Sample records for flower color choices

  1. Inheritance of pink flower color in Styrax japonicus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most Styrax japonicus (Japanese snowbell) cultivars produce white flowers, but a few pink-flowered forms have been reported. ‘Pink Chimes’ is the most widely grown pink-flowered form and the only S. japonicus cultivar with deep pink flowers that hold their color even under hot growing conditions. ...

  2. The flavonoid pathway regulates the petal colors of cotton flower.

    PubMed

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

    2013-01-01

    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

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

    PubMed

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

    2013-08-01

    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

  4. Trees as huge flowers and flowers as oversized floral guides: the role of floral color change and retention of old flowers in Tibouchina pulchra

    PubMed Central

    Brito, Vinícius L. G.; Weynans, Kevin; Sazima, Marlies; Lunau, Klaus

    2015-01-01

    Floral color changes and retention of old flowers are frequently combined phenomena restricted to the floral guide or single flowers in few-flowered inflorescences. They are thought to increase the attractiveness over long distances and to direct nearby pollinators toward the rewarding flowers. In Tibouchina pulchra, a massively flowering tree, the whole flower changes its color during anthesis. On the first day, the flowers are white and on the next 3 days, they change to pink. This creates a new large-scale color pattern in which the white pre-changed flowers contrast against the pink post-changed ones over the entire tree. We describe the spectral characteristics of floral colors of T. pulchra and test bumblebees’ response to this color pattern when viewed at different angles (simulating long and short distances). The results indicated the role of different color components in bumblebee attraction and the possible scenario in which this flower color pattern has evolved. We tested bumblebees’ preference for simulated trees with 75% pink and 25% white flowers resembling the color patterns of T. pulchra, and trees with green leaves and pink flowers (control) in long-distance approach. We also compared an artificial setting with three pink flowers and one white flower (T. pulchra model) against four pink flowers with white floral guides (control) in short-distance approach. Bumblebees spontaneously preferred the simulated T. pulchra patterns in both approaches despite similar reward. Moreover, in short distances, pollinator visits to peripheral, non-rewarding flowers occurred only half as frequently in the simulated T. pulchra when compared to the control. Thefore, this exceptional floral color change and the retention of old flowers in T. pulchra favors the attraction of pollinators over long distances in a deception process while it honestly directs them toward the rewarding flowers at short distances possibly exploring their innate color preferences.

  5. Color as a factor in food choice

    Microsoft Academic Search

    Fergus M. Clydesdale

    1993-01-01

    From birth, nature teaches us to make judgements on our environment based in large measure on color. As such, it plays a key role in food choice by influencing taste thresholds, sweetness perception, food preference, pleasantness, and acceptability. Its role is elusive and difficult to quantify, however, which at times has placed color in a secondary role to the other

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

    Microsoft Academic Search

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

    2007-01-01

    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

  7. Selective Pressures Explain Differences in Flower Color among Gentiana lutea Populations

    PubMed Central

    Domínguez, Paula; Guitián, Javier A.; Guitián, Pablo; Guitián, José M.

    2015-01-01

    Flower color variation among plant populations might reflect adaptation to local conditions such as the interacting animal community. In the northwest Iberian Peninsula, flower color of Gentiana lutea varies longitudinally among populations, ranging from orange to yellow. We explored whether flower color is locally adapted and the role of pollinators and seed predators as agents of selection by analyzing the influence of flower color on (i) pollinator visitation rate and (ii) escape from seed predation and (iii) by testing whether differences in pollinator communities correlate with flower color variation across populations. Finally, (iv) we investigated whether variation in selective pressures explains flower color variation among 12 G. lutea populations. Flower color influenced pollinator visits and differences in flower color among populations were related to variation in pollinator communities. Selective pressures on flower color vary among populations and explain part of flower color differences among populations of G. lutea. We conclude that flower color in G. lutea is locally adapted and that pollinators play a role in this adaptation. PMID:26172378

  8. Pollinator-mediated selection on flower color, flower scent and flower morphology of Hemerocallis: evidence from genotyping individual pollen grains on the stigma.

    PubMed

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

    2013-01-01

    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. PMID:24376890

  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

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

    2013-01-01

    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. PMID:24376890

  10. Flower color-flower scent associations in polymorphic Hesperis matronalis (Brassicaceae).

    PubMed

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

    2007-03-01

    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 both color morphs emitted more scent at dusk than at dawn. Color morphs varied in chemical composition of scent, but this differed between populations. The white morphs exhibited significant differences between populations, while the purple morphs did not. In the white morphs, one population contains color-scent associations that match expectations from classical pollination syndrome theory, where the flowers have aromatic scents, which are expected to maximize night-flying moth pollinator attraction; in the second population, white morphs were strongly associated with terpenoid compounds. The potential impact that pollinators, conserved biosynthetic pathways, and the genetics of small colonizing populations may have in determining population-specific associations between floral color and floral scent are discussed. PMID:17258250

  11. Genetic engineering of flavonoid pigments to modify flower color in floricultural plants

    Microsoft Academic Search

    Masahiro NishiharaTakashi Nakatsuka; Takashi Nakatsuka

    2011-01-01

    Recent advances in genetic transformation techniques enable the production of desirable and novel flower colors in some important\\u000a floricultural plants. Genetic engineering of novel flower colors is now a practical technology as typified by commercialization\\u000a of a transgenic blue rose and blue carnation. Many researchers exploit knowledge of flavonoid biosynthesis effectively to\\u000a obtain unique flower colors. So far, the main

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

    PubMed Central

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

    2012-01-01

    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. PMID:25050239

  13. Individual and Population Shifts in Flower Color by Scarlet Gilia: A Mechanism for Pollinator Tracking

    Microsoft Academic Search

    Ken N. Paige; Thomas G. Whitham

    1985-01-01

    Individual plants and populations of scarlet gilia (Ipomopsis aggregata) shift from darker to lighter corolla colors during the flowering season. Shifts to lighter color coincide with emigration of hummingbirds from the system. In the absence of hummingbirds, lighter colors attract the remaining pollinator, a hawkmoth. Comparison of plants that shift to lighter colors with those that fail to shift shows

  14. Individual and population shifts in flower color by scarlet gilia: a mechanism for pollinator tracking.

    PubMed

    Paige, K N; Whitham, T G

    1985-01-18

    Individual plants and populations of scarlet gilia (Ipomopsis aggregata) shift from darker to lighter corolla colors during the flowering season. Shifts to lighter color coincide with emigration of hummingbirds from the system. In the absence of hummingbirds, lighter colors attract the remaining pollinator, a hawkmoth. Comparison of plants that shift to lighter colors with those that fail to shift shows that shifting is adaptive in that it enhances reproductive success because of the preference of hawkmoths for lighter colored flowers. Color shifting therefore provides a mechanism for plants to track changing pollinator abundances. PMID:17742104

  15. Flower color affects tri-trophic-level biocontrol interactions

    Microsoft Academic Search

    Mahmuda Begum; Geoff M. Gurr; Steve D. Wratten; Helen I. Nicola

    2004-01-01

    The adults of many parasitoid species require nectar for optimal fitness, but very little is known of flower recognition. Flight cage experiments showed that the adults of an egg parasitoid (Trichogramma carverae Oatman and Pinto) benefited from alyssum (Lobularia maritima L.) bearing white flowers to a greater extent than was the case for light pink, dark pink or purple flowered

  16. Evaluation of flower color using a colorimeter and the Royal Horticultural Society charts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The visual appearance of flowers, fresh fruits and vegetables is one of the first quality determinants made by the consumer. Often the appearance of the commodity is the most critical factor in the initial sale. The flower color of Amaryllis (Amaryllis Hippeastrum) cultivars at the U. S. National Ge...

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

    PubMed Central

    2014-01-01

    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. PMID:24602314

  18. Male mate choice selects for female coloration in a fish

    PubMed Central

    Amundsen, Trond; Forsgren, Elisabet

    2001-01-01

    Although sexual selection theory has proved successful in explaining a wide array of male ornaments, the function of ornaments occurring in females is largely unknown. Traditionally, female ornaments have been considered nonfunctional, being merely a genetically correlated response to selection for male ornamentation. However, this hypothesis is only relevant to species in which the ornament is basically the same in the two sexes. Alternatively, female ornaments may be influenced by selection acting directly on the females, either through female–female competition or male choice. We tested the latter hypothesis in mate-choice experiments with two-spotted gobies (Gobiusculus flavescens). In this small marine fish, females have bright yellow-orange bellies during the breeding season, a conspicuous trait that is not present in males. We conducted two aquarium experiments to test whether males preferred to mate with more colorful females. In the first experiment, males had a choice between two females that varied in natural coloration (and belly roundness). In the second experiment, we manipulated belly coloration and kept roundness constant. Males spent more time with colorful than with drab females in both experiments and also performed far more courtship displays toward colorful females. Our study provides experimental evidence that males prefer ornamented females in a fish that is not sex-role reversed, supporting the hypothesis that female ornamentation is sexually selected. PMID:11606720

  19. Flower choice by naïve young crab spiders and the effect of subsequent experience.

    PubMed

    Morse

    2000-05-01

    Initial responses of naïve individuals to critical environmental stimuli provide important information about the innate contribution to behaviour, and subsequent responses to the same stimuli may show the role of experience in mediating those initial responses. To test the role of these factors, I measured initial patch choices and giving-up responses of just-emerged, naïve, second-instar crab spiders, Misumena vatia, on several hunting sites they encountered after leaving their natal nests. In follow-up tests I measured the effects of these experiences on subsequent patch choice decisions. The choice of hunting sites is a vital decision at all stages of the life cycle for sit-and-wait predators such as Misumena. In their initial tests these spiderlings remained more frequently on goldenrod (Solidago spp.) flowers than on green or yellow goldenrod buds, a preference they retained through tests run on 5 consecutive days. Individuals on green and yellow buds shifted sites more quickly and frequently than those from flowers, and made most of these moves to flowers, which attracted many more prey than did buds. These differences were not affected by age, energetic condition, or loss of information over the period of the experiment. Once spiderlings moved from buds, they showed a high, increasing tendency to move from buds in subsequent runs, those from flowers showed a consistently low tendency. These results suggest that spiderlings retain their innate behavioural patterns through the second instar, but that experience also plays a modest role in patch choice at this stage. Copyright 2000 The Association for the Study of Animal Behaviour. PMID:10860521

  20. A new allele of flower color gene W1 encoding flavonoid 3'5'-hydroxylase is responsible for light purple flowers in wild soybean Glycine soja

    PubMed Central

    2010-01-01

    Background Glycine soja is a wild relative of soybean that has purple flowers. No flower color variant of Glycine soja has been found in the natural habitat. Results B09121, an accession with light purple flowers, was discovered in southern Japan. Genetic analysis revealed that the gene responsible for the light purple flowers was allelic to the W1 locus encoding flavonoid 3'5'-hydroxylase (F3'5'H). The new allele was designated as w1-lp. The dominance relationship of the locus was W1 >w1-lp >w1. One F2 plant and four F3 plants with purple flowers were generated in the cross between B09121 and a Clark near-isogenic line with w1 allele. Flower petals of B09121 contained lower amounts of four major anthocyanins (malvidin 3,5-di-O-glucoside, petunidin 3,5-di-O-glucoside, delphinidin 3,5-di-O-glucoside and delphinidin 3-O-glucoside) common in purple flowers and contained small amounts of the 5'-unsubstituted versions of the above anthocyanins, peonidin 3,5-di-O-glucoside, cyanidin 3,5-di-O-glucoside and cyanidin 3-O-glucoside, suggesting that F3'5'H activity was reduced and flavonoid 3'-hydroxylase activity was increased. F3'5'H cDNAs were cloned from Clark and B09121 by RT-PCR. The cDNA of B09121 had a unique base substitution resulting in the substitution of valine with methionine at amino acid position 210. The base substitution was ascertained by dCAPS analysis. The polymorphism associated with the dCAPS markers co-segregated with flower color in the F2 population. F3 progeny test, and dCAPS and indel analyses suggested that the plants with purple flowers might be due to intragenic recombination and that the 65 bp insertion responsible for gene dysfunction might have been eliminated in such plants. Conclusions B09121 may be the first example of a flower color variant found in nature. The light purple flower was controlled by a new allele of the W1 locus encoding F3'5'H. The flower petals contained unique anthocyanins not found in soybean and G. soja. B09121 may be a useful tool for studies of the structural and functional properties of F3'5'H genes as well as investigations on the role of flower color in relation to adaptation of G. soja to natural habitats. PMID:20663233

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

    PubMed Central

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

    2011-01-01

    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. PMID:21490971

  2. The biological significance of color constancy: an agent-based model with bees foraging from flowers under varied illumination.

    PubMed

    Faruq, Samia; McOwan, Peter W; Chittka, Lars

    2013-01-01

    The perceived color of an object depends on its spectral reflectance and the spectral composition of the illuminant. Thus when the illumination changes, the light reflected from the object also varies. This would result in a different color sensation if no color constancy mechanism is put in place-that is, the ability to form consistent representation of colors across various illuminants and background scenes. We explore the quantitative benefits of various color constancy algorithms in an agent-based model of foraging bees, where agents select flower color based on reward. Each simulation is based on 100 "meadows" with five randomly selected flower species with empirically determined spectral reflectance properties, and each flower species is associated with realistic distributions of nectar rewards. Simulated foraging bees memorize the colors of flowers that they have experienced as most rewarding, and their task is to discriminate against other flower colors with lower rewards, even in the face of changing illumination conditions. We compared the performance of von Kries, White Patch, and Gray World constancy models with (hypothetical) bees with perfect color constancy, and color-blind bees. A bee equipped with trichromatic color vision but no color constancy performed only ?20% better than a color-blind bee (relative to a maximum improvement at 100% for perfect color constancy), whereas the most powerful recovery of reflectance in the face of changing illumination was generated by a combination of von Kries photoreceptor adaptation and a White Patch calibration (?30% improvement relative to a bee without color constancy). However, none of the tested algorithms generated perfect color constancy. PMID:23962735

  3. Altering flower color in transgenic plants by RNAi-mediated engineering of flavonoid biosynthetic pathway.

    PubMed

    Tanaka, Yoshikazu; Nakamura, Noriko; Togami, Junichi

    2008-01-01

    Flower color is mainly determined by the structure of flavonoids, a group of secondary metabolites of plants. The biosynthetic pathway and the genes involved in the pathway are well characterized such that it is possible to change flower color by engineering the pathway by overexpression of heterologous genes and/or suppression of endogenous genes in transgenic plants. Trimming an unnecessary pathway by suppression of endogenous genes is often essential to achieve successful engineering of the pathway and the resultant accumulation of desirable compounds. RNAi by transcription of double-stranded RNA (dsRNA) is a powerful and efficient method to command such suppression and is widely used for artificial gene suppression in transgenic plants. PMID:18369790

  4. The role of pollinators in maintaining variation in flower color in the Rocky Mountain columbine, Aquilegia coerulea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flower color varies within and among populations of the Rocky Mountain columbine, Aquilegia coerulea. The abundance of hawkmoths and bumble bees, the two major pollinators of this plant species, also varies among populations. We investigated the preference of hawkmoths and bumble bees for flower col...

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

    PubMed Central

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

    2012-01-01

    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. PMID:22485167

  6. Penstemons are flowering perennials much loved by the gardening public. Gardeners appreciate their diversity of flower colors that are at peak bloom in June and July,

    E-print Network

    even rebloom for seasonlong color. Hot rock penstemon (Penstemon deustus) (Fig. 5) is one of the fewP A G B G Penstemons are flowering perennials much loved by the gardening public. Gardeners some in your own garden. Most people don't realize there are about 280 species of penstemon, all na ve

  7. Floral sexual dimorphism and flower choice by pollinators in a nectarless monoecious vine Akebia quinata (Lardizabalaceae)

    Microsoft Academic Search

    Tetsuhiro Kawagoe; Nobuhiko Suzuki

    2002-01-01

    We investigated the pollination system and movement patterns of pollinators among flowers of the nectarless, monoecious vine Akebia quinata in natural populations and experimental floral arrays. Female flowers did not offer any rewards for pollinators and were larger than male flowers. Pollinators of A.?quinata , such as small solitary bees and hoverflies, clearly discriminated between male and female flowers. Hoverflies

  8. Evaluating the spectral discrimination capabilities of different pollinators and their effect on the evolution of flower colors

    PubMed Central

    Shrestha, Mani; Dyer, Adrian G.; Burd, Martin

    2013-01-01

    Important plant pollinators like bees and birds have very different color visual systems. Previous work has attempted to relate flower syndromes to the respective visual capabilities of the most important pollinators, but has often been limited by the lack of robust means to make between-species comparisons of how flower color signals are processed. In a recent study we solved this dilemma by comparing the raw spectral signals, quantifiable by major inflection points on a wavelength scale, from different flowers whose pollinators were known from direct observation. Here we elaborate on how this method allows robust cross species comparisons that are independent of the requirement to know the complex and often inaccessible physiological data about color processing in different animals. The use of this method should thus allow for the testing of pollinator syndrome hypotheses for different animal pollinators from different regions of the world. PMID:23713140

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

    E-print Network

    Chittka, Lars

    Seeing the light: Illumination as a contextual cue to color choice behavior in bumblebees R. Beau 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

  10. Relative Role of Flower Color and Scent on Pollinator Attraction: Experimental Tests using F1 and F2 Hybrids of Daylily and Nightlily

    Microsoft Academic Search

    Shun K. Hirota; Kozue Nitta; Yuni Kim; Aya Kato; Nobumitsu Kawakubo; Akiko A. Yasumoto; Tetsukazu Yahara

    2012-01-01

    The daylily (Hemerocallis fulva) and nightlily (H. citrina) are typical examples of a butterfly-pollination system and a hawkmoth-pollination system, respectively. H. fulva has diurnal, reddish or orange-colored flowers and is mainly pollinated by diurnal swallowtail butterflies. H. citrina has nocturnal, yellowish flowers with a sweet fragrance and is pollinated by nocturnal hawkmoths. We evaluated the relative roles of flower color

  11. Relative role of flower color and scent on pollinator attraction: experimental tests using F1 and F2 hybrids of daylily and nightlily.

    PubMed

    Hirota, Shun K; Nitta, Kozue; Kim, Yuni; Kato, Aya; Kawakubo, Nobumitsu; Yasumoto, Akiko A; Yahara, Tetsukazu

    2012-01-01

    The daylily (Hemerocallis fulva) and nightlily (H. citrina) are typical examples of a butterfly-pollination system and a hawkmoth-pollination system, respectively. H. fulva has diurnal, reddish or orange-colored flowers and is mainly pollinated by diurnal swallowtail butterflies. H. citrina has nocturnal, yellowish flowers with a sweet fragrance and is pollinated by nocturnal hawkmoths. We evaluated the relative roles of flower color and scent on the evolutionary shift from a diurnally flowering ancestor to H. citrina. We conducted a series of experiments that mimic situations in which mutants differing in either flower color, floral scent or both appeared in a diurnally flowering population. An experimental array of 6 × 6 potted plants, mixed with 24 plants of H. fulva and 12 plants of either F1 or F2 hybrids, were placed in the field, and visitations of swallowtail butterflies and nocturnal hawkmoths were recorded with camcorders. Swallowtail butterflies preferentially visited reddish or orange-colored flowers and hawkmoths preferentially visited yellowish flowers. Neither swallowtail butterflies nor nocturnal hawkmoths showed significant preferences for overall scent emission. Our results suggest that mutations in flower color would be more relevant to the adaptive shift from a diurnally flowering ancestor to H. citrina than that in floral scent. PMID:22720016

  12. Relative Role of Flower Color and Scent on Pollinator Attraction: Experimental Tests using F1 and F2 Hybrids of Daylily and Nightlily

    PubMed Central

    Hirota, Shun K.; Nitta, Kozue; Kim, Yuni; Kato, Aya; Kawakubo, Nobumitsu; Yasumoto, Akiko A.; Yahara, Tetsukazu

    2012-01-01

    The daylily (Hemerocallis fulva) and nightlily (H. citrina) are typical examples of a butterfly-pollination system and a hawkmoth-pollination system, respectively. H. fulva has diurnal, reddish or orange-colored flowers and is mainly pollinated by diurnal swallowtail butterflies. H. citrina has nocturnal, yellowish flowers with a sweet fragrance and is pollinated by nocturnal hawkmoths. We evaluated the relative roles of flower color and scent on the evolutionary shift from a diurnally flowering ancestor to H. citrina. We conducted a series of experiments that mimic situations in which mutants differing in either flower color, floral scent or both appeared in a diurnally flowering population. An experimental array of 6×6 potted plants, mixed with 24 plants of H. fulva and 12 plants of either F1 or F2 hybrids, were placed in the field, and visitations of swallowtail butterflies and nocturnal hawkmoths were recorded with camcorders. Swallowtail butterflies preferentially visited reddish or orange-colored flowers and hawkmoths preferentially visited yellowish flowers. Neither swallowtail butterflies nor nocturnal hawkmoths showed significant preferences for overall scent emission. Our results suggest that mutations in flower color would be more relevant to the adaptive shift from a diurnally flowering ancestor to H. citrina than that in floral scent. PMID:22720016

  13. Flower color changes in three Japanese hibiscus species: further quantitative variation of anthocyanin and flavonols.

    PubMed

    Shimokawa, Satoshi; Iwashina, Tsukasa; Murakami, Noriaki

    2015-03-01

    One anthocyanin and four flavonols were detected from the petals of Hibiscus hamabo, H. tiliaceus and H. glaber. They were identified as cyanidin 3-0- sambubioside, gossypetin 3-O-glucuronide-8-O-glucoside, quercetin 7-O-rutinoside, gossypetin 3-O-glucoside and gossypetin 8-O-glucuronide by UV spectra, LC-MS, acid hydrolysis and HPLC. The flavonoid composition was essentially the same among the petals ofH. hamabo, H. tiliaceus and H. glaber, and there was little quantitative variation, except for cyanidin 3-O-sambubioside, the content of which in the petals ofH. tiliaceus and H. glaber was much higher than in that of H. hamabo. Flower colors of H. tiliaceus and H. glaber change from yellow to red, and that of H. hamabo changes from yellow to orange. These changes were caused by contents of anthocyanin and flavonols, which increased after flowering of H. hamabo, H. tiliaceus and H. glaber. PMID:25924527

  14. Flower Engineers

    NSDL National Science Digital Library

    2014-01-28

    This activity (on pages 24-29) combines science and art to introduce learners to how different animal pollinators spread pollen from one plant to another, and how certain shapes, colors, and smells of different flowers attract particular pollinators. In Part One, learners draw and label a flower based on a Pollinator Chart, then build the flower. In Part Two, learners survey others in their class or group to see if they can tell which kinds of pollinator their model flower would attract.

  15. Quantitative flavonoid variation accompanied by change of flower colors in Edgeworthia chrysantha, Pittosporum tobira and Wisteria floribunda.

    PubMed

    Ono, Megumi; Iwashina, Tsukasa

    2015-03-01

    The flavonoids in the flowers of Edgeworthia chrysantha, Pittosporum tobira and Wisteria floribunda were isolated and identified. Quercetin and kaempferol 3-O-glucosides and 3-O-rutinosides were found in E. chrysantha, and quercetin 3-O-rutinoside, 3-O-glucoside and 3-O-pentosylrhamnosylglucoside, kaempferol 3-O-robinobioside, 3-O-rutinoside, 3-O-glucoside and 3-O-pentosylrhamnosylglucoside, and isorhamnetin 3-O-rutinoside were isolated from P. tobira. Ten flavonoids, quercetin 3-O-sophoroside, 3-O-rutinoside, 3-O-glucoside, kaempferol 3-O-sophoroside and 3-O-glucoside, luteolin 5-O-glucoside, 7- O-glucoside and 7-O-hexoside, and apigenin 7-O-glucoside and 4'-O-hexoside were isolated from W floribunda. The major pigments of E. chrysantha were carotenoids. Their content decreased with the change in flower color to white from yellow via cream, and total flavonoid content also slightly decreased by ca. 0.8 in cream and ca. 0.9 fold in white flowers. In contrast with E. chrysantha, white flowers of P. tobira turn to cream and then yellow in which the major pigments are also carotenoids. In this species, both carotenoid and flavonoid contents are gradually increased from white to yellow flowers. Though the petal color of Wisteria floribunda is mauve, due to anthocyanin pigments, the yellow areas are due to carotenoids; these turn to white in the late flowering stage. However, their flavonoid contents were essentially the same among the yellow, cream and white spots of flags. Thus, it was shown by HPLC analysis of the flower flavonoids of E. chrysantha, P. tobira and W. floribunda, although the visible pigments such as carotenoids and anthocyanins are quantitatively varied, the quantitative variation in UV-absorbing substances, such as flavones and flavonols, differs with plant species. PMID:25924517

  16. The dilemma of flavor and color in the choice of packaging by children

    Microsoft Academic Search

    Mathilde Gollety; Nathalie Guichard

    2011-01-01

    Purpose – The aim of this paper is, by using a semiotic approach to marketing, to evaluate the role of color and its influence on the choice behavior of children with regard to products where flavor is represented by color. Design\\/methodology\\/approach – The study was carried out as an experiment with children aged between 7 and 11 years of age.

  17. Consumers' Willingness to Pay for the Color of Salmon: A Choice Experiment with Real Economic Incentives

    Microsoft Academic Search

    Frode Alfnes; Atle G. Guttormsen; Gro Steine; Kari Kolstad

    2006-01-01

    In most retail markets, sellers post the price and consumers choose which products to buy. We designed an experimental market with posted prices to investigate consumers' willingness to pay for the color of salmon. Salmon fillets varying in color and price were displayed in twenty choice scenarios. In each scenario, the participants chose which of two salmon fillets they wanted

  18. A comparative study on visual choice reaction time for different colors in females.

    PubMed

    Balakrishnan, Grrishma; Uppinakudru, Gurunandan; Girwar Singh, Gaur; Bangera, Shobith; Dutt Raghavendra, Aswini; Thangavel, Dinesh

    2014-01-01

    Reaction time is one of the important methods to study a person's central information processing speed and coordinated peripheral movement response. Visual choice reaction time is a type of reaction time and is very important for drivers, pilots, security guards, and so forth. Previous studies were mainly on simple reaction time and there are very few studies on visual choice reaction time. The aim of our study was to compare the visual choice reaction time for red, green, and yellow colors of 60 healthy undergraduate female volunteers. After giving adequate practice, visual choice reaction time was recorded for red, green, and yellow colors using reaction time machine (RTM 608, Medicaid, Chandigarh). Repeated measures of ANOVA and Bonferroni multiple comparison were used for analysis and P < 0.05 was considered statistically significant. The results showed that both red and green had significantly less choice visual choice reaction (P values <0.0001 and 0.0002) when compared with yellow. This could be because individual color mental processing time for yellow color is more than red and green. PMID:25580294

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

    PubMed

    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

    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

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

    ERIC Educational Resources Information Center

    Sweeney, Kathryn A.

    2013-01-01

    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…

  1. Male mate choice based upon female nuptial coloration in the brook stickleback, Culaea inconstans (Kirtland)

    Microsoft Academic Search

    DEBORAH A. McLENNAN

    1995-01-01

    Female brook sticklebacks develop distinct nuptial coloration following ovulation. When given a choice between a gravid, uncoloured, inter-spawning interval female and a gravid, nuptially coloured female, male brook sticklebacks from two Ontario populations (1) approached the nuptially coloured female first, (2) directed their first courtship pummel towards her, and (3) spent significantly more time with her than with the inter-spawning

  2. The importance of color in mate choice of the blue crab Callinectes sapidus.

    PubMed

    Baldwin, Jamie; Johnsen, Sönke

    2009-11-01

    Visual displays often play a large role in animal communication, particularly in sexual interactions. The blue crab Callinectes sapidus is both colorful and highly visually responsive, yet almost all studies of their courtship have focused on chemical cues. In the blue crab's underwater environment, however, visual cues may function more rapidly and over a longer distance than chemical cues. Given that blue crabs are aggressive and cannibalistic, visual cues may therefore allow blue crabs to quickly evaluate potential mates from safer distances. In the present study we show that courtship and mate choice behavior in C. sapidus can be stimulated by visual cues alone. Further, we show that males have a preference for females with red claw dactyls. In binary choice experiments, males displayed more often to photographs of females with red claws than to those with white claws or to those with black claws that were isoluminant to the red ones. This strongly suggests that male blue crabs made their choices based on the hue of the red claws, further suggesting that blue crabs are capable of color vision and use color in mate choice. PMID:19880739

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

    PubMed

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

    2010-12-01

    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

  4. Do flower color and floral scent of silene species affect host preference of Hadena bicruris, a seed-eating pollinator, under field conditions?

    PubMed

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

    2014-01-01

    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. PMID:24905986

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

    PubMed Central

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

    2014-01-01

    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. PMID:24905986

  6. Sexual Dimorphism of Staminate- and Pistillate-Phase Flowers of Saponaria officinalis (Bouncing Bet) Affects Pollinator Behavior and Seed Set

    PubMed Central

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

    2014-01-01

    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

  7. The biological significance of color constancy: An agent-based model with bees foraging from flowers under varied illumination

    E-print Network

    Chittka, Lars

    with (hypothetical) bees with perfect color constancy, and color-blind bees. A bee equipped with trichromatic color vision but no color constancy performed only ;20% better than a color-blind bee (relative to a maximumThe biological significance of color constancy: An agent-based model with bees foraging from

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

    Microsoft Academic Search

    Ole Seehausen; Jacques J. M. van Alphen

    1998-01-01

    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

  9. In the eyes of the beholders: Female choice and avian predation risk associated with an exaggerated male butterfly color.

    PubMed

    Morehouse, Nathan I; Rutowski, Ronald L

    2010-12-01

    Color ornaments are often viewed as products of countervailing sexual and natural selection, because more colorful, more attractive individuals may also be more conspicuous to predators. However, while evidence for such countervailing selection exists for vertebrate color ornaments (e.g., Trinidadian guppies), similar studies have yet to be reported in invertebrates. Indeed, evidence for female mate choice based on extant variation in male coloration is limited in invertebrates, and researchers have not explicitly asked whether more attractive males are also more conspicuous to predators. Here we provide evidence that more chromatic male cabbage white butterflies (Pieris rapae) are more attractive to females but should also be more conspicuous to predators. Female P. rapae preferentially mate with more chromatic males when choosing from populations of males with naturally occurring or commensurate, experimentally induced color variation. Mathematical models of female color vision confirm that females should be able to discriminate color differences between prospective mates. Further, chromatic and luminance contrast scores from female visual system models better predicted male mating success than did measures of male color derived more directly from color spectra. Last, models of avian color vision suggest that preferred males should be more conspicuous to known avian predators. PMID:20942644

  10. Local adaptation and matching habitat choice in female barn owls with respect to melanic coloration.

    PubMed

    Dreiss, A N; Antoniazza, S; Burri, R; Fumagalli, L; Sonnay, C; Frey, C; Goudet, J; Roulin, Alexandre

    2012-01-01

    Local adaptation is a major mechanism underlying the maintenance of phenotypic variation in spatially heterogeneous environments. In the barn owl (Tyto alba), dark and pale reddish-pheomelanic individuals are adapted to conditions prevailing in northern and southern Europe, respectively. Using a long-term dataset from Central Europe, we report results consistent with the hypothesis that the different pheomelanic phenotypes are adapted to specific local conditions in females, but not in males. Compared to whitish females, reddish females bred in sites surrounded by more arable fields and less forests. Colour-dependent habitat choice was apparently beneficial. First, whitish females produced more fledglings when breeding in wooded areas, whereas reddish females when breeding in sites with more arable fields. Second, cross-fostering experiments showed that female nestlings grew wings more rapidly when both their foster and biological mothers were of similar colour. The latter result suggests that mothers should particularly produce daughters in environments that best match their own coloration. Accordingly, whiter females produced fewer daughters in territories with more arable fields. In conclusion, females displaying alternative melanic phenotypes bred in habitats providing them with the highest fitness benefits. Although small in magnitude, matching habitat selection and local adaptation may help maintain variation in pheomelanin coloration in the barn owl. PMID:22070193

  11. Variability in color-choice Stroop performance within and across EEG and MRI laboratory contexts.

    PubMed

    Fehr, T; Wiechert, J; Erhard, P

    2014-11-01

    To examine the reproducibility of the Stroop effect, behavioral data from 22 healthy female individuals were repeatedly (three-month interval between two separate measurement sessions) obtained while performing a color-choice Stroop task under realistic magnetic resonance imaging (MRI) and electroencephalography (EEG) laboratory conditions. At the group statistical level, the Stroop effect, indicated by longer response times for incongruent than for congruent stimulus conditions, was consistently present for almost all examined measurement levels. However, differential effects of laboratory contexts on retest reproducibility were observed across repeated measurement levels, both within and between sessions. These results challenge existing theories about the underlying nature of Stroop interference processing. It appears necessary to apply a multitheoretical approach, because intraindividual variability within and across measurement sessions suggests potential fluctuations in the individual mental strategies applied, recruitment of varying memory resources, the influence of mediator variables such as working memory capacity and/or attention, and many more possible variations. Single-observation studies run the risk of favoring a single theoretical concept and therefore underestimating the individual factor. We further conclude that dependent analysis-of-variance statistics are a more fit test for reproducibility than are correlative reliability estimations. PMID:25085739

  12. Glowing Flowers

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    Student teams learn about engineering design of green fluorescent proteins (GFPs) and their use in medical research, including stem cell research. They simulate the use of GFPs by adding fluorescent dye to water and letting a flower or plant to transport the dye throughout its structure. Students apply their knowledge of GFPs to engineering applications in the medical, environmental and space exploration fields. Due to the fluorescing nature of the dye, plant life of any color, light or dark, can be used — unlike dyes that can only be seen in visible light.

  13. Indexing Flower Patent Images Using Domain Knowledge

    Microsoft Academic Search

    Madirakshi Das; R. Manmatha; Edward M. Riseman

    1999-01-01

    A new approach to indexing a specialized database by utilizing the color and spatial domain knowledge available for the database is described. This approach is illustrated by using it to provide a solution to the problem of indexing images of flowers for searching a flower patents database by color. The flower region is isolated from the background by using an

  14. Age Differences in the Associations between Felt Temperatures and Color Choices

    ERIC Educational Resources Information Center

    Morgan, George A.; And Others

    1975-01-01

    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)

  15. Hibiscus flower

    NSDL National Science Digital Library

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

    2007-01-13

    The flower is the reproductive structure of the angiosperms. Many angiosperms need insects to transfer pollen from one flower to the stigma of another. After fertilization, the ovules inside the flower develop into seeds. Enclosed seeds distinguish angiosperms from gymnosperms.

  16. Color-Changing Carnations

    NSDL National Science Digital Library

    Museum of Science and Industry, Chicago

    2012-01-01

    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.

  17. Male-specific Iridescent Coloration in the Pipevine Swallowtail (Battus philenor) is Used in Mate Choice

    E-print Network

    Rutowski, Ronald L.

    philenor. mate selection . sexual selection Introduction In many species of butterflies, males are more in butterflies have been experimentally evaluated using manipula- tions of male color for only seven species of butterflies, four pierids (Silberglied and Taylor 1978; Rutowski 1981; Wiernasz and Kingsolver 1992; Kemp 2008

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

    PubMed Central

    2012-01-01

    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. PMID:23176321

  19. Apple Scab of Flowering Crabapples

    E-print Network

    Apple Scab of Flowering Crabapples Flowering crabapples add color and beauty to many home leaves and defoliation by early summer. The cause of this problem is a fungus disease known as apple scab. The same disease is also a common problem on eating apples, refer to BP-1 (Apple Scab in the Home Fruit

  20. Quantitative Genetic Analyses of Male Color Pattern and Female Mate Choice in a Pair of Cichlid Fishes of Lake Malawi, East Africa

    PubMed Central

    Ding, Baoqing; Daugherty, Daniel W.; Husemann, Martin; Chen, Ming; Howe, Aimee E.; Danley, Patrick D.

    2014-01-01

    The traits involved in sexual selection, such as male secondary sexual characteristics and female mate choice, often co-evolve which can promote population differentiation. However, the genetic architecture of these phenotypes can influence their evolvability and thereby affect the divergence of species. The extraordinary diversity of East African cichlid fishes is often attributed to strong sexual selection and thus this system provides an excellent model to test predictions regarding the genetic architecture of sexually selected traits that contribute to reproductive isolation. In particular, theory predicts that rapid speciation is facilitated when male sexual traits and female mating preferences are controlled by a limited number of linked genes. However, few studies have examined the genetic basis of male secondary sexual traits and female mating preferences in cichlids and none have investigated the genetic architecture of both jointly. In this study, we artificially hybridized a pair of behaviorally isolated cichlid fishes from Lake Malawi and quantified both melanistic color pattern and female mate choice. We investigated the genetic architecture of both phenotypes using quantitative genetic analyses. Our results suggest that 1) many non-additively acting genetic factors influence melanistic color patterns, 2) female mate choice may be controlled by a minimum of 1–2 non-additive genetic factors, and 3) F2 female mate choice is not influenced by male courting effort. Furthermore, a joint analysis of color pattern and female mate choice indicates that the genes underlying these two traits are unlikely to be physically linked. These results suggest that reproductive isolation may evolve rapidly owing to the few genetic factors underlying female mate choice. Hence, female mate choice likely played an important role in the unparalleled speciation of East African cichlid fish. PMID:25494046

  1. Composite Flowers

    NSDL National Science Digital Library

    Conrad, Jim

    This site, part of Jim Conrad's Backyard Nature Plant web page, discusses this very large family of plants, which includes the sunflower, dandelion, and chrysanthemum. Here you will find information about the composite family's flower structure and the three kinds of composite flowers: ray only, disk only, and ray and disk. There is also a section on how to analyze disk and ray flower structures.

