rejected items) was predicted by post-choice neural activity in the dorsal MPFC, left lateral prefrontal cortex, and right precentral cortex positively. In addition, interdependent self-construal was correlated with decreased activity in the ventral MPFC in the post-choice than pre-choice sessions. These findings suggest that both negative arousal/regulation and self-reflection are associated with choice justification. This provides evidence for the self-threat theory of choice justification. PMID:21130888

Qin, Jungang; Kimel, Sasha; Kitayama, Shinobu; Wang, Xiaoying; Yang, Xuedong; Han, Shihui

2011-03-01

379

Colors on Jupiter  

NASA Technical Reports Server (NTRS)

The colors present in the clouds of Jupiter at the time of the Voyager encounters are described as they appear in high resolution images. It is shown that latitude, altitude and dwelltime are all critical factors in determining which colors appear where, although the identities of the responsible chromophores remain unestablished. Simultaneous ground-based 5 micron observations are used to determine the relative altitudes of the cloud systems which are characterized as white clouds, tawny clouds, dark brown cloud belts, and blue-grey hot spots in equatorial regions. Correlations between cloud color and certain latitudes have been maintained for decades, which suggests the importance of the internal energy source.

Owen, T.; Terrile, R. J.

1981-01-01

380

Color universal design: analysis of color category dependency on color vision type (3)  

NASA Astrophysics Data System (ADS)

We report on the results of a study investigating the color perception characteristics of people with red-green color confusion. We believe that this is an important step towards achieving Color Universal Design. In Japan, approximately 5% of men and 0.2% of women have red-green confusion. The percentage for men is higher in Europe and the United States; up to 8% in some countries. Red-green confusion involves a perception of colors different from normal color vision. Colors are used as a means of disseminating clear information to people; however, it may be difficult to convey the correct information to people who have red-green confusion. Consequently, colors should be chosen that minimize accidents and that promote more effective communication. In a previous survey, we investigated color categories common to each color vision type, trichromat (C-type color vision), protan (P-type color vision) and deuteran (D-type color vision). In the present study, first, we conducted experiments in order to verify a previous survey of C-type color vision and P-type color vision. Next, we investigated color difference levels within "CIE 1976 L*a*b*" (the CIELAB uniform color space), where neither C-type nor P-type color vision causes accidents under certain conditions (rain maps/contour line levels and graph color legend levels). As a result, we propose a common chromaticity of colors that the two color vision types are able to categorize by means of color names common to C-type color vision. We also offer a proposal to explain perception characteristics of color differences with normal color vision and red-green confusion using the CIELAB uniform color space. This report is a follow-up to SPIE-IS & T / Vol. 7528 7528051-8 and SPIE-IS & T /vol. 7866 78660J-1-8.

Kojima, Natsuki; Ichihara, Yasuyo G.; Ikeda, Tomohiro; Kamachi, Miyuki G.; Ito, Kei

2012-01-01

381

Flavonoids from blue flowers of Nymphaèa caerulea  

Microsoft Academic Search

Seven flavonols including the novel 3-(2?-acetylrhamnosides) of myricetin and quercetin (2 and 6), the rare kaempferol 3-(2?-acetylrhamnoside) and quercetin 3-(3?-acetylrhamnoside), in addition to the 3-rhamnosides of kaempferol, quercetin and were isolated from blue flowers of the African water lily Nymphaèa caerulea (=Nymphaèa capensis). Their structures were elucidated by a combination of chromatography and homo- and heteronuclear two-dimensional NMR techniques and

Torgils Fossen; Åsmund Larsen; Bernard T Kiremire; Øyvind M Andersen

1999-01-01

382

Fibonacci, quasicrystals and the beauty of flowers.  

PubMed

The appearance of Fibonacci sequences and the golden ratio in plant structures is one of the great outstanding puzzles of biology. Here I suggest that quasicrystals, which naturally pack in the golden ratio, may be ubiquitous in biological systems and introduce the golden ratio into plant phyllotaxy. The appearance of golden ratio-based structures as beautiful indicates that the golden ratio may play a role in the development of consciousness and lead to the aesthetic natural selection of flowering plants. PMID:23072998

Gardiner, John

2012-12-01

383

Fibonacci, quasicrystals and the beauty of flowers  

PubMed Central

The appearance of Fibonacci sequences and the golden ratio in plant structures is one of the great outstanding puzzles of biology. Here I suggest that quasicrystals, which naturally pack in the golden ratio, may be ubiquitous in biological systems and introduce the golden ratio into plant phyllotaxy. The appearance of golden ratio-based structures as beautiful indicates that the golden ratio may play a role in the development of consciousness and lead to the aesthetic natural selection of flowering plants.

Gardiner, John

2012-01-01

384

How genes paint flowers and seeds  

Microsoft Academic Search

Mutant analyses have given insight into the various parameters that contribute to flower colour and pattern, which is so important for pollination. One important factor is the accumulation of orange, red and purple anthocyanin pigments in the cell vacuole—patterns arise by cell-specific expression of combinations of regulatory proteins. The overall colour perceived is also influenced by vacuolar pH, co-pigmentation and

Joseph Mol; Erich Grotewold; Ronald Koes

1998-01-01

385

Is the flower fluorescence relevant in biocommunication?  

PubMed

Flower fluorescence has been previously proposed as a potential visual signal to attract pollinators. In this work, this point was addressed by quantitatively measuring the fluorescence quantum yield (?(f)) for flowers of Bellis perennis (white, yellow, pink, and purple), Ornithogalum thyrsoides (petals and ovaries), Limonium sinuatum (white and yellow), Lampranthus productus (yellow), Petunia nyctaginiflora (white), Bougainvillea spectabilis (white and yellow), Antirrhinum majus (white and yellow), Eustoma grandiflorum (white and blue), Citrus aurantium (petals and stigma), and Portulaca grandiflora (yellow). The highest values were obtained for the ovaries of O. thyrsoides (?(f)?=?0.030) and for Citrus aurantium petals (?(f)?=?0.014) and stigma (?(f)?=?0.013). Emitted photons as fluorescence were compared with reflected photons. It was concluded that the fluorescence emission is negligible compared to the reflected light, even for the most fluorescent samples, and it may not be considered as an optical signal in biocommunication. The work was complemented with the calculation of quantum catches for each studied flower species to describe the visual sensitization of eye photoreceptors. PMID:20811871

Iriel, Analía; Lagorio, María Gabriela

2010-10-01

386

FLOWERING BHLH transcriptional activators control expression of the photoperiodic flowering regulator CONSTANS in Arabidopsis  

PubMed Central

Many plants monitor day-length changes throughout the year and use the information to precisely regulate the timing of seasonal flowering for maximum reproductive success. In Arabidopsis thaliana, transcriptional regulation of the CONSTANS (CO) gene and posttranslational regulation of CO protein are crucial mechanisms for proper day-length measurement in photoperiodic flowering. Currently, the CYCLING DOF FACTOR proteins are the only transcription factors known to directly regulate CO gene expression, and the mechanisms that directly activate CO transcription have remained unknown. Here we report the identification of four CO transcriptional activators, named FLOWERING BHLH 1 (FBH1), FBH2, FBH3, and FBH4. All FBH proteins are related basic helix–loop–helix-type transcription factors that preferentially bind to the E-box cis-elements in the CO promoter. Overexpression of all FBH genes drastically elevated CO levels and caused early flowering regardless of photoperiod, whereas CO levels were reduced in the fbh quadruple mutants. In addition, FBH1 is expressed in the vascular tissue and bound near the transcription start site of the CO promoter in vivo. Furthermore, FBH homologs in poplar and rice induced CO expression in Arabidopsis. These results indicate that FBH proteins positively regulate CO transcription for photoperiodic flowering and that this mechanism may be conserved in diverse plant species. Our results suggest that the diurnal CO expression pattern is generated by a concert of redundant functions of positive and negative transcriptional regulators.

