• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 13
  • 10
  • 9
  • 5
  • 1
  • 1
  • 1
  • Tagged with
  • 45
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Floral fragrance and pollination in the yellow monkey flower Mimulus guttatus Fischer ex D.C. (Scrophulariaceae)

Martin, B. E. January 1988 (has links)
A Californian population of the Yellow Monkey Flower, Mimulus guttatus Fischer ex D.C., contains a floral fragrance polymorphism such that the plants can be divided into two classes: fragrant and non-fragrant. This thesis has examined the effects of the fragrance polymorphism on the natural pollinators of M. guttatus, with a view to investigating the role and evolutionary significance of floral fragrance in apidophilous plants. Published work by many researchers has suggested that a fragrance polymorphism in an apidophilous chasmogamous plant would lead to reduced inter-phenotype pollinator movements due to the phenomenon of odour-constancy, and hence to genetic divergence and possibly sympatric speciation. Alternatively, if the fragrance phenotypes differed in pollinator attractiveness, the more attractive phenotype would have a selective advantage, and would therefore eventually become fixed. Both of these possible scenarios have been explored in the course of this project, both by investigation of bee foraging behaviour on experimental plots containing fragrant and non-fragrant Mimulus plants, and by investigation of the fitnesses of the two phenotypes in the natural population and under glasshouse conditions. It was found that the two phenotypes did not differ significantly in terms of measured fitness, and that in the natural population there was no evidence of reduced gene-flow between fragrant and non-fragrant plants. Experimental plot results showed no evidence of odour-constancy by bees, but revealed that some bumblebee species discriminated weakly between the two phenotypes. Pollinators were found to be visiting Mimulus flowers for pollen, and variation in plant pollen production had significant effects on within-plant foraging behaviour. However, bees failed to learn to associate fragrance phenotype with pollen production, in contrast to previously published research that has demonstrated that bees readily learn to associate fragrance phenotype with nectar rewards, suggesting that pollen-collecting bees may respond differently to floral cues than nectar-collecting bees. For a variable such as floral fragrance to have evolutionary significance it is essential that the character is heritable, and part of the investigation has concentrated on investigating the heritability and penetrance of the character. It was found that inheritance of fragrance is best explained by a simple additive genetic model, and that fragrance production is dominant to absence of fragrance. The possibility that this fragrance polymorphism has been previously influenced by other pollen vectors and the population's potential for switching from bee-pollination to alternative pollen vectors is discussed.
2

Oxidation of toluene

Boyle, Sarah Ann January 1997 (has links)
No description available.
3

Common Scents?: Regulating the Use of Fragrances in Workplaces

Ouimette, Monique Y. January 2017 (has links)
Thesis advisor: Juliet B. Schor / Fragrances in consumer products have become a contested topic in daily life. Workplace fragrance policies problematize fragrances, which, for many people, are normal aspects of consumer products. This mixed-method dissertation focuses on employees in a large non-industrial workplace with a fragrance-free policy. It examines employee reactions to a policy that requests behavioral changes based on claims that everyday consumption of fragranced products may be harmful to employee health. In order to develop an understanding of how and to what extent fragrances and indoor air quality are problematized in the workplace, I engage a number of different constructs from environmental and consumer sociology. The dissertation expands upon constructs of contested illness (Brown, Kroll-Smith, & Gunter, 2000; Phillimore, Moffatt, Hudson, & Downey, 2000; Shriver & Webb, 2009); framings of environments in bodies (Kroll-Smith & Kelley, 2008); lay assessments of health impacts (Burton-Jeangros, 2011; Collins, 2010; Heikkinen, Patja, & Jallinoja, 2010; O'Sullivan & Stakelum, 2004; Scammell, Senier, Darrah-Okike, Brown, & Santos, 2009) and understandings of the role of scents in social life (Largey & Watson, 1972; Low, 2006; Synnott, 1991). My findings show that a majority of participants understand fragrance impacts through an individual health frame, as an allergy, that locates the problems associated with fragrance within the bodies of specific individuals who exhibit symptoms due to fragrance exposures. While this orientation has had positive impacts on the implementation of the policy and reducing corresponding impacts on those who are Fragrance Sensitive, the degree to which fragrances have been problematized is limited by understandings of fragrance impacts as allergies. The limiting framework of fragrance sensitivity as allergy has practical efficacy because it helps employees to connect with the idea that fragrances cause health issues for some individuals. However, it also stymies assessments and connections to potential broader environmental health impacts of fragrances in part because allergens such as pollen are generally viewed as benign and only problematic to the anomalous individuals who experience reactions. Limitations of the framework are reinforced by established moral and cultural assessments of good and bad fragrances and the appropriate use of fragrances (Low, 2006; Synnott, 1991). This dissertation examines what happens when people are confronted with information that the industrial traces associated with their consumption practices - in this case wearing and using fragranced products on their bodies and in their work environments - may be contributing to negative health outcomes for their coworkers. This study is the first to analyze the social dimensions of the use of synthetic fragrances in connection to environmental health impacts in the context of everyday life. The findings have relevance for other organizations considering regulation of fragrances as well as for efforts to use health rationales to encourage changes in consumption practices. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Sociology.
4

