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  • 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.
21

Biotransformations of Turpentine Constituents : Oxygenation and Esterification

Lindmark-Henriksson, Marica January 2003 (has links)
<p>This thesis describes methods to obtain value–addedcompounds from TMP-turpentine obtained from the spruce, Piceaabies. The methodology focuses on biotransformations using twoapproaches: an oxygenation approach (i.e. oxygenation ofterpene hydrocarbons by cell cultures) and an esterificationapproach (i.e. lipase-catalysed transesterification of vinylacetate with terpene alcohols, and a further fractionation ofthe TMP-turpentine).</p><p>The main constituents of the turpentine, a-pinene, b-pineneand limonene, were subjected to a P. abies suspension culture.Allylic oxidation formed the major products for α-pineneand β-pinene, which were further oxidised to theirrespective aldehyde or ketone. One of the minor products froma-pinene, cis-verbenol, was not only transformed into verbenonebut also isomerised to trans-verbenol. Limonene gavelimonene-(1,2)-epoxide as the major product.</p><p>Fractionation of monoterpenes is accomplished throughphysical separation methods, chromatography and distillation,and lipase-catalysed transesterification of vinyl acetate withterpene alcohols. The esters of myrtenol and trans-pinocarveolwere separated from the more slowly reacting alcohols such asborneol and carveol by use of a combination of the Mucor mieheilipase and Candida antarctica lipase A as catalysts.Furthermore, the non-reacting tertiary terpene alcohols wereseparated from the reacting alcohols in a single step byCandida antarctica lipase A.</p><p>Lipase-catalysed (Candida antarctica lipase B andPseudomonas cepacia lipase) transesterification of vinylacetate with sterically hindered secondary alcoholsunexpectedly yielded hemiacetals or hemiacetal esters. Thereaction conditions required to obtain these side products havebeen studied.</p><p><b>Keywords:</b>Picea abies, Pinaceae, Essential oilscomposition; Terpene alcohol; Hemiacetal; Hemiacetal ester,TMP-turpentine; Monoterpene; α-Pinene; β-Pinene;Limonene; Verbenol; Pinocarveol; Borneol; Myrtenol; Suspensioncell culture; Biotransformation; Lipase-catalysed; Oxidation;Allylic oxidation; Transesterification; Autoxidation;Separation.</p>
22

Characterization of paint and varnish on a medieval Coptic-Byzantine icon: Novel usage of dammar resin?

Abdel-Ghani, Mona H., Edwards, Howell G.M., Stern, Ben, Janaway, Robert C. January 2009 (has links)
no / A comprehensive study has been undertaken into a 13th century Coptic-Byzantine icon from the St. Mercurius Church, St. Mercurius monastery, Old Cairo, Egypt. The layered structure, pigment composition and varnish identification were revealed by means of optical and Raman microscopy and gas chromatography¿mass spectrometry (GC¿MS). The structure of the icon comprised six layers; wooden panel, canvas, white ground, two bole layers and a single paint layer. Azurite (2CuCO3·Cu(OH)2), cinnabar (mercuric (II) sulfide ¿-HgS), yellow ochre (Fe2O3·H2O), hydromagnesite Mg5(CO3)4(OH)2·4H2O and lamp black (carbon, C) are the pigments identified in the icon. The green paint area is of interest as it is applied neither with a green pigment nor with a mixture of a blue and yellow pigment. Instead, a yellow layer of dammar resin was applied on top of blue azurite to obtain the green colour. Pinaceae sp. resin mixed with drying oil was used as a protective varnish.
23

Red Lustrous Wheelmade ware: analysis of organic residues in Late Bronze Age trade and storage vessels from the eastern Mediterranean