  2. Colorful Collage: Visions of Flowers

    ERIC Educational Resources Information Center

    Skophammer, Karen

    2011-01-01

    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…

  3. Flowers & Weeds.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1996-01-01

    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)

  4. Flowering and expression of flowering-related genes under long-day conditions with light-emitting diodes

    Microsoft Academic Search

    Yoshimi Hori; Koji Nishidate; Manabu Nishiyama; Koki Kanahama; Yoshinori Kanayama

    The effects of light quality on flowering time were investigated in Gypsophila paniculata, which is a long-day cut flower, and with Arabidopsis under long-day conditions with light-emitting diodes (LEDs). Gypsophila paniculata plants were grown under natural daylight and flowering was controlled by long-day treatment with a weak LED light of a single\\u000a color in the night. Flowering was promoted not

  5. College Major Choice for Students of Color: Toward a Model of Recruitment for the Agricultural Education Profession

    ERIC Educational Resources Information Center

    Vincent, Stacy K.; Henry, Anna L.; Anderson, James C., II

    2012-01-01

    The purpose of this study was to gain a deeper understanding of the reasons students, identifying as non-White, made the decision to pursue a career in agricultural education. This phenomenological study allowed the researchers to obtain the overall phenomenon of the thought processes that encompass decisions of students of color when selecting an…

  6. Colors, Colors?

    NSDL National Science Digital Library

    Susan Songstad

    2009-01-01

    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.

  7. Flower Face Face Face Face Flower Tree Tree Tree Tree

    E-print Network

    Chen, Tsuhan

    Flower Flower Flower Flower Flower Face Face Face Face Flower Flower Tree Tree Tree Tree Flower Sign Face Face Face Face Sign Sign Building Sign Water Sky Tree Building Building Building Sign Book Building Building Building Sign Bird Bird Road Tree Grass Road Road Bird Sky #12;Bird Bird Water Bird Grass

  8. Production of red-flowered plants by genetic engineering of multiple flavonoid biosynthetic genes

    Microsoft Academic Search

    Takashi Nakatsuka; Yoshiko Abe; Yuko Kakizaki; Saburo Yamamura; Masahiro Nishihara

    2007-01-01

    Orange- to red-colored flowers are difficult to produce by conventional breeding techniques in some floricultural plants.\\u000a This is due to the deficiency in the formation of pelargonidin, which confers orange to red colors, in their flowers. Previous\\u000a researchers have reported that brick-red colored flowers can be produced by introducing a foreign dihydroflavonol 4-reductase\\u000a (DFR) with different substrate specificity in Petunia

  9. The regulation of carotenoid pigmentation in flowers.

    PubMed

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

    2010-12-01

    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

  10. [Inheritance of the white-flower and its influence to related characters in eggplant (Solanum melongem Linn)].

    PubMed

    Lin, Gui-Rong; Li, Bao-Jiang; Wei, Yu-Tang

    2006-06-01

    The inheritance of the white-flower and its influence to related characters in eggplant were studied with the white-flowered mutant of XIANLVQIE and its maternal bred. Result showed that the flower color was attributed to a couple of complete dominance genes. Purple color flower "Col" was dominant to the white "col". Compared with the purple-flowered strain, the white-flowered strain not only grew more blooming, but also had more stamens in one flower, less pollens in one anther and less seeds in one fruit. In the meanwhile, in white-flowered eggplants, microspore and fruit was bigger, and yield was higher than purple-flowered. The white-flowered strain could be used as a variety and the white-flowered character could be used as a marker to appraise purity of hybrid in eggplant. PMID:16818435

  11. Inheritance of red foliage in flowering dogwood (Cornus florida L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flowering dogwood (Cornus florida L.) is an ornamental tree valued for its showy white, pink, or red spring bract display and red fall color. A ‘‘pseudo’’ F2 flowering dogwood population was recently developed from a honeybee mediated cross of ‘Cherokee Brave’ x ‘Appalachian Spring’. The foliage col...

  12. Chemical and Chromatic Bases for Preferential Visiting By the Cabbage Butterfly, Pieris rapae , to Rape Flowers

    Microsoft Academic Search

    Hisashi Ômura; Keiichi Honda; Nanao Hayashi

    1999-01-01

    Scent and coloration of corolla were examined as floral attributes responsible for preferential visiting by the cabbage butterfly, Pieris rapae, to rape flower, Brassica rapa. Floral volatile components that release the flower-visiting behavior of the butterfly were identified by chemical analyses, electroantennography (EAG), and two behavioral bioassays: proboscis extension reflex (PER) in response to odor and attraction to artificial flowers.

  13. Discovering Flowers in a New Light

    ERIC Educational Resources Information Center

    McNall, Rebecca L.; Bell, Randy L.

    2004-01-01

    Children love observing seeds change as they germinate and grow into tall healthy plants, but how can teachers make investigating plants an exciting and immediate event? Microscopy might just be the answer. Although most students have seen flowers, not many have looked closely at their various structures or seen their colorful designs only…

  14. Regulation of skin color in apples

    Microsoft Academic Search

    J. E. Lancaster; Donald K. Dougall

    1992-01-01

    The literature of the regulation of color in apple skin is reviewed and compared with current knowledge of the regulation of flower color.Color in apple skin is a blend of various amounts of chlorophyll, carotenoids, and anthocyanins\\/flavonols. A variety of red colors are produced by cyanidin glycosides copigmented with flavonols and other compounds. The concentration and identification of flavonols, proanthocyanidins,

  15. Bee on flower

    NSDL National Science Digital Library

    N/A N/A (None; )

    2006-07-15

    Bees visit flowering plants to collect nectar so they can store it as honey back at their hives. As a bee visits one flower after another, pollen collects on its entire body and especially on the legs. Bees help pollinate flowers while they collect nectar. This is a mutualistic behavior.

  16. Flower Dissection Lab

    NSDL National Science Digital Library

    From Fairchild Tropical Botanic Garden, this site presents a simple Flower Dissection Lab using orchids and composite flowers. This pdf document contains the materials needed and instructions for the lab, as well as a worksheet for students to complete as they dissect their flower.

  17. Sepal phenolic profile during Helleborus niger flower development.

    PubMed

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

    2013-11-01

    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

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

    PubMed Central

    2009-01-01

    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. PMID:20003430

  19. Characterization of carotenoid pigments and their biosynthesis in two yellow flowered lines of Sandersonia aurantiaca (Hook)

    Microsoft Academic Search

    Karen M. Nielsen; David H. Lewis; Ed R. Morgan

    2003-01-01

    The basis of the novel cream\\/yellow flower color found in two Sandersonia aurantiaca lines was examined as part of a project to develop new colors for this cut flower crop in New Zealand. The original color,\\u000a bright orange, is due to the accumulation of the carotenoid pigments zeaxanthin and ?-cryptoxanthin. The cream\\/yellow lines\\u000a have much lower levels of total carotenoid

  20. Physiologia Plantarum 2007 Copyright Physiologia Plantarum 2007, ISSN 0031-9317 Temperature-sensitive anthocyanin production in flowers

    E-print Network

    Lacey, Elizabeth P.

    -sensitive anthocyanin production in flowers of Plantago lanceolata Elizabeth A. Stilesa,b , Nadja B. Cecha , Stacy M-3054.2007.00855.x Flower color in the weedy perennial Plantago lanceolata is phenotypically plastic. Darker flowers, Lacey and Herr (2005) showed that for the weedy perennial, Plantago lanceolata L. (Plantagina- ceae

  1. Flowering and expression of flowering-related genes under long-day conditions with light-emitting diodes.

    PubMed

    Hori, Yoshimi; Nishidate, Koji; Nishiyama, Manabu; Kanahama, Koki; Kanayama, Yoshinori

    2011-08-01

    The effects of light quality on flowering time were investigated in Gypsophila paniculata, which is a long-day cut flower, and with Arabidopsis under long-day conditions with light-emitting diodes (LEDs). Gypsophila paniculata plants were grown under natural daylight and flowering was controlled by long-day treatment with a weak LED light of a single color in the night. Flowering was promoted not by blue light, but by far-red light in G. paniculata, while flowering was promoted by both light colors in Arabidopsis. FT homologs of G. paniculata GpFT1 and GpFT2 were differentially expressed under long-day conditions with white light, suggesting that they play roles in flowering at different stages of reproductive development. GpFTs and FT gene expression was not induced by far-red light in G. paniculata or Arabidopsis. Instead, the expression of the SOC1 homolog of G. paniculata GpSOC1 and SOC1 was induced by far-red light in G. paniculata and Arabidopsis. Flowering was promoted by induction of FT and SOC1 expression with blue light in Arabidopsis, whereas GpFTs and GpSOC1 expression was low with blue light induction in G. paniculata. The relationship between flowering and the expression of FT and SOC1 in Arabidopsis was confirmed with ft and soc1 mutants. These results suggest that long-day conditions with far-red light promote flowering through SOC1 and its homologs, while the conditions with blue light do not promote flowering in G. paniculata, because of low expression of GpFTs and GpSOC1 in contrast to that in Arabidopsis. PMID:21431295

  2. Scholarship Awards, College Choice, and Student Engagement in College Activities: A Study of High-Achieving Low-Income Students of Color

    ERIC Educational Resources Information Center

    Hu, Shouping

    2010-01-01

    Using two-wave survey data on the 2001 cohort of the Gates Millennium Scholarship (GMS) recipients and comparison nonrecipients, this study examines the relationship between scholarship awards and student engagement in college activities. The results indicate that scholarship awards such as GMS directly affect student college choice decisions.…

  3. Say it with flowers

    PubMed Central

    Falik, Omer; Hoffmann, Ishay; Novoplansky, Ariel

    2014-01-01

    The timing of reproduction is a critical determinant of fitness, especially in organisms inhabiting seasonal environments. Increasing evidence suggests that inter-plant communication plays important roles in plant functioning. Here, we tested the hypothesis that flowering coordination can involve communication between neighboring plants. We show that soil leachates from Brassica rapa plants growing under long-day conditions accelerated flowering and decreased allocation to vegetative organs in target plants growing under non-inductive short-day conditions. The results suggest that besides endogenous signaling and external abiotic cues, flowering timing may involve inter-plant communication, mediated by root exudates. The study of flowering communication is expected to illuminate neglected aspects of plant reproductive interactions and to provide novel opportunities for controlling the timing of plant reproduction in agricultural settings. PMID:24598343

  4. April showers bring May flowers…and May rains bring botrytis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the old saying goes “April showers bring May flowers” and to the greenhouse production industry May brings “color” to the greenhouse in the form of flowers which are good for both spring sales and Botrytis. This should not come as anything new to the seasoned grower, but hopefully will serve as ...

  5. Odour and colour information in the foraging choice behaviour of the honeybee

    Microsoft Academic Search

    M. Giurfa; J. Núñez; W. Backhaus

    1994-01-01

    1. Honeybees Apis mellifera ligustica were trained to work on a patch with artificial rewarding and non-rewarding flowers, coupled to an air extractor. The perceptual colour distance between the rewarding and the non-rewarding flowers was varied and the flower choice and the repellent scent-marking behaviour of the bees were recorded. 2. The discrimination between rewarding and non-rewarding flowers depended on

  6. Flower constancy in insect pollinators

    PubMed Central

    Ratnieks, Francis L.W.

    2011-01-01

    As first noted by Aristotle in honeybee workers, many insect pollinators show a preference to visit flowers of just one species during a foraging trip. This “flower constancy” probably benefits plants, because pollen is more likely to be deposited on conspecific stigmas. But it is less clear why insects should ignore rewarding alternative flowers. Many researchers have argued that flower constancy is caused by constraints imposed by insect nervous systems rather than because flower constancy is itself an efficient foraging method. We argue that this view is unsatisfactory because it both fails to explain why foragers flexibly adjust the degree of flower constancy and does not explain why foragers of closely related species show different degrees of constancy. While limitations of the nervous system exist and are likely to influence flower constancy to some degree, the observed behavioural flexibility suggests that flower constancy is a successful foraging strategy given the insect’s own information about different foraging options. PMID:22446521

  7. Flower biology in New Zealand

    Microsoft Academic Search

    E. J. Godley

    1979-01-01

    Research on flower biology began in New Zealand in the early 1870s under the influence of Darwin's work on orchids, but from the turn of the century there was a decline in interest until the 1950s. Spring and summer are the main flowering periods, but many species flower in winter and examples are described. Of some 1800 indigenous species of

  8. Estimation and comparison of flowering curves

    Microsoft Academic Search

    Robert M. Clark; Roy Thompson

    2011-01-01

    Background: Many researchers have simply recorded first flowering dates, while others have recorded the full extent of flowering. Such flowering curves show the rate of increase and decrease in flowering, as well as the day on which flowering is a maximum.Aim: To develop objective statistical methods for the estimation and comparison of flowering curves, with particular emphasis on the date

  9. Flowers of Wisteria floribunda

    NSDL National Science Digital Library

    Jer-Ming Hu (University of California; Section of Evolution and Ecology ADR; POSTAL)

    2004-03-09

    Flowers of Wisteria floribunda, a well-known ornamental plant from East Asia. Wisteria has been placed in the predominantly tropical tribe Millettieae by its morphological similarities. However, molecular evidence suggests that Wisteria and a tropical genus Callerya are closer to many temperate herbaceous legumes but not to other Millettieae members.

  10. Flower drinking and masculinity in Taiwan.

    PubMed

    Bedford, Olwen; Hwang, Shu-Ling

    2011-01-01

    This study explores the role of the hostess club culture in the creation and maintenance of masculinity in Taiwan. The article focuses on flower drinking (the consumption of alcohol in bars, often integrated with prostitution), which is a common practice in Taiwan. Data were obtained from 58 in-depth interviews with men from a variety of occupations and social backgrounds (mean age = 38.50, SD = 11.00) and 73 questionnaires administered to soldiers (mean age = 21.00, SD = 1.10). Findings indicated that demonstration of skill at flower drinking and facility with the related social etiquette are important channels for male bonding that were central to the mid- to upper-class participants' professional development. Flower drinking also provided a method of discriminating men from other men through their choices of why and where to go and how to behave while there. Specific ways that Taiwanese masculinity differs from Western and from Japanese masculinity, and support for the continuing relevance of the traditional Confucian ideal of masculinity, wen-wu, are discussed. PMID:19763998

  11. Color Blindness

    MedlinePLUS

    ... three color cone cells to determine our color perception. Color blindness can occur when one or more ... Anyone who experiences a significant change in color perception should see an ophthalmologist (Eye M.D.). Next ...

  12. Flower-Like Nanopowders

    NASA Astrophysics Data System (ADS)

    Shi, Wenyu; Wu, Fang; Wang, Kunlun; Yang, Jingjing; Song, Hongzhang; Hu, Xing

    2014-09-01

    Yttrium-doped Y x Bi2- x Te3 ( x = 0.15, 0.2, 0.25) flower-like nanopowders were synthesized by the hydrothermal method through careful adjustment of the amount of ethylenediaminetetraacetic acid surfactant. The flower-like nanopowders were hot pressed into bulk pellets, and the thermoelectric properties of the pellets were examined. The results showed that the optimized doped sample Y0.25Bi1.75Te3 had a relatively high Seebeck coefficient, a lower electrical resistivity, and a lower thermal conductivity. As a result, the figure of merit of the n-type Y0.25Bi1.75Te3 alloy reached 1.23 at 410 K.

  13. Engineering of the rose flavonoid biosynthetic pathway successfully generated blue-hued flowers accumulating delphinidin.

    PubMed

    Katsumoto, Yukihisa; Fukuchi-Mizutani, Masako; Fukui, Yuko; Brugliera, Filippa; Holton, Timothy A; Karan, Mirko; Nakamura, Noriko; Yonekura-Sakakibara, Keiko; Togami, Junichi; Pigeaire, Alix; Tao, Guo-Qing; Nehra, Narender S; Lu, Chin-Yi; Dyson, Barry K; Tsuda, Shinzo; Ashikari, Toshihiko; Kusumi, Takaaki; Mason, John G; Tanaka, Yoshikazu

    2007-11-01

    Flower color is mainly determined by anthocyanins. Rosa hybrida lacks violet to blue flower varieties due to the absence of delphinidin-based anthocyanins, usually the major constituents of violet and blue flowers, because roses do not possess flavonoid 3',5'-hydoxylase (F3'5'H), a key enzyme for delphinidin biosynthesis. Other factors such as the presence of co-pigments and the vacuolar pH also affect flower color. We analyzed the flavonoid composition of hundreds of rose cultivars and measured the pH of their petal juice in order to select hosts of genetic transformation that would be suitable for the exclusive accumulation of delphinidin and the resulting color change toward blue. Expression of the viola F3'5'H gene in some of the selected cultivars resulted in the accumulation of a high percentage of delphinidin (up to 95%) and a novel bluish flower color. For more exclusive and dominant accumulation of delphinidin irrespective of the hosts, we down-regulated the endogenous dihydroflavonol 4-reductase (DFR) gene and overexpressed the Irisxhollandica DFR gene in addition to the viola F3'5'H gene in a rose cultivar. The resultant roses exclusively accumulated delphinidin in the petals, and the flowers had blue hues not achieved by hybridization breeding. Moreover, the ability for exclusive accumulation of delphinidin was inherited by the next generations. PMID:17925311

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

    Microsoft Academic Search

    Douglass H. Morse

    1999-01-01

    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,

  15. Colored Shadows

    NSDL National Science Digital Library

    2011-10-31

    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.

  16. Historical Choices.

    ERIC Educational Resources Information Center

    Schick, James B. M.

    1988-01-01

    States that history instruction can be made meaningful and enlightening only by examining historical choices and their results against available options and likely consequences. Presenting examples, the author argues that well-crafted historical simulations focusing on such elements as choice and consequence, strategy and tactics provide a useful…

  17. Tough Choice.

    ERIC Educational Resources Information Center

    Shapiro, Walter

    1991-01-01

    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…

  18. Teaching Through Trade Books: Flower Power

    NSDL National Science Digital Library

    Christine Anne Royce

    2009-07-01

    Summer is here and flowers are in bloom! Each flowering plant produces a unique bloom that provides opportunities for students to make observations about plants. By comparing and contrasting flowers, students can connect their learning to the larger pictu

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    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.

  20. Flower Basking by Arctic Insects

    Microsoft Academic Search

    B. Hocking; C. D. Sharplin

    1965-01-01

    DURING observations on insect-flower relationships at Lake Hazen, Ellesmere Island (81° 49' N, 71° 20' W) we were struck by the fact that both males and females of the mosquitoes Aëdes nigripes Zett. and Aëdes impiger (Walker) spent up to 13 min at a time in the flowers of several plants, but especially Dryas integrifolia M. Vahl, although we know

  1. Do pollinators influence the assembly of flower colours within plant communities?

    PubMed

    de Jager, Marinus L; Dreyer, Léanne L; Ellis, Allan G

    2011-06-01

    The co-occurrence of plant species within a community is influenced by local deterministic or neutral processes as well as historical regional processes. Floral trait distributions of co-flowering species that share pollinators may reflect the impact of pollinator preference and constancy on their assembly within local communities. While pollinator sharing may lead to increased visitation rates for species with similar flowers, the receipt of foreign pollen via interspecific pollinator movements can decrease seed set. We investigated the pattern of community flower colour assembly as perceived by native honeybee pollinators within 24 local assemblages of co-flowering Oxalis species within the Greater Cape Floristic Region, South Africa. To explore the influence of pollinators on trait assembly, we assessed the impact of colour similarity on pollinator choices and the cost of heterospecific pollen receipt. We show that flower colour is significantly clustered within Oxalis communities and that this is not due to historical constraint, as flower colour is evolutionarily labile within Oxalis and communities are randomly structured with respect to phylogeny. Pollinator observations reveal that the likelihood of pollinators switching between co-flowering species is low and increases with flower colour similarity. Interspecific hand pollination significantly reduced seed set in the four Oxalis species we investigated, and all were dependant on pollinators for reproduction. Together these results imply that flower colour similarity carries a potential fitness cost. However, pollinators were highly flower constant, and remained so despite the extreme similarity of flower colour as perceived by honeybees. This suggests that other floral traits facilitate discrimination between similarly coloured species, thereby likely resulting in a low incidence of interspecific pollen transfer (IPT). If colour similarity promotes pollinator attraction at the community level, the observed clustering of flower colour within communities might result from indirect facilitative interactions. PMID:21170748

  2. Map Coloring

    NSDL National Science Digital Library

    Mrs. Hadley

    2005-06-18

    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 ...

  3. Identification of Mendel's White Flower Character

    PubMed Central

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

    2010-01-01

    Background The 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 Findings We 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 combination of genetic mapping, fast neutron mutant analysis, allelic diversity, transcript quantification and transient expression complementation studies to confirm the identity of the candidates. Conclusions/Significance We have identified the pea genes A and A2. A is the factor determining anthocyanin pigmentation in pea that was used by Gregor Mendel 150 years ago in his study of inheritance. The A gene encodes a bHLH transcription factor. The white flowered mutant allele most likely used by Mendel is a simple G to A transition in a splice donor site that leads to a mis-spliced mRNA with a premature stop codon, and we have identified a second rare mutant allele. The A2 gene encodes a WD40 protein that is part of an evolutionarily conserved regulatory complex. PMID:20949001

  4. Epigenetic regulation of photoperiodic flowering

    PubMed Central

    2010-01-01

    The cytidine analogue 5-azacytidine, which causes DNA demethylation, induced flowering in the non-vernalization-requiring plants Perilla frutescens var. crispa, Silene armeria and Pharbitis nil (synonym Ipomoea nil) under non-inductive photoperiodic conditions, suggesting that the expression of photoperiodic flowering-related genes is regulated epigenetically by DNA methylation. The flowering state induced by DNA demethylation was not heritable. Changes in the genome-wide methylation state were examined by methylation-sensitive amplified fragment length polymorphism analysis. This analysis indicated that the DNA methylation state was altered by the photoperiodic condition. DNA demethylation also induced dwarfism, and the induced dwarfism of P. frutescens was heritable. PMID:20448475

  5. Chasmogamous Flowering in Viola palustris L

    Microsoft Academic Search

    L. T. Evans

    1956-01-01

    AFTER a short burst of chasmogamous flowering in early spring, plants of V. palustris, like those of many other violet species, produce a succession of cleistogamous flowers throughout the summer. Such a change in flowering habit could be associated with changes in day-length, as in V. fimbriatula and V. papilionacea with which Allard and Garner1 obtained chasmogamous flowers only in

  6. Down the tube: pollinators, predators, and the evolution of flower shape in the alpine skypilot, Polemonium viscosum.

    PubMed

    Galen, C; Cuba, J

    2001-10-01

    We address how a conflict between pollinator attraction and avoidance of flower predation influences the evolution of flower shape in Polemonium viscosum. Flower shape in P. viscosum is the product of an isometric relationship between genetically correlated (rA = 0.70) corolla flare and length. Bumblebee pollinators preferentially visit flowers that are more flared and have longer tubes, selecting for a funnel-shaped corolla. However, flower shape also influences nectar-foraging ants that sever the style at its point of attachment to the ovary. Surveys of ant damage show that plants having flowers with flared, short corollas are most vulnerable to ant predation. Consistent with this result, the ratio of corolla length to flare is significantly greater in a krummholz (high predation risk) population than in a tundra (low predation risk) population. To explicitly test whether the evolution of a better defended flower would exact a cost in pollination, we created tubular flowers by constricting the corolla during development. Performance of tubular flowers and natural controls was compared for defensive and attractive functions. In choice trials, ants entered control flowers significantly more often than tubular ones, confirming that the evolution of tubular flowers would reduce the risk of predation. However, in a bumblebee-pollinated population, tubular flowers received significantly less pollen and set fewer seeds than controls. A fitness model incorporating these data predicts that in the absence of the genetic correlation between corolla length and flare, intermittent selection for defense could allow tubular flowers to spread in the krummholz population. However, in the tundra, where bumblebees account for nearly all pollination, the model predicts that tubular flowers should always confer a fitness disadvantage. PMID:11761057

  7. Metatranscriptome Analysis of Fig Flowers Provides Insights into Potential Mechanisms for Mutualism Stability and Gall Induction

    PubMed Central

    Martinson, Ellen O.; Hackett, Jeremiah D.; Machado, Carlos A.; Arnold, A. Elizabeth

    2015-01-01

    A striking property of the mutualism between figs and their pollinating wasps is that wasps consistently oviposit in the inner flowers of the fig syconium, which develop into galls that house developing larvae. Wasps typically do not use the outer ring of flowers, which develop into seeds. To better understand differences between gall and seed flowers, we used a metatranscriptomic approach to analyze eukaryotic gene expression within fig flowers at the time of oviposition choice and early gall development. Consistent with the unbeatable seed hypothesis, we found significant differences in gene expression between gall- and seed flowers in receptive syconia prior to oviposition. In particular, transcripts assigned to flavonoids and carbohydrate metabolism were significantly up-regulated in gall flowers relative to seed flowers. In response to oviposition, gall flowers significantly up-regulated the expression of chalcone synthase, which previously has been connected to gall formation in other plants. We propose several genes encoding proteins with signal peptides or associations with venom of other Hymenoptera as candidate genes for gall initiation or growth. This study simultaneously evaluates the gene expression profile of both mutualistic partners in a plant-insect mutualism and provides insight into a possible stability mechanism in the ancient fig-fig wasp association. PMID:26090817

  8. Metatranscriptome Analysis of Fig Flowers Provides Insights into Potential Mechanisms for Mutualism Stability and Gall Induction.

    PubMed

    Martinson, Ellen O; Hackett, Jeremiah D; Machado, Carlos A; Arnold, A Elizabeth

    2015-01-01

    A striking property of the mutualism between figs and their pollinating wasps is that wasps consistently oviposit in the inner flowers of the fig syconium, which develop into galls that house developing larvae. Wasps typically do not use the outer ring of flowers, which develop into seeds. To better understand differences between gall and seed flowers, we used a metatranscriptomic approach to analyze eukaryotic gene expression within fig flowers at the time of oviposition choice and early gall development. Consistent with the unbeatable seed hypothesis, we found significant differences in gene expression between gall- and seed flowers in receptive syconia prior to oviposition. In particular, transcripts assigned to flavonoids and carbohydrate metabolism were significantly up-regulated in gall flowers relative to seed flowers. In response to oviposition, gall flowers significantly up-regulated the expression of chalcone synthase, which previously has been connected to gall formation in other plants. We propose several genes encoding proteins with signal peptides or associations with venom of other Hymenoptera as candidate genes for gall initiation or growth. This study simultaneously evaluates the gene expression profile of both mutualistic partners in a plant-insect mutualism and provides insight into a possible stability mechanism in the ancient fig-fig wasp association. PMID:26090817

  9. Interorgan Translocation of 1-Aminocyclopropane-1-Carboxylic Acid and Ethylene Coordinates Senescence in Emasculated Cymbidium Flowers

    PubMed Central

    Woltering, Ernst J.

    1990-01-01

    In Cymbidium flowers, emasculation by removal of the pollinia and the anther cap leads within 24 hours to red coloration of the labellum (lip). Lip coloration, being the first sign of senescence in these flowers, has been ascribed to the action of ethylene in the lip. When a small incision in the base of the lip is made prior to emasculation, or when the lip is excised and placed in water within 10 to 15 hours after emasculation, coloration is considerably delayed. This indicates that a coloration-associated factor is moving in or out of the lip. Measurements of ethylene production of excised flower parts, isolated at different times after emasculation, showed an increase only in the central column; the other flower parts, including the lip, did not show a measurable change. In contrast, in situ measurements of the ethylene production of the central column and the remaining portion of the flower revealed a simultaneous increase in all the flower parts following emasculation. Similarly, application of radiolabeled 1-aminocyclopropane-1-carboxylic acid (ACC) to the top of the central column in situ leads to the production of radiolabeled ethylene by all the flower parts. In addition, the ethylene production of isolated lips, measured immediately after excision, was initially high but ceased within 10 to 15 minutes. Treatment of the central column in situ with ethylene or ethephon did not stimulate ACC production but did stimulate lip coloration and this was accompanied by an increased internal ethylene concentration in the lip. The data indicate that endogenously produced as well as applied ACC is rapidly translocated from the site of production or application to all the other flower parts where it is immediately converted into ethylene. By excision of a flower organ, the influx of ACC is prevented, causing a rapid decrease in ethylene production. In addition, it was found that ethylene may also be translocated in physiologically significant amounts within the flower. The roles of ACC and ethylene as mobile senescence or wilting factors in emasculation- and pollination-induced senescence is discussed. PMID:16667357

  10. Flower constellation optimization and implementation 

    E-print Network

    Bruccoleri, Christian

    2009-05-15

    generally, Walker Constellations. The set of orbital planes and initial spacecraft positions are represented by a set of only three integers and two real parameters rather than by all the orbital elements; Flower Constellations provide a more general...

  11. Farming and Gardening: Flower Garden

    NSDL National Science Digital Library

    PBS TeacherSource - Math

    2010-01-01

    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.

  12. Bright color reflective displays with interlayer reflectors

    NASA Astrophysics Data System (ADS)

    Kitson, Stephen; Geisow, Adrian; Rudin, John; Taphouse, Tim

    2011-08-01

    A good solution to the reflective display of color has been a major challenge for the display industry, with very limited color gamuts demonstrated to date. Conventional side-by-side red, green and blue color filters waste two-thirds of incident light. The alternative of stacking cyan, magenta and yellow layers is also challenging -- a 10% loss per layer compounds to nearly 50% overall. Here we demonstrate an architecture that interleaves absorbing-to-clear shutters with matched wavelength selective reflectors. This increases color gamut by reducing losses and more cleanly separating the color channels, and gives much wider choice of electro-optic colorants.

  13. Angelina's choice.

    PubMed

    Goel, Nishu Singh

    2013-10-01

    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

  14. Color distance derived from a receptor model of color vision in the honeybee

    Microsoft Academic Search

    W. Backhaus; R. Menzel

    1987-01-01

    A model calculation is presented for investigating the domain between the two well-examined fields of color vision in the bee, i.e. choice behavior with respect to color stimuli, and photoreceptor physiology. Based on the properties of the receptors, the model explains quantitatively the results obtained in color discrimination experiments. The model predicts curved lines which connect the loci of most

  15. A new gene, bic, with pleiotropic effects (with T P V) for bicolor flowers and dark olive brown seed coat in common bean.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Painted Lady’ (Phaseolus coccineus L.) has bicolor flowers with vermilion banner petal and white wing petals. This flower color pattern is not known in common bean (P. vulgaris L.). The bicolor trait was backcrossed into common bean and its inheritance was investigated, including allelism tests w...

  16. Color measurement and discrimination

    NASA Technical Reports Server (NTRS)

    Wandell, B. A.

    1985-01-01

    Theories of color measurement attempt to provide a quantative means for predicting whether two lights will be discriminable to an average observer. All color measurement theories can be characterized as follows: suppose lights a and b evoke responses from three color channels characterized as vectors, v(a) and v(b); the vector difference v(a) - v(b) corresponds to a set of channel responses that would be generated by some real light, call it *. According to theory a and b will be discriminable when * is detectable. A detailed development and test of the classic color measurement approach are reported. In the absence of a luminance component in the test stimuli, a and b, the theory holds well. In the presence of a luminance component, the theory is clearly false. When a luminance component is present discrimination judgements depend largely on whether the lights being discriminated fall in separate, categorical regions of color space. The results suggest that sensory estimation of surface color uses different methods, and the choice of method depends upon properties of the image. When there is significant luminance variation a categorical method is used, while in the absence of significant luminance variation judgments are continuous and consistant with the measurement approach.

  17. Color notations

    E-print Network

    Gardner, Nancy

    1981-01-01

    This study presents research regarding the language of colors and of computers. The focus was color: translated through personal imagery, transferred and changed through media, and programmed through the computer. The ...

  18. Manga colorization

    Microsoft Academic Search

    Yingge Qu; Tien-tsin Wong; Pheng-ann Heng

    2006-01-01

    This paper proposes a novel colorization technique that propagates color over regions exhibiting pattern-continuity as well as intensity- continuity. The proposed method works effectively on colorizing black-and-white manga which contains intensive amount of strokes, hatching, halftoning and screening. Such ne details and discon- tinuities in intensity introduce many difculties to intensity-based colorization methods. Once the user scribbles on the drawing,

  19. Synchronous Pulsed Flowering: Analysis of the Flowering Phenology in Juncus (Juncaceae)

    PubMed Central

    Michalski, Stefan G.; Durka, Walter

    2007-01-01

    Background and Aims The timing of flowering within and among individuals is of fundamental biological importance because of its influence on total seed production and, ultimately, fitness. Traditional descriptive parameters of flowering phenology focus on onset and duration of flowering and on synchrony among individuals. These parameters do not adequately account for variability in flowering across the flowering duration at individual and population level. This study aims to analyse the flowering phenology of wind-pollinated Juncus species that has been described as temporally highly variable (‘pulsed flowering’). Additionally, an attempt is made to identify proximate environmental factors that may cue the flowering, and ultimate causes for the flowering patterns are discussed. Methods Flowering phenology was examined in populations of nine Juncus species by estimating flowering synchrony and by using the coefficient of variation (CV) to describe the temporal variation in flowering on individual and population levels. Phenologies were compared with null models to test which patterns deviate from random flowering. All parameters assessed were compared with each other and the performance of the parameters in response to randomization and varying synchrony was evaluated using a model population. Flowering patterns were correlated with temperature and humidity. Key Results Most flowering patterns of Juncus were best described as synchronous pulsed flowering, characterized as population-wide concerted flowering events separated by days with no or few open flowers. Flowering synchrony and variability differed from a random pattern in most cases. CV values in combination with a measure of synchrony differentiated among flowering patterns found. Synchrony varied among species and was independent from variability in flowering. Neither temperature nor humidity could be determined as potential cues for the flowering pulses. Conclusions The results indicate that selection may act independently on synchrony and variability. We propose that synchronous pulsed flowering in Juncus is an evolved strategy that provides selective benefits by increasing outcrossing and by spreading the risk of reproductive failure. PMID:17881343

  20. Seeing Color

    ERIC Educational Resources Information Center

    Texley, Juliana

    2005-01-01

    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…

  1. Bumblebee preference for symmetrical flowers.

    PubMed

    Møller, A P

    1995-03-14

    Fluctuating asymmetry, which represents small random deviations from otherwise bilateral symmetry, is a measure of the phenotypic quality of individuals indicating the ability of controlled development under given environmental and genetic conditions. I tested whether floral symmetry reliably reflects phenotypic quality measured in terms of pollinator rewards and whether pollinators respond to floral symmetry in a series of observations and experiments on Epilobium angustifolium (Onagraceae). Lower petal asymmetry was negatively related to mean lower petal length, whereas asymmetry in leaf width was positively related to mean leaf width. Flowers visited by bumblebees were larger and more symmetrical than the nearest neighboring flower. This relationship between pollinator preference for large and symmetrical flowers was demonstrated to be causal in experiments in which the lower petals were manipulated symmetrically or asymmetrically. Nectar production was larger in symmetrical flowers, and this may explain the bumblebee preference for flower symmetry. Floral symmetry therefore reliably reflects nectar production and hence enhances pollen transport. Extensive embryo abortion has been documented in E. angustifolium and other outcrossing plant species. Floral fluctuating asymmetry, which reflects general developmental homeostasis, may explain such developmental selection in these plants. PMID:11607519

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

    PubMed

    Horth, Lisa; Campbell, Laura; Bray, Rebecca

    2014-01-01

    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. PMID:24585774

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

    PubMed Central

    Horth, Lisa; Campbell, Laura; Bray, Rebecca

    2014-01-01

    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. PMID:24585774

  4. Transcriptome Analysis of Differentially Expressed Genes Relevant to Variegation in Peach Flowers

    PubMed Central

    Yu, Faxin; Li, Shuxian; Yin, Tongming

    2014-01-01

    Background Variegation in flower color is commonly observed in many plant species and also occurs on ornamental peaches (Prunus persica f. versicolor [Sieb.] Voss). Variegated plants are highly valuable in the floricultural market. To gain a global perspective on genes differentially expressed in variegated peach flowers, we performed large-scale transcriptome sequencing of white and red petals separately collected from a variegated peach tree. Results A total of 1,556,597 high-quality reads were obtained, with an average read length of 445 bp. The ESTs were assembled into 16,530 contigs and 42,050 singletons. The resulting unigenes covered about 60% of total predicted genes in the peach genome. These unigenes were further subjected to functional annotation and biochemical pathway analysis. Digital expression analysis identified a total of 514 genes differentially expressed between red and white flower petals. Since peach flower coloration is determined by the expression and regulation of structural genes relevant to flavonoid biosynthesis, a detailed examination detected four key structural genes, including C4H, CHS, CHI and F3H, expressed at a significantly higher level in red than in white petal. Except for the structural genes, we also detected 11 differentially expressed regulatory genes relating to flavonoid biosynthesis. Using the differentially expressed structural genes as the test objects, we validated the digital expression results by using quantitative real-time PCR, and the differential expression of C4H, CHS and F3H were confirmed. Conclusion In this study, we generated a large EST collection from flower petals of a variegated peach. By digital expression analysis, we identified an informative list of candidate genes associated with variegation in peach flowers, which offered a unique opportunity to uncover the genetic mechanisms underlying flower color variegation. PMID:24603808

  5. 186 DARWIN'S HERITAGE TODAY The Effects of Flower Color Transitions

    E-print Network

    Rausher, Mark D.