Encapsulation d'espèces lipophiles actives par émulsion double / Double emulsion for encapsulation of lipophilic active components

Stasse, Margot 06 March 2018 (has links)
De nos jours, l’encapsulation est une technique très répandue dans le domaine de la parfumerie. En effet, elle permet une libération contrôlée du parfum et une protection des molécules de parfumerie qui peuvent s’oxyder avec le temps. L’objectif de cette thèse a été de mettre au point un nouveau concept de capsules fondé sur la formulation d’émulsions doubles huile-dans-eau-dans-huile et de polymériser la phase aqueuse intermédiaire. Les phases huiles, intérieure et extérieure, sont respectivement constituées du parfum et d’un solvant de parfumerie. La phase aqueuse est, elle, composée de monomères hydrophiles dont la polymérisation radicalaire permet l’obtention d’une matrice polymère plus ou moins diffusive vis-à-vis du parfum. L’intérêt de ce nouveau principe d’encapsulation est de séparer la polymérisation et les molécules de parfumerie qui peuvent être réactives en polymérisation radicalaire en les localisant dans des compartiments distincts et ainsi éviter toute interaction. Cette stratégie qui combine la Science des Emulsions, des Polymères et des Parfums et la Formulation a permis l’élaboration de capsules robustes possédant des propriétés de libération progressive par diffusion et de libération provoquée par application d'une contrainte mécanique sans altérer l'intégrité des capsules. Elles se comportent alors comme des micro-éponges capables de se déformer et de reprendre leur forme initiale. Dans ce schéma général, les propriétés peuvent être modulées plus finement par le choix et les concentrations des réactifs lors de la synthèse. / Nowadays, encapsulation is a widespread technology in fragrance applications. Indeed, it allows control of the fragrance release as well as protection of the fragrance molecules with respect to oxidation. The objective of this PhD is the development of a new concept of encapsulation based on the formulation of double oil-in-water-in-oil emulsion and the polymerization of the intermediate aqueous phase. The two, internal and external, oil phases, , are respectively the fragrance and perfume solvent while the aqueous phase is composed of hydrophilic monomers leading to a more or less fragrance-diffusive polymer matrix after their radical polymerization. The main advantage of this encapsulation principle is to locate the polymerization and the possibly reactive fragrance’s molecules in separate compartments. This strategy which combines the Sciences of Emulsion, Polymers and Fragrance but also the Formulation allows obtaining robust capsules exhibiting both diffusive properties and a triggered release under a mechanical stress. These capsules behaves as micrometric sponges that can deform and restore their initial state.. In this general scheme, the capsules' properties can be tuned by an appropriate choice of the polymerization reactants and their concentrations.
5

Do Crossmodal Correspondences Found between Marketed Shampoo Fragrances and the Angularity of Shapes Transfer to the Shape of 2-dimensional and 3-dimensional Shampoo Bottle Designs?

Cessna, Trevor C. 02 June 2016 (has links)
No description available.
6

Les allergies cutanées aux fragrances : mécanisme d'action et rôle du facteur de transcription Nrf2. Du modèle 2D au modèle 3D. / Skin allergy to fragances : mechanism of action and role of the transcription factor Nrf2. From 2D to 3D models.

