A atividade do complexo 1 da proteína alvo mecanístico da rapamicina (mTORC1), importante regulador da adiposidade e do metabolismo de lipídeos, está aumentada no tecido adiposo de camundongos obesos. A inibição completa de mTORC1 reduz a adiposidade, enquanto que sua inibição parcial potencializa a obesidade induzida por dieta. Assim, hipotetizamos que um nível ótimo de ativação de mTORC1 é necessário para promover aumento da adiposidade, de forma que sua superativação é tão inibitória para a deposição de gordura quanto sua inibição completa. Para testar esta hipótese, investigamos os efeitos da ativação constitutiva de mTORC1, induzida pela deleção de Tsc1, especificamente em adipócitos na adiposidade in vivo. A deleção de Tsc1 reduziu a massa do tecido adiposo visceral, mas não do subcutâneo, que foi associado ao aumento da lipólise e browning. Além disso, aumentou em ambos tecidos adiposos a massa e atividade oxidativa mitocondrial. Esses dados apoiam nossa hipótese de que é necessário um nível ótimo de ativação de mTORC1 para promover aumento da adiposidade. / The activity of mechanistic target of rapamycin complex 1 (mTORC1), an important regulator of adiposity and lipid metabolism, is increased in adipose tissue of obese mice. Complete mTORC1 inhibition reduces adiposity, whereas partial mTORC1 inhibition enhances diet-induced obesity. Therefore, we hypothesized that an optimal level of mTORC1 activity is required to increase adiposity, in such a manner that mTORC1 overactivation is as inhibitory to fat deposition as its complete inhibition. To test this hypothesis, we investigated the effects of constitutive mTORC1 activation, induced by Tsc1 deletion, specifically in adipocytes on adiposity in vivo. Tsc1 deletion reduced visceral, but not subcutaneous, fat mass, which was associated with increased lipolysis and browning. Moreover, it enhanced mitochondrial mass and oxidative activity in both visceral and subcutaneous fat. These data support our hypothesis that an optimal level of mTORC1 activation is necessary to increase adiposity.

Zugl.: Jena, Univ., Diss., 2006

A atividade do complexo 1 da proteína alvo mecanístico da rapamicina (mTORC1), importante regulador da adiposidade e do metabolismo de lipídeos, está aumentada no tecido adiposo de camundongos obesos. A inibição completa de mTORC1 reduz a adiposidade, enquanto que sua inibição parcial potencializa a obesidade induzida por dieta. Assim, hipotetizamos que um nível ótimo de ativação de mTORC1 é necessário para promover aumento da adiposidade, de forma que sua superativação é tão inibitória para a deposição de gordura quanto sua inibição completa. Para testar esta hipótese, investigamos os efeitos da ativação constitutiva de mTORC1, induzida pela deleção de Tsc1, especificamente em adipócitos na adiposidade in vivo. A deleção de Tsc1 reduziu a massa do tecido adiposo visceral, mas não do subcutâneo, que foi associado ao aumento da lipólise e browning. Além disso, aumentou em ambos tecidos adiposos a massa e atividade oxidativa mitocondrial. Esses dados apoiam nossa hipótese de que é necessário um nível ótimo de ativação de mTORC1 para promover aumento da adiposidade. / The activity of mechanistic target of rapamycin complex 1 (mTORC1), an important regulator of adiposity and lipid metabolism, is increased in adipose tissue of obese mice. Complete mTORC1 inhibition reduces adiposity, whereas partial mTORC1 inhibition enhances diet-induced obesity. Therefore, we hypothesized that an optimal level of mTORC1 activity is required to increase adiposity, in such a manner that mTORC1 overactivation is as inhibitory to fat deposition as its complete inhibition. To test this hypothesis, we investigated the effects of constitutive mTORC1 activation, induced by Tsc1 deletion, specifically in adipocytes on adiposity in vivo. Tsc1 deletion reduced visceral, but not subcutaneous, fat mass, which was associated with increased lipolysis and browning. Moreover, it enhanced mitochondrial mass and oxidative activity in both visceral and subcutaneous fat. These data support our hypothesis that an optimal level of mTORC1 activation is necessary to increase adiposity.