    - tion of Iochroma (Solanaceae) [J]. Evolution, 2008, 62:793-806. [2] Smith, S D, Izquierdo P R, Hall S J, et al. Comparative pollination biology of sym- patric and allopatric Andean Iochroma (Solanaceae) [J Andean clade Iochromi- nae (Solanaceae) [J]. Am J Bot, 2006, 93:1140-1153. [4] Baum D A, Smith S D

  6. Max-Coloring and Online Coloring with Bandwidths on Interval Graphs

    Microsoft Academic Search

    SRIRAM V. PEMMARAJU

    2008-01-01

    We make a connection between max-coloring and on-line graph coloring and use this to devise a simple 2-approximation algorithm for max-coloring on interval graphs. We also show that a simple first-fit strategy, that is a natural choice for this problem, yields an 8-approximation algorithm. We show this result by proving that the first-fit algorithm for on-line coloring an interval graph

  7. Anatomical and biochemical studies of bicolored flower development in Muscari latifolium.

    PubMed

    Qi, Yinyan; Lou, Qian; Li, Huibo; Yue, Juan; Liu, Yali; Wang, Yuejin

    2013-12-01

    The inflorescence of the broad-leafed grape hyacinth, Muscari latifolium, shows an interesting, two-tone appearance with the upper flowers being pale blue and the lower ones purple. To elucidate the mechanism of the differential color development, anatomical research was carried out and a cytological study of the colored protoplasts in which the shapes of the cells accumulating anthocyanin were observed by scanning electron microscopy. Next, vacuolar pH was recorded using a pH meter with a micro combination pH electrode, and the sap's metal-ion content was measured by inductively coupled plasma mass spectrometry. The anthocyanin and co-pigment composition was determined by high-performance liquid chromatography (HPLC). Chemical analyses reveal that the difference in metal-ion content of the two parts was not great. The vacuolar pHs of the upper and lower flowers were 5.91 and 5.84, respectively, with the difference being nonsignificant. HPLC results indicate that the dihydroflavonol and flavonol contents are also very similar in the two sorts of flower. However, the upper flowers contained only delphinidin, whereas the lower flowers also contained cyanidin. The total anthocyanin content in the lower flowers was 4.36 mg g(-1), which is approximately seven times higher than in the upper flowers, while the delphinidin content is four times higher. Quantitative real-time PCR analysis established that the two-tone flower was a result of different expressions of the F3'5'H, F3'H and DFR genes, and these lead to different amounts of anthocyanin. PMID:23677687

  8. Bee getting nectar from a lavender flower

    NSDL National Science Digital Library

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

    2006-12-30

    The bee obtains nectar to take to the beehive where it is used to make honey and provide food for the bees. The bee grabs pollen and transfers it to other flowers. This is called pollination and helps flowers reproduce.

  9. Color Analysis

    NASA Astrophysics Data System (ADS)

    Wrolstad, Ronald E.; Smith, Daniel E.

    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.

  10. FLOBOTS: ROBOTIC FLOWERS FOR BEE BEHAVIOUR EXPERIMENTS

    PubMed Central

    Essenberg, Carla J.

    2015-01-01

    Studies of pollinator foraging behaviour often require artificial flowers that can refill themselves, allowing pollinators to forage for long periods of time under experimental conditions. Here I describe a design for inexpensive flowers that can refill themselves upon demand and that are easy enough to set up and clean that they can be used in arrays of 30 or more flowers. I also summarize of a variety of artificial flower designs developed by other researchers. PMID:25722755

  11. Spring Flowers: Harvest of a Sensitive Eye

    ERIC Educational Resources Information Center

    Clark, Eloise; Levin, Ted

    1978-01-01

    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…

  12. Flower senescence in monocotyledons: A taxonomic survey

    Microsoft Academic Search

    Robert J. McKenzie; Peter H. Lovell

    1992-01-01

    Flower senescence was observed in representatives of 102 genera from 33 monocotyledon families. This is the first comparative study to cover such a wide range of monocotyledons. All of the species studied are of horticultural importance as ornamentals or cut flowers. Observations were made on attached flowers (i.e., still on the plant) on plants growing under cultured conditions, and on

  13. Original article Increase of flowering

    E-print Network

    Boyer, Edmond

    Original article Increase of flowering in Pinus nigra Arn subsp salzmannii (Dunal) Franco by means 1996) Summary - Behaviour of black pine (Pinus nigra subsp salzmannii) ramets grafted in 1987 on P nigra and P brutia rootstocks was compared in a clonal seed orchard located in Guadalajara (Spain

  14. A Flower of Tibouchina semidecandra,

    NSDL National Science Digital Library

    Susanne Renner (University of Missouri-St. Louis; Department of Biology ADR; POSTAL)

    2004-03-09

    A flower of Tibouchina semidecandra, a well-known ornamental from southeastern Brazil. Tibouchinais a member of the large tropical family Melastomataceae and together with other Melastomeae has been regarded as representing a relatively basal element of the family. Molecular evidence suggests that Tibouchina, Melastoma, Osbeckia, and other Melastomeae represent a derived clade of Melastomataceae that only recently reached Africa and tropical Asia.

  15. Pyrethrum flowers and pyrethroid insecticides.

    PubMed Central

    Casida, J E

    1980-01-01

    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. PMID:6993201

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

    PubMed

    Held, David W; Potter, Daniel A

    2004-07-01

    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

  17. Polar Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 3 May 2004 This nighttime visible color image was collected on January 1, 2003 during the Northern Summer season near the North Polar Troughs.

    This daytime visible color image was collected on September 4, 2002 during the Northern Spring season in Vastitas Borealis. The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude 79, Longitude 346 East (14 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  18. Colored Chaos

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 7 May 2004 This daytime visible color image was collected on May 30, 2002 during the Southern Fall season in Atlantis Chaos.

    The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude -34.5, Longitude 183.6 East (176.4 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. YACCD: Yet Another Color Constancy Database

    NASA Astrophysics Data System (ADS)

    Rizzi, Alessandro; Gatta, Carlo; Marini, Daniele

    2003-01-01

    Different image databases have been developed so far to test algorithms of color constancy. Each of them differs in the image characteristics, according to the features to test. In this paper we present a new image database, created at the University of Milano. Since a database cannot contain all the types of possible images, to limit the number of images it is necessary to make some choices and these choices should be as neutral as possible. The first image detail that we have addressed is the background. Which is the more convenient background for a color constancy test database? This choice can be affected by the goal of the color correction algorithms. In developing this DB we tried to consider a large number of possible approaches considering color constancy in a broader sense. Images under standard illuminants are presented together with particular non-standard light sources. In particular we collect two groups of lamps: with a weak and with a strong color casts. Another interesting feature is the presence of shadows, that allow to test the local effects of the color correction algorithms. The proposed DB can be used to test algorithms to recover the corresponding color under standard reference illuminants or alternatively assuming a visual appearance approach, to test algorithms for their capability to minimize color variations across the different illuminants, performing in this way a perceptual color constancy. This second approach is used to present preliminary tests. The IDB will be made available on the web.

  20. Anthocyanins and other flavonoids as flower pigments from eleven Centaurea species.

    PubMed

    Mishio, Tamaki; Takeda, Kosaku; Iwashina, Tsukasa

    2015-03-01

    Anthocyanins and other flavonoids were isolated from the flowers of eleven Centaurea species, C. macrocephala, C. rupestotilis and C. suaveolens, which produce yellow flowers, and C. achtarovii, C. dealbata, C. montana, C. nigra, C. scabiosa, C. simplicicaulis, C. hypoleuca and C. triumfetti, which have cyanic flowers. Four anthocyanins, cyanidin 3,5-di-O-glucoside, cyanidin 3-O-(6"-malonylglucoside)-5-O-glucoside, cyanidin 3-O-(6"-succinylglucoside)-5- O-glucoside and cyanidin glycoside, were detected in the cyanic flowers of seven Centaurea species. Of these anthocyanins, the first two were found as major anthocyanins. In the cyanic species, four other flavonoids, apigenin 7-O-glucuronide-4'-O-glucoside, malonylated apigenin 7,4'-di-O-glucoside, apigenin 7-0- glucuronide and kaempferol glycoside, were also isolated. On the other hand, nine flavonols and four flavones were isolated from the three yellow-flowered species, and identified as quercetagetin, quercetagetin 7-O-glucoside, quercetagetin 3'-methyl ether 7-O-glucoside, patuletin, patuletin 7-O-glucoside, quercetin 7-O-glucoside, kaempferol 3-methyl ether, kaempferol 3-methyl ether 4'-O-glucuronide and isorhamnetin 3-O-galactoside, and apigenin, apigenin 7- O-glucuronide, luteolin 7-O-glucoside and apigenin 6,8-di-C-glucoside (vicenin-2). Of these flavonoids, the former five flavonols are "yellow flavonols", and it was shown that their flower colors are due to these compounds. PMID:25924526

  1. Effect of glucuronosylation on anthocyanin color stability.

    PubMed

    Osmani, Sarah Anne; Hansen, Esben Halkjaer; Malien-Aubert, Céline; Olsen, Carl-Erik; Bak, Søren; Møller, Birger Lindberg

    2009-04-22

    The effect of glucuronosylation on the color stability of anthocyanins was investigated using glucuronosylated anthocyanins isolated from the flower petals of the red daisy (Bellis perennis) or obtained by enzymatic in vitro synthesis using heterologously expressed red daisy glucuronosyltransferase BpUGT94B1. Color stability toward light and heat stress was assessed by monitoring CIELAB color coordinates and stability at pH 7.0 by A(550). Cyanidin-3-O-2''-O-glucuronosylglucoside showed improved color stability in response to light compared to both cyanidin 3-O-glucoside and cyanidin 3-O-2''-O-diglucoside. A similar increase in color stability was not observed following heat treatment. Glucuronosylation did not increase the stability of anthocyanins at pH 7.0 as determined by A(550). To test for a possible effect of glucuronosylation on the color stability of anthocyanins in plant extracts used for food coloration, an elderberry (Sambucus nigra) extract was glucuronosylated in vitro. Glucuronosylation of approximately 50% of total anthocyanins proceeded fast and resulted in increased color stability in response to both heat and light. The data show that glucuronosylation may be used to stabilize industrially used extracts of natural colorants. PMID:19281238

  2. Tips and Tools for Creating ACCESSIBLE COLOR SCHEMES

    E-print Network

    Grether, Gregory

    : · Low vision (can be caused by aging!) · Color blindness · Intense web use · Mobile devices #12;WHATTips and Tools for Creating ACCESSIBLE COLOR SCHEMES Jennifer Dillon and Heather Wozniak Disabilities and Computing Program UCLA Office of Information Technology #12;WHY COLOR CHOICE MATTERS Not just

  3. Color appearance in stereoscopy

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    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.

  4. Color Blind or Color Conscious?

    ERIC Educational Resources Information Center

    Tatum, Beverly Daniel

    1999-01-01

    A color-blind approach often signifies that an educator has not considered what racial/ethnic identity means to youngsters. Students want to find themselves reflected in the faces of teachers and other students. Color-conscious teachers seek out materials that positively reflect students' identities and initiate discussions about race and racism.…

  5. Flower colour adaptation in a mimetic orchid

    PubMed Central

    Newman, Ethan; Anderson, Bruce; Johnson, Steven D.

    2012-01-01

    Although the tremendous variability in floral colour among angiosperms is often attributed to divergent selection by pollinators, it is usually difficult to preclude the possibility that floral colour shifts were driven by non-pollinator processes. Here, we examine the adaptive significance of flower colour in Disa ferruginea, a non-rewarding orchid that is thought to attract its butterfly pollinator by mimicking the flowers of sympatric nectar-producing species. Disa ferruginea has red flowers in the western part of its range and orange flowers in the eastern part—a colour shift that we hypothesized to be the outcome of selection for resemblance to different local nectar-producing plants. Using reciprocal translocations of red and orange phenotypes as well as arrays of artificial flowers, we found that the butterfly Aeropetes tulbaghia, the only pollinator of the orchid, preferred both the red phenotype and red artificial flowers in the west where its main nectar plant also has red flowers, and both the orange phenotype and orange artificial flowers in the east, where its main nectar plant has orange flowers. This phenotype by environment interaction demonstrates that the flower colour shift in D. ferruginea is adaptive and driven by local colour preference in its pollinator. PMID:22298842

  6. Color Sudoku

    NSDL National Science Digital Library

    OMSI

    2008-01-01

    The popular sudoku puzzles use numbers, but the game could played with any set of 9 different objects! In this activity (on pages 56-75 of PDF), learners use objects of different colors (marbles, paper squares, candies) to solve sudoku puzzles. Learners use logic to determine where all the colored objects go, given the different colors already present on the puzzles. The activity includes suggestions for how to approach the game, 10 puzzles of varying size and difficulty, and links to websites with many more puzzles.

  7. School Choice. IDRA Focus.

    ERIC Educational Resources Information Center

    Robledo Montecel, Maria, Ed.; Supik, Josie Danini, Ed.

    1994-01-01

    This newsletter contains five articles on the implications of school choice for minority and disadvantaged students. "School Choice: Choices for Whom? Promises and Panaceas," by Maria Robledo Montecel, discusses some major problems related to school choice and vouchers, particularly who would have the choice (families or schools), who would pay…

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

    PubMed

    Dai, Can; Galloway, Laura F

    2012-02-01

    • 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

  9. Influence of Riparian Tree Phenology on Lower Colorado River Spring-Migrating Birds: Implications of Flower Cueing

    USGS Publications Warehouse

    McGrath, Laura J.; van Riper, Charles, III

    2005-01-01

    Executive Summary Neotropical migrant birds make choices about which habitats are most likely to provide successful foraging locations during migration, but little is known about how these birds recognize and process environmental clues that indicate the presence of prey species. Aspects of tree phenology, notably flowering of trees along the lower Colorado River corridor, coincide with the migratory stopovers of leaf-gleaning insectivorous songbirds and may be an important indicator of arthropod prey species availability. Shifting tree flowering and leaf flush during the spring migration period presents avian insectivores with an assortment of foraging opportunities. During two field seasons at Cibola National Wildlife Refuge in southwestern Arizona, we examined riparian tree species to test whether leaf-gleaning insectivorous birds are attracted to the flowering condition of trees in choosing foraging sites. We predicted that flowering trees would host more insect prey resources, would thus show increased visit rates, length of stays and attack ratios of migrant avian insectivores, and that those arthropods would be found in the stomach contents of the birds. Paired trees of honey mesquite (Prosopis glandulosa), displaying heavy and light degrees of flowering were observed to test these predictions. To test whether birds are tracking arthropods directly or are using flowers as a proximate cue, we removed flowers from selected trees and paired these treated trees with neighboring high flowering trees, which served as controls. Avian foraging behavior, avian diets, arthropods, and phenology data were collected at the same time to control for temporal differences in insect availability, plant phenology, and differences in stopover arrivals of birds. We documented five patterns from this study: 1) Higher abundance and richness of arthropods were found on honey mesquite trees with greater numbers of flowers. 2) Arthropod abundance and richness increased as flowering level increased. 3) The subset of migrant avian insectivores selected for study disproportionately foraged among honey mesquite trees with significantly greater amounts of flower coverage than they did on trees with less than average flower coverage. 4) Paired field experiments demonstrated that migrant avian insectivores more often visited, stayed longer, and had higher attack rates on insect prey in honey mesquite trees with greater numbers of flowers. 5) Diet analyses of selected avian insectivores showed over half of their diet consisted of prey significantly associated with honey mesquite flowering. Combined, these results suggest that honey mesquite flowering condition is an important cue used by avian insectivores that enables birds to quickly find arthropod prey at stop-over locations, while in transit during spring migration.

  10. EARLY FLOWERING3 Regulates Flowering in Spring Barley by Mediating Gibberellin Production and FLOWERING LOCUS T Expression[C][W

    PubMed Central

    Boden, Scott A.; Weiss, David; Ross, John J.; Davies, Noel W.; Trevaskis, Ben; Chandler, Peter M.; Swain, Steve M.

    2014-01-01

    EARLY FLOWERING3 (ELF3) is a circadian clock gene that contributes to photoperiod-dependent flowering in plants, with loss-of-function mutants in barley (Hordeum vulgare), legumes, and Arabidopsis thaliana flowering early under noninductive short-day (SD) photoperiods. The barley elf3 mutant displays increased expression of FLOWERING LOCUS T1 (FT1); however, it remains unclear whether this is the only factor responsible for the early flowering phenotype. We show that the early flowering and vegetative growth phenotypes of the barley elf3 mutant are strongly dependent on gibberellin (GA) biosynthesis. Expression of the central GA biosynthesis gene, GA20oxidase2, and production of the bioactive GA, GA1, were significantly increased in elf3 leaves under SDs, relative to the wild type. Inhibition of GA biosynthesis suppressed the early flowering of elf3 under SDs independently of FT1 and was associated with altered expression of floral identity genes at the developing apex. GA is also required for normal flowering of spring barley under inductive photoperiods, with chemical and genetic attenuation of the GA biosynthesis and signaling pathways suppressing inflorescence development under long-day conditions. These findings illustrate that GA is an important floral promoting signal in barley and that ELF3 suppresses flowering under noninductive photoperiods by blocking GA production and FT1 expression. PMID:24781117

  11. Colorful Electrophoresis

    NSDL National Science Digital Library

    University of Utah

    2012-01-01

    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.

  12. Color constancy supports cross-illumination color selection

    PubMed Central

    Radonji?, Ana; Cottaris, Nicolas P.; Brainard, David H.

    2015-01-01

    We rely on color to select objects as the targets of our actions (e.g., the freshest fish, the ripest fruit). To be useful for selection, color must provide accurate guidance about object identity across changes in illumination. Although the visual system partially stabilizes object color appearance across illumination changes, how such color constancy supports object selection is not understood. To study how constancy operates in real-life tasks, we developed a novel paradigm in which subjects selected which of two test objects presented under a test illumination appeared closer in color to a target object presented under a standard illumination. From subjects' choices, we inferred a selection-based match for the target via a variant of maximum likelihood difference scaling, and used it to quantify constancy. Selection-based constancy was good when measured using naturalistic stimuli, but was dramatically reduced when the stimuli were simplified, indicating that a naturalistic stimulus context is critical for good constancy. Overall, our results suggest that color supports accurate object selection across illumination changes when both stimuli and task match how color is used in real life. We compared our selection-based constancy results with data obtained using a classic asymmetric matching task and found that the adjustment-based matches predicted selection well for our stimuli and instructions, indicating that the appearance literature provides useful guidance for the emerging study of constancy in natural tasks.

  13. Finding Colors

    NSDL National Science Digital Library

    2014-08-27

    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.

  14. Anthocyanin and Carotenoid Contents in Different Cultivars of Chrysanthemum (Dendranthema grandiflorum Ramat.) Flower.

    PubMed

    Park, Chang Ha; Chae, Soo Cheon; Park, Soo-Yun; Kim, Jae Kwang; Kim, Yong Joo; Chung, Sun Ok; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Park, Sang Un

    2015-01-01

    The flowers of twenty-three cultivars of Dendranthema grandiflorum Ramat. were investigated to determine anthocyanin and carotenoid levels and to confirm the effects of the pigments on the flower colors using high-performance liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (ESI-MS). The cultivars contained the anthocyanins cyanidin 3-glucoside (C3g) and cyanidin 3-(3"-malonoyl) glucoside (C3mg) and the following carotenoids: lutein, zeaxanthin, ?-cryptoxanthin, 13-cis-?-carotene, ?-carotene, trans-?-carotene, and 9-cis-?-carotene. The cultivar "Magic" showed the greatest accumulation of total and individual anthocyanins, including C3g and C3gm. On the other hand, the highest level of lutein and zeaxanthin was noted in the cultivar "Il Weol". The cultivar "Anastasia" contained the highest amount of carotenoids such as trans-?-carotene, 9-cis-?-carotene, and 13-cis-?-carotene. The highest accumulation of ?-cryptoxanthin and ?-carotene was noted in the cultivar "Anastasia" and "Il Weol". Our results suggested that 'Magic", "Angel" and "Relance' had high amounts of anthocyanins and showed a wide range of red and purple colors in their petals, whereas "Il Weol', "Popcorn Ball' and "Anastasia" produced higher carotenoid contents and displayed yellow or green petal colors. Interestingly, "Green Pang Pang", which contained a high level of anthocyanins and a medium level of carotenoids, showed the deep green colored petals. "Kastelli", had high level of carotenoids as well as a medium level of anthocyanins and showed orange and red colored petals. It was concluded that each pigment is responsible for the petal's colors and the compositions of the pigments affect their flower colors and that the cultivars could be a good source for pharmaceutical, floriculture, and pigment industries. PMID:26083041

  15. School Choice vs. School Choice. Policy Backgrounder.

    ERIC Educational Resources Information Center

    Goodman, John C.; Moore, Matt

    This paper recommends replacing the existing U.S. school choice system, which relies on the housing market to ration educational opportunity, with one that creates a level playing field upon which schools compete for students, and students and their parents exercise choice. Section 1 describes the current school choice system, which works well for…

  16. Ploidy analysis of azalea flower colour sports.

    PubMed

    De Schepper, S; De Loose, M; Van Bockstaele, E; Debergh, P

    2001-01-01

    Flower colour variegation is not only a phenomenon of importance to horticulture, the phenotype involved is also often used as a scientific model system for the study of complex gene regulation processes. In the course of such studies on azalea, we observed a correlation between flower colour patterns, flower morphology and somatic polyploidy. Using high-resolution flow cytometry of nuclear DNA, the ploidy level was determined in flowers of different azalea sport families. Sports exhibiting variegated flowers with broad (> 7mm), differently coloured, petal edges (picotee type) proved to be tetraploid in the petal edge while diploid in the rest of the flower tissue. Neither flower colour pattern nor ploidy differences are chimeral in origin, but seem to be correlated with the topographic location of the cells within the flower tissue, i.e. the margin of the petals. The possible role of gene dosage effects and cell size involved in the remarkable correlation between somatic polyploidy, (flavonoid) gene expression and the flower morphology is discussed. PMID:15954634

  17. Flavonoids from Abutilon theophrasti flowers.

    PubMed

    Mat?awska, Irena; Sikorska, Maria

    2005-01-01

    Nine flavonoid compounds: kaempferol 3-0-beta-(6"-p-coumaroyl)-glucopyranoside, myricetin 3-O-beta-glucopyranoside, quercetin 3-0-beta-glucopyranoside, quercetin 3-0-alpha-rhamnopyranosyl (1-->6)-beta-glucopyranoside, kaempferol 3-0-beta-glucopyranoside, kaempferol 3-0-alpha-rhamnopyranosyl (1-->6)-beta-glucopyranoside, quercetin 7-0-beta-glucoside, quercetin 7-0-beta-diglucoside, kaempferol 7-0-beta-diglucoside were isolated and identified from the flowers of Abutilon theophrasti. PMID:16161355

  18. Ornamental plumage coloration and condition are dependent on age in eastern bluebirds Sialia sialis

    Microsoft Academic Search

    Lynn Siefferman; Geoffrey E. Hill; F. Stephen Dobson

    2005-01-01

    Male eastern bluebirds Sialia sialis have striking ultraviolet (UV)-blue coloration on their heads, backs, rumps, wings, and tails and bold chestnut coloration on their breasts. These colored areas are ornaments that correlate with pairing date and reproductive effort, and thus probably influence the choice of mates by females. Such ornaments are expected to increase in color with age and body

  19. Colorful Mathematics

    NSDL National Science Digital Library

    Funded by Industry Canada's SchoolNet initiative with the cooperation of the Canadian Mathematical Society, Colorful Mathematics takes a game-oriented approach to teaching K-12 mathematics. The project has developed five coloring games that teach children about problem solving, and pattern identification, which "are all at the very heart of mathematics." The coloring approach makes difficult graph concepts "that are still the subject of active research by mathematicians, computer scientists and industry researchers" more accessible to children. The software program, which is available for free from this website, is set up to check for mistakes and challenge students to improve on their results. A Teacher's Corner section gives an overview of the games, "some sample questions for discussion with the curious student," and an overview of terminology used in the software program. The website is also available in French.

  20. Kool Colors

    NSDL National Science Digital Library

    Oregon Museum of Science and Industry

    2007-01-01

    Learners investigate how temperature affects the rate of chemical reactions by observing how steel wool reacts with various types of Kool-Aid solutions at different temperatures. The reaction is monitored as the color fades in the Kool-Aid solutions. Background information includes how the dyes change color from an oxidation-reduction reaction. Extensions include investigating how surface area and concentration affect reaction rate. Part of the "No Hassle Messy Science with a Wow" activity guide by OMSI, where all activities use only household materials.

  1. Experimental analysis of choice

    Microsoft Academic Search

    Richard R. Batsell; Jordan J. Louviere

    1991-01-01

    Our paper reviews and summarizes the state-of-the-art in the design and analysis of consumer choice experiments. We emphasize experiments involving discrete choices, but also review related work on the design and analysis of ranking and resource allocation experiments. Major topics include 1) Choice experiments and conjoint analysis, 2) Random utility and constant utility probabilistic discrete choice models as a theoretical

  2. Public School Choice.

    ERIC Educational Resources Information Center

    Hardy, Lawrence

    2000-01-01

    Currently 15 percent of K-12 students attend public schools of choice, including charter, magnet, and controlled-choice schools. Support for choice is growing, but a recent report says 81 percent of adults surveyed know little about charters or vouchers. Profiles of successful choice schools are presented. (MLH)

  3. Associating Polymers: From ``Flowers'' to Transient Networks

    Microsoft Academic Search

    Y. Séréro; R. Aznar; G. Porte; J.-F. Berret; D. Calvet; A. Collet; M. Viguier

    1998-01-01

    We report on a novel telechelic associating polymers that self-assemble in solution into starlike flowers in the dilute regime and develop a fully connected network of flowers above some threshold concentration phi*. Small-angle neutron scattering has been used to investigate the form and structure factors of the starlike aggregates, whereas linear rheology was performed to identify the viscoelastic features of

  4. Genetic control of flowering time in legumes.

    PubMed

    Weller, James L; Ortega, Raúl

    2015-01-01

    The timing of flowering, and in particular the degree to which it is responsive to the environment, is a key factor in the adaptation of a given species to various eco-geographic locations and agricultural practices. Flowering time variation has been documented in many crop legumes, and selection for specific variants has permitted significant expansion and improvement in cultivation, from prehistoric times to the present day. Recent advances in legume genomics have accelerated the process of gene identification and functional analysis, and opened up new prospects for a molecular understanding of flowering time adaptation in this important crop group. Within the legumes, two species have been prominent in flowering time studies; the vernalization-responsive long-day species pea (Pisum sativum) and the warm-season short-day plant soybean (Glycine max). Analysis of flowering in these species is now being complemented by reverse genetics capabilities in the model legumes Medicago truncatula and Lotus japonicus, and the emergence of genome-scale resources in a range of other legumes. This review will outline the insights gained from detailed forward genetic analysis of flowering time in pea and soybean, highlighting the importance of light perception, the circadian clock and the FT family of flowering integrators. It discusses the current state of knowledge on genetic mechanisms for photoperiod and vernalization response, and concludes with a broader discussion of flowering time adaptation across legumes generally. PMID:25914700

  5. 6, 1105111066, 2006 Sea ice, frost flowers

    E-print Network

    Paris-Sud XI, Université de

    ACPD 6, 11051­11066, 2006 Sea ice, frost flowers and halogen activation W. R. Simpson et al. Title Chemistry and Physics Discussions First-year sea-ice contact predicts bromine monoxide (BrO) levels better. Simpson (ffwrs@uaf.edu) 11051 #12;ACPD 6, 11051­11066, 2006 Sea ice, frost flowers and halogen activation

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

    PubMed Central

    2011-01-01

    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. PMID:21521532

  7. Pollinator experience, neophobia and the evolution of flowering time

    E-print Network

    Forrest, Jessica

    bearing genes for early flowering successfully reproduce; for non-selfing, zoophilous species, this means; for outcrossing, zoophilous species, this requires that early flowering individuals receive pollinator visits

  8. Examining Colors, Color Perception, and Sight

    NSDL National Science Digital Library

    John Eichinger

    2009-05-15

    Students of all ages are fascinated by color and how we perceive it. For the main activity in this chapter, your class explores colors and visual perception by mixing colors in several ways. Students learn more about colors, light, vision, and color compo

  9. Color Blind

    ERIC Educational Resources Information Center

    Reid, Karla Scoon

    2004-01-01

    This article talks about a colorblind plan that the Charlotte-Mecklenburg school district adopted for student assignment in 2002 that is producing more racially isolated schools, like Selwyn Elementary School, and more schools enrolling high concentrations of poor children. The 2-year-old plan gives parents a choice of schools and provides all…

  10. Insect Coloration

    Microsoft Academic Search

    G. D. Hale Carpenter

    1936-01-01

    PROF. ARMSTRONG'S criticisms are easily met. It is not going too far to ``assert that an insect deliberately hides''. The taking temporary shelter from sun is a different matter from assuming a position of complete rest in surroundings best suited to concealment for long periods. The case I mentioned was undoubtedly deliberate choice of a cluster of dead leaves, among

  11. 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.

  12. Choosing Choice: School Choice in International Perspective.

    ERIC Educational Resources Information Center

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

    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…

  13. America's Climate Choices, Maryland's Climate Choices

    E-print Network

    Maryland at College Park, University of

    America's Climate Choices, Maryland's Climate Choices Donald F. Boesch Department of Atmospheric on What We Know about Climate Change #12;MVN RSM Program Congress Requested Guidance about What to Do to global climate change and make recommendations regarding what steps must be taken and what strategies

  14. On the purposes of color for living beings: toward a theory of color organization.

    PubMed

    Pinna, Baingio; Reeves, Adam

    2015-01-01

    Phylogenetic and paleontological evidence indicates that in the animal kingdom the ability to perceive colors evolved independently several times over the course of millennia. This implies a high evolutionary neural investment and suggests that color vision provides some fundamental biological benefits. What are these benefits? Why are some animals so colorful? What are the adaptive and perceptual meanings of polychromatism? We suggest that in addition to the discrimination of light and surface chromaticity, sensitivity to color contributes to the whole, the parts and the fragments of perceptual organization. New versions of neon color spreading and the watercolor illusion indicate that the visual purpose of color in humans is threefold: to inter-relate each chromatic component of an object, thus favoring the emergence of the whole; to support a part-whole organization in which components reciprocally enhance each other by amodal completion; and, paradoxically, to reveal fragments and hide the whole-that is, there is a chromatic parceling-out process of separation, division, and fragmentation of the whole. The evolution of these contributions of color to organization needs to be established, but traces of it can be found in Harlequin camouflage by animals and in the coloration of flowers. PMID:24374380

  15. Flower opening and closure: an update.

    PubMed

    van Doorn, Wouter G; Kamdee, Chanattika

    2014-11-01

    This review is an update of a 2003 review (Journal of Experimental Botany 54,1801-1812) by the same corresponding author. Many examples of flower opening have been recorded using time-lapse photography, showing its velocity and the required elongation growth. Ethylene regulates flower opening, together with at least gibberellins and auxin. Ethylene and gibberellic acid often promote and inhibit, respectively, the expression of DELLA genes and the stability of DELLA proteins. DELLA results in growth inhibition. Both hormones also inhibited and promoted, respectively, the expression of aquaporin genes required for cell elongation. Arabidopsis miRNA319a mutants exhibited narrow and short petals, whereby miRNA319a indirectly regulates auxin effects. Flower opening in roses was controlled by a NAC transcription factor, acting through miRNA164. The regulatory role of light and temperature, in interaction with the circadian clock, has been further elucidated. The end of the life span in many flowers is determined by floral closure. In some species pollination resulted in earlier closure of turgid flowers, compared with unpollinated flowers. It is hypothesized that this pollination-induced effect is only found in flowers in which closure is regulated by ethylene. PMID:25135521

  16. A Regulatory Network for Coordinated Flower Maturation

    PubMed Central

    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.

    2012-01-01

    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

  17. Parameter choice methods for downward continuation

    NASA Astrophysics Data System (ADS)

    Gutting, Martin

    2015-04-01

    This presentation investigates the behavior of many parameter choice methods for the ill-posed problem of downward continuation, e.g., of satellite measurements. The corresponding regularization methods are spectral cut-off (i.e. truncation of the spherical harmonics expansion) and Tikhonov regularization. We present the result of a large number of scenarios with regard to white and colored stochastic noise. This study focuses on the stability of the parameter choice methods for different types of noise and identifies the most reliable methods.

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

    PubMed

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

    2010-04-15

    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

  19. Vascular occlusion in stems of cut rose flowers

    Microsoft Academic Search

    Doorn van W. G

    1993-01-01

    The quality of cut rose flowers, a major horticultural crop in the Netherlands, is often unsatisfactory. During vase-life premature signs of water stress occur, such as slow growth of the bud which often results in poor flower opening, wilting of both the flowers and the leaves, and bending of the stem just underneath the flower. These symptoms are due to

  20. Making Smart Food Choices

    MedlinePLUS

    ... Free Stuff Be a Partner Making Smart Food Choices Regular physical activity and a healthy diet go ... in hand. Go4Life points you to wise food choices important for good health: eat a variety of ...

  1. Experimental analysis of choice

    Microsoft Academic Search

    Richard R. Batsell; Jordan J. Louviere

    1991-01-01

    Our paper reviews and summarizes the state-of-the-art in the design and analysis of consumer choice experiments. We emphasize\\u000a experiments involving discrete choices, but also review related work on the design and analysis of ranking and resource allocation\\u000a experiments. Major topics include 1) Choice experiments and conjoint analysis, 2) Random utility and constant utility probabilistic\\u000a discrete choice models as a theoretical

  2. Recent Advances of Flowering Locus T Gene in Higher Plants

    PubMed Central

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

    2012-01-01

    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. PMID:22489182

  3. Recent advances of flowering locus T gene in higher plants.

    PubMed

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

    2012-01-01

    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. PMID:22489182

  4. biotechnologies: technology, choice

    E-print Network

    Sussex, University of

    Emerging biotechnologies: technology, choice and the public good #12;Nuf eld Council on Bioethics on Bioethics or visit the website. http://www.espcolour.co.uk #12;Emerging biotechnologies: technology, choice-opted member of the Council while chairing the Working Party on Emerging biotechnologies: technology, choice

  5. FLOWERING LOCUS C encodes a novel MADS domain protein that acts as a repressor of flowering.

    PubMed Central

    Michaels, S D; Amasino, R M

    1999-01-01

    Winter-annual ecotypes of Arabidopsis are relatively late flowering, unless the flowering of these ecotypes is promoted by exposure to cold (vernalization). This vernalization-suppressible, late-flowering phenotype results from the presence of dominant, late-flowering alleles at two loci, FRIGIDA (FRI) and FLOWERING LOCUS C (FLC). In this study, we report that flc null mutations result in early flowering, demonstrating that the role of active FLC alleles is to repress flowering. FLC was isolated by positional cloning and found to encode a novel MADS domain protein. The levels of FLC mRNA are regulated positively by FRI and negatively by LUMINIDEPENDENS. FLC is also negatively regulated by vernalization. Overexpression of FLC from a heterologous promoter is sufficient to delay flowering in the absence of an active FRI allele. We propose that the level of FLC activity acts through a rheostat-like mechanism to control flowering time in Arabidopsis and that modulation of FLC expression is a component of the vernalization response. PMID:10330478

  6. Antimicrobial activity of flowers from Anthemis cotula

    Microsoft Academic Search

    M. V Quarenghi; M. L Tereschuk; M. D Baigori; L. R Abdala

    2000-01-01

    The flavonoid containing total extract of Anthemis cotula flowers, tested at the concentration of 200 ?g\\/ml, showed interesting antimicrobial activity against both Gram-negative and Gram-positive microorganisms.

  7. Antimicrobial activity of flowers from Anthemis cotula.

    PubMed

    Quarenghi, M V; Tereschuk, M L; Baigori, M D; Abdala, L R

    2000-12-01

    The flavonoid containing total extract of Anthemis cotula flowers, tested at the concentration of 200 microg/ml, showed interesting antimicrobial activity against both Gram-negative and Gram-positive microorganisms. PMID:11077183

  8. Brainard Color Constancy 1 Color Constancy

    E-print Network

    Brainard, David H.

    out likely candidates; our driver's licenses list the color of our eyes and hair for identificationBrainard Color Constancy 1 1 Color Constancy We would rather eat a banana that looks yellow rather than one that looks green, as the banana's color appearance carries reliable information about its

  9. PLANT BIOLOGY: Flower Arranging in Arabidopsis

    NSDL National Science Digital Library

    Paul F. Devlin (Scripps Research Institute; Department of Cell Biology and National Science Foundation for Biological Timing)

    2000-06-02

    Access to the article is free, however registration and sign-in are required. The flowering of plants in response to changes in day length and temperature is controlled by three intricate signaling pathways. In this Perspective, Devlin and Kay examine new research (Samach et al.) that shows how signals from the three pathways converge on the promoters of several key genes to bring about flowering in the model plant Arabidopsis.

  10. PLANT SCIENCES: Deciding When to Flower

    NSDL National Science Digital Library

    Ruth Bastow (John Innes Centre; Department of Cell and Developmental Biology)

    2003-12-05

    Access to the article is free, however registration and sign-in are required. Plants must carefully time the switch from vegetative growth to floral production in order to take advantage of optimal environmental conditions. In their Perspective, Bastow and Dean discuss new work (He et al.) that reveals an elegant mechanism, involving chromatin remodeling of a genetic locus encoding a flowering repressor, which enables plants to regulate flowering time.

  11. Flowering induction of Guzmania by ethylene

    Microsoft Academic Search

    Danijela Dukovski; Robert Bernatzky; Susan Han

    2006-01-01

    Ethylene exposure time required to induce flowering of Guzmania lingulata Mez. ‘Anita’ was investigated by exposing plants to ethylene at 100?ll?1 for 4, 6, 8, 10, 12, 16, or 24h. Plants were also exposed to ethylene-free air for the same lengths of time. Plants exposed to ethylene for 4h did not flower, but exposure for 6h or longer resulted in

  12. Flower solid modeling based on sketches

    Microsoft Academic Search

    Zhan Ding; Shu-chang Xu; Xiu-zi Ye; Yin Zhang; San-yuan Zhang

    2008-01-01

    In this paper we propose a method to model flowers of solid shape. Based on (Ijiri et al., 2005)’s method, we separate individual flower modeling and inflorescence modeling procedures into structure and geometry\\u000a modeling. We incorporate interactive editing gestures to allow the user to edit structure parameters freely onto structure\\u000a diagram. Furthermore, we use free-hand sketching techniques to allow users

  13. Is the flower fluorescence relevant in biocommunication?

    Microsoft Academic Search

    Analía Iriel; María Gabriela Lagorio

    2010-01-01

    Flower fluorescence has been previously proposed as a potential visual signal to attract pollinators. In this work, this point\\u000a was addressed by quantitatively measuring the fluorescence quantum yield (?\\u000a 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

  14. Do focal colors look particularly "colorful"?

    PubMed

    Witzel, Christoph; Franklin, Anna

    2014-04-01

    If the most typical red, yellow, green, and blue were particularly colorful (i.e., saturated), they would "jump out to the eye." This would explain why even fundamentally different languages have distinct color terms for these focal colors, and why unique hues play a prominent role in subjective color appearance. In this study, the subjective saturation of 10 colors around each of these focal colors was measured through a pairwise matching task. Results show that subjective saturation changes systematically across hues in a way that is strongly correlated to the visual gamut, and exponentially related to sensitivity but not to focal colors. PMID:24695195

  15. DNA Methylation, Vernalization, and the Initiation of Flowering

    Microsoft Academic Search

    J. E. Burn; D. J. Bagnall; J. D. Metzger; E. S. Dennis; W. J. Peacock

    1993-01-01

    Late-flowering ecotypes and mutants of Arabidopsis thaliana and the related crucifer Thlaspi arvense flower early after cold treatment (vernalization). Treatment with the DNA demethylating agent 5-azacytidine induced nonvernalized plants to flower significantly earlier than untreated controls. Cytidine at similar concentrations had no effect on time to flower. In contrast, late-flowering mutants that are insensitive to vernalization did not respond to

  16. Synchrony in the phenology of a culturally iconic spring flower

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    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.