Raffalli, Chloé 15 February 2018 (has links)
La dermatite allergique de contact (DAC) est une réaction inflammatoire aiguë, médiée par les cellules dendritiques (DCs) survenant suite à l’exposition répétée de la peau avec une molécule allergisante. La prévalence estimée des cas de DAC aux substances parfumantes est de 1,7 % à 4,1 % dans la population générale. Les molécules allergisantes sont des molécules appelées haptènes, qui vont se conjuguer avec des protéines de l’épiderme ou du derme. C’est le cas du cinnamaldéhyde (CinA), une molécule retrouvée dans la cannelle. Le linalol et le limonène sont des terpènes présents dans la lavande et l’orange, qui vont s’autoxyder au contact de l’air pour former des allergènes puissants, tels que les hydroperoxydes allyliques. Le premier objectif de cette thèse a été d’étudier le mécanisme d’action de ces terpènes et leurs hydroperoxydes allyliques respectifs sur la lignée cellulaire THP-1, qui sert de substitut aux cellules dendritiques. Le rôle du facteur de transcription Nrf2, majeur dans la lutte contre le stress oxydant, a également été investigué.Les consommateurs de produits cosmétiques sont exposés à de faibles concentrations de molécules allergisantes, mais plusieurs fois par jour ou par semaine. Nous avons souhaité étudier l’exposition répétée à de faibles doses d’haptène sur la peau.Les kératinocytes jouent également un rôle dans la DAC : ce sont les premières cellules qui vont rencontrer la molécule allergisante dans la peau. La deuxième partie de ce travail a été d’étudier l’impact d’une exposition répétée de CinA à de faible concentration sur ces KCs et plus particulièrement sur la différenciation de l’épiderme, en utilisant un modèle organotypique de peau en 3D. / Allergic contact dermatitis (ACD) represents a severe health problem. It is a dendritic cells (DCs) mediated skin disease caused by repeated exposure to an allergenic compound. ACD cases of fragrances in general population is estimated from 1.7 % to 4.1%. Contact sensitizers are compounds termed haptens and they will form a conjugate with epidermis and dermis proteins. Example is cinnamaldehyde (CinA), a molecule found in cinnamon. Linalool and limonene are terpenes found in lavender and oranges. In contact with the air, they will autoxidize to form highly allergenic compounds: allylic hydroperoxides. The first aim of this thesis was to study the mechanism of action of those terpenes and their respective allylic hydroperoxides on THP-1 cell-line, described as a surrogate of DCs. The transcription factor Nrf2 is playing a major role in oxidative stress and was also investigated.Consumers of cosmetic products are exposed to low quantities of allergenic compounds, but several times a day or a week. We wanted to study repeated exposure of low concentration of haptens on the skin.KCs also play a key role in ACD: they are the first cells that will encounter the allergenic compound in the skin. The second aim of this thesis was to study the impact of repeated exposure of low concentrations of CinA on those KCs and more particularly on the epidermis differenciation, using a 3D organotypic culture of skin.
7

Bioprospecting for Improved Floral Fragrance in Wild Sunflower

Anandappa, Jason 01 January 2022 (has links) (PDF)
The cultivation of crop sunflower or Helianthus annuus is a 20 billion USD industry globally. Crop wild relatives of H. annuus have a long history of being used to breed improved traits into cultivated varieties. Cultivated H. annuus is not known to have a pleasant aroma, and at times seed yield is limited by pollination services, particularly in the production of hybrid seed. Improved floral fragrance could improve pollinator attraction and would add value to ornamental sunflowers in the context of the cut-flower industry. If volatile organic compounds that together generate favorable scents are present in wild Helianthus species, they could be bred into domesticated varieties. In order to assess the diversity of floral fragrance available in crop wild relatives, 30 diverse accessions of wild Helianthus as well as seven varieties of H. annuus spanning a domestication gradient were grown in a greenhouse experiment and variation in floral volatiles was analyzed by solid phase microextraction-gas chromatography-mass spectrometry. While alpha-pinene made up a significant portion of the volatiles emitted for most taxa, there was substantial diversity present across the genus. Most volatiles emitted were found to be monoterpenoids with a significant share of sesquiterpenoids. Several wild accessions such as H. debilis subsp. tardiflorus and H. praecox subsp. praecox as well as open-pollinated domesticated accessions of H. annuus show promise for breeding for improved floral fragrance due to high volatile abundance and likely favorable compound compositions.
8