In this essay, I am analysing and discussing the possibility of didactic intention and message in the intertextual analysis. The main focus is to connect the intertextual analysis to the Swedish and English curriculum in the Swedish secondary school. Thus, in the analysis, I have used Stephen King’s novels The Gunslinger (I), The Waste Lands(III) and The Dark Tower(VII), and searched for intertextual citations, allusions, and references to the two poets T.S Eliot and Robert Browning. In conclusion, I have found intertexts to Eliot’s The Waste Land and Browning’s Childe Roland to the Dark Tower Came. However, the strongest connection has been found in Eliot, and therefore the intertextual analysis of the novels has its main focus on King’s use of Eliot’s The Waste Land in The Dark Tower-novels, and how these intertexts can be interpreted and used in the Swedish secondary school. The intention of the essay is to encourage the use of more methods whilst teaching literature and hopefully foster students to look at literature with more curiosity. The analysis is made with the prospect of bringing more perspectives to the already scientifically based methods that are used in the Swedish secondary school.

Thesis (MScEng) -- University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The grape juice concentrate (GJC) plant of the KWV at Robertson spent significant amounts of money on the decolourisation of grape juice concentrate. A chemically activated powdered activated carbon (PAC) purchased from Norit, namely CA1, was used as decolourisation product. Apart from the expenses involved, it contributed largely to the solid waste produced at this plant. A way was sought to minimise or prevent GJC discolourisation (and possibly solid waste) without increasing operating expenses. Browning reactions in GJC are as old as the product itself. Numerous researchers have studied the origins of these reactions, the reactants and products involved, as well as the reaction kinetics of these reactions. From the work of these researchers four possible browning reaction pathways were identified, namely: • enzymatic oxidative browning, • non-enzymatic oxidative browning, • non-enzymatic browning (the Maillard reaction), and • caramelisation. It was also identified that 5-hydroxymethylfurfural (HMF) are indicative of the browning potential of GJC. A method to analyse for HMF (quantitative and qualitative) was develop for the purposes of this study, namely positive electron-spray ionisation preceded by high-pressure liquid chromatography (HPLC) and followed by dual mass spectrometry. This method showed good repeatability and was used to analyse all samples generated during this study. It was confirmed that the manufacturing process at this plant favours nonenzymatic browning reactions, since mild heat treatment deactivates enzymes. Further investigation indicated that the overruling browning reaction on this plant was non-enzymatic oxidative browning. It was shown that neither the presence, nor the absence of protein had any effect on the rate of formation of HMF. It was, however, confirmed that HMF formation could be attributed to high temperatures and prolonged exposure to these temperatures. Other adsorption products were evaluated against the then current PAC (CA1), namely a steam activated PAC supplied by Norit, SA4, and a polymeric adsorbent, Polyclar V (polyvinylpolypyrrolidone/PVPP). Both SA4 and PVPP indicated superior HMF adsorption capacities. Replacing CA1 with SA4 could result in operating expenses savings and possible solid waste reduction. However, PVPP were too expensive to be considered an economically viable replacement for CA1. Improved concentration technologies such as reverse osmosis (RO) membrane concentration followed by centrifugal evaporation (CE) or twostage CE should be considered as possible replacement for the existing concentration technology (multi-stage falling film evaporator). This should decrease heat treatment/exposure by more than 90% and thus reduce browning significantly. An added advantage could be the reduction of solid waste, since less (if not no) decolourisation will be required. Alternatively, juice should be stored with added sulphur dioxide (SO2), since it was shown that this juice contained much lower HMF concentrations than diluted concentrate (stored for the same time). This should reduce heat exposure by up to 50% and thus minimise browning reactions. / AFRIKAANSE OPSOMMING: Die druiwesapkonsentraat (DSK) aanleg van die KWV in Robertson het jaarliks aansienlike bedrae geld spandeer tydens die ontkleuringsproses van DSK. ‘n Chemies geaktiveerde verpoeierde koolstof (GVK) verkrygbaar van Norit, naamlik CA1, is gebruik as ontkleuringsproduk. Buiten die kostes verbonde aan hierdie produk het dit ook grootliks bygedra tot soliede afval by hierdie aanleg. Oplossings is gesoek om die verbruining/ontkleuring van DSK (en dalk ook soliede afval) te verminder (of selfs te voorkom) sonder om bedryfskostes te verhoog. Verbruiningsreaksies in DSK bestaan al so lank soos DSK self. Verskeie navorsers het die oorsake, reaktante, produkte en reaksiekinetika van hierdie reaksies oor die jare heen bestudeer. Uit die werk van sommige van hierdie navorsers kon vier moontlike verbruiningsreaksieroetes geïdentifiseer word, naamlik: • ensiematiese oksidatiewe verbruining, • nie-ensiematiese oksidatiewe verbruining, • nie-ensiematiese verbruining (die Maillard-reaksie), en • karamelisering. Daar was verder geïdentifiseer dat 5-hidroksiemetielfurfuraal (HMF) aanduidend is van die verbruiningspotensiaal van DSK. ‘n Analitiese metode (kwalitatief en kwantitatief) om vir HMF te analiseer is vir die doel van hierdie studie ontwikkel, naamlik positiewe elektronsproei ionisasie, voorafgegaan deur hoëdruk vloeistof chromatografie en gevolg deur dubbele massa spektrometrie. Hierdie analitiese metode het goeie herhaalbaarheid getoon en was deurgaans gebruik om monsters te analiseer gedurende hierdie studie. Dit was bevestig dat die vervaardigingsproses by hierdie aanleg nieensiematiese verbruiningsreaksies begunstig, aangesien geredelike hittebehandeling ensieme deaktiveer. Verdere navorsing het getoon dat die oorheersende verbruiningsreaksies by hierdie aanleg nie-ensiematiese oksidatief van aard is. Resultate het getoon dat proteinstabiliteit geen invloed op die vormingstempo van HMF het nie. Dit was egter bevestig dat vorming van HMF direk verband hou met hoë temperature en lang blootstellingsperiodes aan hierdie temperature. Ander adsorpsieprodukte was vergelyk met die huidige GVK (CA1), naamlik ‘n stoom geaktiveerde verpoeierde koolstof (Norit se SA4) en ‘n polimeriese adsorbant, Polyclar V (polivinielpolipirrolidoon/PVPP). Beide SA4 en PVPP het CA1 oortref wat betref HMF adsorpsie. Moontlike bedryfskostebesparings (en soliede afval verminderings) potensiaal bestaan indien CA1 vervang word met SA4. Die teenoorgestelde is egter waar vir PVPP wat bedryfskoste aangaan. Instede van die huidige verdampinstegnologie, naamlik vallendefilmverdamping, hoort verbeterde konsentrasietegnologieë soos tru-osmose membraankonsentrasie gevolg deur sentrifugale verdamping, of, alternatiewelik, twee-stadium sentrifugale verdamping, orrweeg te word. Op hierdie wyse behoort hittebehandeling (en dus verbruining) met sowat 90% verminder te word. ‘n Moonlike addisionele voordeel is die vermindering van soliede afval aangesien minder ontkleuring nodig sal wees. Indien die verbeterde tegnologieë te duur is moet daar gekyk word daarna om die ongekonsentreerde sap met addisionele swaweldioksied (SO2) te stoor, aangesien veel laer HMF konsentrasies in sulke sap waargeneem is as in verdunde direkte konsentraat wat vir dieselfde typerk gestoor is. Hittebehandeling sal op hierdie wyse met tot 50% verminder word (en dus verbruining ook).

Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Thompson Seedless and Regal Seedless are two white seedless table grape cultivars widely produced in South Africa. Both cultivars are susceptible to berry browning, especially Regal Seedless. Browning leads to annual financial losses for table grape growers. Although a correlation between harvest maturity and the occurrence of browning seems to exist, it is still unclear whether maturity levels are the actual contributing factor. The aim of the study was to establish if harvest maturity and crop load could influence the occurrence of browning of both cultivars. The impact of harvest maturity and crop load on phenolic compound concentration in the berry skin of both cultivars was also investigated. Total external browning of Regal Seedless and Thompson Seedless occurred in much higher percentages than internal browning. Regal Seedless showed a tendency to decreased total external browning with harvest maturity. The main reason for this is that net-like browning, which is the greatest contributor to total external browning, decreased with harvest maturity, in all three seasons. External browning of Thompson Seedless increased with harvest maturity in both seasons. Contact browning was the greatest contributor to total external browning of Thompson Seedless. Crop load did not significantly influence berry browning of Regal Seedless or Thompson Seedless grapes. The flavan-3-ol concentration (catechin, epicatechin, procyanidin B1 and procyanidin B2) in Regal Seedless generally increased with harvest maturity, whereas in Thompson Seedless the general tendency was a decrease in the flavan-3-ol concentration with harvest maturity. The development of phenolic compound concentration with maturity could not be correlated with the occurrence of berry browning. Crop load did not affect flavan-3-ol concentration. When the flavan-3-ol concentration of Regal Seedless and Thompson Seedless were compared at different harvest maturities the concentrations of flavan-3-ols were clearly much higher in the skin of Regal Seedless than in the skin of Thompson Seedless (for both the 2008 & 2009 seasons). Comparison of the browning incidence with harvest maturity for these two cultivars (see above) clearly reveals that external browning of Regal Seedless occurred in much higher percentages than on Thompson Seedless. Regal Seedless had much higher levels of external browning than Thompson Seedless. The concentration of flavan-3-ols in the skin of white seedless cultivars may be an indication of the cultivar’s susceptibility to external browning. / AFRIKAANSE OPSOMMING: Thompson Seedless en Regal Seedless is twee wit pitlose tafeldruif kultivars wat ekstensief in Suid-Afrika verbou word. Verbruining kan ‘n probleem wees by beide kultivars, spesifiek Regal Seedless. Die faktore wat aanleiding gee tot verbruining is nog nie duidelik bepaal nie. Alhoewel dit lyk of daar ‘n korrelasie tussen rypheidsgraad van die oes en verbruining kan wees is dit steeds onduidelik of oesrypheidsvlakke die werklike oorsaak van verbruining is. Die doel van die studie was om vas te stel of die rypheidsgraad van die oes en oeslading verbruining van beide kultivars kan beïnvloed. Die effek van oes rypheidsgraad en oeslading op konsentrasie van fenoliese verbindings in die korrelskil van beide kultivars is ook ondersoek. Totale eksterne verbruining van Regal Seedless en Thompson Seedless het in baie hoër persentasies voorgekom as interne verbruining. Daar was ‘n tendens by Regal Seedless dat totale eksterne verbruining verminder het soos die oes ryper geraak het as gevolg van netagtige verbruining, wat die grootste bydrae tot totale eksterne verbruining veroorsaak het. Netagtige verbruining se voorkoms het verminder oor al drie seisoene. Eksterne verbruining van Thompson Seedless het toegeneem met oes rypheid in beide seisoene. Kontak verbruining het grootste byrdae gelewer tot totale eksterne verbruining van Thompson Seedless. Oeslading het nie ‘n betekenisvolle invloed op verbruining van Regal Seedless en Thompson Seedless gehad nie. Die flavan-3-ol (katesjien, epikatesjien, prosianidien B1 en prosianidien B2) konsentrasie van Regal Seedless het met oes rypheid toegeneem. By Thompson Seedless was daar ‘n afname in die flavan-3-ol konsentrasie met oes rypheid. Daar was geen korrrelasie tussen die konsentrasie van fenoliese verbinding en die voorkoms van verbruining vir beide kultivars. Oeslading het nie ‘n betekenisvolle effek op die konsentrasie van fenoliese verbindings gehad nie. Vergelyking van die flavan-3-ol konsentrasie van Regal Seedless en Thompson Seedless by verskillende rypheidsgrade wys dat die konsentrasie baie hoër in die korrel skil van Regal Seedless as in die van Thompson Seedless (vir beide 2008 & 2009 seisoene). Die vergelyking van die voorkoms van verbruining met oesrypheid van beide kultivars wys duidelik dat eksterne verbruining van Regal Seedless in baie hoër persentasies voorkom as in Thompson Seedless. Flavan-3-ol konsentrasie in die skil van wit pitlose kultivars kan ‘n aanduiding wees van die kultivar se moontlike risiko vir die voorkoms van eksterne verbruining.