Steele, Valerie J., Stern, Ben 29 June 2017 (has links)
Yes / Transport and storage vessels in Red Lustrous Wheelmade ware (RLWm ware) were traded across a large area of the eastern Mediterranean for approximately 300 years (c. 1500–1200 BCE) during the Late Bronze Age (c.1600–1000 BCE). The extreme consistency of the ceramic, in form, fabric, chemistry and mineralogy, points to a single production source for the ware, which, although no kiln sites have been identified, is generally accepted to have been on Cyprus. The aim of this study was to determine whether organic residues were present in this very fine, dense ware, and to characterise the contents of RLWm ware vessels from different sites, contexts and periods, and of different forms, to improve our understanding of the trade in this ceramic type. To that end, 101 RLWm ware sherds, together with three visible residues, were examined from sites in Turkey, Cyprus, Egypt and Syria. Residues were identified in more than half of the samples, indicating that organic material is absorbed into and preserved in this very fine fabric. Four commodities were identified: fat (probably plant oil), which in four residues was identified further as castor oil; beeswax; bitumen; and Pinaceae spp. resin. The commodities were found alone or, occasionally, one of the latter three was combined with the fat or oil. Fatty material was the only commodity present at all sites and its wide distribution may indicate that generally the vessels were used for a mixture or mixtures based on plant oils, in some cases containing castor oil. It was impossible to determine whether the beeswax, bitumen and resin formed part of this mixture or represented post-firing treatments of the ceramic to make it less porous. The identification of more than one type of residue indicates that RLWm ware vessels did not always contain the same commodity. No significant correlation could be detected between the vessel forms, and the dating of many of the sherds was not precise enough to reveal any variation through time. The type of residue present did vary depending on the geographical location of its final use. Beeswax was, with two exceptions, only present in samples from Turkey, while bitumen was found exclusively in samples from Cypriot sites. The occurrence of at least one example of every commodity in the samples from Cyprus is consistent with the theory that this ware was manufactured on Cyprus, and indicates that the vessels could also have been filled and exported from there. The variation in content of the vessels found in different geographical areas could highlight a special trading relationship between the Hittite heartland in Turkey and the Cypriot potters who produced the ware, and a possible trade in bitumen as a raw material between the north Syrian coastal area of Ugarit and Cyprus. / This research was funded by an AHRC PhD studentship (number 110786), awarded to V. Steele.
24

Effects of methyl jasmonate on chemical defenses of conifer seedlings in relation to feeding by Hylobius abietis