  17. Phytochrome, plant growth and flowering

    NASA Technical Reports Server (NTRS)

    King, R. W.; Bagnall, D. J.

    1994-01-01

    Attempts to use artificially lit cabinets to grow plants identical to those growing in sunlight have provided compelling evidence of the importance of light quality for plant growth. Changing the balance of red (R) to far-red (FR) radiation, but with a fixed photosynthetic input can shift the phytochrome photoequilibrium in a plant and generate large differences in plant growth. With FR enrichment the plants elongate, and may produce more leaf area and dry matter. Similar morphogenic responses are also obtained when light quality is altered only briefly (15-30 min) at the end-of-the-day. Conversely, for plants grown in natural conditions the response of plant form to selective spectral filtering has again shown that red and far-red wavebands are important as found by Kasperbauer and coworkers. Also, where photosynthetic photon flux densities (PPFD) of sunlight have been held constant, the removal of far-red alone alters plant growth. With FR depletion plants grown in sunlight are small, more branched and darker green. Here we examine the implications for plant growth and flowering when the far-red composition of incident radiation in plant growth chambers is manipulated.

  18. Color Object Recognition Based On Clifford Fourier Transform

    E-print Network

    Paris-Sud XI, Université de

    (Scale-Invariant Feature Transform) descriptors are a popular choice giving very good results [11Color Object Recognition Based On Clifford Fourier Transform Jose Mennesson, Christophe Saint recognition, both using the recently defined color Clifford Fourier transform. The first one deals with so

  19. Strawberry homologue of terminal flower1 integrates photoperiod and temperature signals to inhibit flowering.

    PubMed

    Rantanen, Marja; Kurokura, Takeshi; Jiang, Panpan; Mouhu, Katriina; Hytönen, Timo

    2015-04-01

    Photoperiod and temperature are major environmental signals affecting flowering in plants. Although molecular pathways mediating these signals have been well characterized in the annual model plant Arabidopsis, much less information is known in perennials. Many perennials including the woodland strawberry (Fragaria vesca L.) are induced to flower in response to decreasing photoperiod and temperature in autumn and they flower following spring. We showed earlier that, in contrast with Arabidopsis, the photoperiodic induction of flowering in strawberry occurs in short days (SD) when the decrease in FvFT1 (flowering locus T) and FvSOC1 (suppressor of the overexpression of constans1) expression leads to lower mRNA levels of the floral repressor, FvTFL1 (terminal flower1). By using transgenic lines and gene expression analyses, we show evidence that the temperature-mediated changes in the FvTFL1 mRNA expression set critical temperature limits for the photoperiodic flowering in strawberry. At temperatures below 13 °C, low expression level of FvTFL1 in both SD and long days (LD) allows flower induction to occur independently of the photoperiod. Rising temperature gradually increases FvTFL1 mRNA levels under LD, and at temperatures above 13 °C, SD is required for the flower induction that depends on the deactivation of FvSOC1 and FvTFL1. However, an unknown transcriptional activator, which functions independently of FvSOC1, enhances the expression of FvTFL1 at 23 °C preventing photoperiodic flowering. We suggest that the observed effect of the photoperiod × temperature interaction on FvTFL1 mRNA expression may allow strawberry to induce flowers in correct time in different climates. PMID:25720985

  20. Effects of Stimulus Duration and Choice Delay on Visual Categorization in Pigeons

    ERIC Educational Resources Information Center

    Lazareva, Olga F.; Wasserman, Edward A.

    2009-01-01

    We [Lazareva, O. F., Freiburger, K. L., & Wasserman, E. A. (2004). "Pigeons concurrently categorize photographs at both basic and superordinate levels." "Psychonomic Bulletin and Review," 11, 1111-1117] previously trained four pigeons to classify color photographs into their basic-level categories (cars, chairs, flowers, or people) or into their…

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

    NASA Astrophysics Data System (ADS)

    Hutchings, John

    2002-06-01

    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.

  2. 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

    JUNO MCKEE; A. J. RICHARDS

    1998-01-01

    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,

  3. THE EFFECT OF 6BENZYLADENINE ON Astilbe ? arendsii ARENDS 'AMETHYST' FLOWERING CULTIVATED FOR CUT FLOWERS

    Microsoft Academic Search

    Elbieta Pogroszewska; Patrycja Sadkowska

    The effect of benzyladenine on Astilbe ? arendsii Arends flowering was deter- mined. The cultivation of Astilbe ? arendsii in an unheated plastic tunnel reduces the in- florescence yield in the first and second year of flowering as compared to the field, but in- creases the fresh weight and lenght of inflorescence stems.

  4. Ciborinia gentianae sp. nov., the causal organism of sclerotial flower blight of cut-flower gentians

    Microsoft Academic Search

    Izumi Saito; Kazuhiko Kaji

    2006-01-01

    A new Ciborinia causing sclerotial flower blight of cut-flower gentians (Gentiana triflora var. japonica and interspecific hybrids between related species or varieties) is described as Ciborinia gentianae on the morphological basis of sclerotia and apothecia. The characteristics of Ciborinia gentianae are (1) an abundant production of spermodochia in the hollow cavity of host stems; (2) flat and thin sclerotia produced

  5. Flower Volatiles, Crop Varieties and Bee Responses

    PubMed Central

    Klatt, Björn K.; Burmeister, Carina; Westphal, Catrin; Tscharntke, Teja; von Fragstein, Maximillian

    2013-01-01

    Pollination contributes to an estimated one third of global food production, through both the improvement of the yield and the quality of crops. Volatile compounds emitted by crop flowers mediate plant-pollinator interactions, but differences between crop varieties are still little explored. We investigated whether the visitation of crop flowers is determined by variety-specific flower volatiles using strawberry varieties (Fragaria x ananassa Duchesne) and how this affects the pollination services of the wild bee Osmia bicornis L. Flower volatile compounds of three strawberry varieties were measured via headspace collection. Gas chromatography showed that the three strawberry varieties produced the same volatile compounds but with quantitative differences of the total amount of volatiles and between distinct compounds. Electroantennographic recordings showed that inexperienced females of Osmia bicornis had higher antennal responses to all volatile compounds than to controls of air and paraffin oil, however responses differed between compounds. The variety Sonata was found to emit a total higher level of volatiles and also higher levels of most of the compounds that evoked antennal responses compared with the other varieties Honeoye and Darselect. Sonata also received more flower visits from Osmia bicornis females under field conditions, compared with Honeoye. Our results suggest that differences in the emission of flower volatile compounds among strawberry varieties mediate their attractiveness to females of Osmia bicornis. Since quality and quantity of marketable fruits depend on optimal pollination, a better understanding of the role of flower volatiles in crop production is required and should be considered more closely in crop-variety breeding. PMID:23977347

  6. Flower power: Tree flowering phenology as a settlement cue for migrating birds

    USGS Publications Warehouse

    McGrath, L.J.; van Riper, Charles, III; Fontaine, J.J.

    2009-01-01

    1. Neotropical migrant birds show a clear preference for stopover habitats with ample food supplies; yet, the proximate cues underlying these decisions remain unclear. 2. For insectivorous migrants, cues associated with vegetative phenology (e.g. flowering, leaf flush, and leaf loss) may reliably predict the availability of herbivorous arthropods. Here we examined whether migrants use the phenology of five tree species to choose stopover locations, and whether phenology accurately predicts food availability. 3. Using a combination of experimental and observational evidence, we show migrant populations closely track tree phenology, particularly the flowering phenology of honey mesquite (Prosopis glandulosa), and preferentially forage in trees with more flowers. Furthermore, the flowering phenology of honey mesquite reliably predicts overall arthropod abundance as well as the arthropods preferred by migrants for food. 4. Together, these results suggest that honey mesquite flowering phenology is an important cue used by migrants to assess food availability quickly and reliably, while in transit during spring migration. ?? 2008 The Authors.

  7. Disruptive Coloration

    NSDL National Science Digital Library

    David Ipsen

    2009-04-01

    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.

  8. Flowering time control in European winter wheat

    PubMed Central

    Langer, Simon M.; Longin, C. Friedrich H.; Würschum, Tobias

    2014-01-01

    Flowering time is an important trait in wheat breeding as it affects adaptation and yield potential. The aim of this study was to investigate the genetic architecture of flowering time in European winter bread wheat cultivars. To this end a population of 410 winter wheat varieties was evaluated in multi-location field trials and genotyped by a genotyping-by-sequencing approach and candidate gene markers. Our analyses revealed that the photoperiod regulator Ppd-D1 is the major factor affecting flowering time in this germplasm set, explaining 58% of the genotypic variance. Copy number variation at the Ppd-B1 locus was present but explains only 3.2% and thus a comparably small proportion of genotypic variance. By contrast, the plant height loci Rht-B1 and Rht-D1 had no effect on flowering time. The genome-wide scan identified six QTL which each explain only a small proportion of genotypic variance and in addition we identified a number of epistatic QTL, also with small effects. Taken together, our results show that flowering time in European winter bread wheat cultivars is mainly controlled by Ppd-D1 while the fine tuning to local climatic conditions is achieved through Ppd-B1 copy number variation and a larger number of QTL with small effects. PMID:25346745

  9. Late-Flowering Species are Sensitive to Warming

    NASA Astrophysics Data System (ADS)

    Carter, D. L.; VanderWeide, B. L.

    2012-12-01

    Phenological advancement is one of the most prevalent responses of vegetation to warming. The prevailing view is that that early flowering species are particularly sensitive warming, with greater phenological advancement per °C warming relative to later flowering species. However, we observed a three to four month advancement of late flowering species to the extreme warmth of 2012, which motivated us to ask quantitatively whether late flowering species are indeed less sensitive to warming. We focused on responses to inter-annual variation in mean monthly, seasonal, and annual temperatures, using species for which we have ?10 observations of first flowering near Manhattan, KS between 1891 and 2012 (n = 259). As many other studies have found, early flowering species advanced flowering with warmer temperatures during the year preceding flowering, while late flowering species appeared insensitive to warming during the year preceding flowering. At the seasonal time scale, however, both early and late flowering species responded similarly to spring warming, while late flowering species delayed flowering in response to summer warmth. This divergent response created the illusion that later flowering species were insensitive to temperatures during the year preceding flowering. When absolute values of sensitivities to temperature were summed across months, late flowering species exhibited greater sensitivity to temperature than early flowering species. Late-flowering species were also the most sensitive to variation in precipitation and advanced flowering when summers were wet. We therefore speculate that flowering for late species is delayed by warm, dry summers because both warmth and dryness exacerbate plant water stress and delay growth. Furthermore, warm spring temperatures might allow both early and late flowering species to more quickly attain size or developmental requirements for flowering. Advanced flowering in 2012 provides an extreme example of some typically late species reaching these requirements prior to summer. Based on this analysis, we urge caution in analyses of plant sensitivity to warming. Our findings cast doubt on whether late species are indeed less sensitive to warming or generally delay flowering in response to warming and highlight the need to better incorporate the timing of climate variability when predicting how climate change will affect the timing of life events.

  10. Color Perception Optical Illusions

    NSDL National Science Digital Library

    This website from eChalk contains optical illusions offering proof that our color perception is strongly influenced by surrounding colors. The site also includes educational games related to optical illusions and color.

  11. Female American goldfinches use carotenoid-based bill coloration to signal status

    Microsoft Academic Search

    Troy G. Murphy; Malcolm F. Rosenthal; Robert Montgomerie; Keith A. Tarvinc

    2009-01-01

    Interest in female ornamentation has burgeoned recently, and evidence suggests that carotenoid-based female coloration may function as a mate-choice signal. However, the possibility that females may signal status with coloration has been all but ignored. Bill coloration of female American goldfinches (Spinus tristis) changes seasonally, from dull gray in winter to bright orange in the breeding season. We conducted a

  12. Theory of color symmetry for periodic and quasiperiodic crystals Ron Lifshitz*

    E-print Network

    Lifshitz, Ron

    of isomorphism between L/L0 and e 1192 3. L0 is the lattice of the color-blind density 1192 4. Canonical choiceTheory of color symmetry for periodic and quasiperiodic crystals Ron Lifshitz* Condensed Matter a theory of color symmetry applicable to the description and classification of periodic as well

  13. THE EXPRESSION OF THE GENE FOR LYCOPENE ¿-CYCLASE IS ELEVATED IN LEAVES AND FLOWERS AND DOWN-REGULATED IN BOTH YELLOW- AND RED- FLESHED PAPAYA FRUITS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carotene pigments in flowers and fruits are distinct features related to fitness advantages such as attracting insects for pollination and birds for seeds disposal. In papaya, the flesh color of fruit is considered a quality trait that varies in nutritional values and is linked to shelf life of the ...

  14. Tiger cubs and little flowers.

    PubMed

    1993-01-01

    Short vignettes are related to show the conditions for girls and women in Morocco. Descriptions are given for child labor, literacy, the government's education campaign, youth group efforts to enhance family planning (FP) knowledge, the impact of FP outreach in rural areas, and unmarried mothers. In Morocco's cities, young boys can be seen hawking cigarettes and working in market stalls; in the countryside, boys herd goats or do other farm work. In rural areas girls are hidden by having them perform work around the house or on the farm primarily indoors. Women are supervised by women. 54% work as maids and 39% are apprentices in carpet factories. Parents prefer to have their daughters working and consider it protection from mischief as well as needed income. Only 60% of girls are enrolled in primary school vs. 80% of the boys. In rural areas, only 44% of girls are enrolled, and 20% stay to complete their primary education, while 76% of boys enroll and 63% complete primary school. Literacy of women has an effect on the ability to accurately take birth control pills. All ages of women gather at schools in the evening for lessons in reading and writing in a program supported by the King. Women are pleased with their success in just learning how to write their own names. Television advertisements promote sending children to school, as another part of the Ministry of Education's campaign to increase girl's educational status. There are still not enough schools; many schools are double shift, and communities are building their own schools. Youth clubs, which refer to boys as "tiger cubs" and girls as "little flowers," try to familiarize young people with some basic information about contraception. A traditional midwife relates some problems with girl's education: costs for clothing and supplies, worry about male teachers, and poor role models. In some remote areas, farm families do not send their children to school, because of the distance to schools and the need for farm workers. Husbands divorce wives for not producing children, and turn away FP workers who knock on their doors. Unmarried mothers aged 14-19 are usually illiterate and poor and cannot afford abortion. Orphanages are full. FP is practiced only by the married, after having proven their fertility. PMID:12318178

  15. Are pollinators the agents of selection for the extreme large size and dark color in Oncocyclus irises?

    PubMed

    Lavi, Renana; Sapir, Yuval

    2015-01-01

    Pollinator-mediated selection is a major evolutionary driver of floral traits; yet, such selection has rarely been tested for floral extreme traits. The Oncocyclus irises have exceptionally large, dark-colored flowers, associated with night-sheltering pollination and heat reward by the dark flowers. We quantified phenotypic selection on stem length, floral size and color in two species of iris (Iris atropurpurea and I. haynei), using an experimental approach. We estimated selection gradients for both flowers open to natural pollination and for flowers receiving supplementary hand pollination, assuming that open-pollinated flowers are affected by all factors that could influence fitness, whereas supplementary pollination removes the possible influence of pollinators. We found evidence for pollinator-mediated selection to increase floral size and stem length in I. atropurpurea, but floral color in this species was not under pollinator-mediated selection. In I. haynei, no pollinator-mediated selection on any of the traits was detected. We conclude that the extreme floral size of I. atropurpurea has probably evolved as a result of pollinator behavior. Lack of such evidence for I. haynei and for the dark floral color in both species suggests that other non-pollinator agents are selecting for these prominent traits, or that phenotypic color variation in these irises is neutral. PMID:25157604

  16. Water heaters and energy conservation - choices, choices!

    Microsoft Academic Search

    L. Weingarten; S. Weingarten

    1996-01-01

    This article reviews how to best find an energy efficient water heating system. Most people already know they should look for energy efficiency from the heater itself but additional savings can be found in water distribution, equipment sizing and selection and maintenance. Topic areas in the article include the following: is a new water heater needed; new heater choices; heater

  17. Orchid flowers tolerance to gamma-radiation

    NASA Astrophysics Data System (ADS)

    Kikuchi, Olivia Kimiko

    2000-03-01

    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.

  18. The FLOWERING LOCUS T/TERMINAL FLOWER 1 Gene Family: Functional Evolution and Molecular Mechanisms.

    PubMed

    Wickland, Daniel P; Hanzawa, Yoshie

    2015-07-01

    In plant development, the flowering transition and inflorescence architecture are modulated by two homologous proteins, FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1). The florigen FT promotes the transition to reproductive development and flowering, while TFL1 represses this transition. Despite their importance to plant adaptation and crop improvement and their extensive study by the plant community, the molecular mechanisms controlling the opposing actions of FT and TFL1 have remained mysterious. Recent studies in multiple species have unveiled diverse roles of the FT/TFL1 gene family in developmental processes other than flowering regulation. In addition, the striking evolution of FT homologs into flowering repressors has occurred independently in several species during the evolution of flowering plants. These reports indicate that the FT/TFL1 gene family is a major target of evolution in nature. Here, we comprehensively survey the conserved and diverse functions of the FT/TFL1 gene family throughout the plant kingdom, summarize new findings regarding the unique evolution of FT in multiple species, and highlight recent work elucidating the molecular mechanisms of these proteins. PMID:25598141

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

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

    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.

  20. More Choice, Less Crime

    ERIC Educational Resources Information Center

    Dills, Angela K.; Hernandez-Julian, Rey

    2011-01-01

    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…

  1. Attention in risky choice.

    PubMed

    Brandstätter, Eduard; Körner, Christof

    2014-10-01

    Previous research on the processes involved in risky decisions has rarely linked process data to choice directly. We used a simple measure based on the relative amount of attentional deployment to different components (gains/losses and their probabilities) of a risky gamble during the choice process, and we related this measure to the actual choice. In an experiment we recorded the decisions, decision times, and eye movements of 80 participants who made decisions on 11 choice problems. We used the number of eye fixations and fixation transitions to trace the deployment of attention during the choice process and obtained the following main results. First, different components of a gamble attracted different amounts of attention depending on participants' actual choice. This was reflected in both the number of fixations and the fixation transitions. Second, the last-fixated gamble but not the last-fixated reason predicted participants' choices. Third, a comparison of data obtained with eye tracking and data obtained with verbal protocols from a previous study showed a large degree of convergence regarding the process of risky choice. Together these findings tend to support dimensional decision strategies such as the priority heuristic. PMID:25226548

  2. Making School Choice Work

    ERIC Educational Resources Information Center

    DeArmond, Michael; Jochim, Ashley; Lake, Robin

    2014-01-01

    School choice is increasingly the new normal in urban education. But in cities with multiple public school options, how can civic leaders create a choice system that works for all families, whether they choose a charter or district public school? To answer this question, the Center on Reinventing Public Education (CRPE) researchers surveyed 4,000…

  3. Children's Choices for 2008

    ERIC Educational Resources Information Center

    Reading Teacher, 2008

    2008-01-01

    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…

  4. Latinos and School Choice

    ERIC Educational Resources Information Center

    Gastic, Billie; Coronado, Diana Salas

    2011-01-01

    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.…

  5. My favourite flowering image: the role of cytokinin as a flowering signal.

    PubMed

    Bernier, Georges

    2013-12-01

    My favourite flowering image shows a section in a shoot apical meristem of Sinapis alba undertaking the very first step of its transition to flowering. This step is the activation of the SaSOC1 gene, the Sinapis orthologue of Arabidopsis SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1), in a few central cells of the meristem. Hidden behind this picture is my long quest of physiological signals controlling flowering. Milestones of this story are briefly recounted here and this gives me an opportunity to raise a number of questions about the nature and function of florigen. PMID:21586428

  6. ORIGINAL ARTICLE Artificial selection shifts flowering phenology and

    E-print Network

    Galloway, Laura F.

    ORIGINAL ARTICLE Artificial selection shifts flowering phenology and other correlated traits with shifts in flowering phenologies. We conducted a three-generation artificial selection experiment to a changing climate, phenological shifts may be associated with reduced plant fitness possibly hindering

  7. Polymorphism of the Flower-heads of Centaurea Jacea

    Microsoft Academic Search

    Hermann Müller

    1882-01-01

    IN Centaurea Facea, the flower-heads of the same stem, as far as I have seen, are always of the same form, but different stems of the same locality often present astonishing difference in their flower-heads.

  8. Does flower phenology mirror the slowdown of global warming?

    PubMed Central

    Jochner, Susanne; Menzel, Annette

    2015-01-01

    Although recent global warming trends in air temperature are not as pronounced as those observed only one decade ago, global mean temperature is still at a very high level. Does plant phenology – which is believed to be a suitable indicator of climate change – respond in a similar way, that is, does it still mirror recent temperature variations? We explored in detail long-term flowering onset dates of snowdrop, cherry, and lime tree and relevant spring temperatures at three sites in Germany (1901–2012) using the Bayesian multiple change-point approach. We investigated whether mean spring temperature changes were amplified or slowed down in the past decade and how plant phenology responded to the most recent temperature changes. Incorporating records with different end points (i.e., 2002 and 2012), we compared differences in trends and inferred possible differences caused by extrapolating phenological and meteorological data. The new multiple-change point approach is characterized by an enhanced structure and greater flexibility compared to the one change point model. However, the highest model probabilities for phenological (meteorological) records were still obtained for the one change point (linear) model. Marked warming trends in the recent decade were only revealed for mean temperatures of March to May, here better described with one or two change point models. In the majority of cases analyzed, changes in temperatures were well mirrored by phenological changes. However, temperatures in March to May were linked to less strongly advancing onset dates for lime tree flowering during the period 1901-2012, pointing to the likely influence of photoperiodic constraints or unfulfilled chilling requirements. Due to the slowdown of temperature increase, analyses conducted on records ending in 2002 demonstrated distinct differences when compared with records ending in 2012. Extrapolation of trends could therefore (along with the choice of the statistical method) lead to distinctly different results and most recent data should be integrated in order not to over- or underestimate future phenological changes.

  9. Does flower phenology mirror the slowdown of global warming?

    PubMed

    Jochner, Susanne; Menzel, Annette

    2015-06-01

    Although recent global warming trends in air temperature are not as pronounced as those observed only one decade ago, global mean temperature is still at a very high level. Does plant phenology - which is believed to be a suitable indicator of climate change - respond in a similar way, that is, does it still mirror recent temperature variations? We explored in detail long-term flowering onset dates of snowdrop, cherry, and lime tree and relevant spring temperatures at three sites in Germany (1901-2012) using the Bayesian multiple change-point approach. We investigated whether mean spring temperature changes were amplified or slowed down in the past decade and how plant phenology responded to the most recent temperature changes. Incorporating records with different end points (i.e., 2002 and 2012), we compared differences in trends and inferred possible differences caused by extrapolating phenological and meteorological data. The new multiple-change point approach is characterized by an enhanced structure and greater flexibility compared to the one change point model. However, the highest model probabilities for phenological (meteorological) records were still obtained for the one change point (linear) model. Marked warming trends in the recent decade were only revealed for mean temperatures of March to May, here better described with one or two change point models. In the majority of cases analyzed, changes in temperatures were well mirrored by phenological changes. However, temperatures in March to May were linked to less strongly advancing onset dates for lime tree flowering during the period 1901-2012, pointing to the likely influence of photoperiodic constraints or unfulfilled chilling requirements. Due to the slowdown of temperature increase, analyses conducted on records ending in 2002 demonstrated distinct differences when compared with records ending in 2012. Extrapolation of trends could therefore (along with the choice of the statistical method) lead to distinctly different results and most recent data should be integrated in order not to over- or underestimate future phenological changes. PMID:26078862

  10. Mutation in TERMINAL FLOWER1 reverses the photoperiodic requirement for flowering in the wild strawberry Fragaria vesca.

    PubMed

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

    2012-07-01

    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. PMID:22566495

  11. Field methods for sampling and storing nectar from flowers with low nectar volumes

    PubMed Central

    Morrant, D. S.; Schumann, R.; Petit, S.

    2009-01-01

    Background and Aims Although several methods of sampling and storing floral nectar are available, little information exists on sampling and storing nectar from flowers with low nectar volumes. Methods for sampling and storing nectar from the flowers of species with low floral nectar volumes (<1 µL) were investigated using the flowers of Eucalyptus species. Methods Sampling with microcapillary tubes, blotting up with filter paper, washing and rinsing were compared to determine masses of sugars recovered and differences in sugar ratios. Storage methods included room temperature, refrigeration and freezing treatments; the addition of antimicrobial agents benzyl alcohol or methanol to some of these treatments was also evaluated. Nectar samples were analysed using high-performance liquid chromatography and the masses of sucrose, glucose and fructose in each sample were determined. Key Results Masses of sugars varied significantly among sampling treatments, but the highest yielding methods, rinsing and washing, were not significantly different. A washing time of 1 min was as effective as one of 20 min. Storage trials showed that the sugar concentration measurements of nectar solutions changed rapidly, with the best results achieved for refrigeration with no additive (sucrose and fructose were stable for at least 2 weeks). Sugar ratios, however, remained relatively stable in most treatments and did not change significantly across 4 weeks for the methanol plus refrigerator and freezing treatments, and 2 weeks for the refrigeration treatment with no additive. Conclusions Washing is recommended for nectar collection from flowers with low nectar volumes in the field (with the understanding that one wash underestimates the amounts of sugars present in a flower), as is immediate analysis of sugar mass. In view of the great variation in results depending on nectar collection and storage methods, caution should be exercised in their choice, and their accuracy should be evaluated. The use of pulsed amperometric detection, more specific than refractive index detection, may improve the accuracy of nectar sugar analysis. PMID:19074446

  12. Honeybees mark with scent and reject recently visited flowers

    Microsoft Academic Search

    Martin Giurfa; Josué A. Núñez

    1992-01-01

    Experimental evidence is reported for flower-marking by honeybees (Apis mellifera ligustica) while they were foraging on an artificial patch of flowers yielding a continuous and equal flow of sucrose solution. Honeybees marked with scent and rejected all recently visited and nectar-depleted flowers. The short fade-out time of this scent allowed discrimination of flowers that temporarily provided no food. The repellent

  13. Monosaccharides promote flowering in Kniphofia leucocephala in vitro

    Microsoft Academic Search

    Nicolette J. Taylor; Marnie E. Light; Johannes Van Staden

    2007-01-01

    An investigation into the role of carbohydrates in flowering of the endangered species Kniphofia leucocephala Baijnath. (Asphodelaceae) in vitro revealed that a carbohydrate source is essential for the induction of inflorescences.\\u000a Both the concentration and type of sugar influenced the percentage of flowering, with 60 g l?1 fructose and 10 ?M N6-benzyladenine (BA) inducing the best flowering response. A high percentage of flowering

  14. Variation of L-DOPA in the leaf and flower tissues of seven faba bean accessions with different flower colors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Faba bean (Vicia faba L.) has been selected to adapt to a wide range of environments worldwide and is grown for different end-uses such as food, feed, forage and green manure. Particularly noteworthy in faba bean is the medicinally important component L-3,4-dihydroxy phenylalanine (L-DOPA), the majo...

  15. 2012 Virginia Polytechnic Institute and State University HORT-24 Virginia Cooperative Extension programs and employment are open to all, regardless of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or

    E-print Network

    Liskiewicz, Maciej

    programs and employment are open to all, regardless of race, color, national origin, sex, religion, age species that also have very showy flowers. The Gresham hybrid series and the Little Girl hybrid series

  16. Dependency of boosted tagging algorithms on the event color structure

    NASA Astrophysics Data System (ADS)

    Joshi, K.; Pilkington, A. D.; Spannowsky, M.

    2012-12-01

    The impact of event color structure on the performance of the johns-hopkins, cms, heptoptagger and n-subjettiness algorithms is investigated by studying color singlet and color octet resonances decaying to top-quark pairs. Large differences in top-tagging efficiency are observed due to the different color charge of each resonance. These differences are quantified as a function of the algorithm parameters, the jet size parameter and the probability to misidentify light quarks and gluons as top candidates. We suggest that future experimental searches would benefit from optimizing the choice of algorithm parameters in order to minimize this source of model dependency.

  17. "Flowering Dogwood New Hampshire's Big Tree for May"

    E-print Network

    New Hampshire, University of

    simplicity of the clear white flowers of native dogwood trees (Cornus floridia) that grow along forest edges of the blossoms on boughs laden with flowers. Most yards had both pink and white trees creating a beautiful"Flowering Dogwood New Hampshire's Big Tree for May" By Anne Krantz, NH Big Tree Team The elegant

  18. Original article Nectar and flower production in Vicia faba L

    E-print Network

    Paris-Sud XI, Université de

    of crops such as tomato, let- tuce and cucumber (Wittwer and Robb, 1964) and production of flower crops fewer studies on how elevated CO2 might affect the floral biology of a plant species, for example flower longer-lived flowers with extra rewards such as nectar. No studies were found examining the effects

  19. 75 FR 65256 - Flower Garden Banks National Marine Sanctuary Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-22

    ...100222109-0471-01] RIN 0648-AY35 Flower Garden Banks National Marine Sanctuary Regulations...to amend the regulations for the Flower Garden Banks National Marine Sanctuary (FGBNMS...from 4 p.m. to 8 p.m. at the Flower Garden Banks National Marine Sanctuary...

  20. 77 FR 25060 - Flower Garden Banks National Marine Sanctuary Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-27

    ...100222109-2171-02] RIN 0648-AY35 Flower Garden Banks National Marine Sanctuary Regulations...is amending the regulations for Flower Garden Banks National Marine Sanctuary to improve...are available upon request to Flower Garden Banks National Marine Sanctuary,...

  1. NECTAR SUGAR PRODUCTION AND FLOWER VISITORS OF THE BRAMBLE,

    E-print Network

    Paris-Sud XI, Université de

    NECTAR SUGAR PRODUCTION AND FLOWER VISITORS OF THE BRAMBLE, RUBUS ELLIPTICUS SMITH (ROSACEAE of Horticulture and Forestry, College of Horticulture, Nauni, Solan, India - 173230 SUMMARY Nectar sugar production in flowers of Rubus ellipticus averaged 6.93 mg/flower at 24 h and the accumulation of the sugar

  2. Ultraviolet Patterns on Rear of Flowers: Basis of Disparity of Buds and Blossoms

    PubMed Central

    Eisner, Thomas; Eisner, Maria; Aneshansley, D.

    1973-01-01

    Flowers of Jasminium primulinum and Hypericum spp. have ultraviolet patterns on the reverse surface of the corolla. Those areas of the surface that are exposed to the outside in the bud are ultraviolet absorbent, whereas the portions that come into view at maturity in the open blossom are ultraviolet reflectant. Buds and blossoms, as a result, appear different in color to insects sensitive to ultraviolet light. Experimental evidence indicates that the ultraviolet-absorbent quality of the outer surface of the bud is a consequence of exposure itself, attributable possibly to a “sun tanning” effect. Images PMID:16592074

  3. Color Me Understood.

    ERIC Educational Resources Information Center

    Harris, Judy J.

    2000-01-01

    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…

  4. New color anaglyph method

    Microsoft Academic Search

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

    1997-01-01

    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

  5. Color in architecture 

    E-print Network

    Vrooman, Richard

    1952-01-01

    Good design can be spoiled by poor color. Weak design can be helped by good color. Color is therefore of prime importance as an integral element of architectural design. Color is vitally related to man in many fields. The study of architecture...

  6. Color: A Functionalist Proposal

    Microsoft Academic Search

    Jonathan Cohen

    2003-01-01

    In this paper I propose and defend an account of color that I call color functionalism. I argue that functionalism is a non-traditional species of primary quality theory, and that it accommodates our intuitions about color and the facts of color science better than more widely discussed alternatives.

  7. [Chemical constituents of flower of David lily].

    PubMed

    Feng, S L; He, L; Wang, M; Jiao, K J

    1994-10-01

    Three compounds were isolated from the flower of Lilium devidii. On the basis of chemical reaction, UV, MS, 1HNMR and 13CNMR spectral data, they were identified as beta-sitosterol, stigmasterol and emodin. These compounds are obtained from the plant for the first time. PMID:7873081

  8. Flower development: open questions and future directions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Almost three decades of genetic and molecular analyses have resulted in detailed insights into many of the processes that take place during flower development and in the identification of a large number of key regulatory genes that control these processes. Despite this impressive progress, many ques...

  9. The Genetic Architecture of Maize Flowering Time

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flowering time is the key trait controlling adaptation of plants to their local environment, and, in an outcrossing species like maize, it is a complex trait. Variation for this complex trait was dissected in maize using a novel set of 5000 recombinant inbred lines (maize Nested Association Mapping...

  10. Deficit irrigation effects on flowering of loquat

    Microsoft Academic Search

    J. J. Hueso; J. Cuevas

    SUMMARY - In the tropics and subtropics, natural episodes of drought trigger flower induction in many woody plants. Bearing in mind such effect, we have applied deficit irrigation strategies on loquat with the aim of obtaining earlier bloom and harvest that favours better prices. The experiment was carried out during three consecutive years on trees of cultivar 'Algerie'. Three treatments

  11. Flowering, Capsule and Seed Characteristics in Cuphea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We modeled the flowering and capsule set dynamics, quantified the level of variation in seed characteristics, elucidated the inter-relationships among seed and capsule physical dimensions, and quantified their impact on single seed weight as the main determinant of seed yield in the indeterminate, p...

  12. Colour preferences of flower-naive honeybees

    Microsoft Academic Search

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

    1995-01-01

    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

  13. Headspace Volatiles of Scutellaria Baicalensis Georgi Flowers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile constituents of Baikal skullcap (Scutellaria baicalensis Georgi) flowers were isolated by solid-phase microextraction (SPME) and analyzed by GC and GC/MS. A total of 64 constituents was identified (constituting 57.1 – 89.9% of the total area), 13 of which were tentatively identified. beta...

  14. Flower opening and closure: a review

    Microsoft Academic Search

    Doorn van W. G; Uulke van Meeteren

    2003-01-01

    Flower opening and closure are traits of a reproduct- ive syndrome, as it allows pollen removal and\\/or pollination. Various types of opening can be distin- guished such as nocturnal and diurnal and single or repetitive. Opening is generally due to cell expansion. Osmotic solute levels increase by the conversion of polysaccharides (starch or fructan) to monosacchar- ides, and\\/or the uptake

  15. Identification of Mendel's white flower character

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have identified A, the factor determining anthocyanin pigmentation in pea that was used by Gregor Mendel 150 years ago in his study of inheritance. The A gene encodes a bHLH transcription factor. The white flowered mutant allele most likely used by Mendel is a simple G to A transition in a splice...

  16. Oxfordshire Flowers and the Plot Memorial Windows

    Microsoft Academic Search

    G. Claridge Druce

    1928-01-01

    In NATURE of May 28, 1927, p. 798, in the excellent account of the unveiling of the Wren-Ashmole-Plot Memorial Windows at Oxford, it is said that ``the surrounding wreath is of two Oxfordshire flowers which Plot was the first to recognise as new to the British flora''-Viola palustris and Geranium dissectum.