Ito, Shogo; Song, Young Hun; Josephson-Day, Anna R.; Miller, Ryan J.; Breton, Ghislain; Olmstead, Richard G.; Imaizumi, Takato

2012-01-01

387

Effect of color illumination on color contrast in color vision application  

NASA Astrophysics Data System (ADS)

This paper presents a technique to choose appropriate light source for maximizing the contrast between the object and the background surfaces in color vision application. From the physics of color image formation, three parameters which affect generating signal of color digital camera are researched. An optimal color illumination for enhancing color contrast can be found by maximizing these surfaces spectral reflectance. The discrimination of these surfaces spectral reflectance was estimated by using average color difference in CIELab color space. A printed color patch which have seven several colored characters was used to demonstrate the approach. For each colored character, appropriate Light Emitting Diode (LED) illumination was selected to maximize the discriminability, which is more suitable than D65 illumination. These experiments illustrate the usefulness of properly chosen color illumination in color vision application.

Zhu, Zhen-Min; Qu, Xing-Hua; Liang, Hai-Yu; Jia, Guo-Xin

2010-11-01

388

Matching image color from different cameras  

NASA Astrophysics Data System (ADS)

Can images from professional digital SLR cameras be made equivalent in color using simple colorimetric characterization? Two cameras were characterized, these characterizations were implemented on a variety of images, and the results were evaluated both colorimetrically and psychophysically. A Nikon D2x and a Canon 5D were used. The colorimetric analyses indicated that accurate reproductions were obtained. The median CIELAB color differences between the measured ColorChecker SG and the reproduced image were 4.0 and 6.1 for the Canon (chart and spectral respectively) and 5.9 and 6.9 for the Nikon. The median differences between cameras were 2.8 and 3.4 for the chart and spectral characterizations, near the expected threshold for reliable image difference perception. Eight scenes were evaluated psychophysically in three forced-choice experiments in which a reference image from one of the cameras was shown to observers in comparison with a pair of images, one from each camera. The three experiments were (1) a comparison of the two cameras with the chart-based characterizations, (2) a comparison with the spectral characterizations, and (3) a comparison of chart vs. spectral characterization within and across cameras. The results for the three experiments are 64%, 64%, and 55% correct respectively. Careful and simple colorimetric characterization of digital SLR cameras can result in visually equivalent color reproduction.

Fairchild, Mark D.; Wyble, David R.; Johnson, Garrett M.

2008-01-01

389

Multilayer polymeric color-shifting polarizer films  

NASA Astrophysics Data System (ADS)

Color-shifts have been used in the field of optical security for many years. Through the use of birefringent polymers, 3M has pioneered highly reflective, multilayer, all-polymeric interference optical films for use as mirrors and polarizers. Polarizer and mirror multilayer films with reflectance bands covering all of the visible wavelengths have found uses in LCD displays and solar light pipes. Color-shifting polarizer (CSP) films may be made by uniaxially orienting a multilayer stack that has sharp band edges and does not cover all of the visible wavelengths. By judicious choice of polymers, the refractive indices of the two polymers have a large difference in refractive index in the stretch direction and match in the transverse direction. The resulting film has a noticeable color shift to the unaided eye, and a readily verifiable feature when viewed with both polarization states. In the pass condition, the film becomes colorless; in the block direction, the color is very saturated and noticeably shifts in hue when the viewing angle is changed. The films may have reverse printing under the CSP films, which hides during verification. The indelible marking of the film for the intended end use and the tamper resistance of labels made from these films will also be discussed.

Jonza, James M.; Dubner, Andrew D.

2004-06-01

390

Intangibility in intertemporal choice.  

PubMed

Since the advent of the discounted utility (DU) model, economists have thought about intertemporal choice in very specific terms. DU assumes that people make explicit trade-offs between costs and benefits occurring at different points in time. While this explicit trade-off perspective is simple and tractable, and has stimulated productive research, it does not provide a very realistic representation of a wide range of the most important intertemporal trade-offs that people face in daily life. If one considers the most important and commonly discussed examples of intertemporal choices, a striking pattern emerges: in almost all cases, early outcomes tend to be concrete (e.g. purchasing this latte), but later outcomes tend to be much less tangible (e.g. the unknown item that could have been purchased later with the money spent on this latte). We propose that people rely on anticipatory emotions as a proxy for intangible outcomes when trade-offs are implicit. This paper reviews neuroeconomic evidence that has begun to elucidate the role of anticipatory emotions in decisions involving intangible outcomes. Although most progress has been made in the domain of spending and saving, we discuss how the existing neuroeconomic research could be extended to other domains where trade-offs are ill defined. PMID:18829432

Rick, Scott; Loewenstein, George

2008-12-12

391

Frontline: The Choice 2000  

NSDL National Science Digital Library

According to the polls, many Americans have yet to make up their minds about who they will vote for next Tuesday in the Presidential race. This Website could help them decide. The companion site to a recent two-hour Frontline special on the backgrounds and character of Al Gore and George W. Bush, The Choice offers the entire broadcast in RealPlayer as well as significant additional materials. Among these are issue briefs from Frontline on the candidates's stands on issues such as abortion, health care, education, the environment, campaign finance reform, and others, as well as supplemental video interviews with friends and family of the candidates and a photo gallery of both candidates from birth to the present. A Tools for Choice feature invites visitors to take a 20-question quiz to find out which candidate, including Nader and Buchanan, better reflects their views and offers links to NPR and Newshour stories about the "Nader Factor," the candidates's economic plans, the decision process for undecideds in the battleground state of Ohio, and a review of the candidates's Websites, entitled WWW.Dull.

392

Of Colored Numbers and Numbered Colors: Interactive Processes in Grapheme-Color Synesthesia  

Microsoft Academic Search

Grapheme-color synesthetes experience a specific color when they see a grapheme but they do not report to perceive a grapheme when a color is presented. In this study, we investigate whether color can still evoke number-processes even when a vivid number experience is absent. We used color-number and number-color priming, both revealing faster responses in congruent compared to incongruent conditions.

Titia Gebuis; Tanja C. W. Nijboer; Maarten J. van der Smagt

2009-01-01

393

Color and Camouflage  

NSDL National Science Digital Library

In this video, Jonathan explores how animals in the ocean use color, not just for camouflage, but to stand out. Please see the accompanying lesson plan for educational objectives, discussion points and classroom activities.

Productions, Jonathan B.

2012-03-01

394

Three Colors of Light  

NSDL National Science Digital Library

Have fun with additive mixing! Observe what happens when the three primary colors of light--red, green and blue--are mixed together, resulting in white light. This activity works best in a darkened room and requires adult supervision.

Museum Of Science And Industry, Chicago

2012-01-01

395

Colors of the Sky.  

ERIC Educational Resources Information Center

Explains the physical principles which result in various colors of the sky. Topics addressed include: blueness, mystical properties of water vapor, ozone, fluctuation theory of scattering, variation of purity and brightness, and red sunsets and sunrises. (DH)

Bohren, Craig F.; Fraser, Alistair B.

1985-01-01

396

Skin of Color  

MedlinePLUS

... a dermatologist. Skin cancer Anyone, regardless of skin color or ethnicity, can develop skin cancer, so it is important to practice sun safety. Melanoma, the deadliest form of skin cancer, can ...

397

Colorful Convection Currents  

NSDL National Science Digital Library

In this activity, students create artifical convection currents using hot and cold water, food coloring, and bottles. A materials list, instructions, and a brief explanation of the convection phenomenon are included.

398

'Jibsheet' in False Color  

NASA Technical Reports Server (NTRS)

NASA's Mars Exploration Rover Spirit drove up to this outcrop, called 'Jibsheet,' on the flank of 'Husband Hill,' in early March 2005. This view of Jibsheet by Spirit's panoramic camera is presented in false color.

2005-01-01

399

THE COLOR GLASS CONDENSATE.  

SciTech Connect

The Color Glass Condensate is a state of high density gluonic matter which controls the high energy limit of hadronic interactions. Its properties are important for the initial conditions for matter produced at RHIC.

MCLERRAN,L.

2001-08-26

400

Color Video Petrography.  

ERIC Educational Resources Information Center

Describes the production and use of color videocassettes with an inexpensive, conventional TV camera and an ordinary petrographic microscope. The videocassettes are used in optical mineralogy and petrology courses. (Author/WB)

Nagle, Frederick

1981-01-01

401

Chemistry, Color, and Art.  