Analýza internetového marketingu vybraného e-shopu (parfumerie) / Internet marketing analysis of selected fragrance shop

Cibulka, Martin January 2010 (has links)
The aim of this work is the analysis of selected online store. The introduction describes the possibilities of the Internet for marketing and online marketing mix. The next chapter describes selected products and the biggest online perfume sellers in the Czech Republic. In the fourth chapter is analyzed in detail a specific marketing of selected store.
9

Contribuições a quimica das recompensas florais de Guttiferae (Clusia) e Orchidaceae (Maxillariinae) / The chemical contribution to floral rewards of Guttiferae (Clusia) and Orchidaceae (Maxillariinae)

Lapis, Mirele Sanches Fernandes 03 July 2005 (has links)
Orientador: Anita Jocelyne Marsaioli / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-04T15:47:17Z (GMT). No. of bitstreams: 1 Lapis_MireleSanchesFernandes_M.pdf: 6468600 bytes, checksum: 6af92e23ef4b2fdd6be4740a8ba9f443 (MD5) Previous issue date: 2005 / Resumo: Este trabalho teve como objetivo elucidar algumas interações ecológicas de espécies de Orchidaceae e Guttiferae. No primeiro capítulo, é descrita a determinação da composição química das fragrâncias florais de cinco espécies de orquídeas pertencentes ao complexo Maxillaria madida (M. juergensii, M. madida, M. vernicosa, M. ferdinandiana e M. pachyphylla), através da técnica de headspace dinâmico e análise por CG/EM. Monoterpenóides e sesquiterpenóides não oxigenados são os principais compostos voláteis emitidos e provavelmente responsáveis pela atração dos insetos polinizadores. No segundo capítulo, demos continuidade ao estudo da composição química do látex dos frutos de C. grandiflora iniciado por Cláudio A. G. da Câmara. Este estudo resultou no isolamento de 3 compostos, sendo 2 inéditos e derivados do ácido cis-d-tocotrienólico. Estes compostos quando submetidos ao teste em CCD com b-caroteno, apresentaram propriedades antioxidantes. No último capítulo deste trabalho, é apresentada a análise da composição química das resinas florais do híbrido interespecífico de C. weddelliana X paralicola, comparada com a das resinas florais de seus parentais. Observou-se que todos os compostos isolados também estão presentes nas espécies genitoras, variando apenas suas abundâncias. Finalmente, foi avaliada a atividade antineoplástica das resinas florais de C. grandiflora, C. hilariana, C. renggerioides, C. fluminensis, C. spiritu-sanctensis, C. lanceolata, C. nemorosa hermafrodita e C. paralicola, em 8 diferentes linhagens de células. Os resultados revelaram que os metabólitos secundários (benzofenonas poliisopreniladas) presentes nestas espécies são eficientes agentes antitumorais e o mecanismo de ação destes compostos envolve a inibição de topoisomerases. / Abstract: The aim of this research was the elucidation of ecological interactions in Orchidaceae and Guttiferae species. The first chapter describes the floral fragrance chemical compositions of five orchid species belonging to the Maxillaria madida group (M. juergensii, M. madida, M. vernicosa, M. ferdinandiana and M. pachyphylla) obtained by applying dynamic headspace sampling technique and GC/MS analysis. Monoterpenoids and sesquiterpenoids without oxygen in its structure are the main emitted volatile compounds and probably responsible for the pollinator attractions. In the second chapter the investigation of Clusia grandiflora fruit latex chemical composition initiated some years ago by Dr Cláudio A. G. da Câmara was concluded with the isolation of novel compounds derived from tocotrienolic acid. Two of which (methyl-(2Z, 6E, 10E)-13-(6-hydroxy-2,7,8-trimethyl-3, 4-dihydro-2H-2chromenyl)-2,6,10-trimethyl-2,6,10-tridecatrienoate and methyl-(2Z, 6E,10E)-13-(6-formyl-5-hydroxy-2,8-dimethyl -3, 4-dihydro-2H-2-chromenyl)-2,6,10-trimethyl-2,6,10-tridecatrienoate) are novel secondary metabolites which have antioxidant properties revealed by b-carotene TLC test. Evaluation of the interespecific hybrid of Clusia weddelliana x paralicola floral resin and revealed that the chemical constituents in the parents and hybrid species were identical with different relative abundances. Finally, we have evaluated the anticancer activity of the floral resins of C. grandiflora, C. hilariana, C. renggerioides, C. fluminensis, C. spiritu-sanctensis, C. lanceolata, C. nemorosa hermafrodita and C. paralicola in eigth cell lines. The results showed that the secondary metabolites (polyisoprenylated benzophenones) were efficient antitumor agents by topoisomerase inhibition. / Mestrado / Quimica Organica / Mestre em Química
10