Les vitraux du Moyen Âge, dont les pièces de verre contiennent du manganèse, sont fréquemment atteints d'une pathologie communément appelée «brunissement ». Ce phénomène, qui se traduit par la présence de taches brunes riches en manganèse en surface ou subsurface du verre limitant le passage de la lumière et gênant la lisibilité de l'œuvre, est peu documenté et son occurrence parmi les vitraux n'est pas précisément connue. Un des problèmes majeurs pour ce qui concerne la conservation/restauration des œuvres est l'absence de traitements efficaces et durables pour cette pathologie. En France actuellement, l'absence de traitement est donc préconisée, ce qui ne satisfait ni les architectes, ni les conservateurs, ni les restaurateurs. La connaissance approfondie des processus physico-chimiques à l'origine du phénomène de brunissement est donc nécessaire pour proposer des réponses aux questions et aux attentes des conservateurs/restaurateurs. Au cours de cette thèse un panel de 24 échantillons de verres de vitraux historiques et de 3 échantillons archéologiques ont été étudiés par des méthodes microscopiques et spectroscopiques afin i) d'établir des critères d'identification du phénomène de brunissement dû au manganèse et ii) d'obtenir des informations sur la nature des phases brunes et sur le degré d'oxydation du manganèse dans ces phases. Parallèlement à l'étude des échantillons anciens, des verres modèles de composition proche de celle des vitraux médiévaux ont été synthétisés avec deux objectifs : i) la compréhension de la réaction entre le manganèse et le fer et de l'influence des paramètres de fabrication sur la couleur des verres et ii) l'étude de l'influence que peuvent avoir les bactéries dans le développement du phénomène de brunissement / The medieval stained glass windows, which glass composition contain manganese, are often affected by an alteration commonly designated as "browning". This phenomenon results in the presence of Mn-rich brown spots at the surface or subsurface of the glass thus limiting the passage of light and hindering the interpretation of the artwork. Poorly documented, the occurrence of browning among stained glass windows is not precisely described. Currently, one of the major problems in terms of conservation and restoration is that long-term treatments are not available. In these conditions, the recommendations are not to treat the affected glasses, a solution that satisfies neither the architects nor the curators, nor the restorers. In order to answer the questions and expectations of curators and restorers the comprehension of this phenomenon is essential. In this work, a panel of 24 historical and 3 archaeological stained glass samples were studied by microscopic and spectroscopic methods in order to i) establish reliable criteria for identifying the browning phenomenon due to manganese and ii) obtain information on the nature of the dark phases and the oxidation state of manganese in these phases. In parallel with the study of ancient samples, synthetic glasses with medieval-like compositions were synthesized for: i) understanding the reaction between manganese and iron, as well as the influence of the process parameters on the color of glasses and ii) studying the influence of bacteria in the development of the browning phenomenon

Informe de Seminario para optar al grado de Licenciado en Lengua y Literatura Hispánica

Made available in DSpace on 2015-04-22T22:17:25Z (GMT). No. of bitstreams: 1 SALOMAO ROCHA.pdf: 785933 bytes, checksum: 2a406f595cf4495ac889e48923ddd00c (MD5) Previous issue date: 2012-08-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / During the freezing of fruits pulps, the enzyme activity is not finished completely. Sensory, nutritional and coloring changes may occur on fruits due to the action of oxidative enzymes such as peroxidase and polyphenoloxidase. The frozen cupuaçu pulps, sold in Brazil, have a shelf life of one year and become browned during this period. The aim of this study was to evaluate the effect of frozen storage on the physicochemical characteristics, polyphenoloxidase activity and soluble and ionically bound peroxidases presented in the pulps of four new cupuaçu genotypes over twelve months. The cupuaçu genotypes developed by the West Amazonian Agroforestry Research Center (EMBRAPA) were pulped, frozen and stored at 30 °C. The polyphenoloxidase of the four cupuaçu genotypes showed an increase in activity according to the storage time with peaks in