ERIC Educational Resources Information Center

Describes pigments and artists' colors from a chronological perspective. Explains how chemical analysis can be used to distinguish the differences between artists' palettes, identify the evolution of art, and lead to restoration of an art work. (Contains 13 references.) (YDS)

Orna, Mary Virginia

2001-01-01

402

Crystalline color superconductors  

NASA Astrophysics Data System (ADS)

Inhomogeneous superconductors and inhomogeneous superfluids appear in a variety of contexts including quark matter at extreme densities, fermionic systems of cold atoms, type-II cuprates, and organic superconductors. In the present review the focus is on properties of quark matter at high baryonic density, which may exist in the interior of compact stars. The conditions realized in these stellar objects tend to disfavor standard symmetric BCS pairing and may favor an inhomogeneous color superconducting phase. The properties of inhomogeneous color superconductors are discussed in detail and in particular of crystalline color superconductors. The possible astrophysical signatures associated with the presence of crystalline color superconducting phases within the core of compact stars are also reviewed.

Anglani, Roberto; Casalbuoni, Roberto; Ciminale, Marco; Ippolito, Nicola; Gatto, Raoul; Mannarelli, Massimo; Ruggieri, Marco

2014-04-01

403

Ocean color measurements  

NASA Technical Reports Server (NTRS)

Ocean color observations by the Coastal Zone color scanner (CZCS) aboard the Nimbus-7 satellite are discussed, together with the factors contributing to the 'apparent' color of the ocean. The CZCS optical systems and the tecniques for extraction of the phytoplankton pigment concentration and the diffuse attenuation coefficient K from the 'apparent' water color are described in detail. Special consideration is given to the use of biooptical algorithms and the development of the K algorithm for the CZCS imagery. It is shown that under typical atmospheric conditions, the pigment concentration can be extracted from the satellite imagery to within + or - 30 percent over concentration ranges from 0 to 5 mg/cu m for the Morel case 1 water (Morel and Prieur, 1977), to which the oceanic waters belong as a rule.

Gordon, H. R.; Austin, R. W.; Clark, D. K.; Hovis, W. A.; Yentsch, C. S.

1985-01-01

404

Phoenix Color Targets  

NASA Technical Reports Server (NTRS)

These images of three Phoenix color targets were taken on sols 1 and 2 by the Surface Stereo Imager (SSI) on board the Phoenix lander. The bottom target was imaged in approximate color (SSI's red, green, and blue filters: 600, 530, and 480 nanometers), while the others were imaged with an infrared filter (750 nanometers). All of them will be imaged many times over the mission to monitor the color calibration of the camera. The two at the top show grains 2 to 3 millimeters in size that were likely lifted to the Phoenix deck during landing. Each of the large color chips on each target contains a strong magnet to protect the interior material from Mars' magnetic dust.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

2008-01-01

405

Color Theory Tutorial  

NSDL National Science Digital Library

Color theory has been worked on by a number of individuals over the years, and those with an interest in the field include artists, scientists, and of course, interior designers. Janet Ford, a web designer in Minneapolis, has been interested in this field for over a decade, and her website explores some of the issues surrounding color theory in a way that is both accessible and interesting. On the site, visitors can learn about the basics of color, complementary colors, and concepts such as contrast, dominance, proportion, and intensity. The site is rounded out by a very good âÂÂResourcesâ area, which contains a bibliography of recommended works drawn from the past several decades.

Ford, Janet

406

Developing a method for customized induction of flowering  

PubMed Central

Background The ability to induce flowering on demand is of significant biotechnological interest. FT protein has been recently identified as an important component of the mobile flowering hormone, florigen, whose function is conserved across the plant kingdom. We therefore focused on manipulation of both endogenous and heterologous FT genes to develop a floral induction system where flowering would be inhibited until it was induced on demand. The concept was tested in the model plant Arabidopsis thaliana (Arabidopsis). Results Our starting point was plants with strongly delayed flowering due to silencing of FT with an artificial microRNA directed at FT (amiR-FT) [1]. First, we showed that constitutive expression of a heterologous FT gene (FTa1), from the model legume Medicago truncatula, (Medicago) was able to rescue the amiR-FT late-flowering phenotype. In order to induce flowering in a controlled way, the FTa1 gene was then expressed under the control of an alcohol-inducible promoter in the late flowering amiR-FT plants. Upon exposure to ethanol, FTa1 was rapidly up regulated and this resulted in the synchronous induction of flowering. Conclusions We have thus demonstrated a controlled-inducible flowering system using a novel combination of endogenous and heterologous FT genes. The universal florigenic nature of FT suggests that this type of system should be applicable to crops of economic value where flowering control is desirable.

2011-01-01

407

The Colors of Light  

NSDL National Science Digital Library

This is an activity about the electromagnetic spectrum and how light is split into its component frequencies or colors. Using a diffraction grating, learners will observe four different light sources and sketch their spectra. This activity requires access to a sodium vapor or mercury vapor light and two neon signs of differing color, as well as diffraction grating material. This is Astronomy Activity 2 in the Space Update collection of activities.

408

Auroral Colors and Spectra  

NSDL National Science Digital Library

This site, co-produced by the NCAR High Altitude Observatory and the COMET Program, provides an explanation of how auroral colors are produced. The emission of specific colors of light is discussed in relation to oxygen and nitrogen emission spectra. Numerous images, graphs, and a video of an aurora are included. The site is part of "Physics of the Aurora: Earth Systems," an interactive learning module about the aurora.

2007-01-26

409

The lure of 'patient choice'  

PubMed Central

As primary care practitioners are the health professionals closest to patients' everyday lives, they are most likely to experience the impact of policies that support the patient choice agenda. The government's approach to increasing patient choice has been subject to criticism by those sceptical of its politics and by those concerned with its influence on health providers and some patient groups. A perspective missing from the debate is one informed by research on the psychology of choice. Some psychologists have argued that a seemingly inbuilt preference for choice can adversely affect the decision-making process and that presenting healthcare decisions as choices may result in less reasoned decision making. It is important that GPs encourage patients to make reasoned healthcare decisions that are informed by an evaluation of the options rather than by a simple preference for choice. Patients are likely to be less satisfied with, and experience more regret about, choices made without reasoning.

Bryant, Louise D; Bown, Nicola; Bekker, Hilary L; House, Allan

2007-01-01

410

Color planner for designers based on color emotions  

NASA Astrophysics Data System (ADS)

During the color perception process, an associated feeling or emotion is induced in our brains, and this kind of emotion is termed as 'color emotion.' The researchers in the field of color emotions have put many efforts in quantifying color emotions with the standard color specifications and evaluating the influence of hue, lightness and chroma to the color emotions of human beings. In this study, a color planner was derived according to these findings so that the correlation of color emotions and standard color specifications was clearly indicated. Since people of different nationalities usually have different color emotions as different cultural and traditional backgrounds, the subjects in this study were all native Hong Kong Chinese and the color emotion words were all written in Chinese language in the visual assessments. Through the color planner, the designers from different areas, no matter fashion, graphic, interior or web site etc., can select suitable colors for inducing target color emotions to the customers or product-users since different colors convey different meanings to them. In addition, the designers can enhance the functionality and increase the attractiveness of their designed products by selecting suitable colors.

Cheng, Ka-Man; Xin, John H.; Taylor, Gail

2002-06-01

411

Four soil color charts compared in CIELAB color space  

Microsoft Academic Search

Soil color charts, which contain standard color chips arranged following the Munsell system, are useful tools for visual assessment of soil color in the field and laboratory. Several editions of these charts, manufactured in USA and Japan, are used indifferently by soil scientists. One new and one old edition of both USA and Japanese soil color charts have been studied

Manuel SÁNCHEZ-MARAÑÓN; Rafael DELGADO; Encarnación GÁMIZ; Juan Manuel MARTÍN-GARCÍA; Rafael HUERTAS; Manuel MELGOSA

412

From Color Code to Color Cue: Remembering Graphic Information.  

ERIC Educational Resources Information Center

This paper reports on a study which was conducted to determine the impact of color on learning. The entire seventh-grade class from a Midwest junior high school was used in the study. Each student was randomly assigned into one of four treatment groups: (1) color-cued presentation, color-cued assessment; (2) color-cued presentation, black/white…

Pruisner, Peggy A. P.

413

Color Lens: Adaptive Color Scale Optimization for Visual Exploration  

Microsoft Academic Search

Visualization applications routinely map quantitative attributes to color using color scales. Although color is an effective visualization channel, it is limited by both display hardware and the human visual system. We propose a new interaction technique that overcomes these limitations by dynamically optimizing color scales based on a set of sampling lenses. The technique inspects the lens contents in data

Niklas Elmqvist; Pierre Dragicevic; Jean-Daniel Fekete

2011-01-01

414

Color-Blindness Study: Color Discrimination on the TICCIT System.  