Lundborg, Lina January 2016 (has links)
The chemical elicitor methyl jasmonate (MeJA) could replace insecticides in Europe and Asia for protection of young conifers against the pine weevil (Hylobius abietis). This thesis mainly focuses on the effects of MeJA treatment on chemical defenses of conifers from seedling batches with documented field resistance. Tissues of three pine species and one spruce species, with various treatments, were here extracted in hexane, whereafter volatile contents of tissues were separated and analyzed by 2D GC-MS. Induced responses of seedlings of Maritime pine (Pinus pinaster) and Monterey pine (Pinus radiata) to the folivore pine processionary (Thaumetopoea pityocampa), and the phloem-feeder H. abietis, have been studied. Amounts of mono- and sesqui-terpenes (and also non-volatile resin) in conifer tissues (needles and phloem) were less induced by T. pityocampa than by H. abietis. The MeJA-treated seedlings of Scots pine (Pinus sylvestris) changed their composition of phloem monoterpenes (induction of (-)-β-pinene), and were better protected in field than the seedlings of Norway spruce (Picea abies), which increased their total amounts of monoterpenes. Orientation bioassays with H. abietis showed deterrent effects of (-)-β-pinene, (+)-3-carene, (-)-bornyl acetate and 1,8-cineole. Conversely, (-)-α-pinene (induced in P. abies but not in P. sylvestris) was non-deterrent. MeJA-treated seedlings fed on by H. abietis contained higher amounts of the H. abietis antifeedant 2-phenylethanol, in tissues and emissions. Phloem of control seedlings instead induced the (+)-α-pinene, which is one of the enantiomers of the H. abietis attractant α-pinene. In response to MeJA treatment, the relative amounts of the (+)-α-pinene increased in the phloem of  P. radiata, while it decreased in P. pinaster phloem. The preference of H. abietis in the field for P. radiata before P. pinaster may be explained by these changes in enantiomers of the H. abietis attractant α-pinene. / Barrträd är viktiga för skogsindustrin. I Sverige består 57% av ytan av produktiv skogsmark, och av dessa träd utgörs 80% av gran och tall. Som försvar mot insekter och sjukdomar, producerar barrträden kådämnen. För unga barrträd i Europa och Asien är snytbaggen (Hylobius abietis) en allvarlig skadegörare, som orsakar skogsnäringen stora kostnader. För att skydda små gran- och tallplantor före utplanteringen, skulle växthormonet metyljasmonat (MeJA) kunna användas. I denna avhandling har effekter av MeJA-behandling och insektsangrepp undersökts på de två viktigaste barrträden i Sverige, tall och gran (Pinus sylvestris och Picea abies) och på två arter i medelhavsområdet (Pinus radiata och Pinus pinaster). De kemiska försvarsämnena i barrträd har analyserats för att utvärdera effekterna av MeJA-behandling. Vävnader från barrträd med olika behandling har extraherats i organiska lösningsmedel och dofterna från plantorna har insamlats genom fastfas-mikroextraktion. De flyktiga ämnena har separerats och identifierats med hjälp av gaskromatografi och masspektrometri (GC-MS). Dessutom har optiskt aktiva doftämnen separerats med hjälp av en tvådimensionell GC-MS. Plantornas olika försvarsreaktioner har studerats vid angrepp av snytbaggen, som är en floemätare, och av tallfjärilslarv (Thaumetopoea pityocampa), som huvudsakligen äter barr. De lättflyktiga ämnena (mono- och seskviterpener) och de icke-flyktiga ämnena (kådsyror) ökade mer i stam och barr från angrepp av H. abietis än av T. pityocampa. Sammansättning av monoterpener ändrades i de MeJA-behandlade tallplantorna i Sverige, specifikt ökade (-)-β-pinene i stamfloemet. Tallplantorna var bättre skyddade i fält än granplantorna, där den totala mängden monoterpener ökade. (-)-β-Pinene, (+)-3-carene, (-)-bornyl acetate och 1,8-cineole visade sig ha en negativ effekt på snytbaggens orientering mot talldoft i orienteringstester. En av monoterpenerna, (-)-α-pinene, som av MeJA-behandlingen inducerats i granen, men inte i tallen, hade ingen negativ effekt på snytbaggen. MeJA-behandlade tallplantor som angripits av snytbaggen, innehöll större mängder av snytbagge-äthämmaren 2-fenyletanol, både i vävnader och i emissioner. Stam från kontrollplantor inducerade istället (+)-α-pinene, vilken är en av de optiska isomererna av snytbagge-attrahenten α-pinene. För de spanska arterna, som svar på MeJA-behandling, ökade de lättflyktigaste terpenerna i barren hos P. radiata men inte hos P. pinaster, vilken redan innehöll en hög terpenhalt. De relativa mängderna av (+)-α-pinene ökade också i stammen hos P. radiata, medan de minskade i P. pinaster. I fält väljer snytbaggen att gå till P. radiata- framför P. pinaster-plantor, vilket kan vara kopplat till de skillnader i α-pinene-isomerer, vilka här har observerats. / <p>QC 20160304</p>
25

Antiobesity and antidiabetic activity of P. balsamifera, its active Salicortin, and L. laricina, medicinal plants from the traditional pharmacopoeia of the James Bay Cree