Duftpräferenz von Hochbetagten und ihre Wirkung auf die epidermale Barriere. Eine olfaktorische, psychophysiologische und hautphysiologische Untersuchung / Fragrance preference of the elderly and their effect on the epidermal barrier. An olfactory, psychophysiological and skin-physiological investigation

Kukshausen, Olga 23 July 2015 (has links)
Mit zunehmendem Alter lassen viele körperliche Funktionen nach, darunter auch das Riechvermögen und die Hautbarrierefunktion. Mit dem reduzierten Riechvermögen nehmen Lebensqualität und Wohlbefinden ab, der psychische Stress nimmt zu. Eine verminderte Hautbarrierefunktion korreliert mit einer fragilen Barriereintegrität und einer langsamen Barriereregeneration. Darüber hinaus ist bei jungen Probanden die Regeneration der Hautbarriere unter psychischem Stress verlangsamt und unter dem Einfluss sedierender Duftstoffe beschleunigt. Vergleichbare Untersuchungen mit älteren Probanden fehlen bis dato. Die Altershaut bedarf einer speziellen Pflege um die Hautbarrierefunktion zu festigen. Die Akzeptanz eines Produktes korreliert mit der Akzeptanz seines Duftes. Untersucht wurde, ob Hochbetagte definierte Duftfamilien präferieren und ob dieser potentiell präferierte Duft in einer Magistralrezeptur die Barriereregeneration katalysiert. In einer Fall–Kontroll–Studie mit Hochbetagten wurde durch die Darbietung der 5 Duftfamilien (Chypre, Fougère, Floral, Citral und Oriental) die Präferenz für Fougère gegenüber den anderen Duftfamilien festgestellt (p < .01) In einer einfach verblindeten Crossover-Studie wurde der Einfluss von Fougère auf die epidermale Barriere bei Hochbetagten untersucht. Im Seniorenheim (unselbstständige Hochbetagte, UH) sowie im eigenen Haushalt, selbstständig lebende Hochbetagte (SH) wendeten in der 1. Phase die Testemulsion A ohne Parfumöl (PÖ) und in der 2. Phase die Testemulsion B mit PÖ Fougère am Rücken und Dekolleté an. Die Phasen permutierten. Um den Einfluss des Duftes auf die Barriereregeneration an den Unterarmen zu untersuchen, wurde eine Barriereschädigung mittels Tesafilmabrisse bis zum dreifachen Anstieg des Basis-TEWL durchgeführt. Die Barriereregeneration ist bei den SH hochsignifikant schneller als bei den UH (p < .001). Die Anzahl der Tesafilm-Abrisse reflektiert die Barriereintegrität. Bei den UH wurden hochsignifikant weniger Tesafilm-Abrisse (M = 17) als bei den SH (M = 50) benötigt (p < .001), um einen Barriereschaden mit einem 3-fach erhöhten TEWL zu erreichen. Es ist davon auszugehen, dass SH in einer vergleichsweise guten psychischen Konstitution eine signifikant bessere Barriereintegrität aufweisen als die im Seniorenheim lebende UH. Unter dem Einfluss der Fougère-haltigen Emulsion regenerierte die Barriere bei den UH signifikant schneller als unter dem Einfluss der PÖ-freien Emulsion (p < .01): 70%ige vs. 53%ige Regeneration 24h nach Barriereschädigung, obwohl die Rezeptur nicht am Ort der Barriereuntersuchung (Unterarm) angewendet wurde. Der biologische Mechanismus bedarf weiterer Untersuchungen. Das PÖ Fougère wird für die Hautpflege der heutigen Hochbetagtengeneration empfohlen.

Page generated in 0.1214 seconds