National Technical Information Service (NTIS)

The question studied whether the specific seven TICCIT system colors used within color coding schemes can be a source of confusion, or not seen at all, by the color-blind segment of target populations. Subjects were 11 color-blind and three normally sight...

C. S. Asay E. W. Schneider

1974-01-01

415

Salicylic acid and the flowering gene FLOWERING LOCUS T homolog are involved in poor-nutrition stress-induced flowering of Pharbitis nil  

Microsoft Academic Search

The short-day plants Pharbitis nil (synonym Ipomoea nil), var. Violet and Tendan were grown in a diluted nutrient solution or tap water for 20 days under long-day conditions. Violet plants were induced to flower and vegetative growth was inhibited, whereas Tendan plants were not induced to flower, although vegetative growth was inhibited under these conditions. The Violet plants induced to

Kaede C. Wada; Mizuki Yamada; Takeshi Shiraya; Kiyotoshi Takeno

2010-01-01

416

Flowering Time Modulation by a Vacuolar SNARE via FLOWERING LOCUS C in Arabidopsis thaliana  

PubMed Central

The transition of plant growth from vegetative to reproductive phases is one of the most important and dramatic events during the plant life cycle. In Arabidopsis thaliana, flowering promotion involves at least four genetically defined regulatory pathways, including the photoperiod-dependent, vernalization-dependent, gibberellin-dependent, and autonomous promotion pathways. Among these regulatory pathways, the vernalization-dependent and autonomous pathways are integrated by the expression of FLOWERING LOCUS C (FLC), a negative regulator of flowering; however, the upstream regulation of this locus has not been fully understood. The SYP22 gene encodes a vacuolar SNARE protein that acts in vacuolar and endocytic trafficking pathways. Loss of SYP22 function was reported to lead to late flowering in A. thaliana plants, but the mechanism has remained completely unknown. In this study, we demonstrated that the late flowering phenotype of syp22 was due to elevated expression of FLC caused by impairment of the autonomous pathway. In addition, we investigated the DOC1/BIG pathway, which is also suggested to regulate vacuolar/endosomal trafficking. We found that elevated levels of FLC transcripts accumulated in the doc1-1 mutant, and that syp22 phenotypes were exaggerated with a double syp22 doc1-1 mutation. We further demonstrated that the elevated expression of FLC was suppressed by ara6-1, a mutation in the gene encoding plant-unique Rab GTPase involved in endosomal trafficking. Our results indicated that vacuolar and/or endocytic trafficking is involved in the FLC regulation of flowering time in A. thaliana.

Ebine, Kazuo; Uemura, Tomohiro; Nakano, Akihiko; Ueda, Takashi

2012-01-01

417

Appearance can be deceiving: using appearance models in color imaging  

NASA Astrophysics Data System (ADS)

As color imaging has evolved through the years, our toolset for understanding has similarly evolved. Research in color difference equations and uniform color spaces spawned tools such as CIELAB, which has had tremendous success over the years. Research on chromatic adaptation and other appearance phenomena then extended CIELAB to form the basis of color appearance models, such as CIECAM02. Color difference equations such as CIEDE2000 evolved to reconcile weaknesses in areas of the CIELAB space. Similarly, models such as S-CIELAB were developed to predict more spatially complex color difference calculations between images. Research in all of these fields is still going strong and there seems to be a trend towards unification of some of the tools, such as calculating color differences in a color appearance space. Along such lines, image appearance models have been developed that attempt to combine all of the above models and metric into one common framework. The goal is to allow the color imaging research to pick and choose the appropriate modeling toolset for their needs. Along these lines, the iCAM image appearance model framework was developed to study a variety of color imaging problems. These include image difference and image quality evaluations as well gamut mapping and high-dynamic range (HDR) rendering. It is important to stress that iCAM was not designed to be a complete color imaging solution, but rather a starting point for unifying models of color appearance, color difference, and spatial vision. As such the choice of model components is highly dependent on the problem being addressed. For example, with CIELAB it clearly evident that it is not necessary to use the associated color difference equations to have great success as a deviceindependent color space. Likewise, it may not be necessary to use the spatial filtering components of an image appearance model when performing image rendering. This paper attempts to shed some light on some of the confusions involved with selecting the desired components for color imaging research. The use of image appearance type models for calculating image differences, like S-CIELAB and those recommended by CIE TC8-02 will be discussed. Similarly the use of image appearance for HDR applications, as studied by CIE TC8-08, will also be examined. As with any large project, the easiest way to success is in understanding and selecting the right tool for the job.

Johnson, Garrett M.

2007-01-01

418

Making Healthy Food Choices  

NSDL National Science Digital Library

Objective: Students will see that food advertisements may not be the best information to use when deciding what to eat. They will investigate several resources for good information about foods and nutrition. Allow several weeks to complete this unit. UEN Core CurriculumStandard 1 Students will develop a sense of self. Objective 1 Describe and practice responsible behaviors for health and safety. a. Practice appropriate personal hygiene (e.g., bathe, wash hands, clean clothes). b. Describe the benefits of eating a variety of nutritious foods. c. Describe the benefits of physical activity. d. Describe substances that are helpful and harmful to the body. e. Practice basic safety and identify hazards. Making Healthy Food Choices #1 Task Definition - ...

Fox, Miss

2011-12-15

419

Color preferences are not universal.  

PubMed

Claims of universality pervade color preference research. It has been argued that there are universal preferences for some colors over others (e.g., Eysenck, 1941), universal sex differences (e.g., Hurlbert & Ling, 2007), and universal mechanisms or dimensions that govern these preferences (e.g., Palmer & Schloss, 2010). However, there have been surprisingly few cross-cultural investigations of color preference and none from nonindustrialized societies that are relatively free from the common influence of global consumer culture. Here, we compare the color preferences of British adults to those of Himba adults who belong to a nonindustrialized culture in rural Namibia. British and Himba color preferences are found to share few characteristics, and Himba color preferences display none of the so-called "universal" patterns or sex differences. Several significant predictors of color preference are identified, such as cone-contrast between stimulus and background (Hurlbert & Ling, 2007), the valence of color-associated objects (Palmer & Schloss, 2010), and the colorfulness of the color. However, the relationship of these predictors to color preference was strikingly different for the two cultures. No one model of color preference is able to account for both British and Himba color preferences. We suggest that not only do patterns of color preference vary across individuals and groups but the underlying mechanisms and dimensions of color preference vary as well. The findings have implications for broader debate on the extent to which our perception and experience of color is culturally relative or universally constrained. PMID:23148465

Taylor, Chloe; Clifford, Alexandra; Franklin, Anna

2013-11-01

420

How Safe Are Color Additives?  

MedlinePLUS

... Here are more facts you should know about color additive safety. FDA regulates color additives used in the United ... must comply with regulatory requirements. Both types of color additives are subject to rigorous safety standards. Approval of a color additive for one ...

421

The Color Preferences of Children  

Microsoft Academic Search

The object of the investigation was to determine (1) whether certain colors are per se and generally pleasing, (2) whether color preference varies with increase in age and intellectual development, (3) whether the colors preferred during the adolescent period differ from those preferred during the pre-adolescent period, (4) whether social status is a determining factor in the preference for colors,

S. E. Katz; F. S. Breed

1922-01-01

422

Identification of Colors for Building.  

ERIC Educational Resources Information Center

A demonstration of how colors may be specified for use by all those trades and professions involved in building science. This is of vital importance in furthering the use of color, not only in structures but in every other aspect of our daily usage. Free enterprise requires a color language in order to expand the use of color, and to allow for…

Building Research Inst., Inc., Washington, DC.

