Doctor of Philosophy (PhD) / The Flesh Browning (FB) disorder of ‘Cripps Pink’ apples presents a significant threat to the established market identity of the ‘Cripps Pink’ apple in Australian and export markets. Climatic conditions during fruit growth and development predispose ‘Cripps Pink’ apples to developing the FB disorder during storage. The FB disorder can be classified into two distinct disorders based on their physiological and structural differences and by seasonal climatic conditions. The diffuse type of FB (DFB) is a chilling injury, occurring in districts or seasons accumulating less than 1100 growing degree days (GDD) above 10oC between full bloom and harvest. In these climatic conditions, ‘Cripps Pink’ apples have delayed postharvest ethylene production. Diffuse FB effects fruit cortex tissue and is characterised as cellular collapse. Storing fruit at 3oC can reduce the incidence of DFB. The radial type of FB (RFB) is primarily a senescent disorder, occurring in districts or seasons accumulating greater than 1400 GDD above 10oC between full bloom and harvest. In these climatic conditions, postharvest ethylene production is not delayed. Radial FB affects the cells adjacent to the vascular tissue of the fruit and is characterised by damaged cell walls. Storing fruit at 1oC can reduce the incidence of RFB. Harvest maturity and the level of CO2 in the storage atmosphere are additive influences on the development of RFB. Seasons or districts accumulating more than 1700 GDD have a very low risk for developing RFB. Seasonal climatic conditions can provide a guide for predicting the risk of developing RFB and DFB during storage.

Thesis (Ph. D.)--University of Michigan.

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Orientador: Valdir Augusto / Banca: Valdir Augusto Neves / Banca: José Paschoal Batistuti / Banca: Jonas Contiero / Resumo: A família das anonáceas é composta por muitos gêneros e espécies; dentre essas, a atemóia (Annona cherimola Mill. X Annona squamosa L.), resultante do cruzamento entre a fruta-do-conde (Annona squamosa L.) e a cherimóia (Annona cherimola Mill.). No Brasil, a atemóia vem despertando grande interesse na produção/comercialização dos seus frutos; no entanto um dos obstáculos enfrentados é a facilidade de escurecimento enzimático que a fruta apresenta. Esse tem como responsável a polifenoloxidase (PPO, E.C. 1.14.18.1); que sob diferentes condições de armazenamento e processamento de vegetais na sua fase póscolheita pode atuar sob substratos naturais e resultar na formação de compostos escuros, acarretando diminuição do valor nutricional, modificação das propriedades organolépticas e sensoriais, com consequente rejeição. Os objetivos desse trabalho foram isolar, purificar e caracterizar algumas propriedades da polifenoloxidase de atemóia. Condições de extração para a PPO foram estabelecidas e a enzima foi isolada por precipitação com sulfato de amônio e eluição em Sephadex G-100. Somente um pico de atividade foi eluído no processo de purificação com um fator de purificação de 7,12. O peso molecular determinado foi 82 kDa com valores ótimos de pH 6,0 e 7,0 para 4-metil catecol e catecol, respectivamente; sendo estável por 12 e 24 horas à incubação na faixa de pH 4,0-8,0. A temperatura ótima de atividade foi 35°C e 28°C para 4-metil catecol e catecol, respectivamente. Os valores calculados de energia de ativação (Ea) para esses substratos foram 87,29 cal/mol-1 e 180,97 cal/mol-1. As constantes cinéticas Km e Vmax foram 5,52mmol/L e 1428,57 UA/mL, para 4-metil catecol, e 79,3 mmol/L e 5000 UA/mL, para catecol. A relação Km/Vmax determinou uma maior afinidade da enzima pelo primeiro substrato. A enzima mostrou desprezível atividade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The family of annonaceae is composed of many genus and species, among these, the atemoya (Annona cherimola Mill. X Annona squamosa L.), resulting from a cross between custard apple (Annona squamosa L.) and cherimoya (Annona cherimola Mill.). In Brazil, the atemoya is attracting great interest in the production / marketing of its fruits, however one of the obstacles faced is the ease of enzymatic browning that gives the fruit. This is as responsible for polyphenoloxidase (PPO, EC 1.14.18.1), which under different conditions of storage and processing plant in its post-harvest can act on natural substrates and result in the formation of dark compounds, causing decrease in nutritional value, modification of the organoleptic and sensory properties, with consequent rejection. The objectives of this study were to isolate, purify and characterize some properties of polyphenoloxidase from atemoya. Conditions for the extraction of PPO were established and the enzyme was isolated by precipitation with ammonium sulfate and elution on Sephadex G-100. Only one peak of activity was eluted in the process of purification with a purification factor of 7.12. The molecular weight of 82 kDa was determined with the optimum values of pH 6.0 and 7.0 for 4-methylcatechol and catechol, respectively. The enzyme was stable for 12 and 24 hours incubation in the pH range 4.0-8.0. The optimum temperatures for activity were 35 °C and 28 °C for 4-methylcatechol and catechol, respectively. The values of activation energy (Ea) for these substrates cal/mol-1 were 87.29 and 180.97 cal/mol-1. The kinetic constants Km and Vmax were 5.52 mmol/L and 1428.57 UA/mL for 4-methylcatechol, and 79.3 mmol/L and 5000 AU / mL for catechol. The Km/Vmax determined a higher affinity of the enzyme by the first substrate. The enzyme showed negligible activity for caffeic acid and chlorogenic as any for L-DOPA, catechin... (Complete abstract click electronic access below) / Mestre