  17. Morphogenetic lability of the Ruppia maritima (Ruppiaceae, Alismatales) reproductive organs: From two lateral flowers to a terminal flower

    Microsoft Academic Search

    I. E. Lock; D. D. Sokoloff; M. V. Remizowa

    2011-01-01

    Flowers of Ruppia are usually arranged into an open two-flowered spike, but sometimes two lateral flowers are congenitally united with each\\u000a other forming a terminal flower-like structure. This deviation from the morphogenesis of reproductive structures typical of\\u000a Ruppia resembles those described in well-studied mutants of the model organisms of developmental genetics, such as Arabidopsis and Antirrhinum. A study of Ruppia

  18. MoneyTips4Texas Lifestyle Choices & Your Health

    E-print Network

    MoneyTips4Texas Lifestyle Choices & Your Health Andrew B. Crocker Angela B. Burkham Sara L. Dodd, color, sex, religion, national origin, age, disability, genetic information or veteran status. #12;Goal: To gain knowledge about factors that may affect personal health and wellness. Objectives: 1. Learn about

  19. 2009 Virginia Polytechnic Institute and State University 2906-1296 Virginia Cooperative Extension programs and employment are open to all, regardless of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, o

    E-print Network

    Liskiewicz, Maciej

    years. Good site planning and build-up of soils is important prior to planting. Variety choice is an important first consideration. Normally, asparagus is dioecious, meaning that male and female flowers are produced on different plants. The female flowers produce seeds that fall to the ground, creating a seedling

  20. Flower colour and cytochromes P450†

    PubMed Central

    Tanaka, Yoshikazu; Brugliera, Filippa

    2013-01-01

    Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 3?-hydroxylase (F3?H) and flavonoid 3?,5?-hydroxylase (F3?5?H) and thus they play a crucial role in the determination of flower colour. F3?H and F3?5?H mostly belong to CYP75B and CYP75A, respectively, except for the F3?5?Hs in Compositae that were derived from gene duplication of CYP75B and neofunctionalization. Roses and carnations lack blue/violet flower colours owing to the deficiency of F3?5?H and therefore lack the B-ring-trihydroxylated anthocyanins based upon delphinidin. Successful redirection of the anthocyanin biosynthesis pathway to delphinidin was achieved by expressing F3?5?H coding regions resulting in carnations and roses with novel blue hues that have been commercialized. Suppression of F3?5?H and F3?H in delphinidin-producing plants reduced the number of hydroxyl groups on the anthocyanidin B-ring resulting in the production of monohydroxylated anthocyanins based on pelargonidin with a shift in flower colour to orange/red. Pelargonidin biosynthesis is enhanced by additional expression of a dihydroflavonol 4-reductase that can use the monohydroxylated dihydrokaempferol (the pelargonidin precursor). Flavone synthase II (FNSII)-catalysing flavone biosynthesis from flavanones is also a P450 (CYP93B) and contributes to flower colour, because flavones act as co-pigments to anthocyanins and can cause blueing and darkening of colour. However, transgenic plants expression of a FNSII gene yielded paler flowers owing to a reduction of anthocyanins because flavanones are precursors of anthocyanins and flavones. PMID:23297355

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

    E-print Network

    Giron, David - Institut de Recherche sur la Biologie de l'Insecte, Université François Rabelais

    Specific color sensitivities of prey and predator explain camouflage in different visual systems pollinators. To evaluate the efficiency of spider camouflage on flowers, we measured by spectroradiometry and predator are involved in camouflage. The analysis suggests more research on bird predation and vision

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

    Microsoft Academic Search

    Marc Théry; Martine Debut; Doris Gomez; Jérôme Casas

    2005-01-01

    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

  3. How Happiness Affects Choice

    E-print Network

    Mogilner, Cassie

    Consumers want to be happy, and marketers are increasingly trying to appeal to consumers’ pursuit of happiness. However, the results of six studies reveal that what happiness means varies, and consumers’ choices reflect ...

  4. Effect of Ethylene on Flower Abscission: a Survey

    PubMed Central

    VAN DOORN, WOUTER G.

    2002-01-01

    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

  5. Models for forecasting the flowering of Cornicabra olive groves

    NASA Astrophysics Data System (ADS)

    Rojo, Jesús; Pérez-Badia, Rosa

    2015-02-01

    This study examined the impact of weather-related variables on flowering phenology in the Cornicabra olive tree and constructed models based on linear and Poisson regression to forecast the onset and length of the pre-flowering and flowering phenophases. Spain is the world's leading olive oil producer, and the Cornicabra variety is the second largest Spanish variety in terms of surface area. However, there has been little phenological research into this variety. Phenological observations were made over a 5-year period (2009-2013) at four sampling sites in the province of Toledo (central Spain). Results showed that the onset of the pre-flowering phase is governed largely by temperature, which displayed a positive correlation with the temperature in the start of dormancy (November) and a negative correlation during the months prior to budburst (January, February and March). A similar relationship was recorded for the onset of flowering. Other weather-related variables, including solar radiation and rainfall, also influenced the succession of olive flowering phenophases. Linear models proved the most suitable for forecasting the onset and length of the pre-flowering period and the onset of flowering. The onset and length of pre-flowering can be predicted up to 1 or 2 months prior to budburst, whilst the onset of flowering can be forecast up to 3 months beforehand. By contrast, a nonlinear model using Poisson regression was best suited to predict the length of the flowering period.

  6. The male blue crab, Callinectes sapidus, uses both chromatic and achromatic cues during mate choice.

    PubMed

    Baldwin, Jamie; Johnsen, Sönke

    2012-04-01

    In the blue crab, Callinectes sapidus, claw color varies by sex, sexual maturity and individual. Males rely in part on color cues to select appropriate mates, and these chromatic cues may be perceived through an opponent interaction between two photoreceptors with maximum wavelength sensitivities at 440 and 508 nm. The range of color discrimination of this dichromatic visual system may be limited, however, and it is unclear whether male blue crabs are capable of discriminating the natural variations in claw color that may be important in mate choice. By testing males' innate color preferences in binary choice tests between photographs of red-clawed females and six variations of orange-clawed females, we examined both the chromatic (opponent interaction) and achromatic (relative luminance) cues used in male mate choice. Males significantly preferred red-clawed females to orange-clawed females, except when the test colors were similar in both opponency and relative luminance. Our results are unusual in that they indicate that male mate choice in the blue crab is not guided solely by achromatic or chromatic mechanisms, suggesting that both color and intensity are used to evaluate female claw color. PMID:22399664

  7. Microsporogenesis and flower development in Eucalyptus urophylla × E. tereticornis

    PubMed Central

    Yang, Jun; Kang, Xiangyang

    2015-01-01

    We compared microsporogenesis and flower development in Eucalyptus urophylla × E. tereticornis. In this study, although microsporogenesis and cytokinesis occurred simultaneously during meiosis of pollen mother cells, we observed a strong asynchronism in different anthers from a flower bud. The developmental period of microsporogenesis in anthers originated from the long thrum before the short thrum. Flower development was also asynchronous at different locations on a branch. The flower buds grew on the lower side of the branch and showed greater increases in diameter. In addition, we observed a relationship between microsporogenesis development and flower bud diameter growth. Generally, when the pachytene stage was first observed in a small single flower bud growing on top of a flowering branch, the remaining microsporogenesis stages (from diplotene to tetrad) in the whole branch occurred over the next 5–9 days. Thus, the start of microsporogenesis in E. urophylla × E. tereticornis could be determined, which may be applicable to future breeding studies. PMID:26069443

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

    PubMed

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

    2014-05-01

    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

  9. Biotechnological production of colorants.

    PubMed

    de Boer, Lex

    2014-01-01

    The color of food and drinks is important, as it is associated with freshness and taste. Despite that natural colorants are more expensive to produce, less stable to heat and light, and less consistent in color range, natural colorants have been gaining market share in recent years. The background is that artificial colorants are often associated with negative health aspects. Considerable progress has been made towards the fermentative production of some colorants. Because colorant biosynthesis is under close metabolic control, extensive strain and process development are needed in order to establish an economical production process. Another approach is the synthesis of colors by means of biotransformation of adequate precursors. Algae represent a promising group of microorganisms that have shown a high potential for the production of different colorants, and dedicated fermentation and downstream technologies have been developed. This chapter reviews the available information with respect to these approaches. PMID:24037500

  10. Tropism in azalea and lily flowers

    NASA Astrophysics Data System (ADS)

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

    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.

  11. The Influence of Cultural Social Identity on Graduate Student Career Choice

    ERIC Educational Resources Information Center

    Haley, Karen J.; Jaeger, Audrey J.; Levin, John S.

    2014-01-01

    This study examines and enriches understanding of the career choice process for graduate students of color. Social identity theory (SIT) is used as a framework to expand our understanding of how and why graduate students choose (or do not choose) faculty careers. Graduate students' cultural social identities influenced their career choice

  12. Using daily temperature to predict phenology trends in spring flowers

    NASA Astrophysics Data System (ADS)

    Kim, Jin-Hee; Kim, Soo-Ock; Kim, Dae-Jun; Moon, Kyung Hwan; Yun, Jin I.

    2015-05-01

    The spring season in Korea features a dynamic landscape with a variety of flowers blooming sequentially one after another. This enables local governments to earn substantial sightseeing revenues by hosting festivals featuring spring flowers. Furthermore, beekeepers move from the southern tip of the Korean Peninsula all the way northward in a quest to secure spring flowers as nectar sources for a sustained period of time. However, areal differences in flowering dates of flower species are narrowing, which has economic consequences. Analysis of data on flowering dates of forsythia ( Forsythia koreana) and cherry blossom ( Prunus serrulata), two typical spring flower species, as observed for the past 60 years at six weather stations of the Korea Meteorological Administration (KMA) indicated that the difference between the flowering date of forsythia, the earliest blooming flower in spring, and cherry blossom, which flowers later than forsythia, was 14 days on average in the climatological normal year for the period 1951-1980, compared with 11 days for the period 1981-2010. In 2014, the gap narrowed further to 7 days, making it possible in some locations to see forsythias and cherry blossoms blooming at the same time. Synchronized flowering of these two flower species is due to acceleration of flowering due to an abnormally high spring temperature, and this was more pronounced in the later-blooming cherry blossom than forsythia. While cherry blossom flowering dates across the nation ranged from March 31 to April 19 (an areal difference of 20 days) for the 1951-1980 normal year, the difference ranged from March 29 to April 12 (an areal difference of 16 days) for the 1981-2010 normal year, and in 2014, the flowering dates spanned March 25 and March 30 (an areal difference of 6 days). In the case of forsythia, the gap was narrower than in cherry blossoms. Climate change in the Korean Peninsula, reflected by rapid temperature hikes in late spring in contrast to a slow temperature rise in early spring immediately after dormancy release, likely brought forward the flowering date of cherry blossom. We derived a thermal time-based flowering model from this analysis and used it to predict the flowering dates of forsythia and cherry blossom in 2014. The root mean square error for the prediction was within 2 days from the observed flowering dates in both species, showing a feasibility of prediction under the changing climate.

  13. Fruits and Vegetables: Color Your Plate

    NSDL National Science Digital Library

    2014-04-30

    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.

  14. Preferred skin color enhancement for photographic color reproduction

    NASA Astrophysics Data System (ADS)

    Zeng, Huanzhao; Luo, Ronnier

    2011-01-01

    Skin tones are the most important colors among the memory color category. Reproducing skin colors pleasingly is an important factor in photographic color reproduction. Moving skin colors toward their preferred skin color center improves the color preference of skin color reproduction. Several methods to morph skin colors to a smaller preferred skin color region has been reported in the past. In this paper, a new approach is proposed to further improve the result of skin color enhancement. An ellipsoid skin color model is applied to compute skin color probabilities for skin color detection and to determine a weight for skin color adjustment. Preferred skin color centers determined through psychophysical experiments were applied for color adjustment. Preferred skin color centers for dark, medium, and light skin colors are applied to adjust skin colors differently. Skin colors are morphed toward their preferred color centers. A special processing is applied to avoid contrast loss in highlight. A 3-D interpolation method is applied to fix a potential contouring problem and to improve color processing efficiency. An psychophysical experiment validates that the method of preferred skin color enhancement effectively identifies skin colors, improves the skin color preference, and does not objectionably affect preferred skin colors in original images.

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

    PubMed Central

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

    2013-01-01

    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

  16. [Morphogenetic lability of reproductive structures in Ruppia maritima (Ruppiaceae, Alismatales): from two lateral flowers to a terminal flower].

    PubMed

    Lokk, I É; Sokolov, D D; Remizova, M V

    2011-01-01

    Flowers of Ruppia are normally arranged into an open two-flowered spike, but sometimes the two lateral flowers are congenitally united with each other and form a terminal flower-like structure. This developmental abnormality resembles those described in well-investigated mutants of model organisms of developmental genetics such as Arabidopsis Antirrhinum. A study of Ruppia allows investigating morphogenetic lability of this feature in natural populations. These data will be important for understanding evolutionary transitions between open and closed inflorescences. This paper presents first data on frequencies ofterminal flower-like structures in natural populations of Ruppia maritima and first observations of their development. Vascular supply of inflorescences with free and united flowers is compared for the first time. Strong differences in frequencies of occurrence of terminal flower-like structures among examined natural populations are revealed. Data on variation of organ numbers in flowers of plants from different populations allow hypothesizing that increased size of floral primordia is a factor that plays a role in their amalgamation into ajoint primordium of a terminal structure. Vascular system of inflorescences of R. maritima with united flowers is quite similar to the vascular system of a flower and nothing contradicts a hypothesis on terminal position ofthis structure. Transversally inserted stamens in inflorescences with united flowers are usually of inverted polarity. This appears to be the first documented example of an inversion of relative polarity of stamens and carpels in angiosperms. PMID:21950054

  17. Radiation coloration resistant glass

    DOEpatents

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

    1986-01-01

    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.

  18. Radiation coloration resistant glass

    DOEpatents

    Tomozawa, M.; Watson, E.B.; Acocella, J.

    1986-11-04

    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. 3 figs.

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

    PubMed

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

    2013-01-01

    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

  20. Causes and consequences of lexicographic choices in stated choice studies

    Microsoft Academic Search

    Kjartan Saelensminde

    2006-01-01

    Stated Choice (SC) methods, and other choice experiments, are now becoming increasingly popular for the valuation of environmental goods. This paper shows that lexicographic choices (LCs) in an SC task, or other types of choice experiments, do not imply that the respondent has lexicographic preferences. LCs may be a result of (i) study designs where differences between the alternatives are

  1. Integrative genome-wide analysis reveals HLP1, a novel RNA-binding protein, regulates plant flowering by targeting alternative polyadenylation.

    PubMed

    Zhang, Yong; Gu, Lianfeng; Hou, Yifeng; Wang, Lulu; Deng, Xian; Hang, Runlai; Chen, Dong; Zhang, Xiansheng; Zhang, Yi; Liu, Chunyan; Cao, Xiaofeng

    2015-07-01

    Alternative polyadenylation (APA) is a widespread mechanism for gene regulation and has been implicated in flowering, but the molecular basis governing the choice of a specific poly(A) site during the vegetative-to-reproductive growth transition remains unclear. Here we characterize HLP1, an hnRNP A/B protein as a novel regulator for pre-mRNA 3'-end processing in Arabidopsis. Genetic analysis reveals that HLP1 suppresses Flowering Locus C (FLC), a key repressor of flowering in Arabidopsis. Genome-wide mapping of HLP1-RNA interactions indicates that HLP1 binds preferentially to A-rich and U-rich elements around cleavage and polyadenylation sites, implicating its role in 3'-end formation. We show HLP1 is significantly enriched at transcripts involved in RNA metabolism and flowering. Comprehensive profiling of the poly(A) site usage reveals that HLP1 mutations cause thousands of poly(A) site shifts. A distal-to-proximal poly(A) site shift in the flowering regulator FCA, a direct target of HLP1, leads to upregulation of FLC and delayed flowering. Our results elucidate that HLP1 is a novel factor involved in 3'-end processing and controls reproductive timing via targeting APA. PMID:26099751

  2. Integrative genome-wide analysis reveals HLP1, a novel RNA-binding protein, regulates plant flowering by targeting alternative polyadenylation

    PubMed Central

    Zhang, Yong; Gu, Lianfeng; Hou, Yifeng; Wang, Lulu; Deng, Xian; Hang, Runlai; Chen, Dong; Zhang, Xiansheng; Zhang, Yi; Liu, Chunyan; Cao, Xiaofeng

    2015-01-01

    Alternative polyadenylation (APA) is a widespread mechanism for gene regulation and has been implicated in flowering, but the molecular basis governing the choice of a specific poly(A) site during the vegetative-to-reproductive growth transition remains unclear. Here we characterize HLP1, an hnRNP A/B protein as a novel regulator for pre-mRNA 3?-end processing in Arabidopsis. Genetic analysis reveals that HLP1 suppresses Flowering Locus C (FLC), a key repressor of flowering in Arabidopsis. Genome-wide mapping of HLP1-RNA interactions indicates that HLP1 binds preferentially to A-rich and U-rich elements around cleavage and polyadenylation sites, implicating its role in 3?-end formation. We show HLP1 is significantly enriched at transcripts involved in RNA metabolism and flowering. Comprehensive profiling of the poly(A) site usage reveals that HLP1 mutations cause thousands of poly(A) site shifts. A distal-to-proximal poly(A) site shift in the flowering regulator FCA, a direct target of HLP1, leads to upregulation of FLC and delayed flowering. Our results elucidate that HLP1 is a novel factor involved in 3?-end processing and controls reproductive timing via targeting APA. PMID:26099751

  3. Sugars, the clock and transition to flowering

    PubMed Central

    Moghaddam, Mohammad R. Bolouri; den Ende, Wim Van

    2013-01-01

    Sugars do not only act as source of energy, but they also act as signals in plants. This mini review summarizes the emerging links between sucrose-mediated signaling and the cellular networks involved in flowering time control and defense. Cross-talks with gibberellin and jasmonate signaling pathways are highlighted. The circadian clock fulfills a crucial role at the heart of cellular networks and the bilateral relation between sugar signaling and the clock is discussed. It is proposed that important factors controlling plant growth (DELLAs, PHYTOCHROME INTERACTING FACTORS, invertases, and trehalose-6-phosphate) might fulfill central roles in the transition to flowering as well. The emerging concept of “sweet immunity,” modulated by the clock, might at least partly rely on a sucrose-specific signaling pathway that needs further exploration. PMID:23420760

  4. Energy Choices Game

    NSDL National Science Digital Library

    2014-09-18

    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 – 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.

  5. Color associations for days and letters across different languages.

    PubMed

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

    2014-01-01

    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. PMID:24904447

  6. Color and Streptomycetes1

    PubMed Central

    Pridham, Thomas G.

    1965-01-01

    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. PMID:14264847

  7. Fibonacci, quasicrystals and the beauty of flowers.

    PubMed

    Gardiner, John

    2012-12-01

    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

  8. Pseudoguaianolides from the flowers of Parthenium hysterophorus

    Microsoft Academic Search

    C. Ramesh; N. Ravindranath; Biswanath Das; A. Prabhakar; Jagadeesh Bharatam; K. Ravikumar; A. Kashinatham; T. C. McMorris

    2003-01-01

    Chemical investigation on the flowers of Parthenium hysterophorus has resulted in the isolation of four new pseudoguaianolides, hysterones A–D along with the known compounds, parthenin, coronopilin, 2?-hydroxycoronopilin and tetraneurin-A. The structures of the new compounds were established by interpretation of their spectral (1D and 2D NMR) data. The X-ray crystallographic analysis of hysterones A and C was also carried out.

  9. Fibonacci, quasicrystals and the beauty of flowers

    PubMed Central

    Gardiner, John

    2012-01-01

    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

  10. Structural features of Rhododendron luteum flower

    Microsoft Academic Search

    Thomas Sawidis; Theano Theodoridou; Elzbieta Weryszko-Chmielewska; Artemios M. Bosabalidis

    2011-01-01

    The flower of Rhododendron luteum (L.) Sweet has a pentamerous structure with radial symmetry. The anthers filament surface is covered by dense non-glandular\\u000a hairs to the half of the height. The tubular anther dehisces along creating two openings in the anther-sac walls and the viscous\\u000a pollen is released through two splits along the anther lobes. The pistil is pentamerous and

  11. Volatile Components of Mimusops elengi L. Flowers

    Microsoft Academic Search

    K. C. Wong; Y. E. Teng

    1994-01-01

    The headspace and solvent extract of the flowers of Mimusops elengi L. were analyzed by capillary GC and GC\\/MS.A total of 74 compounds were identified, of which the major chemical classes were aromatic alcohols and esters derived from the phenylpropanoid metabolism. Headspace analysis showed 2-phenylethanol (37.80%), methyl benzoate (13.40%), p-methylanisole (9.94%) and 2-phenylethyl acetate (7.16%) as most abundant, whereas in

  12. Flowering phenology and female reproductive success in Silene acutifolia Link ex Rohrb

    Microsoft Academic Search

    María Luisa Buide; José Antonio Díaz-Peromingo; Javier Guitián

    2002-01-01

    We investigated flowering phenology and female reproductive success intwo populations of Silene acutifolia in northwest Spain,over one year (population A) or two consecutive years (population B). Floweringphenology was similar in the two populations and two years. However,significantinterannual and interindividual variation was detected in flowering start date,flowering finish date, flowering duration, relative flowering intensity,flowering synchrony index, and median flowering date (the

  13. Carbohydrate Status of Tulip Bulbs during Cold-Induced Flower Stalk Elongation and Flowering.

    PubMed Central

    Lambrechts, H.; Rook, F.; Kolloffel, C.

    1994-01-01

    The effect of a cold treatment on the carbohydrate status of the scales and flower stalk of Tulipa gesneriana L. cv Apeldoorn bulbs during growth after planting was studied and compared with bulbs not given cold treatment. Bulbs were stored dry for 12 weeks at 5[deg]C (precooled) or 17[deg]C (noncooled). Only the 5[deg]C treatment led to rapid flower stalk elongation and flowering following planting at higher temperatures. Precooling enhanced mobilization of starch, fructans, and sucrose in the scales. The cold-stimulated starch breakdown was initially accompanied by increased [alpha]-amylase activity per scale. In noncooled bulbs, [alpha]-amylase activity slightly decreased or remained more or less constant. Cold-induced flower stalk elongation was partially accompanied by a decrease in the sucrose content and an increase in the glucose content and invertase activity per g dry weight. The starch content in internodes initially decreased and subsequently increased; [alpha]-amylase activity per g dry weight of the lowermost internode showed a peak pattern during starch breakdown and increased thereafter. The internodes of noncooled bulbs, on the contrary, accumulated sucrose. Their glucose content and invertase activity per g dry weight remained low. Starch breakdown was not found and [alpha]-amylase activity per g dry weight of the lowermost internode remained at a low level. Precooling of tulip bulbs thus favors reserve mobilization in the scales and flower stalk and glucose accumulation in the elongating internodes. PMID:12232100

  14. Is the flower fluorescence relevant in biocommunication?

    NASA Astrophysics Data System (ADS)

    Iriel, Analía; Lagorio, María Gabriela

    2010-10-01

    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.

  15. FLOWERING LOCUS T regulates stomatal opening.

    PubMed

    Kinoshita, Toshinori; Ono, Natsuko; Hayashi, Yuki; Morimoto, Sayuri; Nakamura, Suguru; Soda, Midori; Kato, Yuma; Ohnishi, Masato; Nakano, Takeshi; Inoue, Shin-ichiro; Shimazaki, Ken-ichiro

    2011-07-26

    Stomatal pores surrounded by a pair of guard cells in the plant epidermis control gas exchange for photosynthesis in response to light, CO(2), and phytohormone abscisic acid. Phototropins (phot1 and phot2) are plant blue-light receptor kinases and mediate stomatal opening via activation of the plasma membrane H(+)-ATPase. However, the signaling mechanism from phototropins to the H(+)-ATPase has yet to be determined. Here, we show that FLOWERING LOCUS T (FT) is expressed in guard cells and regulates stomatal opening. We isolated an scs (suppressor of closed-stomata phenotype in phot1 phot2) 1-1 mutant of Arabidopsis thaliana and showed that scs1-1 carries a novel null early flowering 3 (elf3) allele in a phot1 phot2 background. scs1-1 (elf3 phot1 phot2 triple mutant) had an open-stomata phenotype with high H(+)-ATPase activity and showed increased levels of FT mRNA in guard cells. Transgenic plants overexpressing FT in guard cells showed open stomata, whereas a loss-of-function FT allele, ft-1, exhibited closed stomata and failed to activate the H(+)-ATPase in response to blue light. Our results define a new cell-autonomous role for FT and demonstrate that the flowering time genes ELF3 and FT are involved in the regulation of H(+)-ATPase by blue light in guard cells. PMID:21737277

  16. DNA methylation, vernalization, and the initiation of flowering.

    PubMed

    Burn, J E; Bagnall, D J; Metzger, J D; Dennis, E S; Peacock, W J

    1993-01-01

    Late-flowering ecotypes and mutants of Arabidopsis thaliana and the related crucifer Thlaspi arvense flower early after cold treatment (vernalization). Treatment with the DNA demethylating agent 5-azacytidine induced nonvernalized plants to flower significantly earlier than untreated controls. Cytidine at similar concentrations had no effect on time to flower. In contrast, late-flowering mutants that are insensitive to vernalization did not respond to 5-azacytidine treatment. Normal flowering time was reset in the progeny of plants induced to flower early with 5-azacytidine, paralleling the lack of inheritance of the vernalized condition. Arabidopsis plants, either cold-treated or 5-azacytidine-treated, had reduced levels of 5-methylcytosine in their DNA compared to nonvernalized plants. A Nicotiana plumbaginifolia cell line also showed a marked decrease in the level of 5-methylcytosine after treatment with either 5-azacytidine or low temperature. We suggest that DNA methylation provides a developmental control preventing early flowering in Arabidopsis and Thlaspi ecotypes. Vernalization, through its general demethylating effect, releases the block to flowering initiation. We propose that demethylation of a gene critical for flowering permits its transcription. We further suggest, on the basis of Thlaspi data, that the control affects transcription of kaurenoic acid hydroxylase, a key enzyme in the gibberellic acid biosynthetic pathway. PMID:11607346

  17. Fingers that change color

    MedlinePLUS

    Blanching of the fingers; Fingers - pale; Toes that change color; Toes - pale ... Necrotizing vasculitis Peripheral artery disease Raynaud's phenomenon - sudden change in the finger color ranges from pale to ...

  18. Color and form

    E-print Network

    Buchanan, Mark C. (Mark Calvin)

    1992-01-01

    I have always been interested in painting, particularly in the use of color to describe space, time and emotion. This thesis integrates painterly concepts in the making of architecture. Some issues explored include color ...

  19. Show Your Colors!

    NSDL National Science Digital Library

    2011-08-20

    In this family or group activity, learners conduct a chromatography experiment to reveal the colors that leaves "hide" under their green pigments. Use this experiment to predict what colors the leaves will "turn" in the fall.

  20. The Trouble with Color.

    ERIC Educational Resources Information Center

    Merchant, David

    1999-01-01

    Discusses problems with color quality in Web sites. Topics include differences in monitor settings, including contrast; amount of video RAM; user preference settings; browser-safe colors; cross-platform readability; and gamma values. (LRW)

  1. Social choice Approximate MAX CUT

    E-print Network

    Pansu, Pierre

    Social choice Un-friends Approximate MAX CUT Unique games Hardness of approximation P. Pansu;Social choice Un-friends Approximate MAX CUT Unique games Today's menu: A theorem in social choice theory-Sud Hardness of approximation #12;Social choice Un-friends Approximate MAX CUT Unique games Influences Noise

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

    PubMed Central

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

    2011-01-01

    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. PMID:21829604

  3. Mixed graph colorings

    Microsoft Academic Search

    Pierre Hansen; Julio Kuplinsky; Dominique de Werra

    1997-01-01

    A mixed graphGp contains both undirected edges and directed arcs. Ak-coloring ofGp is an assignment to its vertices of integers not exceedingk (also called colors) so that the endvertices of an edge have different colors and the tail of any arc has a smaller color than its head. The chromatic number ?p(G) of a mixed graph is the smallestk such

  4. Quantum Dots and Colors

    NSDL National Science Digital Library

    2014-09-18

    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.

  5. The influence of body coloration on shoaling preferences in fish.

    PubMed

    McROBERT; Bradner

    1998-09-01

    Shoaling behaviour provides antipredator benefits that rely, to some extent, on a high degree of phenotypic homogeneity between individuals within the shoal. Therefore, fish should have the ability to discriminate between potential shoalmates, choosing to associate with individuals of similar appearance to themselves. We studied the effects of a single phenotypic character, body coloration, on association choices made by black and white mollies (Poecilia latipinna). When given a choice between a group of mollies of similar coloration and an empty compartment, individual test fish (black or white) spent significantly more time near the fish group. When given a choice between a group of black mollies and a group of white mollies, individual fish (black or white) spent significantly more time near the group of mollies of similar coloration to their own. When given a choice between a group of mollies of dissimilar coloration and an empty compartment, black and white mollies reacted differently. Black mollies spent significantly more time on the side of the central compartment closest to the white mollies, while there was no significant difference between the time spent by white mollies on either side of the test tank. Our results indicate that fish can use visual cues to discriminate actively between potential shoalmates on the basis of body coloration. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9784209

  6. PERCEIVING COLOR Visual Perception

    E-print Network

    Majumder, Aditi

    Visual Mechanisms Category Based Perception Slide 4 Aditi Majumder, UCI The Color Stimuli #12;3 Slide 5 Aditi Majumder, UCI Color is due to.. Selective emission/reflection of different wavelengths by surfaces ­ I() #12;4 Slide 7 Aditi Majumder, UCI Reflectance ­ R() Slide 8 Aditi Majumder, UCI Color Stimuli

  7. COLOR-MUSIC

    Microsoft Academic Search

    Theodore F. Karwoski; Henry S. Odbert

    1938-01-01

    Colored hearing is a phenomenon with important implications both for the psychologist and for the artist interested in developing new art forms. The present findings thus pertain to the problem of color-music as a possible art form. A determination of the nature and frequency of colored responses to music requires some sort of standard material which can easily be presented

  8. Biology of Skin Color.

    ERIC Educational Resources Information Center

    Corcos, Alain

    1983-01-01

    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)

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

    Microsoft Academic Search

    Hadley Kruczek-Aaron

    2002-01-01

    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,

  10. Rainbow Coloring of Graphs Rainbow Coloring of Graphs

    E-print Network

    Narasayya, Vivek

    Rainbow Coloring of Graphs Rainbow Coloring of Graphs L. Sunil Chandran Computer Science and Automation Indian Institute of Science, Bangalore Email: sunil@csa.iisc.ernet.in #12;Rainbow Coloring of Graphs What is Rainbow Coloring? Consider an edge coloring, not necessarily proper. #12;Rainbow Coloring

  11. Choices, Values, and Frames

    Microsoft Academic Search

    Daniel Kahneman; Amos Tversky

    1984-01-01

    We discuss the cognitive and the psy- chophysical determinants of choice in risky and risk- less contexts. The psychophysics of value induce risk aversion in the domain of gains and risk seeking in the domain of losses. The psychophysics of chance induce overweighting of sure things and of improbable events, relative to events of moderate probability. De- cision problems can

  12. NBNews Editor's Choice Awards

    NSDL National Science Digital Library

    An online newsletter, NBNews Editor's Choice Awards, an annotated listing of new Internet sites that is issued every ten days, has been added to the Internet Publications--Internet Webzines section of the Scout Toolkit. In addition, about one third of all the annotations in the Toolkit have been revised and updated in the last two weeks.

  13. Green Lighting Choices

    NSDL National Science Digital Library

    Benya, James R.

    This brief article looks at sustainable choices in home and commercial lighting. The author discusses the energy use of several different types of bulbs, and their appropriate uses. The suggestions the author includes in the article are intended to be both environmentally responsible and have an appearance similar to other lighting projects. This document may be downloaded in Microsoft Word Doc file format.

  14. Learning from School Choice.

    ERIC Educational Resources Information Center

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

    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).…

  15. Paper Choices Mock Presentation

    E-print Network

    George, Steven C.

    Paper Choices Mock Presentation Fluorescence-guided optical coherence tomography imaging for colon-dimensional optical coherence tomography imaging of retinal sheet implants in live rats Seiler, M. J., Rao, B. Label-Free Biomedical Imaging with High Sensitivity by Stimulated Raman Scattering Microscopy Brown, P

  16. A Matter of Choice

    ERIC Educational Resources Information Center

    Vriend, John

    1973-01-01

    Since the goal of helping the client make wise decisions is at the core of counseling, it is suggested that existentialism as a state of mind may give the contemporary counselor an outlook most conducive to achieving that goal. The entire role of choice must be dealt with by the counselor in light of the reality of current events. (Author)

  17. Assessment Choices The challenge

    E-print Network

    Fuerschbach, Phillip

    , a vulnerability assessment, a red team assessment, or some combination of the three? How do you knowAssessment Choices The challenge If you have systems and assets you must defend, you have no doubt faced the challenge of decoding the wide variety of available service offerings and assessment types

  18. Supporting Family Choice

    ERIC Educational Resources Information Center

    Murray, Mary M.; Christensen, Kimberly A.; Umbarger, Gardner T.; Rade, Karin C.; Aldridge, Kathryn; Niemeyer, Judith A.

    2007-01-01

    Supporting family choice in the decision-making process is recommended practice in the field of early childhood and early childhood special education. These decisions may relate to the medical, educational, social, recreational, therapeutic/rehabilitative, and community aspects of the child's disability. Although this practice conveys the message…

  19. Mate choice turns cognitive

    Microsoft Academic Search

    Geoffrey F. Miller; Peter M. Todd

    1998-01-01

    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

  20. Multiple Choice Test

    NSDL National Science Digital Library

    Jay Parkes

    This site presents a guide to developing and deploying effective multiple choice tests. The site also discusses the costs and benefits of this method, as well as the philosophy of this commonly used assessment method. Links to more detailed information are included as well.

  1. Choice of Living Arrangements

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

  2. Choices, frameworks and refinement

    Microsoft Academic Search

    Roy H. Campbell; Nayeem Islam; Ralph Johnson; Panos Kougiouris; Peter Madany

    1991-01-01

    Presents a method for designing operating systems using object-oriented frameworks. A framework can be refined into subframeworks. Constraints specify the interactions between the subframeworks. The authors describe how they used object-oriented frameworks to design Choices, an object-oriented operating system

  3. Choices, Frameworks and Refinement

    NASA Technical Reports Server (NTRS)

    Campbell, Roy H.; Islam, Nayeem; Johnson, Ralph; Kougiouris, Panos; Madany, Peter

    1991-01-01

    In this paper we present a method for designing operating systems using object-oriented frameworks. A framework can be refined into subframeworks. Constraints specify the interactions between the subframeworks. We describe how we used object-oriented frameworks to design Choices, an object-oriented operating system.

  4. Factors Influencing Flower Initiation in Caraway (Carum carvi L.)

    Microsoft Academic Search

    Éva Németh; Jenö Bernáth; Zsuzsanna Pluhár

    1998-01-01

    The ecological and biological factors which may influence flowering of caraway were investigated. Temperature and the length of the induction had a role in flower initiation. Among the examined variations, seven weeks of cold temperatures (8°C day and 5°C night) proved to be the optimal for flowering (100%). Shorter periods of cold temperatures (1–2 weeks) or higher temperature regimes (15°C

  5. The Early Years: First Explorations in Flower Anatomy

    NSDL National Science Digital Library

    Peggy Ashbrook

    2008-04-01

    Help children explore the idea that there are many different flower shapes, all with the function of forming seeds, by allowing children to dissect flowers after drawing them, using their fingers or plastic picnic knives. As children take apart the flowers, they are involved in many parts of science investigations referred to in state and national standards, including counting, measuring, describing things and comparing with others' observations, and using tools such as magnifiers.

  6. Patterns of seagrass ( Posidonia oceanica ) flowering in the Western Mediterranean

    Microsoft Academic Search

    Elena Diaz-Almela; Nuria Marbà; Elvira Álvarez; Elena Balestri; Juan M. Ruiz-Fernández; Carlos M. Duarte

    2006-01-01

    The intensive reconstructive sampling (1957–2004, 39 localities), a systematic direct observation (1992–2004, 1 locality)\\u000a and particular direct observations (66 localities) of Posidonia oceanica meadows were analysed together with temporal series of flowering available in the literature (19 localities). This allowed\\u000a the examination of temporal and spatial variability in annual flowering prevalence (FP, the fraction of meadows flowering\\u000a in a given

  7. Effects of urbanization on plant flowering phenology: A review

    Microsoft Academic Search

    Kaesha Neil; Jianguo Wu

    2006-01-01

    Studies of flowering and leafing phenology have dramatically increased during the last few decades because changes in plant\\u000a phenology can be indicative of possible effects of climate change at multiple scales. This article reviews the available literature\\u000a focusing on the effects of urbanization on flowering phenology. The literature of flowering phenology in urban environments\\u000a suggests that spring-blooming plants in a

  8. Effect of storage temperature on the quality of edible flowers

    Microsoft Academic Search

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

    2003-01-01

    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

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

    Microsoft Academic Search

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

    2009-01-01

    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

  10. Transcriptomic Analysis of Flower Development in Wintersweet (Chimonanthus praecox)

    PubMed Central

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

    2014-01-01

    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

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

    PubMed

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

    2014-01-01

    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

  12. Pollinator effectiveness varies with experimental shifts in flowering time.

    PubMed

    Rafferty, Nicole E; Ives, Anthony R

    2012-04-01

    The earlier flowering times exhibited by many plant species are a conspicuous sign of climate change. Altered phenologies have caused concern that species could suffer population declines if they flower at times when effective pollinators are unavailable. For two perennial wildflowers, Tradescantia ohiensis and Asclepias incarnata, we used an experimental approach to explore how changing phenology affects the taxonomic composition of the pollinator assemblage and the effectiveness of individual pollinator taxa. After finding in the previous year that fruit set varied with flowering time, we manipulated flowering onset in greenhouses, placed plants in the field over the span of five weeks, and measured pollinator effectiveness as the number of seeds produced after a single visit to a flower. The average effectiveness of pollinators and the expected rates of pollination success were lower for plants of both species flowering earlier than for plants flowering at historical times, suggesting there could be reproductive costs to earlier flowering. Whereas for A. incarnata, differences in average seed set among weeks were due primarily to changes in the composition of the pollinator assemblage, the differences for T. ohiensis were driven by the combined effects of compositional changes and increases over time in the effectiveness of some pollinator taxa. Both species face the possibility of temporal mismatch between the availability of the most effective pollinators and the onset of flowering, and changes in the effectiveness of individual pollinator taxa through time may add an unexpected element to the reproductive consequences of such mismatches. PMID:22690631

  13. Pollinator-induced twisting of flowers sidesteps floral architecture constraints.

    PubMed

    Bartoš, Michael; Jane?ek, St?pán

    2014-09-01

    Specific pollen placement by zygomorphic flowers on pollinators is one of the key innovations of angiosperm evolution [1]. In most phylogenetic lineages that have evolved zygomorphic flowers, reproductive organs are positioned either in the lower or upper part of the flower. Although these specific positions largely enhance pollen economy, they also represent architectural constraints such that flowers are able to place pollen only on the dorsal or ventral part of pollinators' bodies [2]. Such constraints can lead to interspecific pollen placement in situations where phylogenetically related species with the same floral architecture share pollinators [3]. PMID:25202867

  14. Pollinator effectiveness varies with experimental shifts in flowering time

    PubMed Central

    Rafferty, Nicole E.; Ives, Anthony R.