423

Color scales for image data  

Microsoft Academic Search

Desirable properties of color scales are examined, and a linearized optimal color scale (LOCS) is introduced. The merits of color scales for medical image data were studied, and it was found that, in tests, although observers performed somewhat better with the newly developed LOCS than with the previously advocated heated-object color scale, they performed significantly better with a linearized gray

Haim Levkowitz; Gabor T. Herman

1992-01-01

424

Acceleration of Flowering during Shade Avoidance in Arabidopsis Alters the Balance between FLOWERING LOCUS C-Mediated Repression and Photoperiodic Induction of Flowering1[W][OA  

PubMed Central

The timing of the floral transition in Arabidopsis (Arabidopsis thaliana) is influenced by a number of environmental signals. Here, we have focused on acceleration of flowering in response to vegetative shade, a condition that is perceived as a decrease in the ratio of red to far-red radiation. We have investigated the contributions of several known flowering-time pathways to this acceleration. The vernalization pathway promotes flowering in response to extended cold via transcriptional repression of the floral inhibitor FLOWERING LOCUS C (FLC); we found that a low red to far-red ratio, unlike cold treatment, lessened the effects of FLC despite continued FLC expression. A low red to far-red ratio required the photoperiod-pathway genes GIGANTEA (GI) and CONSTANS (CO) to fully accelerate flowering in long days and did not promote flowering in short days. Together, these results suggest a model in which far-red enrichment can bypass FLC-mediated late flowering by shifting the balance between FLC-mediated repression and photoperiodic induction of flowering to favor the latter. The extent of this shift was dependent upon environmental parameters, such as the length of far-red exposure. At the molecular level, we found that far-red enrichment generated a phase delay in GI expression and enhanced CO expression and activity at both dawn and dusk. Finally, our analysis of the contribution of PHYTOCHROME AND FLOWERING TIME1 (PFT1) to shade-mediated rapid flowering has led us to suggest a new model for the involvement of PFT1 in light signaling.

Wollenberg, Amanda C.; Strasser, Barbara; Cerdan, Pablo D.; Amasino, Richard M.

2008-01-01

425

Reliable detection of LSB steganography in color and grayscale images  

US Patent & Trademark Office Database

A system and method that efficiently, accurately, and simply detect reliably least-significant-bit ("LSB") embedding of a secret message in randomly scattered pixels. The system and method apply to both 24-bit color images and 8-bit grayscale or color images. Many commercial steganographic programs use Least Significant Bit embedding (LSB) as the method of choice to hide messages in 24-bit, 8-bit color images and in grayscale images. They do so based on the common belief that changes to the LSBs of colors cannot be detected because of noise that is always present in digital images. By inspecting the differences in capacity for lossless (invertible) embedding in the LSB and the shifted LSB plane, the present invention reliably detects messages as short as 1% of the total number of pixels (assuming 1 bit per sample). The system and method of the present invention are fast, and they provide accurate estimates for the length of the embedded secret message.

2004-12-14

426

Color holography using the angular selectivity of volume recording media  

NASA Astrophysics Data System (ADS)

A display hologram of an object can be recorded and reconstructed in three primary colors if the angular selectivity of volume recording media is exploited. Three holograms are recorded in the same medium, each at a different primary color. These three holograms are reconstructed by simultaneous illumination of the hologram with the original reference beams. By proper choice of the angles that the reference beams make to the hologram, it is possible to suppress strongly cross talk between the different reconstructions (e.g., the red object reconstruction in green light). The technique exhibits high resolution, high diffraction efficiency, and vivid colors. Through the addition of three holographically recorded volume gratings it is possible to reconstruct the hologram with a beam of white light. The saturation and brightness of each primary color in the reconstruction can be adjusted by selection of an appropriate thickness for the corresponding grating.

Zhu, Peiping; Xu, Zhizhan; Liu, Xinsen

1995-02-01

427

Color rendering of color camera data  

NASA Technical Reports Server (NTRS)

Conditions under which a computational procedure can be applied to arbitrary camera sensors to permit estimation of the human photoreceptor response are considered. The adopted procedures recover the effective surface reflectance at the time of measurement, and the reflectance estimates depend not only on the surface, but upon the viewing geometry. The present method for color rendering assumes that the observer's state of adaptation at the time of viewing the original and the rendered images is the same. The analysis aids in specifying which classes of surfaces are required to be accurately rendered, and for which surfaces some error can be tolerated.

Wandell, Brian A.

1986-01-01

428

Effect of storage temperature on the quality of edible flowers  

Microsoft Academic Search

Five species of edible flowers were stored in polyethylene bags at ?2.5 to 20°C. Flowers were rated for visual quality each day for 2 weeks on a scale of 1–5 (5 being the highest quality). Viola tricolor L. ‘Helen Mount’ (viola), V. ×wittrockiana L. ‘Accord Banner Clear Mixture’ (pansy), and Tropaeolum majus L. ‘Jewel Mix’ (nasturtium) flowers showed similar losses

Kathleen M. Kelley; Arthur C. Cameron; John A. Biernbaum; Kenneth L. Poff

2003-01-01

429

Volatiles From Leaves and Flowers of Borage (Borago officinalis L.)  

Microsoft Academic Search

The essential oils obtained from the fresh leaves and flowers of Borago officinalis collected in the region of Amdoun (northwestern Tunisia) were examined by GC and GC\\/MS. Twenty-three volatile compounds were identified. The oil yields expressed on a dry weight basis were 0.14% and 0.24% for the leaves and flowers, respectively. The main compound determined in flower and leaf oil

Baya Mhamdi; Wissem A. Wannes; Wissal Dhiffi; Brahim Marzouk

2009-01-01

430

Hydrocarbon Footprints as a Record of Bumblebee Flower Visitation  

Microsoft Academic Search

Bumblebees leave traces of cuticular hydrocarbons on flowers they visit, with the amount deposited being positively related\\u000a to the number of visits. We asked whether such footprint hydrocarbons are retained on flowers for sufficiently long periods\\u000a of time so as to reflect bee visitation in pollination studies. In laboratory experiments, flower corollae (Primula veris, Digitalis grandiflora) visited by Bombus terrestris

Sebastian Witjes; Thomas Eltz

2009-01-01

431

1-Methylcyclopropene inhibits ethylene action in cut phlox flowers  

Microsoft Academic Search

Phlox (Phlox paniculata cv. Rembrandt) flowers were found to be very sensitive to ethylene. Exposure to ethylene enhanced flower abscission in a concentration-dependent manner, with 50% abscission attained after treatment with 1 ?l l?1 ethylene for 12 h. As a result, ethylene also reduced the number of open flowers on the stems throughout their vase life. A 6-h pre-treatment with

Ron Porat; Eitan Shlomo; Margrethe Serek; Edward C. Sisler; Amihud Borochov

1995-01-01

432

Transcriptomic analysis of flower development in wintersweet (Chimonanthus praecox).  

PubMed

Wintersweet (Chimonanthus praecox) is familiar as a garden plant and woody ornamental flower. On account of its unique flowering time and strong fragrance, it has a high ornamental and economic value. Despite a long history of human cultivation, our understanding of wintersweet genetics and molecular biology remains scant, reflecting a lack of basic genomic and transcriptomic data. In this study, we assembled three cDNA libraries, from three successive stages in flower development, designated as the flower bud with displayed petal, open flower and senescing flower stages. Using the Illumina RNA-Seq method, we obtained 21,412,928, 26,950,404, 24,912,954 qualified Illumina reads, respectively, for the three successive stages. The pooled reads from all three libraries were then assembled into 106,995 transcripts, 51,793 of which were annotated in the NCBI non-redundant protein database. Of these annotated sequences, 32,649 and 21,893 transcripts were assigned to gene ontology categories and clusters of orthologous groups, respectively. We could map 15,587 transcripts onto 312 pathways using the Kyoto Encyclopedia of Genes and Genomes pathway database. Based on these transcriptomic data, we obtained a large number of candidate genes that were differentially expressed at the open flower and senescing flower stages. An analysis of differentially expressed genes involved in plant hormone signal transduction pathways indicated that although flower opening and senescence may be independent of the ethylene signaling pathway in wintersweet, salicylic acid may be involved in the regulation of flower senescence. We also succeeded in isolating key genes of floral scent biosynthesis and proposed a biosynthetic pathway for monoterpenes and sesquiterpenes in wintersweet flowers, based on the annotated sequences. This comprehensive transcriptomic analysis presents fundamental information on the genes and pathways which are involved in flower development in wintersweet. And our data provided a useful database for further research of wintersweet and other Calycanthaceae family plants. PMID:24489818

Liu, Daofeng; Sui, Shunzhao; Ma, Jing; Li, Zhineng; Guo, Yulong; Luo, Dengpan; Yang, Jianfeng; Li, Mingyang