Climate change and human land use leads to browning of waters with decreased visual conditions. This impacts the fish community via changes in foraging ability and food chain efficiency. There are indications that brownification leads to decreased body size of the Eurasian perch (Perca fluviatilis) and that roach (Rutilus rutilus) are favoured over perch in brown lakes since roach is less dependent on its eyesight when foraging. The aim with this project is to examine how browning impacts the fish community in lakes in the south of Sweden and if browning reduces the size of perch in relation to their age. Data on water colour and length-at-age for 1+ and 5+ perch as well as the number of perch and roach captured was collected from 20 lakes. The data was examined using linear regression and paired samples T-test in SPSS. The results show that browning does reduce the body size of perch. Perch is smaller in relation to their age in brown lakes. There was however no evidence indicating that roach is favoured over perch in brown lakes, but there was a difference between the number of 1+ and 5+ perch caught in relation to roach. The perch: roach ration decreased for older fish (from 1+ to 5+) indicating that there is a difference in survival rate. Survival rate of perch was however not dependent on water colour or TOC. This shows that climate change and increased browning could result in changes of the fish community and size structure of fish.

Metformin has been used clinically since 1957 for its efficacy and safety as therapy for type 2 diabetes. Besides ameliorating hyperglycemia without risk of hypoglycemia, metformin also lowers plasma triglyceride levels. Furthermore, a wealth of data shows that metformin facilitates weight loss in mice as well as humans. Due to its numerous metabolic benefits, researchers and clinicians are interested in the possibility of using metformin as treatment to combat obesity and other metabolic disorders such as non-alcoholic fatty liver disease (NAFLD). Despite being the most commonly prescribed anti-diabetic, metformin’s complete mechanism(s) for weight loss or for lowering glucose and lipids remains an enigma. Our studies show that metformin-treated mice exhibited decreased caloric intake, providing a viable mechanism for metformin to bring about weight loss. Intriguingly, we found that metformin induces PRDM16 to promote browning of iWAT and increase expression of thermogenic genes such as UCP1 and DIO2. However, metformin did not appear to increase energy expenditure. It’s possible that metformin’s effect on energy expenditure was masked since energy expenditure measurements were taken when metformin-treated mice were still losing weight and were in a state of negative energy balance. Recently, there has been much attention given to AMPK activators as exercise mimetics. Metformin is known to activate AMPK and similarly brings about many beneficial effects as exercise such as alleviation of obesity-induced NAFLD. SIRT1 stimulation by resveratrol and delivery of exogenous FGF21 mimics metformin’s ability to combat obesity and improve NAFLD. Collectively, these results implicate metformin, resveratrol, and exogenous administration of FGF21 as beneficial therapies for weight loss and amelioration of NAFLD.

Proceeding from the general judgment that The Ring and the Book is, indeed, Browning's greatest achievement, and that it, more than any other of his works, was responsible for establishing him in an extraordinary position of public acceptance and esteem, I propose, in this study, to examine the four features of The Ring and the Book which have most frequently attracted critical attention and to which the greater portion of analysis and review of The Ring and the Book have been devoted.

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