    2013-01-01

    The earlier flowering times exhibited by many plant species are a conspicuous sign of climate change. Altered phenologies have caused concern that species could suffer population declines if they flower at times when effective pollinators are unavailable. For two perennial wildflowers, Tradescantia ohiensis and Asclepias incarnata, we used an experimental approach to explore how changing phenology affects the taxonomic composition of the pollinator assemblage and the effectiveness of individual pollinator taxa. After finding in the previous year that fruit set varied with flowering time, we manipulated flowering onset in greenhouses, placed plants in the field over the span of five weeks, and measured pollinator effectiveness as the number of seeds produced after a single visit to a flower. The average effectiveness of pollinators and the expected rates of pollination success were lower for plants of both species flowering earlier than for plants flowering at historical times, suggesting there could be reproductive costs to earlier flowering. Whereas for A. incarnata, differences in average seed set among weeks were due primarily to changes in the composition of the pollinator assemblage, the differences for T. ohiensis were driven by the combined effects of compositional changes and increases over time in the effectiveness of some pollinator taxa. Both species face the possibility of temporal mismatch between the availability of the most effective pollinators and the onset of flowering, and changes in the effectiveness of individual pollinator taxa through time may add an unexpected element to the reproductive consequences of such mismatches. PMID:22690631

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed

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

    2014-06-01

    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

  17. Overexpression of Petunia SOC1 -like Gene FBP21 in Tobacco Promotes Flowering Without Decreasing Flower or Fruit Quantity

    Microsoft Academic Search

    Guangying Ma; Guogui Ning; Wei Zhang; Jing Zhan; Haiyan Lv; Manzhu Bao

    2011-01-01

    FBP21 is one of the SOC1-like genes isolated from Petunia hybrida. Based on sequence analysis, FPB21 is suggested to have a role in promoting flowering. In this study, FBP21 was expressed in a tobacco host plant under the control of the CaMV 35S promoter. Our results showed that the transgene accelerated flowering, i.e. the transgenic plants flowered just 3 months\\u000a after

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

    Microsoft Academic Search

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

    2004-01-01

    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

  19. Influence of plant bioregulators on pecan flowering and implications for regulation of pistillate flower initiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mitigation of alternate bearing (AB) through regulation of floral initiation of pistillate flowers is central to improving crop-load management of pecan [Carya illinoinensis (Wangenh.) K. Koch] trees and orchards. The present study examines the influence of key bioregulators {i.e., an auxin [as B-na...

  20. Structural Features Determining Flower-Promoting Activity of Arabidopsis FLOWERING LOCUS T[W][OPEN

    PubMed Central

    Ho, William Wing Ho; Weigel, Detlef

    2014-01-01

    In Arabidopsis thaliana, the genes FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1) have antagonistic roles in regulating the onset of flowering: FT activates and TFL1 represses flowering. Both encode small, closely related transcription cofactors of ?175 amino acids. Previous studies identified a potential ligand binding residue as well as a divergent external loop as critical for the differences in activity of FT and TFL1, but the mechanisms for the differential action of FT and TFL1 remain unclear. Here, we took an unbiased approach to probe the importance of residues throughout FT protein, testing the effects of hundreds of mutations in vivo. FT is surprisingly robust to a wide range of mutations, even in highly conserved residues. However, specific mutations in at least four different residues are sufficient to convert FT into a complete TFL1 mimic, even when expressed from TFL1 regulatory sequences. Modeling the effects of these mutations on the surface charge of FT protein suggests that the affected residues regulate the docking of an unknown ligand. These residues do not seem to alter the interaction with FD or 14-3-3 proteins, known FT interactors. Potential candidates for differential mediators of FT and TFL1 activities belong to the TCP (for TEOSINTE BRANCHED1, CYCLOIDEA, PCF) family of transcription factors. PMID:24532592

  1. Asynchronous flowering and within-plant flowering diversity in wheat and the implications for crop resilience to heat

    PubMed Central

    Lukac, Martin; Gooding, Michael J.; Griffiths, Simon; Jones, Hannah E.

    2012-01-01

    Background and Aims Self-pollination dominates in wheat, with a small level of out-crossing due to flowering asynchrony and male sterility. However, the timing and synchrony of male and female flowering in wheat is a crucial determinant of seed set and may be an important factor affecting gene flow and resilience to climate change. Here, a methodology is presented for assessing the timing and synchrony of flowering in wheat, Triticum aestivum. Methods From the onset of flowering until the end of anthesis, the anther and stigma activity of each floret was assessed on the first five developing ears in potted plants grown under ambient conditions and originating from ‘Paragon’ or ‘Spark-Rialto’ backgrounds. At harvest maturity, seed presence, size and weight was recorded for each floret scored. Key Results and Conclusions The synchrony between pollen dehiscence and stigma collapse within a flower was dependent on its relative position in a spike and within a floret. Determined on the basis of synchrony within each flower, the level of pollination by pollen originating from other flowers reached approx. 30 % and did not change throughout the duration of flowering. A modelling exercise parameterized by flowering observations indicated that the temporal and spatial variability of anther activity within and between spikes may influence the relative resilience of wheat to sudden, extreme climatic events which has direct relevance to predicted future climate scenarios in the UK. PMID:22186277

  2. Introduction Strict vector coloring Vector coloring Quantum coloring Further work Hedetniemi conjecture for strict vector

    E-print Network

    Severini, Simone

    Introduction Strict vector coloring Vector coloring Quantum coloring Further work Hedetniemi conjecture for strict vector chromatic number Robert Sámal (joint with C.Godsil, D.Roberson, S vector coloring Vector coloring Quantum coloring Further work Outline 1 Introduction 2 Strict vector

  3. Color constancy and a changing illumination

    NASA Astrophysics Data System (ADS)

    Finlayson, Graham D.

    1994-05-01

    The color constancy problem has proven to be very hard to solve. This is even true in the simple Mondriaan world where a planar patchwork of matte surfaces is viewed under a single illuminant. In this paper we consider the color constancy problem given two images of a Mondriaan viewed under different illuminants. We show that if surface reflectances are well modeled by 3 basis functions and illuminants by up to 5 basis functions then we can, theoretically, solve for color constancy given 3 surfaces viewed under 2 illuminants. The number of recoverable dimensions in the illuminant depends on the spectral characteristics of the sensors. Specifically if for a given sensor set a von Kries type, diagonal model of color constancy is sufficient then we show that at most 2 illuminant parameters can be retrieved. Recent work has demonstrated that for the human visual system a diagonal matrix is a good model of color constancy given an appropriate choice of sensor basis. We might predict therefore, that we can recover at most 2 illuminant parameters. We present simulations which indicate that this in fact the case.

  4. CropChoice

    NSDL National Science Digital Library

    2007-04-16

    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.

  5. The nature of colors

    NASA Astrophysics Data System (ADS)

    da Pos, Osvaldo

    2002-06-01

    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.

  6. Interference of verbal labels in color categorical perception

    NASA Astrophysics Data System (ADS)

    Yokoi, Kenji; Nishimori, Tomoaki; Saida, Shinya

    2008-11-01

    Previous studies demonstrated that color categorical perception (CP; better cross-category than within-category discrimination) was reduced by verbal interference, suggesting that CP is mediated by verbal labeling. Here, we examined chromatic generality and experience-dependency of verbal interference in CP using the Stroop effect. We employed a simultaneous two-alternative forced choice discrimination task. Congruent or incongruent words were presented prior to discrimination. In experiment 1, incongruent color names reduced CP regardless of color boundary pairs. Next, we used noncolor words that seemed to be associated with color through experience. The results showed that the tested noncolor words did not modify CP (experiment 2). However, combined presentation of color and shape produced Stroop interference (experiment 3). Our finding suggests that familiarity or mastery of categorized information through experience may be evaluated by verbal interference.

  7. CONSTANS is a photoperiod regulated activator of flowering in sorghum

    PubMed Central

    2014-01-01

    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 time QTL on SBI-10 revealed that BTx642 encodes a recessive CONSTANS allele containing a His106Tyr substitution in B-box 2 known to inactivate CONSTANS in Arabidopsis thaliana. Genetic analysis characterized sorghum CONSTANS as a floral activator that promotes flowering by inducing the expression of EARLY HEADING DATE 1 (SbEHD1) and sorghum orthologs of the maize FT genes ZCN8 (SbCN8) and ZCN12 (SbCN12). The floral repressor PSEUDORESPONSE REGULATOR PROTEIN 37 (PRR37) inhibits sorghum CONSTANS activity and flowering in long days. Conclusion Sorghum CONSTANS is an activator of flowering that is repressed post-transcriptionally in long days by the floral inhibitor PRR37, contributing to photoperiod sensitive flowering in Sorghum bicolor, a short day plant. PMID:24884377

  8. Color Image Segmentation in Color and Spatial Domain

    Microsoft Academic Search

    Tie Qi Chen; Yi Lu Murphey; Robert Karlsen; Grant Gerhart

    2003-01-01

    In this paper we describe a color image segmentation system that performs color clustering in a color space followed by a\\u000a color region segmentation algorithm in the image domain. In color space, we describe two different algorithms that clusters\\u000a similar colors using different measuring criteria and present our evaluation results on these two algorithms in comparison\\u000a with three well-known color

  9. 75 FR 16074 - Availability of Conservation Seat for the Flower Garden Banks National Marine Sanctuary Advisory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-31

    ...Availability of Conservation Seat for the Flower Garden Banks National Marine Sanctuary Advisory...the following vacant seat on the Flower Garden Banks National Marine Sanctuary Advisory...obtained from Jennifer Morgan, NOA- Flower Garden Banks National Marine Sanctuary,...

  10. 78 FR 2957 - Availability of Seats for the Flower Garden Banks National Marine Sanctuary Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-15

    ...Administration Availability of Seats for the Flower Garden Banks National Marine Sanctuary Advisory...the following vacant seats on the Flower Garden Banks National Marine Sanctuary Advisory...from Jennifer Morgan, NOAA--Flower Garden Banks National Marine Sanctuary,...

  11. New color anaglyph method

    NASA Astrophysics Data System (ADS)

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

    1997-05-01

    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.

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

    ERIC Educational Resources Information Center

    Martinez, Aja Y.

    2009-01-01

    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…

  13. Color flow mapping

    Microsoft Academic Search

    Katherine Ferrara; Gia DeAngelis

    1997-01-01

    Color flow mapping systems have become widely used in the short time since their development. These systems overlay a pseudo-color velocity map upon the gray-scale two-dimensional image. Between 4 and 16 pulses are directed to each line-of-sight, and this requirement reduces the frame rate in comparison with the gray-scale image. Other limitations of color flow mapping include its ability to

  14. 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.

  15. Color Control in Shrimp

    NSDL National Science Digital Library

    Mary-Jane O'Halloran (Dalhousie University; )

    1989-06-06

    Sand shrimp, Crangon septemspinosus, are capable of varying their color or shading in response to several environmental changes (background color, light intensity, light wavelength, and temperature). The degree of color change can be determined quantitatively by examining the chromatophores under a dissecting microscope and staging the amount of pigment dispersion, (b) the location or type of receptors involved, and (c) the type of communication between receptors and effectors.

  16. Color Sines Classroom Activity

    NSDL National Science Digital Library

    Thomas, Fred

    In this lesson from Math Machines, the class will use an RGB Color Mixer and a graphing calculator to control the color of a single pixel. In addition to learning about color, the students will gain experience using and programming calculators. A participant handout (including worksheet) and facilitator notes are made available for download in DOC file format. A link to a required calculator program is also included.

  17. Seasonal flowering and evolution: the heritage from Charles Darwin

    Microsoft Academic Search

    To survive, plants optimise their seasonal flowering time and set seed to avoid extremes of the environment including frost, heat and drought. Additionally, pollination may need to betightly regulated in time so that it coincides with flowering of other individuals and\\/or with the presence of bird or insect pollinators. It is now clear that plants use seasonal changes in natural

  18. Interspecific hybridizations in ornamental flowering cherries (Prunus species)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flowering cherries belong to the genus Prunus L., consisting primarily of species native to Asia. Despite the popularity of ornamental cherry trees in the landscape, most ornamental Prunus planted in the U.S. are derived from a limited genetic base of Japanese flowering cherry taxa. Controlled cross...

  19. Sparse-flowering orchardgrass is stable across temperate North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Orchardgrass (Dactylis glomerata L.) is a major component of many pastures in temperate North America. Early and profuse flowering in pastures is a nuisance to graziers due to livestock refusal to consume flowering stems, prompting many graziers to avoid use of this species. The objective of this re...

  20. Stabilizing Selection and the Structural Variability of Flowers within Species

    Microsoft Academic Search

    J. E. CRESSWELL

    1998-01-01

    Zoophilous flowers often appear to be precisely formed for pollen transfer and exhibit relatively little variability in structure within species. Functional optimization by the seemingly exacting requirements of pollen transfer may account for these observations. I used the results of a literature survey to examine the levels of intraspecific variation in flowers across a wide range of taxa. The least

  1. Irreversible commitment to flowering in two mango cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, the state of Nayarit, Mexico has experienced variations in rainfall distribution and warmer temperatures during the autumn-winter season which have caused erratic flowering of mango. The early-flowering cultivars, such as ‘Ataulfo’, have been less affected than tardy ones such as ‘T...

  2. PHENOLOGY MILWAUKEE 2012 A phylogenetic comparative study of flowering phenology

    E-print Network

    Davies, Jonathan

    Introduction Arctic and subarctic tundra represent one of the major global biomes where climate warming) and flowering duration across subarctic species composing different commu- nities, from boreal forest to tundra reproduction can be severe. For exam- ple, early flowering of plants growing on wind-blown open tundra areas

  3. Biochemical differentiation in the tobacco flower probed with monoclonal antibodies

    Microsoft Academic Search

    Phillip T. Evans; Brian L. Holaway; Russell L. Malmberg

    1988-01-01

    We have isolated a series of monoclonal antibodies that react to antigens in flowers of Nicotiana tabacum L. (tobacco) displaying specificity or preferentiality in their cell and tissue distributions. We immunized mice with extracts from tobacco flowers and then screened the hybridomas by enzyme-linked immunosorbent assay (ELISA) against extracts from leaves, sepals, petals, stamens and pistils; twenty five were chosen

  4. Epidemiology of Powedery Mildew on Flowering Dogwood in Tennessee

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew, caused by Erysiphe pulchra (syn. Microsphaera pulchra) is an important disease on flowering dogwood (Cornus florida) in the Eastern United States. Temporal progress of powdery mildew on flowering dogwood cultivars with different levels of resistance was investigated in the field in 2...

  5. Qualitative and quantitative analyses of flower scent in Silene latifolia

    Microsoft Academic Search

    Stefan Dötterl; Lorne M. Wolfe; Andreas Jürgens

    2005-01-01

    The quantitative and qualitative variability in floral scent of 98 specimens of the dioecious species Silene latifolia belonging to 15 European and 19 North American populations was determined. Floral scent was collected from single flowers using dynamic headspace methods, and analysed by Micro-SPE and GC-MS methods. The flowers showed a nocturnal rhythm, and scent was emitted only at night. The

  6. Anatomical investigation of flower of Butea monosperma Lam.

    PubMed Central

    Muthuswamy, Ragunathan; Senthamarai, R.

    2014-01-01

    Background: Butea frondosa Roxb. and Koen. syn. Butea monosperma Lam. (Leguminosae or Fabaceae) is a tree grows up to the height of 8 m at the age 50 years. Its flowers are being used in traditional medicine for the treatment of ulcer, inflammation, hepatic disorder, and eye diseases. Aims: The present study was aimed at establishing the microscopic characteristics of flower B. monosperma Lam. Materials and Methods: Histological evaluation of flowers was done using standard procedures. Images of microscopic characters were taken at different magnifications using Nikon Labphoto 2 microscopic Unit. Perkin Elmer 5000 an atomic absorption spectrophotometer was employed for elemental analysis. Results: In the study, microscopic characters of floral parts were investigated in transverse section and the flower powder. The current study reveals the presence of pollen grains, ovary (OV), and trichomes in their flower powder. Different cell components were studied, and their sizes were measured. Elemental analysis showed the presence of Zn 52.2 ?g/g and Cu 36.3 ?g/g were major contents, whereas Cr, Mn, and Pd were minor contents in dried flower powder. Conclusion: The current study paves the way to provide standard information related to the presence of essential elements in the flower. Microscopic characters of the flower and its quantitative measurement of cell components will help to identify the plant and also help to improvise the existing monograph of B. monosperma in the Ayurvedic pharmacopoeia. PMID:25861140

  7. Comparison methods for branching and axillary flowering sequences

    Microsoft Academic Search

    Y. Guédon; P. Heuret; E. Costes

    2003-01-01

    Comparing branching and axillary flowering patterns accurately is a major issue both in botany and in various agronomic contexts. Data take the form of sequences which naturally represent the underlying structural information of branching and axillary flowering patterns. Various comparison methods are proposed based either on sequence alignment or on the computation of dissimilarity measures between (hidden) Markovian models built

  8. BINOMIAL COUNT SAMPLING FOR WESTERN FLOWER THRIPS IN GREENHOUSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Counts of western flower thrips in garden impatiens (Impatiens wallerana) and cucumber flowers were fit to incidence-mean models to determine whether a generic model could be used for binomial count sampling. The crop did not significantly alter the parameters for incidence-mean models, and perform...

  9. Shifts in flowering phenology reshape a subalpine plant community

    PubMed Central

    CaraDonna, Paul J.; Iler, Amy M.; Inouye, David W.

    2014-01-01

    Phenology—the timing of biological events—is highly sensitive to climate change. However, our general understanding of how phenology responds to climate change is based almost solely on incomplete assessments of phenology (such as first date of flowering) rather than on entire phenological distributions. Using a uniquely comprehensive 39-y flowering phenology dataset from the Colorado Rocky Mountains that contains more than 2 million flower counts, we reveal a diversity of species-level phenological shifts that bring into question the accuracy of previous estimates of long-term phenological change. For 60 species, we show that first, peak, and last flowering rarely shift uniformly and instead usually shift independently of one another, resulting in a diversity of phenological changes through time. Shifts in the timing of first flowering on average overestimate the magnitude of shifts in the timing of peak flowering, fail to predict shifts in the timing of last flowering, and underrepresent the number of species changing phenology in this plant community. Ultimately, this diversity of species-level phenological shifts contributes to altered coflowering patterns within the community, a redistribution of floral abundance across the season, and an expansion of the flowering season by more than I mo during the course of our study period. These results demonstrate the substantial reshaping of ecological communities that can be attributed to shifts in phenology. PMID:24639544

  10. Vegetative Propagation from the Broccoli Curd after Suppression of Flowering

    Microsoft Academic Search

    K. E. Haine

    1951-01-01

    IN the course of an inspection of early varieties of autumn cauliflower and broccoli grown for seed production in Cyprus during 1946, it was observed in certain crops that after the inflorescence had formed very few flower buds developed. Suppression of flower development also occurred in a seed crop in the Scilly Isles later that year, and in a glasshouse

  11. BIOLOGY IN PICTURES FLOWER PIGMENTATION Colouring the snapdragon

    E-print Network

    Jackson, David

    BIOLOGY IN PICTURES FLOWER PIGMENTATION Colouring the snapdragon Pigmentation pattern, one '· ·. . : Whereas the flower buds of wild-type Antirrhinum majus show a pattern of anthocyanin pigmentation that is stongest at the base of the petal tube and in the lobes (a), there is no pigment in the petal tube

  12. On selection for flowering time plasticity in response to density.

    PubMed

    Vermeulen, Peter J

    2015-01-01

    Different genotypes often exhibit opposite plastic responses in the timing of the onset of flowering with increasing plant density. In experimental studies, selection for accelerated flowering is generally found. By contrast, game theoretical studies predict that there should be selection for delayed flowering when competition increases. Combining different optimality criteria, the conditions under which accelerated or delayed flowering in response to density would be selected for are analysed with a logistic growth simulation model. To maximize seed production at the whole-stand level (simple optimization), selection should lead to accelerated flowering at high plant density, unless very short growing seasons select for similar onset of flowering at all densities. By contrast, selection of relative individual fitness will lead to delayed flowering when season length is long and/or growth rates are high. These different results give a potential explanation for the observed differences in direction of the plastic responses within and between species, including homeostasis, as a result of the effect of the variation in season length on the benefits of delayed flowering. This suggests that limited plasticity can evolve without the costs and limits that are currently thought to constrain the evolution of plasticity. PMID:25124368

  13. FlowerPot : an anonymous BitTorrent client

    E-print Network

    Cohen, Jeffrey Steven

    2007-01-01

    This thesis presents and analyzes FlowerPot, an anonymous client for the BitTorrent file-sharing system. FlowerPot is peer-to-peer, providing scalability and making it difficult to attack with techniques like denial-of-service. ...

  14. Susceptibility of blackberry flower parts to subfreezing temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Injury of tight buds, open flowers and green fruit often occur in fruit crops in later winter to early spring frosts. In this study, freezing tolerance of ‘Triple Crown’ blackberry flowers at various maturity ranging from tight bud to green drupe stage was determined using two freezing methods. On...

  15. Abundance of adult hoverflies (Diptera: Syrphidae) on different flowering plants

    Microsoft Academic Search

    H. Sadeghi

    2008-01-01

    Encouraging natural enemies by growing attractive plants is considered an effective method of pest control in organic farming. However, it is important to identify which flowers best attract beneficial insects. In this study, relative attractiveness of 16 species of flowering plants to adult hoverflies was assessed by conducting timed observations of feeding-visit frequencies. The experiments were conducted at two sites,

  16. Social Choice Majority Vote Graphs

    E-print Network

    Goddard, Wayne

    #12;Social Choice Majority Vote Graphs Supermajority Voting Supermajority Vote Graphs Clemson Miniconference on Discrete Mathematics October 2004 Craig A. Tovey Georgia Tech #12;Social Choice HOW should maximizes the probability of the better alternative being chosen. #12;Social Choice Majority Vote Graphs

  17. Dynamics of Choice: A Tutorial

    ERIC Educational Resources Information Center

    Baum, William M.

    2010-01-01

    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…

  18. After Busing: Education and Choice.

    ERIC Educational Resources Information Center

    Armor, David J.

    1989-01-01

    Argues that mandatory busing, while resulting in cases of "White flight," has had positive consequences in the re-emergence of "choice" programs and magnet schools. Contends that choice programs can be expanded on intradistrict, metropolitan, and statewide levels. Suggests that Federal funding and private education should be included in choice

  19. Asychronous distributed graph coloring Keith Briggs & James Evans

    E-print Network

    , dotted n=1000. Left: C=-1, C=, C=+1. Right: C=4, C=5, C=6, C=7, C=8. #12;Heuristic VCD if clock time a proper coloring). Left: FCD (check rate =1), VCD (check rate =1+#conflicts), VCD & terminate after resolving all conflicts, VCD, exp(#conflicts). Right: same with stochastic choice (FCS, VCS). #12;Heuristic

  20. Matching Background Color

    NSDL National Science Digital Library

    David Ipsen

    2008-04-01

    This chapter introduces an especially important subject in the concealment of animals--countershading. One observes many animals with colors that match the general color of their usual backgrounds. Many leaf-eating insects appear green, for example, making them relatively inconspicuous against their normal background of leaves. The manner of coloration that will provide such a color match is not as obvious as one might imagine. It depends significantly on the nature of the lighting. The inquiry-based activities included in this section effectively illustrate this concept.

  1. Crater Floor in Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 5 May 2004 This daytime visible color image was collected on November 18, 2003 during the Southern Summer season in Terra Cimmeria.

    This daytime visible color image was collected on September 4, 2002 during the Northern Spring season in Vastitas Borealis. The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude -23.7, Longitude 135.6 East (224.4 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  2. [Flower essences: vibrational intervention of diagnostic and therapeutic possibilities].

    PubMed

    Gimenes, Olympia Maria Piedade; da Silva, Maria Júlia Paes; Benko, Maria Antonieta

    2004-12-01

    The purpose of this study was to know the probable diagnosis and therapeutic action of the flower essences under the light of the Theory of the Imaginary by Gilbert Durand, through the AT.9 test and flower essence interview sessions. It was applied to 30 people, who were being treated with flower essences, by a private practitioner in São Paulo. The study contains 60 AT.9 test protocols and 60 flower essence formulae. It analyzed the common traces, both the attuned and the dissonant ones, by the relationships established between the AT.9 and the flower essence formulae, bringing forward evidences of the capacity diagnosis and the therapeutic actions of these essences. The two essences that translated the characteristic tone of this population were California Wild Rose and Evening Primrose. PMID:15688996

  3. Genetics and genomics of flower initiation and development in roses

    PubMed Central

    Bendahmane, Mohammed

    2013-01-01

    Roses hold high symbolic value and great cultural importance in different societies throughout human history. They are widely used as garden ornamental plants, as cut flowers, and for the production of essential oils for the perfume and cosmetic industries. Domestication of roses has a long and complex history, and the rose species have been hybridized across vast geographic areas such as Europe, Asia, and the Middle East. The domestication processes selected several flower characters affecting floral quality, such as recurrent flowering, double flowers, petal colours, and fragrance. The molecular and genetic events that determine some of these flower characters cannot be studied using model species such as Arabidopsis thaliana, or at least only in a limited manner. In this review, we comment on the recent development of genetic, genomic, and transcriptomic tools for roses, and then focus on recent advances that have helped unravel the molecular mechanisms underlying several rose floral traits. PMID:23364936

  4. The role of fructan in flowering of Campanula rapunculoides.

    PubMed

    Vergauwen, R; Van den Ende, W; Van Laere, A

    2000-07-01

    Inulin type fructan was detected in all vegetative organs of Campanula rapunculoides L. plants. All flower parts contained fructan at some developmental stage. A steady decrease was found in sepals during development. Petals, however, stored fructan in the bud stage. A rapid breakdown during opening of the flower resulted in high concentrations of glucose and especially fructose that may contribute to the osmotic driving force involved in petal expansion. Before complete shrivelling, the hexoses were apparently exported from flower parts. Fructans were hydrolysed and exported from the stamen and style tissue upon flower opening. Similarly, the major fructan reserves in the ovary were broken down almost simultaneously with those in other flower parts. Hexoses did not reach high levels in the ovary, probably because they were rapidly metabolized and/or incorporated by developing seeds. PMID:10937702

  5. Flower Size Variation in Rosmarinus officinalis: Individuals, Populations and Habitats

    PubMed Central

    HERRERA, JAVIER

    2004-01-01

    • Background and Aims Flowers are relatively invariant organs within species, but quantitative variation often exists among conspecifics. These variations represent the raw material that natural selection can magnify, eventually resulting in morphological divergence and diversification. This paper investigates floral variability in Rosmarinus officinalis, a Mediterranean shrub. • Methods Nine populations were selected in three major southern Spanish habitats (coast, lowland and mountains) along an elevation gradient. Flower samples from randomly chosen plants were collected from each population, and a total of 641 flowers from 237 shrubs were weighed while still fresh to the nearest 0·1 mg. Leaves from the same plants were also measured. Variations among habitats, sites and plants were explored with general linear model ANOVA. Leaf–flower covariation was also investigated. • Key Results Most (58 %) mass in flowers was accounted for by the corolla, whose linear dimensions correlated directly with flower mass. Averaged over plants, the mass of a flower varied between 12 mg and 38 mg. Habitat, site (within habitat) and shrub identity had significant effects on mass variance. Flowers from the coast were the smallest (17 mg) and those from the mountains the largest (25 mg on average). A pattern of continuously increasing flower size with elevation emerged which was largely uncoupled from the geographical pattern of leaf size variation. • Conclusions As regards flower size, a great potential to local differentiation exists in Rosmarinus. Observed divergences accord with a regime of large-bodied pollinator selection in the mountains, but also with resource–cost hypotheses on floral evolution that postulate that reduced corollas are advantageous under prevailingly stressful conditions. PMID:15585545

  6. Promoting flowering, lateral shoot outgrowth, leaf development, and flower abscission in tobacco plants overexpressing cotton FLOWERING LOCUS T (FT)-like gene GhFT1

    PubMed Central

    Li, Chao; Zhang, Yannan; Zhang, Kun; Guo, Danli; Cui, Baiming; Wang, Xiyin; Huang, Xianzhong

    2015-01-01

    FLOWERING LOCUS T (FT) encodes a mobile signal protein, recognized as major component of florigen, which has a central position in regulating flowering, and also plays important roles in various physiological aspects. A mode is recently emerging for the balance of indeterminate and determinate growth, which is controlled by the ratio of FT-like and TERMINAL FLOWER 1 (TFL1)-like gene activities, and has a strong influence on the floral transition and plant architecture. Orthologs of GhFT1 was previously isolated and characterized from Gossypium hirsutum. We demonstrated that ectopic overexpression of GhFT1 in tobacco, other than promoting flowering, promoted lateral shoot outgrowth at the base, induced more axillary bud at the axillae of rosette leaves, altered leaf morphology, increased chlorophyll content, had higher rate of photosynthesis and caused flowers abscission. Analysis of gene expression suggested that flower identity genes were significantly upregulated in transgenic plants. Further analysis of tobacco FT paralogs indicated that NtFT4, acting as flower inducer, was upregulated, whereas NtFT2 and NtFT3 as flower inhibitors were upregulated in transgenic plants under long-day conditions, but downregulated under short-day conditions. Our data suggests that sufficient level of transgenic cotton FT might disturb the balance of the endogenous tobacco FT paralogs of inducers and repressors and resulted in altered phenotype in transgenic tobacco, emphasizing the expanding roles of FT in regulating shoot architecture by advancing determine growth. Manipulating the ratio for indeterminate and determinate growth factors throughout FT-like and TFL1-like gene activity holds promise to improve plant architecture and enhance crop yield. PMID:26136765

  7. Polar Cap Colors

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 12 May 2004 This daytime visible color image was collected on June 6, 2003 during the Southern Spring season near the South Polar Cap Edge.

    The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude -77.8, Longitude 195 East (165 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  8. Contextual processing of brightness and color in Mongolian gerbils.

    PubMed

    Garbers, Christian; Henke, Josephine; Leibold, Christian; Wachtler, Thomas; Thurley, Kay

    2015-01-01

    Brightness and color cues are essential for visually guided behavior. However, for rodents, little is known about how well they do use these cues. We used a virtual reality setup that offers a controlled environment for sensory testing to quantitatively investigate visually guided behavior for achromatic and chromatic stimuli in Mongolian gerbils (Meriones unguiculatus). In two-alternative forced choice tasks, animals had to select target stimuli based on relative intensity or color with respect to a contextual reference. Behavioral performance was characterized using psychometric analysis and probabilistic choice modeling. The analyses revealed that the gerbils learned to make decisions that required judging stimuli in relation to their visual context. Stimuli were successfully recognized down to Weber contrasts as low as 0.1. These results suggest that Mongolian gerbils have the perceptual capacity for brightness and color constancy. PMID:25589297

  9. Image color reduction method for color-defective observers using a color palette composed of 20 particular colors

    NASA Astrophysics Data System (ADS)

    Sakamoto, Takashi

    2015-01-01

    This study describes a color enhancement method that uses a color palette especially designed for protan and deutan defects, commonly known as red-green color blindness. The proposed color reduction method is based on a simple color mapping. Complicated computation and image processing are not required by using the proposed method, and the method can replace protan and deutan confusion (p/d-confusion) colors with protan and deutan safe (p/d-safe) colors. Color palettes for protan and deutan defects proposed by previous studies are composed of few p/d-safe colors. Thus, the colors contained in these palettes are insufficient for replacing colors in photographs. Recently, Ito et al. proposed a p/dsafe color palette composed of 20 particular colors. The author demonstrated that their p/d-safe color palette could be applied to image color reduction in photographs as a means to replace p/d-confusion colors. This study describes the results of the proposed color reduction in photographs that include typical p/d-confusion colors, which can be replaced. After the reduction process is completed, color-defective observers can distinguish these confusion colors.

  10. Variation, Repetition, And Choice

    PubMed Central

    Abreu-Rodrigues, Josele; Lattal, Kennon A; dos Santos, Cristiano V; Matos, Ricardo A

    2005-01-01

    Experiment 1 investigated the controlling properties of variability contingencies on choice between repeated and variable responding. Pigeons were exposed to concurrent-chains schedules with two alternatives. In the REPEAT alternative, reinforcers in the terminal link depended on a single sequence of four responses. In the VARY alternative, a response sequence in the terminal link was reinforced only if it differed from the n previous sequences (lag criterion). The REPEAT contingency generated low, constant levels of sequence variation whereas the VARY contingency produced levels of sequence variation that increased with the lag criterion. Preference for the REPEAT alternative tended to increase directly with the degree of variation required for reinforcement. Experiment 2 examined the potential confounding effects in Experiment 1 of immediacy of reinforcement by yoking the interreinforcer intervals in the REPEAT alternative to those in the VARY alternative. Again, preference for REPEAT was a function of the lag criterion. Choice between varying and repeating behavior is discussed with respect to obtained behavioral variability, probability of reinforcement, delay of reinforcement, and switching within a sequence. PMID:15828592

  11. Context effects on choice.

    PubMed Central

    Goldshmidt, J N; Lattal, K M; Fantino, E

    1998-01-01

    Four pigeons responded on a concurrent-chains schedule in four experiments that examined whether the effectiveness of a stimulus as a conditioned reinforcer is best described by a global approach, as measured by the average interreinforcement interval, or by a local contextual approach, as measured by the onset of the stimulus preceding the conditioned reinforcer. The interreinforcement interval was manipulated by the inclusion of an intertrial interval, which increased the overall time to reinforcement but did not change the local contingencies on a given trial A global analysis predicted choice for the richer alternative to decrease with the inclusion of an intertrial interval, whereas a local analysis predicted no change in preference. Experiment 1 examined sensitivity to intertrial intervals when each was signaled by the same houselight that operated throughout the session. In Experiment 2, the intertrial interval always was signaled by the stimulus correlated with the richer terminal link. In Experiment 3, the intertrial interval was signaled by the keylights correlated with the initial links and two novel houselights. Experiment 4 provided free food pseudorandomly during the intertrial interval. In all experiments, subjects' preferences were consistent with a local analysis of choice in concurrent chains. These results are discussed in terms of delay-reduction theory, which traditionally has failed to distinguish global and local contexts. PMID:9821681

  12. Colors of Stars

    NSDL National Science Digital Library

    Mary Kay Hemenway

    2011-01-01

    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.

  13. Science Shorts: Seeing Color

    NSDL National Science Digital Library

    Juliana Texley

    2005-09-01

    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.

  14. Colored diagonal loading

    Microsoft Academic Search

    John D. Hiemstra

    2002-01-01

    We develop a beamforming technique called colored diagonal loading. This technique is a generalization of diagonal loading in which the covariance matrix is augmented with a scaled version of a colored matrix as opposed to using the identity matrix as with conventional diagonal loading. Thus as the loading is increased, the beampattern increasingly takes on the form of a desired

  15. Segmentation of Color Textures

    Microsoft Academic Search

    Majid Mirmehdi; Maria Petrou

    2000-01-01

    This paper describes an approach to perceptual segmentation of color image textures. A multiscale representation of the texture image, generated by a multiband smoothing algorithm based on human psychophysical measurements of color appearance is used as the input. Initial segmentation is achieved by applying a clustering algorithm to the image at the coarsest level of smoothing. The segmented clusters are

  16. Color of Evaporated Milks

    Microsoft Academic Search

    Byron H. Webb; George E. Holm

    1930-01-01

    Agriculture The color of evaporated milk is of considerable commercial im- portance since it is one of the fundamental characteristics by which the consumer judges the product. Some of the various factors concerned in the production of color are recognized in a general qualitative way by the producer. No data, however, are available dealing with the factors concerned in the

  17. [The changes in spectral features of the staple-food bamboos of giant panda after flowering].

    PubMed

    Liu, Xue-Hua; Wu, Yan

    2012-12-01

    Large-area flowering of the giant pandas' staple food is an important factor which can influence their survival. Therefore, it is necessary to predict the bamboo flowering. Foping Nature Reserve was taken as the study area. The research selected the giant pandas' staple-food bamboos Bashania fargesii, Fargesia qinlingensis and Fargesia dracocephala with different flowering situations (i. e., flowering, potential flowering, non-flowering with far distance) to measure the spectral reflectance of bamboo leaves. We studied the influence of bamboo flowering on the spectral features of three bamboo species through analyzing the original spectral reflectance and their red edge parameters. The results showed that (1) the flowering changed the spectra features of bamboo species. The spectral reflectance of B. fargesii shows a pattern: flowering bamboo < potential flowering bamboo < non-flowering bamboo with far distance, while F. qinlingensis and F. dracocephala show the different pattern: flowering bamboo > or = potential flowering bamboo > non-flowering bamboo with far distance. Among three bamboo species, F. dracocephala showed the greatest change, and then F. qinlingensis. (2) After bamboo flowering, the red edge of B. fargesii has no obvious shifting, while the other two bamboos have distinctive shifting towards the shorter waves. The study found that the original spectral feature and the red edge all changed under various flowering states, which can be used to provide the experimental basis and theoretic support for the future prediction of bamboo flowering through remote sensing. PMID:23427564

  18. Uniform color space based on color vision mechanisms

    NASA Astrophysics Data System (ADS)

    Nakano, Yasuhisa; Yamashita, Ryuzo; Fukuda, Yukinari; Suehara, Ken-ichiro; Yano, Takuo

    2002-06-01

    A uniform color space based on color vision mechanisms was proposed. The mechanisms considered to construct the uniform color space were, proportion of three types of cones, compressive response nonlinearity at receptor and post- receptor stages, constant noise or dark response added to the receptor response, and fractional expressions of opponent and S channel in the postreceptor stage. The present uniform color space explains, three dimensional color discrimination data, supra-threshold color differences such as Munsell color chips, and luminance dependence of the color differences.