2014-01-01

433

Milk Thistle, Silybum marianum (L.) Gaertn., Flower Head Development and Associated Marker Compound Profile  

Microsoft Academic Search

Flower head development and marker compound changes were examined for milk thistle grown under dryland conditions during the 1998 and 1999 growing seasons. Flower heads harvested at the early flowering, mid-flowering, late flowering, and dehiscing (seed development) growth stages had average seed\\/ovule weights of 5 mg, 13 mg, 21 mg, and 26 mg, respectively. At the time of harvest, the

Danielle Julie Carrier; Trever Crowe; Shahab Sokhansanj; Jazeem Wahab; Branka Barl

2003-01-01

434

Record-Breaking Early Flowering in the Eastern United States  

PubMed Central

Flowering times are well-documented indicators of the ecological effects of climate change and are linked to numerous ecosystem processes and trophic interactions. Dozens of studies have shown that flowering times for many spring-flowering plants have become earlier as a result of recent climate change, but it is uncertain if flowering times will continue to advance as temperatures rise. Here, we used long-term flowering records initiated by Henry David Thoreau in 1852 and Aldo Leopold in 1935 to investigate this question. Our analyses demonstrate that record-breaking spring temperatures in 2010 and 2012 in Massachusetts, USA, and 2012 in Wisconsin, USA, resulted in the earliest flowering times in recorded history for dozens of spring-flowering plants of the eastern United States. These dramatic advances in spring flowering were successfully predicted by historical relationships between flowering and spring temperature spanning up to 161 years of ecological change. These results demonstrate that numerous temperate plant species have yet to show obvious signs of physiological constraints on phenological advancement in the face of climate change.

Ellwood, Elizabeth R.; Temple, Stanley A.; Primack, Richard B.; Davis, Charles C.

2013-01-01

435

Edge-Based Color Constancy  

Microsoft Academic Search

Color constancy is the ability to measure colors of objects independent of the color of the light source. A well-known color constancy method is based on the Grey-World assumption which assumes that the average reflectance of surfaces in the world is achromatic. In this article, we propose a new hypothesis for color constancy namely the Grey-Edge hypothesis, which assumes that

Joost Van De Weijer; Theo Gevers; Arjan Gijsenij

2007-01-01

436

Children's Emotional Associations with Colors  

Microsoft Academic Search

In this study children's emotional associations with colors were investigated. Sixty children (30 girls, 30 boys), equally divided into groups of 5-year-olds and 6 1\\/2-year-olds, were asked their favorite color and were then shown nine different colors, one at a time and in a random order. For each color, children were asked, “How does (the color) make you feel?” All

Chris J. Boyatzis; Reenu Varghese

1994-01-01

437

Sloan Digital Sky Survey - Color  

NSDL National Science Digital Library

This project, authored by the Sloan Digital Sky Survey (SDSS), shows the user the importance of a color-color diagram, which allows to identify a star as a thermal source or not. First it establishes a theoretical foundation by explaining the magnitude system, defining color, black body radiation and the nature of light. Using the SDSS data, the user can obtain star properties and plot a color-color diagram.

2010-08-10

438

The Inherent Reward of Choice  

PubMed Central

Research suggests that the exercise of control is desirable and adaptive, but the precise mechanisms underlying the value of control are not well understood. The current study characterizes the affective experience of personal control by examining the neural substrates recruited when anticipating the opportunity for choice, the means by which individuals exercise control. Using an experimental paradigm that probed the value of choice, participants reported liking cues that predicted future choice opportunity more than cues predicting no-choice. Anticipation of choice itself was associated with increased activity in corticostriatal regions involved in affective and motivational processes, particularly the ventral striatum. This study provides the first direct examination of the affective value of having the opportunity to choose. These findings have important implications for understanding the role of perception of control, and choice itself, in self-regulatory processes.

Leotti, Lauren A.; Delgado, Mauricio R.

2012-01-01

439

Colors of Centaurs  

NASA Astrophysics Data System (ADS)

Minor planets on outer planet-crossing orbits, called Centaur objects, are important members of the solar system in that they dynamically link Kuiper belt objects to Jupiter-family comets. In addition, perhaps 6% of near-Earth objects have histories as Centaur objects. The total mass of Centaurs (10-4&) Earth masses) is significant, about one-tenth of the mass of the asteroid belt. Centaur objects exhibit a physical property not seen among any other objects in the solar system; their B-R colors divide into two distinct populations: a gray and a red population. Application of the dip test to B-R colors in the literature indicates there is a 99.5% probability that Centaurs exhibit a bimodal color distribution. Although there are hints that gray and red Centaurs exhibit different orbital elements, application of the Wilcoxon rank sum test finds no statistically significant difference between the orbital elements of the two color groups. On theother hand, gray and red Centaurs exhibit a statistically significant difference in albedo, with the gray Centaurs having a lower median albedo than the red Centaurs. Further observational and dynamical work is necessary to determine whether the two color populations are the result of (1) evolutionary processes such as radiation-reddening, collisions, and sublimation or (2) a primordial, temperature-induced, composition gradient.

Tegler, S. C.; Bauer, J. M.; Romanishin, W.; Peixinho, N.

440

Natural soil microbes alter flowering phenology and the intensity of selection on flowering time in a wild Arabidopsis relative.  

PubMed

Plant phenology is known to depend on many different environmental variables, but soil microbial communities have rarely been acknowledged as possible drivers of flowering time. Here, we tested separately the effects of four naturally occurring soil microbiomes and their constituent soil chemistries on flowering phenology and reproductive fitness of Boechera stricta, a wild relative of Arabidopsis. Flowering time was sensitive to both microbes and the abiotic properties of different soils; varying soil microbiota also altered patterns of selection on flowering time. Thus, soil microbes potentially contribute to phenotypic plasticity of flowering time and to differential selection observed between habitats. We also describe a method to dissect the microbiome into single axes of variation that can help identify candidate organisms whose abundance in soil correlates with flowering time. This approach is broadly applicable to search for microbial community members that alter biological characteristics of interest. PMID:24698177

Wagner, Maggie R; Lundberg, Derek S; Coleman-Derr, Devin; Tringe, Susannah G; Dangl, Jeffery L; Mitchell-Olds, Thomas

2014-06-01

441

Color Memory of University Students: Influence of Color Experience and Color Characteristic  

ERIC Educational Resources Information Center

The ability to select a previously viewed color specimen from an array of specimens that differ in hue, value, or chroma varies among individuals, and may be related to one's basic color discrimination ability or to prior experience with color. This study investigated short-term color memory of 40 college students, 20 of whom were interior design…

Bynum, Carlisle; Epps, Helen H.; Kaya, Naz

2006-01-01

442

Behavioral frontiers in choice modeling  

Microsoft Academic Search

We review the discussion at a workshop whose goal was to achieve a better integration among behavioral, economic, and statistical\\u000a approaches to choice modeling. The workshop explored how current approaches to the specification, estimation, and application\\u000a of choice models might be improved to better capture the diversity of processes that are postulated to explain how consumers\\u000a make choices. Some specific

Wiktor Adamowicz; David Bunch; Trudy Ann Cameron; Benedict G. C. Dellaert; Michael Hanneman; Michael Keane; Jordan Louviere; Robert Meyer; Thomas Steenburgh; Joffre Swait

2008-01-01

443

Color preferences revealed by statistical color rendition metric  

NASA Astrophysics Data System (ADS)

The color rendition engine based on the statistical metric allows us to uniquely quantify the characteristics of color quality of illumination and assess the color rendition preferences. We now report on using the color rendition engine for revealing individual and cultural differences in color quality preferences of 205 American and Chinese subjects. Our study demonstrated that the majority of individuals preferred the color blend with the same statistical figures of merit on the average but with a much larger spread of blends for Americans. For both groups, the color rendition preferences depended on the object being illuminated. This was demonstrated by illuminating a set of common colored objects and three different paintings. We conclude that the color quality of lighting can be optimized and enhanced using the feedback to change the spectral power distribution of the illuminating source depending on the object being illuminated and on the preferences of an individual observer and a cultural group.