the sixth, ninth and tenth months, but the peroxidases exhibited oscillations in the enzyme activity. The physicochemical properties of the pulps showed variations during the twelve months of storage under freezing. The vitamin C content of D 28-10 and P 3-10 genotypes decreased from the fourth and tenth months, respectively. Moreover P 9-8 e B 28-7 genotypes remained stable. In relation the acidity of citric acid, the B-28-7, D 28-10 and P 9-8 samples were not different, but P 3-10 genotype presented a reduction. The pH and total soluble solids of all genotypes decreased over the study period. There was an increase in sugar concentration of B 28-7, P 3-10 and P 9-8 genotypes, except for D 28-10 sample which remained unchanged. All genotypes were in accordance with physical-chemicals standards required by legislation, except for P 3-10 genotype that showed a lower acidity. In respect of the enzymatic parameters, there were variations in the activity of peroxidase and polyphenoloxidases of all genotypes. / No congelamento de polpas de frutas a atividade enzimática não é completamente cessada. Podem ocorrer mudanças sensoriais, nutricionais e de coloração devido à ação de enzimas oxidativas, como a peroxidase e a polifenoloxidase. Considerando que as polpas de cupuaçu congeladas, comercializadas no Brasil, têm um prazo de validade de um ano e tornam-se escurecidas ao longo deste período, objetivou-se neste estudo avaliar o efeito do tempo de congelamento nas características físico-químicas e nas atividades da polifenoloxidase e peroxidases solúvel e insolúvel presentes nas polpas de quatro novos genótipos de cupuaçu, durante doze meses. Os frutos dos genótipos de cupuaçu, desenvolvidos pela Embrapa Amazônia Ocidental, foram despolpados, congelados e armazenados à temperatura de -30 ºC. A polifenoloxidase das polpas dos quatro genótipos apresentou aumento na sua atividade com picos no sexto, nono e décimo mês e as peroxidases apresentaram oscilações na atividade enzimática. As propriedades físico-químicas das polpas apresentaram variações durante os doze meses de armazenamento sob congelamento. O teor de vitamina C dos genótipos D 28-10 e P 3-10 diminuiu a partir do 4º e 10º mês, respectivamente. Por outro lado os genótipos B 28-7 e P 9-8 permaneceram estáveis. Em relação à acidez em ácido cítrico, as amostras B-28-7, D 28-10 e P 9-8 não diferiram, havendo redução no genótipo P 3-10. O valores de pH e sólidos solúveis totais de todos os genótipos diminuíram ao longo do período avaliado. Houve aumento na concentração de açúcares das polpas dos genótipos B 28-7, P 3-10 e P 9-8, com exceção da amostra D 28-10 que permaneceu inalterada. Todos os genótipos apresentaram-se dentro dos padrões físico-químicos exigidos pela legislação, com exceção do genótipo P 3-10 que apresentou acidez inferior. Em relação aos parâmetros enzimáticos, houve variações na atividade das peroxidases e polifenoloxidases de todos os genótipos avaliados.

The formation of green trihydroxy benzacridine (TBA) derivatives when chlorogenic acid (CGA) quinones and amino acids react can be visually unappealing in some applications where CGA containing ingredients are used. Cysteine was studied as an amino acid anti-greening strategy, because cysteine-CGA conjugates are colorless. Buffered CGA: lysine: cysteine solutions at pH 8.0 and 9.0 were prepared and incubated for a maximum of 48 h at ambient temperature. Color intensity was periodically monitored using a UV-Vis spectrophotometer. Quantification and identification of conjugate formation were conducted by HPLC and LC-MS, while Antioxidant capacity was assessed by Trolox Equivalent Antioxidant Capacity and Folin-Ciocalteu reagent reducing capacity assays. More intense greening was detected at higher pH. Lysyl amine- CGA conjugates were identified as the predominant precursor of green TBA. Concentration-dependent cysteine inhibition of CGA-lysine greening was primarily by redox diphenol regeneration when pH was below cysteinyl thiol pKa 8.3 while primarily by forming cysteinyl-CGA conjugates when pH was above 8.3. Visible greening was fully inhibited with a cysteine: lysine 1:1 molar ratio in pH 9 CGA: Lys: Cys solutions, indicating that cysteinyl thiol was a stronger nucleophile than ε-lysyl amine to react with CGA o-quinones. Mono- and di-cysteine-CGA conjugates contributed to antioxidant capacity. Cysteine concentration, pH and incubation time all significantly affected color intensities and antioxidant capacity (p