  19. Color-detection thresholds in rhesus macaque monkeys and humans.

    PubMed

    Gagin, Galina; Bohon, Kaitlin S; Butensky, Adam; Gates, Monica A; Hu, Jiun-Yiing; Lafer-Sousa, Rosa; Pulumo, Reitumetse L; Qu, Jane; Stoughton, Cleo M; Swanbeck, Sonja N; Conway, Bevil R

    2014-01-01

    Macaque monkeys are a model of human color vision. To facilitate linking physiology in monkeys with psychophysics in humans, we directly compared color-detection thresholds in humans and rhesus monkeys. Colors were defined by an equiluminant plane of cone-opponent color space. All subjects were tested on an identical apparatus with a four-alternative forced-choice task. Targets were 2° square, centered 2° from fixation, embedded in luminance noise. Across all subjects, the change in detection thresholds from initial testing to plateau performance (“learning”) was similar for +L ? M (red) colors and +M ? L (bluish-green) colors. But the extent of learning was higher for +S (lavender) than for ?S (yellow-lime); moreover, at plateau performance, the cone contrast at the detection threshold was higher for +S than for ?S. These asymmetries may reflect differences in retinal circuitry for S-ON and S-OFF. At plateau performance, the two species also had similar detection thresholds for all colors, although monkeys had shorter reaction times than humans and slightly lower thresholds for colors that modulated L/M cones. We discuss whether these observations, together with previous work showing that monkeys have lower spatial acuity than humans, could be accounted for by selective pressures driving higher chromatic sensitivity at the cost of spatial acuity amongst monkeys, specifically for the more recently evolved L ? M mechanism. PMID:25027164

  20. [The flower and blossom morphology of Asteraceae correlates with composition of their pollinators].

    PubMed

    Dlusski?, G M; Glazunova, K P; Lavrova, N V

    2004-01-01

    The correlation between flower morphology and share of different insect groups visiting them was studied for 15 Asteraceae species. We measured length and width of corolla tube of 100 flowers of each plant species and determined proportions of main groups of anthophilous insects during all blooming period. According to corolla length species under study ranged more or less uniformly from 2.16 mm (Tripleurospermum inodorum) up to 21.06 mm (Cirsium heterophyllum). The correlation between share of long-tongued bees (mainly bumblebees) among all visitors of inflorescens and corolla length was positive (r = 0.737, P < 0.01) while for short-tongued flies (Syrphidae, Muscidae, Calliphoridae) it was negative (r = -0.869, P < 0.01). It is interesting, that the point of crossing of regression lines (12 mm) approximately coincides with change in inflorescences coloration. Plants with corolla length less than 10 mm have yellow or white inflorescences that are visited primarily by flies, while the plants with longer corolla have violet or dark blue inflorescences, by bumblebees. The dependence of proportion of short-tongued solitary bees (Andrenidae, Halictidae) on a corolla length was non-linear. It increased with increase in corolla length in an interval of 2.16-6.26 mm (r = 0.930, P < 0.1), but decreased for longer corollas (r = -0.680, P < 0.05). The correlation between corolla length and proportions of beetles and butterflies were insignificant. PMID:15609481

  1. [Nutritional content, functional properties and conservation of edible flowers. Review].

    PubMed

    Lara-Cortés, Estrella; Osorio-Díaz, Perla; Jiménez-Aparicio, Antonio; Bautista-Bañios, Silvia

    2013-09-01

    The floriphagia that is the consumption of flowers as a food, is an old practice not widespread among consumers until some decades ago. Edible flowers contribute to increasing the appearance of food. They can provide biologically active substances including vitamin A, C, riboflavins, niacin, minerals such as calcium, phosphorous, iron and potassium that are eventually beneficial to consumers' health. This review includes some examples of edible flowers including roses, violets and nasturtium among others, uses and applications, sensorial characteristics and nutritional values that lead them to be considered as functional food: An important factor that affects the quality of edible flowers is the form in which they are preserved since it may affect their sensorial and nutritional characteristics. However, not all flowers can be eaten as food since there are some of them that can be toxic or even mortal. Finally, although the consumption of flowers is an ancient practice, there is little regulation in this regard. Of the review on edible flowers, it is concluded that there are still numerous aspects about them to evaluate such as nutritional and functional characteristics, conservation and regulation with the aim to extend its consumption. PMID:25362819

  2. Flower thermoregulation facilitates fertilization in Asian sacred lotus

    PubMed Central

    Li, Jiao-Kun; Huang, Shuang-Quan

    2009-01-01

    Background and Aims The thermoregulatory flower of the Asian sacred lotus (Nelumbo nucifera) can maintain a relatively stable temperature despite great variations in ambient temperature during anthesis. The thermoregulation has been hypothesized to offer a direct energy reward for pollinators in lotus flowers. This study aims to examine whether the stable temperature maintained in the floral chamber influences the fertilization process and seed development. Methods An artificial refrigeration instrument was employed to cool flowers during the fertilization process and post-fertilization period in an experimental population. The effect of temperature on post-pollination events was also examined by removing petals in two field populations. Key Results Treatments with low floral temperature did not reduce stigma receptivity or pollen viability in undehisced anthers. Low temperature during the fertilization period significantly decreased seed set per flower but low temperature during the phase of seed development had no effect, suggesting that temperature regulation by lotus flowers facilitated fertilization success. Hand-pollination treatments in two field populations indicated that seed set of flowers with petals removed was lower than that of intact flowers in north China, where ambient temperatures are low, but not in south China, confirming that reducing the temperature of carpels did influence post-pollination events. Conclusions The experiments suggest that floral thermoregulation in lotus could enhance female reproductive success by facilitating fertilization. PMID:19282320

  3. Color in Nature Barb Cutler

    E-print Network

    Durand, Frédo

    , structural · Purpose of Color warning, mimicry, camouflage, transparency #12;Blue Sapphire (intervalence for individuality, mood, courtship, warning, mimicry, camouflage · Blushing · Internal color is probably that is more dangerous, poisonous or distasteful Eyed hawk moth #12;Camouflage · Imitate or reproduce color

  4. Exact Reproduction of Colored Images

    E-print Network

    Horn, Berthold K.P.

    The problem of producing a colored image from a colored original is analyzed. Conditions are determined for the production of an image, in which the colors cannot be distinguished from those in the original by a human ...

  5. Folivory versus florivory--adaptiveness of flower feeding.

    PubMed

    Bandeili, Babak; Müller, Caroline

    2010-01-01

    The distribution of resources and defence is heterogeneous within plants. Specialist insects may prefer tissue with high concentrations of the plant's characteristic defence compounds. Most herbivorous butterfly or sawfly larvae are considered to be folivores, so also the turnip sawfly Athalia rosae (Hymenoptera: Tenthredinidae), a specialist herbivore on Brassicaceae. We investigated which tissue larvae choose to feed upon and how they perform on flowers, young or old leaves of Sinapis alba. Furthermore, constitutive and inducible levels of glucosinolates and myrosinases were investigated and nutrients analysed. Larvae moved from leaves to flowers for feeding from the third larval instar on. Flowers were not actively chosen, but larvae moved upwards on the plant, regardless of how plants were orientated (upright or inverted). Flower-feeding larvae were heavier and developed faster than larvae feeding on young leaves, and adults laid more eggs. Old leaves as food source resulted in the lowest growth rates. Flowers contained three and ten times higher myrosinase activities than young and old leaves, respectively, whereas glucosinolate concentrations and nitrogen levels of flowers and young leaves were comparable. Glucosinolate concentrations of old leaves were very low. Changes in tissue chemistry caused by larval feeding were tissue specific. Defence levels did not change in flowers and old leaves after A. rosae feeding in contrast to young leaves. The high insect performance on flowers cannot be explained by differences in chemical defence. Instead, the lack of mechanical defence (trichomes) is probably responsible. Movement to the flowers and folivory is overall highly adaptive for this sawfly species. PMID:19826770

  6. Folivory versus florivory—adaptiveness of flower feeding

    NASA Astrophysics Data System (ADS)

    Bandeili, Babak; Müller, Caroline

    2010-01-01

    The distribution of resources and defence is heterogeneous within plants. Specialist insects may prefer tissue with high concentrations of the plant’s characteristic defence compounds. Most herbivorous butterfly or sawfly larvae are considered to be folivores, so also the turnip sawfly Athalia rosae (Hymenoptera: Tenthredinidae), a specialist herbivore on Brassicaceae. We investigated which tissue larvae choose to feed upon and how they perform on flowers, young or old leaves of Sinapis alba. Furthermore, constitutive and inducible levels of glucosinolates and myrosinases were investigated and nutrients analysed. Larvae moved from leaves to flowers for feeding from the third larval instar on. Flowers were not actively chosen, but larvae moved upwards on the plant, regardless of how plants were orientated (upright or inverted). Flower-feeding larvae were heavier and developed faster than larvae feeding on young leaves, and adults laid more eggs. Old leaves as food source resulted in the lowest growth rates. Flowers contained three and ten times higher myrosinase activities than young and old leaves, respectively, whereas glucosinolate concentrations and nitrogen levels of flowers and young leaves were comparable. Glucosinolate concentrations of old leaves were very low. Changes in tissue chemistry caused by larval feeding were tissue specific. Defence levels did not change in flowers and old leaves after A. rosae feeding in contrast to young leaves. The high insect performance on flowers cannot be explained by differences in chemical defence. Instead, the lack of mechanical defence (trichomes) is probably responsible. Movement to the flowers and folivory is overall highly adaptive for this sawfly species.

  7. An Analysis of Combining Ability for Height, Leaf Out, Bloom Date and Flower Color for Crapemyrtle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding of crapemyrtle (Lagerstroemia) in the United States has focused on developing hybrids between parents with disease or pest resistance and those with good floral characteristics. The objective of this work was to study the general and specific combining ability of several horticulturally im...

  8. Small Silencing RNAs: Upon injection of gene for purple color, the flower became veriegated

    E-print Network

    Dever, Jennifer A.

    using double stranded RNA Figure 21.3 Gene silencing by dsRNA is called RNA interference (RNAi) RNAi different than antisense inhibition of gene expression · RNAi works with double- stranded RNA, not with antisense strand only · RNAi works catalytically ­ tiny amount needs to be added to decrease gene expression

  9. Matching image color from different cameras

    NASA Astrophysics Data System (ADS)

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

    2008-01-01

    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.

  10. Inference of domestication history and differentiation between early- and late-flowering varieties in pearl millet.

    PubMed

    Dussert, Y; Snirc, A; Robert, T

    2015-04-01

    Pearl millet (Pennisetum glaucum) is a staple crop in Sahelian Africa. Farmers usually grow varieties with different cycle lengths and complementary functions in Sahelian agrosystems. Both the level of genetic differentiation of these varieties and the domestication history of pearl millet have been poorly studied. We investigated the neutral genetic diversity and population genetic structure of early- and late-flowering domesticated and wild pearl millet populations using 18 microsatellite loci and 8 nucleotide sequences. Strikingly, early- and late-flowering domesticated varieties were not differentiated over their whole distribution area, despite a clear difference in their isolation-by-distance pattern. Conversely, our data brought evidence for two well-differentiated genetic pools in wild pearl millet, allowing us to test scenarios with different numbers and origins of domestication using approximate Bayesian computation (ABC). The ABC analysis showed the likely existence of asymmetric migration between wild and domesticated populations. The model choice procedure indicated that a single domestication from the eastern wild populations was the more likely scenario to explain the polymorphism patterns observed in cultivated pearl millet. PMID:25705965

  11. Nectar minerals as regulators of flower visitation in stingless bees and nectar hoarding wasps.

    PubMed

    Afik, Ohad; Delaplane, Keith S; Shafir, Sharoni; Moo-Valle, Humberto; Quezada-Euán, J Javier G

    2014-05-01

    Various nectar components have a repellent effect on flower visitors, and their adaptive advantages for the plant are not well understood. Persea americana (avocado) is an example of a plant that secretes nectar with repellent components. It was demonstrated that the mineral constituents of this nectar, mainly potassium and phosphate, are concentrated enough to repel honey bees, Apis mellifera, a pollinator often used for commercial avocado pollination. Honey bees, however, are not the natural pollinator of P. americana, a plant native to Central America. In order to understand the role of nectar minerals in plant-pollinator relationships, it is important to focus on the plant's interactions with its natural pollinators. Two species of stingless bees and one species of social wasp, all native to the Yucatan Peninsula, Mexico, part of the natural range of P. americana, were tested for their sensitivity to sugar solutions enriched with potassium and phosphate, and compared with the sensitivity of honey bees. In choice tests between control and mineral-enriched solutions, all three native species were indifferent for mineral concentrations lower than those naturally occurring in P. americana nectar. Repellence was expressed at concentrations near or exceeding natural concentrations. The threshold point at which native pollinators showed repellence to increasing levels of minerals was higher than that detected for honey bees. The results do not support the hypothesis that high mineral content is attractive for native Hymenopteran pollinators; nevertheless, nectar mineral composition may still have a role in regulating flower visitors through different levels of repellency. PMID:24888745

  12. Stork Color Proofing Technology

    NASA Astrophysics Data System (ADS)

    Ekman, C. Frederick

    1989-04-01

    For the past few years, Stork Colorproofing B.V. has been marketing an analog color proofing system in Europe based on electrophoto-graphic technology it pioneered for the purpose of high resolution, high fidelity color imaging in the field of the Graphic Arts. Based in part on this technology, it will make available on a commercial basis a digital color proofing system in 1989. Proofs from both machines will provide an exact reference for the user and will look, feel, and behave in a reproduction sense like the printed press sheet.

  13. Functional Analysis of Synchronous Dichogamy in Flowering Rush, Butomus umbellatus (Butomaceae)

    Microsoft Academic Search

    Michael Bhardwaj; Christopher G. Eckert

    2001-01-01

    Dichogamy is one of the most widespread floral mechanisms in flowering plants and is thought to have evolved to reduce interference between pollen import and export within flowers, especially self-pollination. Self-pollination between flowers may also be reduced if dichogamy is synchronous among flowers on an inflorescence. The analysis of dichogamy at both levels requires that the sexual phases of individual

  14. Analysis of the Molecular Basis of Flowering Time Variation in Arabidopsis Accessions1[w

    E-print Network

    Howard, Martin

    Analysis of the Molecular Basis of Flowering Time Variation in Arabidopsis Accessions1[w] Silvia (FRIGIDA) and FLC (FLOWERING LOCUS C) loci are major determinants of flowering time in Arabidopsis- tively. Many early flowering accessions carry loss-of-function fri alleles containing one of two

  15. Effects of elevated CO 2 on flowering phenology and nectar production

    Microsoft Academic Search

    Andreas Erhardt; Hans-Peter Rusterholz

    1997-01-01

    Effects of elevated CO2 on flowering phenology and nectar production were studied in five important nectar plants of calcareous grasslands, i.e. Lotus corniculatus, Trifolium pratense, Betonica officinalis, Scabiosa columbaria and Centaurea jacea. Glasshouse experiments showed that flowering probability was significantly enhanced in C. jacea. B. officinalis flowered carlier and L. corniculatus produced more flowers under elevated CO2. In contrast, the

  16. Flight patterns of foraging bees relative to density of artificial flowers and distribution of nectar

    Microsoft Academic Search

    Keith D. Waddington

    1980-01-01

    Flight patterns of honeybees (Apis mellifera ligustica) were quantified as the bees foraged among artificial ‘flowers’ for sugar solution (‘nectar’). Bees exhibited considerable directionality on successive flights which minimized repeat visits to flowers and they usually made short flights to nearby flowers, thus minimizing flight time. The change in direction on successive flights between flowers were independent of the number

  17. Spatial fragrance patterns in flowers of Silene latifolia : Lilac compounds as olfactory nectar guides?

    Microsoft Academic Search

    S. Dötterl; A. Jürgens

    2005-01-01

    Floral odour can differ qualitatively and quantitatively between different parts of the flowers, and these spatial fragrance patterns within the flowers can be used by pollinators for orientation on flowers. Here we present results of spatial fragrance patterns within flowers of the dioecious Silene latifolia (Caryophyllaceae). Volatiles were collected and analysed using a highly sensitive dynamic headspace method, which allows

  18. Consequences of flower heliotropism for reproduction in an alpine buttercup ( Ranunculus adoneus )

    Microsoft Academic Search

    Maureen L. Stanton; Candace Galen

    1989-01-01

    The flowers of the alpine snow buttercup Ranunculus adoneus track the sun's movement from early morning until mid-afternoon. Individual blooms last up to a week: younger female stage flowers show greater solar tracking fidelity than older hermaphrodite or dehisced flowers. Flowers aligned parallel to the sun's rays reach mean internal temperatures several degrees Celsius above ambient air temperature. As a

  19. Relationships between flowering phenology, plant size and reproductive success in Lotus corniculatus (Fabaceae)

    Microsoft Academic Search

    Jeff Ollerton; Andrew Lack

    1998-01-01

    Over three years the flowering phenology of individuals of Lotus corniculatus has been studied in relation to fruit set and seed predation to determine the relationships between four components of flowering time, plant size and reproductive success. Timings of first and peak flowering, and duration and synchrony of flowering differed between individuals in the same years. Between years, timing of

  20. Relationships between flowering phenology, plant size and reproductive success in shape Lotus corniculatus (Fabaceae)

    Microsoft Academic Search

    Jeff Ollerton; Andrew Lack

    1998-01-01

    Over three years the flowering phenology of individuals of Lotus corniculatus has been studied in relation to fruit set and seed predation to determine the relationships between four components of flowering time, plant size and reproductive success. Timings of first and peak flowering, and duration and synchrony of flowering differed between individuals in the same years. Between years, timing of

  1. Flowering phenology, floral display and reproductive success in dioecious, Aralia nudicaulis L. (Araliaceae)

    Microsoft Academic Search

    Lawrence B. Flanagan; Walter Moser

    1985-01-01

    Aralia nudicaulis L. is a dioecious, perennial, herbaceous plant that is commonly found in the understory vegetation throughout the boreal forest of North America. Female remets have fewer flowers per inflorescence, initiate flowering earlier, and reach peak flowering before male ramets. The consequences of the asynchrony in flowering between the sexes on pollination and seed set were examined during a

  2. School Choice 2000 Annual Report

    NSDL National Science Digital Library

    2000-01-01

    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.

  3. Pollen consumption by flower mites in three hummingbird-pollinated plant species.

    PubMed

    Velázquez, Tonatiuh; Ornelas, Juan Francisco

    2010-02-01

    Laboratory studies suggest that pollen consumption by flower mites may decrease the male fitness of the plant by reducing the available pollen for dispersal. Here we assessed pollen consumption by flower mites under natural conditions in three plant species with long-lived, protandrous flowers, Moussonia deppeana (Gesneriaceae), Lobelia laxiflora and L. cardinalis (Lobeliaceae). Total pollen mass was measured after 24 and 48 h in flowers exposed to flower mites and excluded from hummingbirds, flowers exposed to mites and hummingbird visitation, and in flowers recently opened with dehisced anthers. Compared with recently opened flowers, pollen availability was reduced about half in the presence of flower mites and the same effect was observed in the three plant species. Our results suggest that flower mites are removing a great deal of pollen and the reduction of pollen implies the possibility of direct impact on pollen transfer. PMID:19763848

  4. Impact of Urbanisation on Flower Visitors revealed by Citizen Science

    E-print Network

    Impact of Urbanisation on Flower Visitors revealed by Citizen Science Nicolas Deguines, Colin ? ??? #12;A monitoring programme based on citizen science Community of volunteers Team of researchers « Citizen science, the involvement of volunteers in research » (Dickinson, Zuckerberg, & Bonter 2010

  5. Antibacterial effect of Melia azedarach flowers on rabbits.

    PubMed

    Saleem, Rubeena; Ahmed, Syed Iqbal; Shamim, Syed Mohammad; Faizi, Shaheen; Siddiqui, Bina Shaheen

    2002-12-01

    A methanol extract of Melia azedarach flowers showed potent antibacterial action in rabbits suffering from a skin infection produced by Stapyhlococcus aureus. The healing effects were found comparable to neomycin. PMID:12458483

  6. Anthocyanin-dependent anoxygenic photosynthesis in coloured flower petals?

    PubMed Central

    Lysenko, Vladimir; Varduny, Tatyana

    2013-01-01

    Chlorophylless flower petals are known to be composed of non-photosynthetic tissues. Here, we show that the light energy storage that can be photoacoustically measured in flower petals of Petunia hybrida is approximately 10-12%. We found that the supposed chlorophylless photosynthesis is an anoxygenic, anthocyanin-dependent process occurring in blue flower petals (ADAPFP), accompanied by non-respiratory light-dependent oxygen uptake and a 1.5-fold photoinduced increase in ATP levels. Using a simple, adhesive tape stripping technique, we have obtained a backside image of an intact flower petal epidermis, revealing sword-shaped ingrowths connecting the cell wall and vacuole, which is of interest for the further study of possible vacuole-related photosynthesis. Approaches to the interpretations of ADAPFP are discussed, and we conclude that these results are not impossible in terms of the known photochemistry of anthocyanins. PMID:24284801

  7. Selenium accumulation in flowers and its effects on pollination

    E-print Network

    , floral visitor, hyperaccumulator, pollen germination, selenium (Se), Stanleya pinnata. Summary · Selenium­pollinator interactions. · Floral Se distribution and speciation were compared in Stanleya pinnata, an Se hyperaccumulator. · Stanleya pinnata preferentially allocated Se to flowers, as nontoxic methyl- selenocysteine (Me

  8. Flavonol glycosides from the flowers of Bellis perennis.

    PubMed

    Gudej, J; Nazaruk, J

    2001-11-01

    Three flavonol glycosides, isorhamnetin 3-O-beta-D-galactopyranoside, isorhamnetin 3-O-beta-D-(6"-acetyl)-galactopyranoside and kaempferol 3-O-beta-D-glucopyranoside were isolated from the flowers of Bellis perennis. PMID:11677029

  9. Flavonol glycosides from the flowers of Bellis perennis

    Microsoft Academic Search

    J Gudej; J Nazaruk

    2001-01-01

    Three flavonol glycosides, isorhamnetin 3-O-?-d-galactopyranoside, isorhamnetin 3-O-?-d-(6?-acetyl)-galactopyranoside and kaempferol 3-O-?-d-glucopyranoside were isolated from the flowers of Bellis perennis.

  10. FEASIBILITY of “TRACEABLE” COLOR STANDARDS for COTTON COLOR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton color is measured on the Uster® High Volume Instrument (HVI) for Rd (diffuse reflectance) and +b (yellowness). Rd and +b are cotton-specific color parameters, and they are not as well known as other globally recognized color systems (e.g., L*a*b*). Further, the standards used for HVI color...

  11. Color naming and categorization in inherited color vision deficiencies

    Microsoft Academic Search

    VALÉRIE BONNARDEL

    2006-01-01

    Dichromatic subjects can name colors accurately, even though they cannot discriminate among red-green hues ~Jameson & Hurvich, 1978!. This result is attributed to a normative language system that dichromatic observers developed by learning subtle visual cues to compensate for their impoverished color system. The present study used multidimensional scaling techniques to compare color categorization spaces of color-vision deficient ~CVD! subjects

  12. Thickening the colored regions in a color volume dataset

    Microsoft Academic Search

    Dong-xing Wang; Dong-ming Guo; Zhen-yuan Jia; Lian-hui Jiang

    2005-01-01

    The colored regions in the surface colored models (SCMs) made by the rapid prototyping processes should be of a certain thickness, so that they can be post-processed by ‘subtracting’ processes like grinding. A method based on the principle of mathematical morphology was proposed, which can be used to thicken the colored regions in a color volume dataset (CVD) obtained from

  13. Novel color palettization scheme for preserving important colors

    NASA Astrophysics Data System (ADS)

    Luo, Jiebo; Spaulding, Kevin E.; Yu, Qing

    2003-01-01

    Color palettization is the process that converts an input color image having a large set of possible colors to an output color image having a reduced set of palette colors. For example, a typical input 24-bit input image has possibly millions of colors, whereas a typical color palette has only 256 colors. It is desirable to determine the set of palette colors based on the distribution of colors in the input image. Furthermore, it is also desirable to preserve important colors such as human skin tones in the palettized image. We propose a novel scheme to accomplish these goals through supplementing the distribution of input colors by a distribution of selected important colors. In particular, skin color supplementation is achieved by appending to the input image skin tone patches generated from statistical sampling of the skin color probability density function. A major advantage of this scheme is that explicit skin detection, which can be error-prone and time consuming is avoided. In addition, this scheme can be used with any color palettization algorithms. Subjective evaluation has shown the efficacy of this scheme.

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

    ERIC Educational Resources Information Center

    Asay, Calvin S.; Schneider, Edward W.

    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 sighted students at Brigham Young University. After a preliminary training exercise to acquaint the…

  15. Color planner for designers based on color emotions

    NASA Astrophysics Data System (ADS)

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

    2002-06-01

    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.

  16. Colored Contact Lens Dangers

    MedlinePLUS Videos and Cool Tools

    ... Without a Prescription It started as an impulsive buy from a souvenir shop, but 10 hours after ... are being sold illegally," Dr. Steinemann said. Never buy colored contact lenses from a retailer that does ...

  17. The Four Color Theorem

    NSDL National Science Digital Library

    Robertson, Neil.

    1997-01-01

    Neil Robertson, Daniel P. Sanders, Paul Seymour, and Robin Thomas created this page to provide a short description of their new proof of the four color theorem and a four-coloring algorithm. The four color theorem began as the concept that a map can be shaded so that no connected areas have the same color. On this page the creators of this new proof provide a history of the proof, the need for a new proof, and a brief overview of the proof itself. The full text paper is available as a downloadable postscript file or online at the Electronic Research Announcements of the American Mathematical Society (link provided in reference 8 at the site). Programs and data used in the proof are also available under the section Pointers.

  18. Tooth - abnormal colors

    MedlinePLUS

    ... of tooth development can cause changes in the color and hardness of the enamel. ... temporarily stain the teeth, such as tea or coffee Genetic ... overuse of fluoride rinses, toothpaste, and fluoride supplements

  19. Color harmonization for images

    NASA Astrophysics Data System (ADS)

    Tang, Zhen; Miao, Zhenjiang; Wan, Yanli; Wang, Zhifei

    2011-04-01

    Color harmonization is an artistic technique to adjust a set of colors in order to enhance their visual harmony so that they are aesthetically pleasing in terms of human visual perception. We present a new color harmonization method that treats the harmonization as a function optimization. For a given image, we derive a cost function based on the observation that pixels in a small window that have similar unharmonic hues should be harmonized with similar harmonic hues. By minimizing the cost function, we get a harmonized image in which the spatial coherence is preserved. A new matching function is proposed to select the best matching harmonic schemes, and a new component-based preharmonization strategy is proposed to preserve the hue distribution of the harmonized images. Our approach overcomes several shortcomings of the existing color harmonization methods. We test our algorithm with a variety of images to demonstrate the effectiveness of our approach.

  20. Transparency and imaginary colors

    E-print Network

    Koenderink, Jan J.

    Unlike the Metelli monochrome transparencies, when overlays and their backgrounds have chromatic content, the inferred surface colors may not always be physically realizable, and are in some sense “imaginary.” In these ...

  1. The color of cheese

    NSDL National Science Digital Library

    American Association for the Advancement of Science (AAAS; )

    2003-06-27

    If milk is white, what makes cheddar cheese orange? The cheese coloring comes from a pigment called bixin. Scientists are researching ways to produce bixin without having to harvest from the Bixa plant.

  2. Chemistry, Color, and Art.

    ERIC Educational Resources Information Center

    Orna, Mary Virginia

    2001-01-01

    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)

  3. Three Colors of Light

    NSDL National Science Digital Library

    2012-06-26

    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.

  4. Gapless color superconductivity

    E-print Network

    Kouvaris, Christoforos N

    2005-01-01

    In this thesis, we propose and investigate the "Gapless Color-Flavor Locked" (gCFL) phase, a possible new phase of dense and cold quark matter. At high enough densities, quarks interact with each other and form pairs ...

  5. Color Video Petrography.

    ERIC Educational Resources Information Center

    Nagle, Frederick

    1981-01-01

    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)

  6. Physics of structural colors

    NASA Astrophysics Data System (ADS)

    Kinoshita, S.; Yoshioka, S.; Miyazaki, J.

    2008-07-01

    In recent years, structural colors have attracted great attention in a wide variety of research fields. This is because they are originated from complex interaction between light and sophisticated nanostructures generated in the natural world. In addition, their inherent regular structures are one of the most conspicuous examples of non-equilibrium order formation. Structural colors are deeply connected with recent rapidly growing fields of photonics and have been extensively studied to clarify their peculiar optical phenomena. Their mechanisms are, in principle, of a purely physical origin, which differs considerably from the ordinary coloration mechanisms such as in pigments, dyes and metals, where the colors are produced by virtue of the energy consumption of light. It is generally recognized that structural colors are mainly based on several elementary optical processes including thin-layer interference, diffraction grating, light scattering, photonic crystals and so on. However, in nature, these processes are somehow mixed together to produce complex optical phenomena. In many cases, they are combined with the irregularity of the structure to produce the diffusive nature of the reflected light, while in some cases they are accompanied by large-scale structures to generate the macroscopic effect on the coloration. Further, it is well known that structural colors cooperate with pigmentary colors to enhance or to reduce the brilliancy and to produce special effects. Thus, structure-based optical phenomena in nature appear to be quite multi-functional, the variety of which is far beyond our understanding. In this article, we overview these phenomena appearing particularly in the diversity of the animal world, to shed light on this rapidly developing research field.

  7. Somatic embryogenesis and in vitro flowering in Brassica nigra

    Microsoft Academic Search

    U. J. Mehta; S. Hazra; A. F. Mascarenhas

    1993-01-01

    Summary  This report describes a protocol for regeneration ofBrassica nigra in vitro from unorganized callus to a highly differentiated stage of flowering. Callus is initiated from seedling hypocotyl,\\u000a and root explants and plantlets are obtained via somatic embryogenesis. Shoot cultures can be established from these plantlets.\\u000a These shoots can either be induced to flower in vitro or rooted to produce plants

  8. Pigments responsible for ultraviolet patterns in flowers of Oenothera (Onagraceae)

    Microsoft Academic Search

    William A. Dement

    1974-01-01

    MANY insect-pollinated flowers have nectar guides1 which increase the foraging and pollination efficiency of their insect visitors2. Some of these are visible only by their contrasting ultraviolet patterns, visible to insects but not to humans3. In such flowers, the nectar guides absorb ultraviolet light, and the compounds responsible were early suspected to be phenolics4. Recently, in Rudbeckia hirta L. (Asteraceae),

  9. Environmental Control of Flowering in some Northern Carex Species

    Microsoft Academic Search

    O. M. HEIDE

    1997-01-01

    The environmental control of flowering in some arctic-alpineCarexspecies has been studied in controlled environments.Carex nigra, C. brunnescens, C. atrata, C. norwegicaandC. serotinaall had a dual induction requirement for flowering. In all exceptC. nigraeither low temperature (12 °C or lower) or short days (SD) over a wider range of temperatures were needed for primary floral induction and inflorescence formation. InC. nigraprimary

  10. Chirality and biosynthesis of lilac compounds in Actinidia arguta flowers

    Microsoft Academic Search

    A. J. Matich; B. J. Bunn; D. J. Comeskey; M. B. Hunt; D. D. Rowan

    2007-01-01

    Biosynthesis of lilac compounds in ‘Hortgem Tahi’ kiwifruit (Actinidia arguta) flowers was investigated by treating inflorescences with d5-linalool. The incorporation of the deuterium label into 8-hydroxylinalool, 8-oxolinalool, the lilac aldehydes, alcohols, and alcohol epoxides was followed by GC-MS and enantioselective GC-MS. Both (R)- and (S)-linalool were produced naturally by the flowers, but 8-hydroxylinalool, 8-oxolinalool, and the lilac aldehydes and alcohols

  11. Arabidopsis MSI1 functions in photoperiodic flowering time control

    PubMed Central

    Steinbach, Yvonne; Hennig, Lars

    2014-01-01

    Appropriate timing of flowering is crucial for crop yield and the reproductive success of plants. Flowering can be induced by a number of molecular pathways that respond to internal and external signals such as photoperiod, vernalization or light quality, ambient temperature and biotic as well as abiotic stresses. The key florigenic signal FLOWERING LOCUS T (FT) is regulated by several flowering activators, such as CONSTANS (CO), and repressors, such as FLOWERING LOCUS C (FLC). Chromatin modifications are essential for regulated gene expression, which often involves the well conserved MULTICOPY SUPRESSOR OF IRA 1 (MSI1)-like protein family. MSI1-like proteins are ubiquitous partners of various complexes, such as POLYCOMB REPRESSIVE COMPLEX2 or CHROMATIN ASSEMBLY FACTOR 1. In Arabidopsis, one of the functions of MSI1 is to control the switch to flowering. Arabidopsis MSI1 is needed for the correct expression of the floral integrator gene SUPPRESSOR OF CO 1 (SOC1). Here, we show that the histone-binding protein MSI1 acts in the photoperiod pathway to regulate normal expression of CO in long day (LD) photoperiods. Reduced expression of CO in msi1-mutants leads to failure of FT and SOC1 activation and to delayed flowering. MSI1 is needed for normal sensitivity of Arabidopsis to photoperiod, because msi1-mutants responded less than wild type to an intermittent LD treatment of plants grown in short days. Finally, genetic analysis demonstrated that MSI1 acts upstream of the CO-FT pathway to enable an efficient photoperiodic response and to induce flowering. PMID:24639681

  12. [Hyperspectrum based prediction model for nitrogen content of apple flowers].

    PubMed

    Zhu, Xi-Cun; Zhao, Geng-Xing; Wang, Ling; Dong, Fang; Lei, Tong; Zhan, Bing

    2010-02-01

    The present paper aims to quantitatively retrieve nitrogen content in apple flowers, so as to provide an important basis for apple informationization management. By using ASD FieldSpec 3 field spectrometer, hyperspectral reflectivity of 120 apple flower samples in full-bloom stage was measured and their nitrogen contents were analyzed. Based on the apple flower original spectrum and first derivative spectral characteristics, correlation analysis was carried out between apple flowers original spectrum and first derivative spectrum reflectivity and nitrogen contents, so as to determine the sensitive bands. Based on characteristic spectral parameters, prediction models were built, optimized and tested. The results indicated that the nitrogen content of apple was very significantly negatively correlated with the original spectral reflectance in the 374-696, 1 340-1 890 and 2 052-2 433 nm, while in 736-913 nm they were very significantly positively correlated; the first derivative spectrum in 637-675 nm was very significantly negatively correlated, and in 676-746 nm was very significantly positively correlated. All the six spectral parameters established were significantly correlated with the nitrogen content of apple flowers. Through further comparison and selection, the prediction models built with original spectral reflectance of 640 and 676 nm were determined as the best for nitrogen content prediction of apple flowers. The test results showed that the coefficients of determination (R2) of the two models were 0.825 8 and 0.893 6, the total root mean square errors (RMSE) were 0.732 and 0.638 6, and the slopes were 0.836 1 and 1.019 2 respectively. Therefore the models produced desired results for nitrogen content prediction of apple flowers with average prediction accuracy of 92.9% and 94.0%. This study will provide theoretical basis and technical support for rapid apple flower nitrogen content prediction and nutrition diagnosis. PMID:20384136

  13. High generalization in flower-visiting networks of social wasps

    NASA Astrophysics Data System (ADS)

    Mello, Marco A. R.; Santos, Gilberto Marcos de Mendonça; Mechi, Maria Rita; Hermes, Marcel G.

    2011-01-01

    Flower-visiting interactions, such as nectarivory and pollination, are considered to form networks with higher interaction specialization than other plant-animal facultative mutualisms. However, subsets within each network sometimes are different from the complete system. Social wasps are one subset within flower-visiting networks; they use nectar as a secondary food of adults. Some of the visited plants depend on wasps for pollination, and many are further benefited through predation of herbivores captured to feed wasp larvae. Therefore, mutual dependence is lower in the wasp subset compared to complete pollination networks, so we expected wasp-flower networks to exhibit more generalistic interactions. Quantitative datasets were built by recording wasp visits to flowers in six Brazilian localities in four ecoregions, and comparisons were made with complete pollination networks from the literature (with different taxa included). Nestedness (NODF = 0.39 ± 0.06) was similar in wasp-flower and complete pollination networks (NODF = 0.32 ± 0.18). Interaction specialization in wasp-flower networks was lower (median H2' = 0.31 ± 0.09) than in complete pollination networks (median H2' = 0.55 ± 0.17). Modularity in wasp-flower networks (M = 0.36 ± 0.05) was also lower than in complete pollination networks (M = 0.47 ± 0.09); there were on average 5 ± 1 modules on each network formed by species of different genera. In summary, our findings confirm that wasps that feed on nectar interact with similar subsets of plants; therefore, wasp-flower networks are more generalistic than other pollination networks. Our results corroborate the hypothesis that, despite some universal properties found in facultative mutualisms, parts of a system differ from the complete system. Furthermore, mutual dependence influences interaction specialization, and so it is an important structuring factor of mutualistic networks.