Liu, Anqing; Tuzikas, ArÅ«nas; Žukauskas, ArtÅ«ras; Vaicekauskas, Rimantas; Vitta, Pranciškus; Shur, Michael

2013-09-01

444

A novel color mapping method for preferred color reproduction  

NASA Astrophysics Data System (ADS)

We propose a novel color mapping method that generates smooth color transition and can accommodate the color preference. The method consists of two stages; rough calibration and black generation. The rough calibration process generates a three dimensional (3-D) Look-Up-Table converting input RGB data to printable CMY values. When the 3-D LUT is created, a new intent for color mapping, target color is internally used. The target color is predefined from a reference color book based on the color preferences of testers involved in the target definition phase. All of the input data of the 3-D LUT are mapped to the printable values in a printer based on the target color, and then simply converted to CMYK values. We evaluated the proposed algorithm comparing with a commercial printer profiler and found that the proposed algorithm makes better printing quality.

Kim, Kyeong Man; Oh, Hyun Soo; Kim, Sang Ho; Choi, Don Chul

2007-01-01

445

Color removal method of considering distance in color space  

NASA Astrophysics Data System (ADS)

In a color-to-gray conversion, which only considers lightness components, difference of colors are not appropriately reflected in monochrome images. Gooch et al. have proposed a color removal method that considers the differences of colors. Although the method can obtain good results in many cases, there is room for improvement. In this paper, a new color removal method that introduces a weight to Gooch's algorithm is proposed. In the proposed method, for combinations of colors of each pixel in an input image, weights are determined by distance in color space. In the proposed method, unimportant color combinations are not considered by weight and color information in an input image is appropriately reflected in a monochrome image. The validity of the proposed method is shown by experiments using some images.

Bao, Shi; Tanaka, Go

2014-03-01

446

Desert star (Monoptilon bellioides) flowers in bloom.  

NSDL National Science Digital Library

Desert star (Monoptilon bellioides) flowers in bloom. Desert star is an annual plant that grows in very arid regions of the southwestern United States. Desert star and other desert annuals may delay germination of some of their seeds in a bet-hedging strategy that maximizes their chances of reproductive success in a variable environment. By producing a subset of dormant seeds, plants increase the odds that some seeds will germinate in a year with conditions (such as higher rainfall amount) favorable for growth and reproduction. This photograph originally appeared on the cover of Ecology (88:5) in May of 2007.

Venable, D. L.

2010-02-12

447

[Chemical constituents from flowers of Chrysanthemum indicum].  

PubMed

Thirteen compounds were isolated from the flowers of Chrysanthemum indicum by chromatographic techniques. Their structures were elucidated by spectroscopic methods as acacetin-7-0-beta-D-glucopyranoside (1), luteolin (2), luteolin-7-O-beta-D-glucopyranoside (3), acaciin (4), acacetin 7-0-(6"-0-alpha-L-rhamnopyranosyl)-beta-sophoroside (5), 3-0-caffeoylquinic acid (6), syringaresinol 0-beta-D-glucopyranoside (7), 5,7-dihydroxychromone (8), uracil (9), p-hydroxybenzoic acid (10), 4-0-beta-D-glucopyranosyloxybenzoic acid (11), boscialin (12), blumenol A (13). Compounds 5, 7, 8, 11-13 were isolated from C. indicum for the first time. PMID:21438395

Feng, Ziming; Yang, Yanan; Jiang, Jianshuang; Zhang, Peicheng

2010-12-01

448

Medicinal flowers. XXX. Eight new glycosides, everlastosides F-M, from the flowers of Helichrysum arenarium.  

PubMed

Eight new glycosides, everlastosides F (1), G (2), H (3), I (4), J (5), K (6), L (7), and M (8), were isolated from the methanolic extract of the flowers of Helichrysum arenarium. Their structures were elucidated on the basis of chemical and physicochemical evidence. PMID:19652412

Morikawa, Toshio; Wang, Li-Bo; Ninomiya, Kiyofumi; Nakamura, Seikou; Matsuda, Hisashi; Muraoka, Osamu; Wu, Li-Jun; Yoshikawa, Masayuki

2009-08-01

449

Assessing the suitability of flowering herbs as parasitoid food sources: flower attractiveness and nectar accessibility  

Microsoft Academic Search

Eleven insect-pollinated plant species were investigated with respect to their olfactory attractiveness and nectar accessibility for the parasitoid species Cotesia glomerata (Hymenoptera: Braconidae), Heterospilus prosopidis (Hymenoptera: Braconidae), and Pimpla turionellae (Hymenoptera: Ichneumonidae). Flowers differed considerably with respect to both their attractiveness and nectar accessibility. The results obtained from the three parasitoid species, on the other hand, showed a high level

F. L. Wäckers

2004-01-01

450

Sustainable flower bulb production: prototyping integrated flower bulb production systems on sandy soils in The Netherlands  

Microsoft Academic Search

Flower bulb production in The Netherlands is economically successful. However, production methods rely heavily on external inputs, causing contamination of surface and ground water. The use of pesticides has been estimated 100 kg active ingredient (a.i.) per ha in 1994. In the same year the annual use of nitrogen and phosphate was 310 and 130 kg per ha respectively. Over

J. E. Jansma; A. J. Snoek; M. J. Wondergem

2002-01-01

451

SINGLE FLOWER TRUSS regulates the transition and maintenance of flowering in tomato  

Microsoft Academic Search

The characterisation of the single flower truss ( sft) mutant phenotype of tomato ( Lycopersicon esculentum Mill.), as well as its genetic interactions with other mutations affecting FALSIFLORA ( FA) and SELF PRUNING ( SP) genes, has revealed that SFT is a key gene in the control of floral transition and floral meristem identity. The single sft mutation produces a

Nuria Molinero-Rosales; Antonio Latorre; Manuel Jamilena; Rafael Lozano

2004-01-01

452

Sexual allocation in single-flowered hermaphroditic individuals in relation to plant and flower size  

Microsoft Academic Search

Gender expression in hermaphroditic plant species usually departs from strict equisexuality. Study of those departures can aid understanding of non hermaphroditic breeding systems and prevalence of hermaphroditism within angiosperms. Plant size is one of the most studied factors in relation to gender modification. We studied variation in gender expression in the hermaphroditic, mostly single-flowered Paeonia cambessedesii. We separately studied gender

Marcos Méndez; Anna Traveset

2003-01-01

453

School Choice 2000 Annual Report  

NSDL National Science Digital Library

This online version of the Heritage Foundation's annual report on school choice provides a substantive, if somewhat biased, state-by-state report on political, judicial, communal, and education developments linked to the issues of school choice. Each state's profile gives a status report on the numbers of charter schools and publicly funded private school choices as well as data on enrollment, expenditures, and results on the National Assessment of Educational Progress (NAEP, see the October 1, 1999 Scout Report). A background report, complete with developments in 1999 and 2000, is also posted for each state. The report's introduction was written by Florida governor and school choice advocate Jeb Bush.

2000-01-01

454

Career choices of lesbian women.  

PubMed

I focus on lesbian women's career choices and analyse how they explain their choices in relation to their sexuality. In addition to personal accounts and experiences, I use survey data that shows that several factors influence lesbian women's occupational circumstances. The Sexual Minority Survey included 726 respondents, of which 415 are women. The survey was conducted as part of the project Sexual and Gender Minorities at Work. Although many lesbian women claim that their sexuality did not influence their career choices, their career choice processes seem to be linked in many ways with sexuality, gender, and heteronormativity in society. PMID:19042296

Lehtonen, Jukka

2008-01-01

455

Crystalline color superconductivity  

SciTech Connect

In any context in which color superconductivity arises in nature, it is likely to involve pairing between species of quarks with differing chemical potentials. For suitable values of the differences between chemical potentials, Cooper pairs with nonzero total momentum are favored, as was first realized by Larkin, Ovchinnikov, Fulde, and Ferrell (LOFF). Condensates of this sort spontaneously break translational and rotational invariance, leading to gaps which vary periodically in a crystalline pattern. Unlike the original LOFF state, these crystalline quark matter condensates include both spin-zero and spin-one Cooper pairs. We explore the range of parameters for which crystalline color superconductivity arises in the QCD phase diagram. If in some shell within the quark matter core of a neutron star (or within a strange quark star) the quark number densities are such that crystalline color superconductivity arises, rotational vortices may be pinned in this shell, making it a locus for glitch phenomena.

Alford, Mark; Bowers, Jeffrey A.; Rajagopal, Krishna

2001-04-01

456

A pseudoisochromatic test of color vision for human infants.  