Harbilas, Despina 01 1900 (has links)
La prévalence de l’obésité, du diabète de type 2, et du syndrome métabolique, sont à la hausse chez les Cris d’Eeyou Istchee (CEI-Nord du Québec). Ces problèmes sont aggravés par leur diète non traditionnelle, leur sédentarité, ainsi que par une résistance culturelle aux produits pharmaceutiques. Afin de développer des traitements antidiabétiques culturellement adaptés, notre équipe a effectué une enquête ethnobotanique qui a identifié 17 plantes provenant de la pharmacopée traditionnelle des CEI. À partir des études de criblage effectuées in vitro, deux plantes parmi les 17 ont attiré notre attention. Populus balsamifera L. (Salicaceae) pour ses propriétés anti-obésité et Larix laricina K. Koch (Pinaceae) pour ses propriétés antidiabétiques. P. balsamifera et son composé actif salicortin ont inhibé l’accumulation de triglycérides durant l’adipogénèse dans les adipocytes 3T3-L1. L. laricina a augmenté le transport de glucose et l’activation de l’AMPK dans les cellules musculaires C2C12, l’adipogénèse dans les 3T3-L1 et a démontré un fort potentiel découpleur (propriété anti-obésité). Les objectifs de cette thèse sont d'évaluer les potentiels anti-obésité et antidiabétique et d’élucider les mécanismes d'action de P. balsamifera, salicortin, et L. laricina chez la souris C57BL/6 rendue obèse par une diète riche en gras (HFD). Les souris ont été soumises pendant huit (étude préventive) ou seize semaines (étude traitement) à une HFD, ou à une HFD dans laquelle P. balsamifera, salicortin, ou L. laricina a été incorporé soit dès le départ (prévention), ou dans les 8 dernières des 16 semaines d'administration de HFD (traitement). iv Les résultats démontrent que P. balsamifera (dans les deux études) et salicortin (évalué dans l’étude traitement) diminuent: le poids corporel, le gras rétropéritonéal, la sévérité de la stéatose et l’accumulation de triglycérides hépatique (ERK impliqué), les niveaux de glycémie et d'insuline, et le ratio leptine/adiponectine. Dans les deux études, P. balsamifera a significativement réduit la consommation de nourriture mais cet effet coupe-faim nécessite d’être approfondi. Dans l'étude préventive, P. balsamifera a augmenté la dépense énergétique (hausse de la température à la surface de la peau et de l’activation de la protéine découplante-1; UCP-1). Les voies de signalisation activées par P. balsamifera et par salicortin (de façon plus modeste) sont impliquées dans: la production de glucose hépatique (Akt), l’expression de Glut4 dans le muscle squelettique, la captation du glucose et du métabolisme des lipides (Akt dans le tissu adipeux), la différenciation des adipocytes (ERK et PPARg), l’inflammation dans le foie (IKKαβ), et l'oxydation des acides gras dans le muscle, le foie, ou le tissu adipeux (PPARa et CPT-1). D’autre part, L. laricina a également diminué les niveaux de glycémie et d’insuline, le ratio leptine/adiponectine, le gras rétropéritonéal et le poids corporel. Ces effets ont été observés en conjonction avec une augmentation de la dépense énergétique: hausse de température à la surface de la peau (prévention) et amélioration de la fonction mitochondriale et de la synthèse d'ATP (traitement). En conclusion, l’utilisation de P. balsamifera, salicortin et L. laricina comme des traitements alternatifs et culturellement adaptés aux CEI représente une contribution importante dans la prévention et le traitement de l’obésité et du diabète. / The prevalence of obesity, insulin resistance, and the metabolic syndrome is increasing among the Cree of Eeyou Istchee (CEI - Northern Quebec). Non-traditional diet and sedentary lifestyle along with cultural disconnect of modern type 2 diabetes (T2D) therapies are involved. In order to establish culturally adapted antidiabetic treatments, our research team conducted an ethnobotanical survey, where 17 plants were identified from the CEI traditional pharmacopoeia. Based on data obtained from in vitro screening studies, two plant species out of 17 were of particular interest for their properties as antiobesity, namely Populus balsamifera L. (Salicaceae), and antidiabetic agents, namely Larix laricina K. Koch (Pinaceae). P. balsamifera and its active salicortin inhibited triglyceride accumulation during adipogenesis in 3T3-L1 adipocytes. L. laricina increased glucose uptake and AMPK activation in C2C12 myotubes, adipogenesis in the 3T3-L1 adipocyte cell line, and was observed as one of the strongest uncouplers, severely disrupting mitochondrial function (increasing fuel consumption/metabolic rate; antiobesity property). The purpose of this PhD thesis is to evaluate the antiobesity and antidiabetic potential of P. balsamifera, salicortin, and L. laricina, in an in vivo model of diet-induced obese (DIO) C57BL/6 mice, as well as to investigate their possible mechanisms of action. Mice were subjected for eight (prevention study) or sixteen weeks (treatment study) to a high fat diet (HFD), or HFD to which P. balsamifera, salicortin, or L. laricina were incorporated either at onset (prevention), or in the last 8 of the 16 weeks of administration of the HFD (treatment). The results showed that P. balsamifera (in either study) and salicortin (incorporated in HFD only in treatment study) decreased the weight of whole vii body, retroperitoneal fat pad, reduced the severity of hepatic macrovesicular steatosis and triglyceride accumulation (ERK pathway implicated). They also decreased glycemia and improved insulin sensitivity by diminishing insulin levels, and altering adipokine secretion whereby reducing the leptin/adiponectin ratio. In both studies, P. balsamifera significantly reduced food intake. This appetite-reducing effect needs to be investigated further. In the prevention study this was accompanied by an increase in energy expenditure (increase in skin temperature and tends to increase expression of uncoupling protein-1; UCP-1). The signaling pathways activated by P. balsamifera and slightly by salicortin are implicated in either controlling hepatic glucose output (Akt), skeletal muscle Glut4 expression, glucose uptake and lipid metabolism in adipose tissue (Akt), adipocyte differentiation (ERK pathway and PPARg), decreasing the hepatic inflammatory state (IKKab), and increasing muscular, hepatic, or adipose tissue fatty acid oxidation (PPARa, CPT-1). As for L. laricina, it effectively decreased glycemia levels, insulin levels and the leptin/adiponectin ratio, improved insulin sensitivity and slightly decreased abdominal fat pad and body weights. This occurred in conjunction with increased energy expenditure as demonstrated by elevated skin temperature in the prevention study, and tendency to improve mitochondrial function and ATP synthesis in the treatment protocol. In conclusion, these results represent a major contribution, identifying P. balsamifera, salicortin, and L. laricina, as promising alternative, and culturally adapted therapies for the prevention and treatment care of obesity and diabetes among the CEI.
26