  14. Spatial fragrance patterns within the flowers of Ranunculus acris ( Ranunculaceae )

    Microsoft Academic Search

    Gunnar Bergström; Heidi E. M. Dobson; Inga Groth

    1995-01-01

    Floral scents emitted from different flower parts ofRanunculus acris were investigated by trapping headspace volatiles onto Porapak Q followed by solvent desorption and GC-MS analysis. Isoprenoids, strongly dominated bytrans-ß-ocimene, constituted the principal class of volatiles in all flower parts except pollen; sesquiterpenes were especially diverse. Odors collected separately from petals, stamens, and sepals + gynoecium comprised the same volatiles, but

  15. Wavelet Analysis of Flowering and Climatic Niche Identification

    Microsoft Academic Search

    Irene L. Hudson; In Kang; Marie R. Keatley

    \\u000a This chapter discusses wavelet analysis which is a robust statistical method capable of handling noisy and non-stationary\\u000a data which phenological time series often are.\\u000a \\u000a \\u000a We used a maximal overlap discrete wavelet transform (MODWT) analysis to examine the flowering records (1940–1970) of E. leucoxylon and Eucalyptus tricarpa, E. microcarpa and E. polyanthemos. We identified four subcomponents in each flowering series: characterised

  16. Addiction: Choice or Compulsion?

    PubMed Central

    Henden, Edmund; Melberg, Hans Olav; Røgeberg, Ole Jørgen

    2013-01-01

    Normative thinking about addiction has traditionally been divided between, on the one hand, a medical model which sees addiction as a disease characterized by compulsive and relapsing drug use over which the addict has little or no control and, on the other, a moral model which sees addiction as a choice characterized by voluntary behavior under the control of the addict. Proponents of the former appeal to evidence showing that regular consumption of drugs causes persistent changes in the brain structures and functions known to be involved in the motivation of behavior. On this evidence, it is often concluded that becoming addicted involves a transition from voluntary, chosen drug use to non-voluntary compulsive drug use. Against this view, proponents of the moral model provide ample evidence that addictive drug use involves voluntary chosen behavior. In this article we argue that although they are right about something, both views are mistaken. We present a third model that neither rules out the view of addictive drug use as compulsive, nor that it involves voluntary chosen behavior. PMID:23966955

  17. The couple's choices.

    PubMed

    Seewald, R

    1993-03-01

    The Secretary of Health under President Ramos emphasizes prevention rather than curative medicine and plans on starting a family planning program in the Philippines. Family planning was basically neglected during 1986-1992. The goal of the program is to reduce infant and maternal mortality and to curb population growth which is outstripping the country's ability to feed itself (annual population growth - 2.3%, agriculture growth rate - 1%). Family planning includes limiting the number of births, birth spacing, and helping infertile women (10-12% of women). The entire health budget of the Philippines is only 2% of the national budget which is smaller than the 5% recommended by WHO. Thus, the Secretary intends to ask for international assistance, but not until he first develops the program. The guideline he uses for program development is that any program must be simple, practical, economical, effective, and duplicable (SPEED). He wants to incorporate nongovernmental organizations into the program since they are flexible and innovative, emphasize quality, and change quickly. Many women (17% of all women of reproductive age in 4 villages in Cavite Province) have had at least 1 abortion, even though it is illegal. The leading reason for abortions is unwanted or unplanned pregnancy, so family planning will reduce the number of abortions. The Secretary wants people to participate in family planning for instance, to make their own choice about what method to use, be it artificial or natural. PMID:12286380

  18. Three-dimensional fluorescence characteristics of white chrysanthemum flowers

    NASA Astrophysics Data System (ADS)

    Fan, Yunchang; Li, Yang; Cai, Hongxin; Li, Jing; Miao, Juan; Fu, Dexue; Su, Kun

    2014-09-01

    White chrysanthemum flower is one of the most popular plants found everywhere in China and used as herbs. In the present work, three-dimensional fluorescence technique was used to discriminate species of white chrysanthemum flowers. Parameters affecting extraction efficiency were investigated. Under the optimal conditions, the three-dimensional fluorescence characteristics of three types of white chrysanthemum flowers were obtained. It was found that there were two main fluorescence peaks with remarkable difference in fluorescence intensity, one was corresponding to flavonoids and another was attributed to chlorophyll-like compounds. There were remarkable differences among the contours of the three white chrysanthemum flowers. Further studies showed that the fluorescence intensity ratios of chlorophyll-like compounds to flavonoids had a certain relationship with the species; those for Huai, Hang and Huangshan white chrysanthemum flowers were 6.9-7.4, 18.9-21.4 and 73.6-84.5, respectively. All of the results suggest that three-dimensional fluorescence spectra can be used for the discrimination of white chrysanthemum flowers with the advantages of low cost, ease for operation and intuition.

  19. Floral scents repel facultative flower visitors, but attract obligate ones

    PubMed Central

    Junker, Robert R.; Blüthgen, Nico

    2010-01-01

    Background and Aims Biological mutualisms rely on communication between partners, but also require protective measures against exploitation. Animal-pollinated flowers need to attract pollinators but also to avoid conflicts with antagonistic consumers. The view of flower visitors as mutualistic and antagonistic agents considers primarily the plants' interest. A classification emphasizing the consumer's point of view, however, may be more useful when considering animal's adaptations to flower visits which may include a tolerance against defensive floral scent compounds. Methods In a meta-analysis covering 18 studies on the responses of animals to floral scents, the animals were assigned to the categories of obligate and facultative flower visitors which considers their dependency on floral resources. Their responses on floral scents were compared. Key Results On average, obligate flower visitors, often corresponding to pollinators, were attracted to floral scent compounds. In contrast, facultative and mainly antagonistic visitors were strongly repelled by floral scents. The findings confirm that floral scents have a dual function both as attractive and defensive cues. Conclusions Whether an animal depends on floral resources determines its response to these signals, suggesting that obligate flower visitors evolved a tolerance against primarily defensive compounds. Therefore, floral scent bouquets in conjunction with nutritious rewards may solve the conflicting tasks of attracting mutualists while repelling antagonists. PMID:20228087

  20. Flower bouquet variation in four species of Crocus ser. Verni.

    PubMed

    Carta, Angelino; Flamini, Guido; Cioni, Pier Luigi; Pistelli, Luisa; Peruzzi, Lorenzo

    2015-01-01

    Flowering plants employ a wide variety of signals, including scent, to attract pollinators. The aim of this work was to examine whether flower volatiles in four closely related Crocus species are linked to species divergence and to the current knowledge on their pollination syndromes. Fragrances of freshly opened flowers in Crocus etruscus, C. ilvensis, C. neglectus, and C. vernus, all belonging to ser. Verni, were analyzed using GC/MS. Results coincide with present knowledge about systematic relationships among taxa. The four species fall into two main fragrance types, based on similarities of their volatile compounds. In C. etruscus, C. ilvensis, and C. neglectus, oxygenated monoterpenes (lilac aldehyde B and A) are most abundant, while C. vernus has a fragrance rich in monoterpene hydrocarbons (?-pinene and limonene). Our results point towards outcrossing mating strategies for C. etruscus, C. ilvensis, and C. neglectus, whose volatile compounds are known as pollinator attractants. This is in line with their flower architecture, showing a style of variable height, often overtopping stamens. On the other hand, a self-pollination strategy was repeatedly suggested in the literature for C. vernus, marked by flowers with the style deeply inserted in the stamens and also by a completely different flower bouquet. PMID:25547989

  1. Three-dimensional fluorescence characteristics of white chrysanthemum flowers.

    PubMed

    Fan, Yunchang; Li, Yang; Cai, Hongxin; Li, Jing; Miao, Juan; Fu, Dexue; Su, Kun

    2014-09-15

    White chrysanthemum flower is one of the most popular plants found everywhere in China and used as herbs. In the present work, three-dimensional fluorescence technique was used to discriminate species of white chrysanthemum flowers. Parameters affecting extraction efficiency were investigated. Under the optimal conditions, the three-dimensional fluorescence characteristics of three types of white chrysanthemum flowers were obtained. It was found that there were two main fluorescence peaks with remarkable difference in fluorescence intensity, one was corresponding to flavonoids and another was attributed to chlorophyll-like compounds. There were remarkable differences among the contours of the three white chrysanthemum flowers. Further studies showed that the fluorescence intensity ratios of chlorophyll-like compounds to flavonoids had a certain relationship with the species; those for Huai, Hang and Huangshan white chrysanthemum flowers were 6.9-7.4, 18.9-21.4 and 73.6-84.5, respectively. All of the results suggest that three-dimensional fluorescence spectra can be used for the discrimination of white chrysanthemum flowers with the advantages of low cost, ease for operation and intuition. PMID:24810027

  2. SolaColor: space coloration with solar light

    Microsoft Academic Search

    Tomoko Hashida; Yasuaki Kakehi; Takeshi Naemura

    2011-01-01

    SolaColor is a scheme for creating a place (namely, a floor space) whose color is varied in response to sunlight. The aim of this work is to create sustainable spatial rendition by utilizing sunlight. A feature of this spatial-rendition scheme is rendering places by color--rather than contrast---of lighting. By means of SolaColor, areas in sunlight are colored in pink, while

  3. The genetics of mirror-image flowers.

    PubMed Central

    Jesson, Linley K; Barrett, Spencer C H

    2002-01-01

    Conspicuous asymmetries in forms that are polymorphic within a species can be genetically or environmentally determined. Here, we present a genetic analysis of the inheritance of dimorphic enantiostyly, a sexual polymorphism in which all flowers on a plant have styles that are consistently deflected either to the left or the right side of the floral axis. Using Heteranthera multiflora (Pontederiaceae), a short-lived herb, we conducted crosses within and between left- and right-styled plants and scored progeny ratios of the style morphs in F(1), F(2) and F(3) generations. Crosses conducted in the parental generation between morphs or right-styled plants resulted in right-styled progeny, whereas crosses between left-styled plants resulted in left-styled progeny. When putative heterozygous F(1) plants were selfed, the resulting F(2) segregation ratios were not significantly different from a 3 : 1 ratio for right- and left-styled plants. Crosses between left- and right-styled plants in the F(2) generation yielded F(3) progeny with either a 1 : 1 ratio of left- and right-styled plants or right-styled progeny. Our results are consistent with a model in which a single Mendelian locus with two alleles, with the right-styled allele (R) dominant to the left-styled allele (r), governs stylar deflection. The simple inheritance of dimorphic enantiostyly has implications for the evolution and maintenance of this unusual sexual polymorphism. PMID:12350272

  4. Flies and flowers in Darwin's race.

    PubMed

    Pauw, Anton; Stofberg, Jaco; Waterman, Richard J

    2009-01-01

    The idea of coevolution originated with Darwin's proposal that long-proboscid pollinators and long-tubed flowers might be engaged in reciprocal selection, but this has not been demonstrated. Here we test key aspects of Darwin's hypothesis of reciprocal selection in an experiment with naturally interacting populations of extremely long-proboscid flies (Moegistorhynchus longirostris: Nemestinidae) and long-tubed irises (Lapeirousia anceps: Iridaceae). We show that the benefit derived by both the fly (volume of nectar consumed) and the plant (number pollen grains received) depends on the relative length of their interacting organs. Each trait is shown to act both as agent and target in directional reciprocal selection, potentially leading to a race. This understanding of how fitness in both species varies in relation to the balance of their armament allows us to make tentative predictions about the nature of selection across multiple communities. We find that in each community a core group of long-tubed plant species might together be involved in diffuse coevolution with the fly. In poorly matched populations, the imbalance in armament is too great to allow reciprocal selection to act, and these species might instead experience one-sided selection that leads to convergence with the core species. Reciprocal selection drives the evolution of the community, then, additional species become attached to the network of interacting mutualists by convergence. PMID:19146595

  5. Influence of biochar, mycorrhizal inoculation, and fertilizer rate on growth and flowering of Pelargonium (Pelargonium zonale L.) plants

    PubMed Central

    Conversa, Giulia; Bonasia, Anna; Lazzizera, Corrado; Elia, Antonio

    2015-01-01

    Peat is the most common substrate used in nurseries despite being a very expensive and a non-renewable material. Peat replacement with biochar could be a sound environmental practice, as it is produced from waste biomass, but evaluation of biochar as a potting substrate is needed. Ratios of peat:biochar of 100:0, 70:30, 30:70 (BC0, BC30, and BC70, respectively), two fertilizer rates (FERT1, FERT2), and arbuscular mycorrhizal fungi (AMF) inoculation were tested on potted Pelargonium plants. Plant growth, flowering, bio-physiological and nutritional responses, and root mycorrhization were evaluated. The BC30 mixture did not affect plant growth compared with pure peat. However, BC30 in combination with FERT2 treatment was more effective in enhancing nitrogen (N) and chlorophyll (CHL) leaf concentrations, and leaf and flower numbers. The BC70 mixture depressed plant growth, flowering traits, and root mycorrhization. Leaf N concentration was below the sufficiency range reported for Pelargonium growth. Leaf concentration of phosphorous (P) was adequate in pure peat and in BC30 but it dropped close to sub-optimal values in BC70. The pH value of the mixtures lowered P availability, though in BC30 the mycorrhizal activity could have allowed adequate P plant uptake. In BC70 plants, the deficiency of both N and P might be a reason for the observed growth reduction. The inoculation of the substrate with selected AMF improved plant growth (higher dry biomass, greater floral clusters, larger and more abundant leaves) and quality resulting in unstressed (lower electrolyte leakage and higher relative water content values) and greener leaves (low L? and C?, high CHL content) and in more intensely colored flowers. We conclude that biochar can be applied in nursery/potted plant production provided that the proportion in the peat mixture does not exceed 30%. Furthermore, AMF inoculation contributed to achieving the best plant performance in 30% biochar amended medium. PMID:26136757

  6. Influence of biochar, mycorrhizal inoculation, and fertilizer rate on growth and flowering of Pelargonium (Pelargonium zonale L.) plants.

    PubMed

    Conversa, Giulia; Bonasia, Anna; Lazzizera, Corrado; Elia, Antonio

    2015-01-01

    Peat is the most common substrate used in nurseries despite being a very expensive and a non-renewable material. Peat replacement with biochar could be a sound environmental practice, as it is produced from waste biomass, but evaluation of biochar as a potting substrate is needed. Ratios of peat:biochar of 100:0, 70:30, 30:70 (BC0, BC30, and BC70, respectively), two fertilizer rates (FERT1, FERT2), and arbuscular mycorrhizal fungi (AMF) inoculation were tested on potted Pelargonium plants. Plant growth, flowering, bio-physiological and nutritional responses, and root mycorrhization were evaluated. The BC30 mixture did not affect plant growth compared with pure peat. However, BC30 in combination with FERT2 treatment was more effective in enhancing nitrogen (N) and chlorophyll (CHL) leaf concentrations, and leaf and flower numbers. The BC70 mixture depressed plant growth, flowering traits, and root mycorrhization. Leaf N concentration was below the sufficiency range reported for Pelargonium growth. Leaf concentration of phosphorous (P) was adequate in pure peat and in BC30 but it dropped close to sub-optimal values in BC70. The pH value of the mixtures lowered P availability, though in BC30 the mycorrhizal activity could have allowed adequate P plant uptake. In BC70 plants, the deficiency of both N and P might be a reason for the observed growth reduction. The inoculation of the substrate with selected AMF improved plant growth (higher dry biomass, greater floral clusters, larger and more abundant leaves) and quality resulting in unstressed (lower electrolyte leakage and higher relative water content values) and greener leaves (low L(?) and C(?), high CHL content) and in more intensely colored flowers. We conclude that biochar can be applied in nursery/potted plant production provided that the proportion in the peat mixture does not exceed 30%. Furthermore, AMF inoculation contributed to achieving the best plant performance in 30% biochar amended medium. PMID:26136757

  7. School Choice with Chinese Characteristics

    ERIC Educational Resources Information Center

    Wu, Xiaoxin

    2012-01-01

    This paper explores the major characteristics of school choice in the Chinese context. It highlights the involvement of cultural and economic capital, such as choice fees, donations, prize-winning certificates and awards in gaining school admission, as well as the use of social capital in the form of "guanxi". The requirement for these resources…

  8. The Supply Side of Choice

    ERIC Educational Resources Information Center

    Hill, Paul T.

    2005-01-01

    New school creation is key to success of choice. For the last two decades, the struggle over school choice has focused on freeing up parents to choose. It continues to this day, with growing success in the forms of public and private voucher programs, charter school laws in 40 states and the District of Columbia, and state and federal laws that…

  9. Demystifying the Delayed Choice Experiments

    E-print Network

    Bram Gaasbeek

    2010-07-22

    The delayed choice experiments are a collection of experiments where the counterintuitive laws of quantum mechanics are manifested in a very striking way. Although the delayed choice experiments can be very accurately described with the standard framework of quantum optics, a more didactical and intuitive explanation seems not to have been given so far. In this note, we fill that gap.

  10. School Choice: Examining the Evidence.

    ERIC Educational Resources Information Center

    Rasell, Edith, Ed.; Rothstein, Richard, Ed.

    This book presents a summary of school-choice issues, and is organized around a 1992 seminar entitled "Choice: What Role in American Education?" Each part presents a set of conference papers, followed by discussants' remarks and excerpts from audience discussion. The introduction summarizes the papers' positions and conclusions. Participants…

  11. Rational choice theory in sociology

    Microsoft Academic Search

    Robert J. Holton

    1995-01-01

    James Coleman attempted to reconcile rational choice theory with the classical sociological concerns: the relationship between the individual and society, and the historical and normative status of rationality. He identifies limits to the rational choice model, and suggests some promising but ultimately unconvincing ways around them. His project does, however, offer an important critique of Weber's theory of bureaucracy, which

  12. Guest Editorial Color image processing

    E-print Network

    Plataniotis, Konstantinos N.

    Guest Editorial Color image processing 1. Background and motivation The perception of color and recognize objects of interest, and convey information. Color image processing and anal- ysis deal with the manipulation of digital color images through the utilization of signal processing techniques. Like most

  13. Color Scheme - State Cancer Profiles

    Cancer.gov

    Diverging (Div) color schemes are best for highlighting areas of both high and low rates. They have a neutral color in the middle and darker colors in contrasting hues at the high and low extremes. Diverging color schemes are not good for black and white printing.

  14. European hair and eye color

    Microsoft Academic Search

    Peter Frost

    2006-01-01

    Human hair and eye color is unusually diverse in northern and eastern Europe. The many alleles involved (at least seven for hair color) and their independent origin over a short span of evolutionary time indicate some kind of selection. Sexual selection is particularly indicated because it is known to favor color traits and color polymorphisms. In addition, hair and eye

  15. Color preferences are not universal.

    PubMed

    Taylor, Chloe; Clifford, Alexandra; Franklin, Anna

    2013-11-01

    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

  16. Characterization of calendula flower, milk-thistle fruit, and passion flower tinctures by HPLC-DAD and HPLC-MS

    Microsoft Academic Search

    A. R. Bilia; D. Salvini; G. Mazzi; F. F. Vincieri

    2000-01-01

    Summary  As a part of an investigation of the content of herbal drug preparations and herbal medicinal products, we have investigated\\u000a tinctures (prepared with 40:60 and 60:40 (%,v\\/v) ethanolwater) of calendular flower, milk-thistle fruit, and passion flower, which are, respectively, widely used for their\\u000a anti-inflammatory properties, to treat hepatic injuries, and to treat tension and difficulty falling asleep. The aim of

  17. Structural colors, cosmetics, and fabrics

    NASA Astrophysics Data System (ADS)

    Dushkina, Natalia; Lakhtakia, Akhlesh

    2009-08-01

    Structural colors are non-pigment colors that originate from the scattering of light from ordered microstructures, thin films, and even irregular arrays of scatterers. Examples include the flashing sparks of colors in opals and the brilliant hues of some butterflies such as Morpho rhetenor. Structural colors arise in nature from one or more of a palette of physical mechanisms that are now understood quite well and can be implemented industrially to produce structurally colored paints, fabrics, and cosmetics.

  18. Artificial color perception using microwaves

    E-print Network

    Choudhury, Debesh

    2013-01-01

    We report the feasibility of artificial color perception under microwave illumination using a standard microwave source and an antenna. We have sensed transmitted microwave power through color objects and have distinguished the colors by analyzing the sensed transmitted power. Experiments are carried out using a Gunn diode as the microwave source, some colored liquids as the objects and a microwave diode as the detector. Results are presented which open up an unusual but new way of perceiving colors using microwaves.

  19. Short-term effects of burn season on flowering phenology of savanna plants

    USGS Publications Warehouse

    Pavlovic, N.B.; Leicht-Young, S. A.; Grundel, R.

    2011-01-01

    We examined the effect of season of burn on flowering phenology of groundlayer species, in the year following burns, in a mesic-sand Midwestern oak savanna. Burn treatments were fall, early-season, growing-season, late-season, and 1 or 5 years after a prior early-season wildfire. For these treatments, we compared the number of flowering stems and of flowers for species overall, for the 20 most prolifically flowering species, as well as for species grouped by flowering phenoperiods, and by growth form. Growing-season burn had a significant negative effect on number of flowering stems and total number of flowers. This effect occurred when either the burn occurred during the flowering season or during the season prior to the flowering phenoperiod. Tradescantia ohiensis showed expedited flowering and Phlox pilosa showed delayed flowering in response to early-season burning. Flowering of early shrubs was reduced by the previous fall and early-spring fires, while flowering of mid-season blooming shrubs was reduced by the early- and growing-season burns. Vaccinium and Gaylussacia, early-flowering shrubs, produced fewer flowers 1 year after than 5 years after an early-season burn. Arabis lyrata showed reduced flowering from the early-season burn. We also found four instances where the early-spring burn effect on flowering was more severe than the fall burn effect, suggesting that many frequent early-season burns may be deleterious to flowering and reproduction of some species. Burns occurring too frequently in the same season could negatively affect future flowering and reproduction of these plant species.

  20. Stop-sign-recognition based on color processing 

    E-print Network

    Kang, Dae-Seong

    1991-01-01

    , the wavelength, or the amount of white light in a color image is changed. A digital image is suitably described by a function, f(r, y), defined at chosen gricl points of the images. For a gray level (achromatic) image, the function f(z:, y) is scalar valued... representing tlie intensity values at the image pixels. For color (chromatic) images. three component values must be specified at each point, i. e. , the function f(z, y) is vector valued. In this respect, it has three components. A common choice...

  1. A novel color mapping method for preferred color reproduction

    NASA Astrophysics Data System (ADS)

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

    2007-01-01

    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.

  2. Bioactive steroidal saponins from Agave offoyana flowers.

    PubMed

    Pérez, Andy J; Calle, Juan M; Simonet, Ana M; Guerra, José O; Stochmal, Anna; Macías, Francisco A

    2013-11-01

    Bioguided studies of flowers of Agave offoyana allowed the isolation of five steroidal saponins never described previously, Magueyosides A-E (1-5), along with six known steroidal saponins (6-11). The structures of compounds were determined as (25R)-spirost-5-en-2?,3?-diol-12-one 3-O-{?-d-xylopyranosyl-(1?3)-O-?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (1), (25R)-spirost-5-en-2?,3?-diol-12-one 3-O-{?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (2), (25R)-spirost-5-en-2?,3?,12?-triol 3-O-{?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (3), (25R)-5?-spirostan-2?,3?-diol-12-one 3-O-{?-d-xylopyranosyl-(1?3)-O-?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (4), and (25R)-5?-spirostan-2?,3?-diol-9(11)-en-12-one 3-O-{?-d-xylopyranosyl-(1?3)-O-?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (5), by comprehensive spectroscopic analysis, including one- and two-dimensional NMR techniques, mass spectrometry and chemical methods. The bioactivities of the isolated compounds on the standard target species Lactuca sativa were evaluated. A dose-dependent phytotoxicity and low dose stimulation were observed. PMID:23859261

  3. Attraction of pea moth Cydia nigricana to pea flower volatiles.

    PubMed

    Thöming, Gunda; Knudsen, Geir K

    2014-04-01

    The pea moth Cydia nigricana causes major crop losses in pea (Pisum sativum) production. We investigated attraction of C. nigricana females to synthetic pea flower volatiles in a wind tunnel and in the field. We performed electroantennogram analysis on 27 previously identified pea plant volatiles, which confirmed antennal responses to nine of the compounds identified in pea flowers. A dose-dependent response was found to eight of the compounds. Various blends of the nine pea flower volatiles eliciting antennal responses were subsequently studied in a wind tunnel. A four-compound blend comprising hexan-1-ol, (E)-2-hexen-1-ol, (Z)-?-ocimene and (E)-?-ocimene was equally attractive to mated C. nigricana females as the full pea flower mimic blend. We conducted wind-tunnel tests on different blends of these four pea flower compounds mixed with a headspace sample of non-flowering pea plants. By considering the effects of such green leaf background odour, we were able to identify (Z)- and (E)-?-ocimene as fundamental for host location by the pea moths, and hexan-1-ol and (E)-2-hexen-1-ol as being of secondary importance in that context. In the field, the two isomers of ?-ocimene resulted in trap catches similar to those obtained with the full pea flower mimic and the four-compound blend, which clearly demonstrated the prime significance of the ?-ocimenes as attractants of C. nigricana. The high level of the trap catches of female C. nigricana noted in this first field experiment gives a first indication of the potential use of such artificial kairomones in pea moth control. PMID:24508043

  4. Tree size and its relationship with flowering phenology and reproductive output in Wild Nutmeg trees.

    PubMed

    Otárola, Mauricio Fernández; Sazima, Marlies; Solferini, Vera N

    2013-09-01

    Reproductive strategies, sexual selection, and their relationship with the phenotype of individuals are topics widely studied in animals, but this information is less abundant for plants. Variability in flowering phenology among individuals has direct impact on their fitness, but how reproductive phenology is affected by the size of the individuals needs further study. We quantified the flowering intensity, length, and reproductive synchronization of two sympatric dioecious Wild Nutmeg tree species (Virola, Myristicaceae) in the Brazilian Atlantic forest, and analyzed its relationships with tree size. Two distinct strategies in flowering timing and intensity were found between species (annual versus biennial flowering), and among individuals in the annual flowering species (extended versus peak flowering). Only for the annual flowering species the reproductive output is related to tree size and large trees present proportionally higher flower coverage, and lower synchronization than smaller ones. Flowering is massive and highly synchronized in the biennial species. Sex ratios are not different from 1:1 in the two species, and in the two segregated reproductive subgroups in the biennial flowering species. The biennial flowering at individual level is a novelty among reproductive patterns in plants, separating the population in two reproductive subgroups. A proportional increase in the reproductive output with size exists only for the annual flowering species. A biennial flowering can allow resource storage favouring massive flowering for all the individuals diluting their relationship with size. PMID:24223288

  5. Tree size and its relationship with flowering phenology and reproductive output in Wild Nutmeg trees

    PubMed Central

    Otárola, Mauricio Fernández; Sazima, Marlies; Solferini, Vera N

    2013-01-01

    Reproductive strategies, sexual selection, and their relationship with the phenotype of individuals are topics widely studied in animals, but this information is less abundant for plants. Variability in flowering phenology among individuals has direct impact on their fitness, but how reproductive phenology is affected by the size of the individuals needs further study. We quantified the flowering intensity, length, and reproductive synchronization of two sympatric dioecious Wild Nutmeg tree species (Virola, Myristicaceae) in the Brazilian Atlantic forest, and analyzed its relationships with tree size. Two distinct strategies in flowering timing and intensity were found between species (annual versus biennial flowering), and among individuals in the annual flowering species (extended versus peak flowering). Only for the annual flowering species the reproductive output is related to tree size and large trees present proportionally higher flower coverage, and lower synchronization than smaller ones. Flowering is massive and highly synchronized in the biennial species. Sex ratios are not different from 1:1 in the two species, and in the two segregated reproductive subgroups in the biennial flowering species. The biennial flowering at individual level is a novelty among reproductive patterns in plants, separating the population in two reproductive subgroups. A proportional increase in the reproductive output with size exists only for the annual flowering species. A biennial flowering can allow resource storage favouring massive flowering for all the individuals diluting their relationship with size. PMID:24223288

  6. Modelling Portfolio Choice in Transportation Research

    Microsoft Academic Search

    James B. Wiley; Harry J. P. Timmermans

    2009-01-01

    This paper argues that certain choice problems in transportation research can be best conceptualized as problems of portfolio choice. It discusses how portfolio choice problems can be studied using discrete choice experiments, stated choice (conjoint) methods. Issues in the construction in the design of experiments, model specification and estimation are discussed. A working example illustrates the basic approach. Finally, possible

  7. Memnonia Fossae (Enhanced Color)

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Tharsis-centered volcanic and tectonic activity resulted in the formation of radial grabens of Memnonia Fossae, which cut materials of the ancient cratered highlands and the relatively young, highland-embaying lava flows from the Tharsis volcanoes. Center of picture is at latitude 16 degrees S., longitude 142 degrees W. The enhanced color version (following decorrelation stretch) reveals a diversity of subtle color variations; many of the color variations may be due to different lava flow units and variable amounts of weathering, possible alteration by water, and eolian redistributions. Viking Orbiter Picture Numbers 41B52 (green) 41B54 (red), and 41B56 (blue) at 198 m/pixel resolution. Picture width is 206 km. North is 119 degrees counter-clockwise from top.

  8. Visual fields and eye morphology support color vision in a color-changing crab-spider.

    PubMed

    Insausti, Teresita C; Defrize, Jérémy; Lazzari, Claudio R; Casas, Jérôme

    2012-03-01

    Vision plays a major role in many spiders, being involved in prey hunting, orientation or substrate choice, among others. In Misumena vatia, which experiences morphological color changes, vision has been reported to be involved in substrate color matching. Electrophysiological evidence reveals that at least two types of photoreceptors are present in this species, but these data are not backed up by morphological evidence. This work analyzes the functional structure of the eyes of this spider and relates it to its color-changing abilities. A broad superposition of the visual field of the different eyes was observed, even between binocular regions of principal and secondary eyes. The frontal space is simultaneously analyzed by four eyes. This superposition supports the integration of the visual information provided by the different eye types. The mobile retina of the principal eyes of this spider is organized in three layers of three different types of rhabdoms. The third and deepest layer is composed by just one large rhabdom surrounded by dark screening pigments that limit the light entry. The three pairs of secondary eyes have all a single layer of rhabdoms. Our findings provide strong support for an involvement of the visual system in color matching in this spider. PMID:22309704

  9. Direct mate choice maintains diversity among sympatric cichlids in Lake Victoria

    Microsoft Academic Search

    O. Seehausen; F. Witte; J. J. M. van Alphen; N. Bouton

    1998-01-01

    Mate choice may play an important role in animal speciation. The haplochromine cichlids of Lake Victoria are suitable to test this hypothesis. Diversity in ecology, coloration and anatomy evolved in these fish faster than postzygotic barriers to gene flow, and little is known about how this diversity is maintained. It was tested whether recognizable forms are selection-maintained morphs or reproductively

  10. Sterile flowers increase pollinator attraction and promote female success in the Mediterranean herb Leopoldia comosa

    PubMed Central

    Morales, Carolina L.; Traveset, Anna; Harder, Lawrence D.

    2013-01-01

    Background and Aims Large floral displays have opposing consequences for animal-pollinated angiosperms: they attract more pollinators but also enable elevated among-flower self-pollination (geitonogamy). The presence of sterile flowers as pollinator signals may enhance attraction while allowing displays of fewer open fertile flowers, limiting geitonogamy. The simultaneous contributions of fertile and non-fertile display components to pollinator attraction and reproductive output remain undetermined. Methods The simultaneous effects of the presence of sterile flowers and fertile-flower display size in two populations of Leopoldia comosa were experimentally assessed. Pollinator behaviour, pollen removal and deposition, and fruit and seed production were compared between intact plants and plants with sterile flowers removed. Key Results The presence of sterile flowers almost tripled pollinator attraction, supplementing the positive effect of the number of fertile flowers on the number of bees approaching inflorescences. Although attracted bees visited more flowers on larger inflorescences, the number visited did not additionally depend on the presence of sterile flowers. The presence of sterile flowers improved all aspects of plant performance, the magnitude of plant benefit being context dependent. During weather favourable to pollinators, the presence of sterile flowers increased pollen deposition on stigmas of young flowers, but this difference was not evident in older flowers, probably because of autonomous self-pollination in poorly visited flowers. Total pollen receipt per stigma decreased with increasing fertile display size. In the population with more pollinators, the presence of sterile flowers increased fruit number but not seed set or mass, whereas in the other population sterile flowers enhanced seeds per fruit, but not fruit production. These contrasts are consistent with dissimilar cross-pollination and autonomous self-pollination, coupled with the strong predispersal inbreeding depression exhibited by L. comosa populations. Conclusions Sterile flowers enrich pollination quality by promoting pollen export and import, while limiting the mating costs of geitonogamy associated with large fertile displays. PMID:23131298

  11. Color optical biopsy

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    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'.

  12. Flowering Dynamics and Pollinator Visitation of Oilseed Echium (Echium plantagineum)

    PubMed Central

    Eberle, Carrie A.; Forcella, Frank; Gesch, Russ; Weyers, Sharon; Peterson, Dean; Eklund, James

    2014-01-01

    Echium (Echium plantagineum L.) is an alternative oilseed crop in summer-wet temperate regions that provides floral resources to pollinators. Its seed oil is rich in omega-3 fatty acids, such as stearidonic acid, which is desired highly by the cosmetic industry. Seeds were sown in field plots over three years in western Minnesota in spring (early-sown) or early summer (late-sown), and flower abundance, pollinator visitation, and seed yields were studied. Initial flowering commenced 41 to 55 d after sowing, and anthesis duration (first flowering to harvest) was 34 to 70 d. Late sowing dates delayed anthesis, but increased the intensity of visitation by pollinators. Cumulative flower densities ranged from 1 to 4.5 billion ha?1. Flowers attracted numerous honey bees (Apis mellifera L.), as many as 35 per minute of observation, which represented about 50% of all insect visitors. Early-sown echium produced seed yields up to 750 kg ha?1, which were 2–29 times higher than those of late-sown echium. Early sowing of echium in Minnesota provides abundant floral resources for pollinators for up to two months and simultaneously produces seed yields whose profits rival those of corn (Zea mays L.). PMID:25427071

  13. Biosynthesis and Emission of Terpenoid Volatiles from Arabidopsis Flowers

    PubMed Central

    Chen, Feng; Tholl, Dorothea; D'Auria, John C.; Farooq, Afgan; Pichersky, Eran; Gershenzon, Jonathan

    2003-01-01

    Arabidopsis is believed to be mostly self-pollinated, although several lines of genetic and morphological evidence indicate that insect-mediated outcrossing occurs with at least a low frequency in wild populations. Here, we show that Arabidopsis flowers emit both monoterpenes and sesquiterpenes, potential olfactory cues for pollinating insects. Of the 32 terpene synthase genes in the Arabidopsis genome, 20 were found to be expressed in flowers, 6 of these exclusively or almost exclusively so. Two terpene synthase genes expressed exclusively in the flowers and one terpene synthase gene expressed almost exclusively in the flowers were characterized and found to encode proteins that catalyze the formation of major floral volatiles. A ?-glucuronidase fusion construct with a promoter of one of these genes demonstrated that gene expression was restricted to the sepals, stigmas, anther filaments, and receptacles, reaching a peak when the stigma was receptive to cross pollen. The observation that Arabidopsis flowers synthesize and emit volatiles raises intriguing questions about the reproductive behavior of Arabidopsis in the wild and allows detailed investigations of floral volatile biosynthesis and its regulation to be performed with this model plant system. PMID:12566586

  14. Foreign Language Experience and Color Word Interference.

    ERIC Educational Resources Information Center

    Sisson, Cyrus R.

    If various color names are printed in various color inks, an observer has great difficulty in rapidly naming the ink colors (Stroop Color Word Test) unless the color names and the ink colors are mutually reinforcing, or the color names are unknown to the observer. The latter suggests a partial measure of second-language fluency, the feasibility of…

  15. PUBLIC FINANCE AND PUBLIC CHOICE

    Microsoft Academic Search

    James M. Poterba

    Abstract - This paper,explores the contribution,that public choice models can make,to the traditional efficiency and,distributional analyses of tax policy. It notes the relative lack of attention to political economy,issues in public finance, at least in comparison with other policy-oriented subfields in economics. It then discusses two,key insights that emerge,from,public choice models,of taxation. The first is the notion,that different tax systems

  16. Evoked Emotions Predict Food Choice

    PubMed Central

    Dalenberg, Jelle R.; Gutjar, Swetlana; ter Horst, Gert J.; de Graaf, Kees; Renken, Remco J.; Jager, Gerry

    2014-01-01

    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores. PMID:25521352

  17. Effects of subprimal type, quality grade, and aging time on display color of ground beef patties.

    PubMed

    Garner, C M; Unruh, J A; Hunt, M C; Boyle, E A E; Houser, T A

    2014-10-01

    A factorial design was used to evaluate the effects of two subprimal types (chuck roll and knuckle), two quality grades (Premium Choice and Select), and three vacuum-storage aging times before processing (7, 21, and 42d) ground beef patty display color attributes. Patties from chuck roll and Premium Choice subprimals had brighter red visual color scores, less discoloration, and higher L*, a*, b*, and chroma values than those from knuckle and Select subprimals, respectively. With an increased display time, patties became darker red, more discolored, and had decreased L*, a*, b*, and chroma values. Therefore, aging Premium Choice chuck rolls for less time (fewer than 21d) could maximize display color life. PMID:24880976

  18. On the Limitations of the Color Dipole Picture

    E-print Network

    Carlo Ewerz; Andreas von Manteuffel; Otto Nachtmann

    2007-10-15

    We discuss two aspects of the color dipole picture of high energy photon-proton scattering. First we present bounds on various ratios of deep inelastic structure functions resulting from the dipole picture that, together with the measured data, can be used to restrict the kinematical range of its applicability. The second issue that we address is the choice of energy variable in the dipole-proton cross section.

  19. Color naming: color scientists do it between Munsell sheets of color

    NASA Astrophysics Data System (ADS)

    Beretta, Giordano B.; Moroney, Nathan M.

    2010-01-01

    With the advent of high dynamic range imaging and wide gamut color spaces, gamut mapping algorithms have to nudge image colors much more drastically to constrain them within a rendering device's gamut. Classical colorimetry is concerned with color matching and the developed color difference metrics are for small distances. For larger distances, categorization becomes a more useful concept. In the gamut mapping case, lexical distance induced by color names is a more useful metric, which translates to the condition that a nudged color may not cross a name boundary. The new problem is to find these color name boundaries. We compare the experimental procedures used for color naming by linguists, ethnologists, and color scientists and propose a methodology that leads to robust repeatable experiments.

  20. Approximating Interval Coloring and Max-Coloring in Chordal Graphs

    Microsoft Academic Search

    Sriram V. Pemmaraju; Sriram Penumatcha; Rajiv Raman

    2004-01-01

    \\u000a We consider two coloring problems: interval coloring and max-coloring for chordal graphs. Given a graph G = (V, E) and positive integral vertex weights w: V ?N, the interval coloring problem seeks to find an assignment of a real interval I(u) to each vertex u???V such that two constraints are satisfied: (i) for every vertex u???V, |I(u)| = w(u) and