PubMed

Despite the development of experimental methods capable of measuring early human color vision, we still lack a procedure comparable to those used to diagnose the well-identified congenital and acquired color vision anomalies in older children, adults, and clinical patients. In this study, we modified a pseudoisochromatic test to make it more suitable for young infants. Using a forced choice preferential looking procedure, 216 3-to-23-mo-old babies were tested with pseudoisochromatic targets that fell on either a red/green or a blue/yellow dichromatic confusion axis. For comparison, 220 color-normal adults and 22 color-deficient adults were also tested. Results showed that all babies and adults passed the blue/yellow target but many of the younger infants failed the red/green target, likely due to the interaction of the lingering immaturities within the visual system and the small CIE vector distance within the red/green plate. However, older (17-23 mo) infants, color- normal adults and color-defective adults all performed according to expectation. Interestingly, performance on the red/green plate was better among female infants, well exceeding the expected rate of genetic dimorphism between genders. Overall, with some further modification, the test serves as a promising tool for the detection of early color vision anomalies in early human life. PMID:24768799

Mercer, Michele E; Drodge, Suzanne C; Courage, Mary L; Adams, Russell J

2014-07-01

457

Emotion-regulation choice.  

PubMed

Despite centuries of speculation about how to manage negative emotions, little is actually known about which emotion-regulation strategies people choose to use when confronted with negative situations of varying intensity. On the basis of a new process conception of emotion regulation, we hypothesized that in low-intensity negative situations, people would show a relative preference to choose to regulate emotions by engagement reappraisal, which allows emotional processing. However, we expected people in high-intensity negative situations to show a relative preference to choose to regulate emotions by disengagement distraction, which blocks emotional processing at an early stage before it gathers force. In three experiments, we created emotional contexts that varied in intensity, using either emotional pictures (Experiments 1 and 2) or unpredictable electric stimulation (Experiment 3). In response to these emotional contexts, participants chose between using either reappraisal or distraction as an emotion-regulation strategy. Results in all experiments supported our hypothesis. This pattern in the choice of emotion-regulation strategies has important implications for the understanding of healthy adaptation. PMID:21960251

Sheppes, Gal; Scheibe, Susanne; Suri, Gaurav; Gross, James J

2011-11-01

458

3 TABU SEARCH FOR GRAPH COLORING, T-COLORINGS AND SET T-COLORINGS  

Microsoft Academic Search

In this paper, a generic tabu search is presented for three coloring problems: graph coloring, T-colorings and set T-colorings. This algorithm inte- grates important features such as greedy initialization, solution re-generation, dynamic tabu tenure, incremental evaluation of solutions and constraint han- dling techniques. Empirical comparisons show that this algorithm approaches the best coloring algorithms and outperforms some hybrid algorithms on

Raphael Dorne; Jin-Kao Hao

1998-01-01

459

Contact-type color image sensor using color phototransistors  

NASA Astrophysics Data System (ADS)

We have developed a contact-type color image sensor for use in color scanners and color copy machines. This sensor features a high-precision array of phototransistor chips fitted with RGB color filters. It scans an A4-size document in 10 seconds with a high resolution 400 DPI. This sensor is compact and easy to use, and does not require special sensor drivers, a read-position compensation memory or spurious color suppression circuit. A color image sensor, rod lens array, fluorescent lamp, and drive circuit board are built in.

Hamaguchi, Tadahiko; Takeda, Takashi; Sato, Tsuneo; Katoh, Masatoshi; Nagata, Yoshihiro

1994-05-01

460

Color optical biopsy  

NASA Astrophysics Data System (ADS)

Progress has been made towards the development of a flexible true color holographic imaging device for direct optical biopsy. This can potentially be used for surgical techniques employing direct visualization, including endoscopy and laparoscopy. A novel panchromatic `ultrahigh precision' recording media, with a thin layer of ultrafine grain of silver halide crystals of 10-20 nm average diameter, has been utilized. The significance of the development so far, has been the ability to emulate `color optical biopsy' providing useful information of `medical relevance'.

Osanlou, Ardieshir; Bjelkhagen, Hans I.; Snashall, Emma; Osanlou, Orod; Osanlou, Rostam

2014-02-01

461

Hybrid color holograms  

NASA Astrophysics Data System (ADS)

The familiar optically recorded rainbow hologram is frequently used to produce color holograms. It is simple to compute the corresponding synthetic hologram structures, which would require no recording process and would be capable of displaying virtual three-dimensional objects. It is difficult, however, to materialize the computed structures because of the high space-bandwidth product required. To find a way around this problem we used a set of three computer-generated holograms as master holograms for an optical recording process in which each master hologram contains information about a different color. This reduces the space-bandwidth product requirements for the synthetic structures to convenient values.

Wesskamp, Bernhard; Jendral, Andreas; Bryngdahl, Olof

1996-11-01

462

Red-green color vision in three catarrhine primates  

PubMed Central

The evolution of the red-green visual subsystem in trichromatic primates has been linked to foraging advantages, specifically the detection of either ripe fruits or young leaves amid mature foliage, and to the intraspecific socio-sexual communication, namely the signal of the male rank, the mate choice and the reproductive strategies in females. New data should be added to the debate regarding the evolution of trichromatic color vision. Three catarrhine primates were observed to achieve this goal. The research was performed on captive groups of vervet monkeys (Chlorocebus aethiops), pig-tailed macaques (Macaca nemestrina) and chimpanzees (Pan troglodytes) housed at Parco Natura Viva - Garda Zoological Park (Italy). Using pairs of red-green bags containing the same hidden reward in comparable outdoor enclosures, we recorded the choices by observed individuals (n = 25) to investigate the role of color cues in choosing an object. The results indicate that chimpanzees used red color as cue to choose an object that contains food by showing a preference toward red objects; in contrast, vervet monkeys and pig-tailed macaques do not demonstrate a clear choice based on the color of the object. Our findings highlight the importance of the foraging hypothesis but not rule out the potential role of the intraspecific socio-sexual communication and may serve to add useful information to the debate regarding the adaptive value of the evolution of color vision in order to fill a phylogenetic gap from Old World monkeys to humans. Future studies should address the role of socio-sexual communication, such as the selection of the reproductive partner of both high genetic quality and with compatible genes, to determine how this influenced the evolution of color vision in non-human primates.

Fornale, Francesca; Vaglio, Stefano; Spiezio, Caterina; Previde, Emanuela Prato

2012-01-01

463

Ray florets color and shape mutants induced by 12C 5+ ion beam irradiation in chrysanthemum  

Microsoft Academic Search

Ion beam irradiation is attracting attention in floriculture as a means of inducing mutations. We investigated the effect of ion beam irradiation on induction of ray florets color\\/shape mutants from two strains of chrysanthemum to create new flower cultivars. The ray florets and leaf explants of chrysanthemum cultivars, ‘Shiroyamate’ and ‘H13’, respectively, cultured on MS medium were irradiated with 12C5+

Atsushi Matsumura; Toshikazu Nomizu; Noriyuki Furutani; Ken Hayashi; Yasuhiro Minamiyama; Yoshihiro Hase

2010-01-01

464

CONSTANS is a photoperiod regulated activator of flowering in sorghum  

PubMed Central

Background Sorghum genotypes used for grain production in temperate regions are photoperiod insensitive and flower early avoiding adverse environments during the reproductive phase. In contrast, energy sorghum hybrids are highly photoperiod sensitive with extended vegetative phases in long days, resulting in enhanced biomass accumulation. SbPRR37 and SbGHD7 contribute to photoperiod sensitivity in sorghum by repressing expression of SbEHD1 and FT-like genes, thereby delaying flowering in long days with minimal influence in short days (PNAS_108:16469-16474, 2011; Plant Genome_in press, 2014). The GIGANTEA (GI)-CONSTANS (CO)-FLOWERING LOCUS T (FT) pathway regulates flowering time in Arabidopsis and the grasses (J Exp Bot_62:2453-2463, 2011). In long day flowering plants, such as Arabidopsis and barley, CONSTANS activates FT expression and flowering in long days. In rice, a short day flowering plant, Hd1, the ortholog of CONSTANS, activates flowering in short days and represses flowering in long days. Results Quantitative trait loci (QTL) that modify flowering time in sorghum were identified by screening Recombinant Inbred Lines (RILs) derived from BTx642 and Tx7000 in long days, short days, and under field conditions. Analysis of the flowering