Antiobesity and antidiabetic activity of P. balsamifera, its active Salicortin, and L. laricina, medicinal plants from the traditional pharmacopoeia of the James Bay Cree

Harbilas, Despina 01 1900 (has links)
No description available.
27

Late Quaternary Plant Zonation and Climate in Southeastern Utah

Betancourt, Julio L. January 1983 (has links)
Plant macrofossils from packrat middens in two southeastern Utah caves outline development of modern plant zonation from the late Wisconsin. Allen Canyon Cave (2195 m) and Fishmouth Cave (1585 m) are located along a continuous gradient of outcropping Navajo Sandstone that extends from the Abajo Mountains south to the San Juan River. By holding the site constant, changes in the floral composition for a plot of less than one hectare can be observed, even if sporadically, over tens of millennia. At Allen Canyon Cave, engelmann spruce-alpine fir forest was replaced by the present vegetation consisting of pinyon-juniper woodland on exposed ridgetops and cliffside stands of Douglas fir, ponderosa pine, and aspen. Xerophytic woodland plants such as pinyon, Plains prickly pear, and narrowleaf yucca arrived sometime in the middle Holocene between 7200 and 3400 B.P. At Fishmouth Cave, Utah juniper in Holocene middens replaced blue spruce, limber pine, Douglas fir, and dwarf and Rocky Mountain junipers in late Wisconsin samples. Disharmonious associations for the late Wisconsin occur only at the lower site with the xerophytes Mormon tea, Plains prickly pear, and narrowleaf yucca growing alongside subalpine conifers. One possible explanation involves the late Wisconsin absence of ponderosa and pinyon pines from the Colorado Plateaus. Released from competition at their lower limits, subalpine conifers were able to expand into lower elevations and mix with xerophytic plants found today in understories of pinyon-juniper and ponderosa pine woodlands. Quantitative climatic estimates are derived for the late Wisconsin by applying vertical lapse rates for temperature and precipitation to the amount of vegetation depression. The Fishmouth Cave sequence indicates a minimum lowering of 850 m for blue spruce, limber pine, and dwarf juniper. A depression of at least 700 m for engelmann spruce and alpine fir is suggested for the Allen Canyon locality. Use of conservatively low lapse rates for stations below 2080 m yields a 3-4°C cooling from present mean annual temperature and 35 to 60 percent more rainfall than today. Steeper lapse rates associated with more mountainous terrain suggest a 5°C lowering in temperature and up to 120 percent increase over modern precipitation.

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