Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Kimberly A. Williams / Ivy geranium (Pelargonium peltatum L’Herr ex. Ait.) and tomato (Solanum lycopersicum L.) are two economically important greenhouse crops known to be affected by non-pathogenic lesions on leaf tissues. These physiological disorders are often termed edema (oedema) or intumescences, but several other names have been used including enations, non-pathogenic galls or tumors, and neoplasms. These lesions, characterized by small protrusions on leaf tissues that become necrotic over time, are considered to be the result of environmental factors. Our research focused on determining what environmental factors affect these disorders on ivy geranium and tomato. The physiological disorder of ivy geranium is thought to be the result of water uptake exceeding transpiration, resulting in a build-up of water and solutes in leaf tissue that results in the blister-like protrusions in the epidermal layer. Current convention suggests that susceptible plants be grown in an environment that promotes transpiration with low humidity and infrequent watering. Over four experiments, we evaluated the effects of four root medium water contents, five rates of supplemental calcium application and two vapor pressure deficit (VPD) environments on three cultivars of ivy geranium. Our results indicate that high root medium water contents do not increase the incidence of edema on ivy geranium, but increase overall plant growth. Supplemental calcium had no affect on edema or growth, while our VPD results were inconclusive. These results suggest that current convention regarding cultural practices that abate the disorder be revisited. In tomato var. hirsutum ‘Maxifort’, the physiological disorder is characterized by individual epidermal cells swelling, which is unlike the disorder in ivy geranium where solutes build up across a group of epidermal cells. The environmental factors we focused on were two root medium water contents and supplemental UVB light. Our results suggest that root medium water content may play a role in development of tomato intumescences based on visual observation, and UVB light supplementation helps prevent the lesions from forming.

A luz do sol possui radiação ultravioleta (UV) que pode ser dividida em luz UVA, com comprimentos de onda na região de 400 a 320 nm; luz UV-B, na região de 320 a 290 nm e luz UV-C para radiações com comprimento de onda menor do que 290 nm, sendo esta última absorvida na atmosfera pelo ozônio. O ser humano dispõe de mecanismos protetores naturais contra as radiações solares, tal como a melanogênese. Entretanto, estes são insuficientes e, por isso, torna-se necessário proteger adequadamente a pele utilizando protetores solares, a fim de minimizar as lesões cutâneas causadas pela radiação solar. Quimicamente, a função dos protetores solares é a absorção da radiação UV, protegendo a pele dos efeitos da exposição à luz solar. Este trabalho visa a preparação de compostos de cério, via método Pechini, com a finalidade de utilizá-los como um componente inorgânico de protetores solares de elevado FPS, juntamente ou substituindo substâncias tais como ZnO e TiO2. A caracterização dos compostos deverá ser realizada por difratometria de raios X, microscopias de eletrônicas de varredura e transmissão, espectroscopia eletrônica de reflectância difusa (ERD) e testes de atividade catalítica e fotocatalítica, pelo método da determinação condutométrica (adaptação RANCIMAT®). / Sunlight emits ultraviolet radiation (UV) which is subdivided into three different UV wavelengths: UV-A band in the range of 400-320 nm; UV-B band in the range of 320-290 nm and UV-C band for radiations lesser than 290 nm. The latter is absorbed in the atmospheres ozone layer. Human beings have natural protective mechanisms against solar radiations, such as melanogenys. However, it has been reported that these mechanisms are insufficient to prevent skin damage. Thus, adequate the use of sunscreen (or UV filters) is needed in order to minimize cutaneous injuries caused by solar radiation. Chemically, the function of solar protectors relies on the absorption of UV radiation, which protects the skin from the effect of the exposition to solar light. The present study reports on the synthesis of CeO2-ZnO systems according to Pechini\'s method. Our objective is to further understand how ZnO modifies the CeO2 nanostructured as we search for a new UV filter material. The characterization of composites will be carried through by X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), diffuse reflectance spectroscopic and tests of catalytic activity and photocatalytic activity, for the method of the conductometric determination (RANCIMAT adaptation).

BACKGROUND: The prevalence of Vitamin D deficiency is roughly 40% in the world and is increasing every year. Populations 65 years and older show a higher prevalence of vitamin D deficiency, because the aging process decreases the capacity of the skin to produce vitamin D. Some studies have reported that the prevalence of vitamin D deficiency is higher in the winter, however the effect of seasonal change on serum vitamin D level remains controversial in some specific populations. Moreover, this association remains uncertain in the elderly population because there is no study that specifically targets individuals over the age of 65. This study investigated the effect of seasonal changes and serum 25-hydroxyvitamin D among individuals 65 years and older residing in the Boston, Massachusetts and Stockholm, Sweden. METHODS: Cross-sectional and longitudinal cohort designs were both adapted to examine an existing data from VIVE2 parent study; the data was collected from 2012 to 2014. Data from the subjects who had finished this 6-month trial were analyzed for this study. Serum 25(OH)D levels, BMI, sex, study sites and age were collected and analyzed by univariate regression analysis and t-test. Serum 25(OH)D and confounders were included in multivariate analysis. Study sites were analyzed by effect modification model. RESULTS: In total, the prevalence of vitamin D deficiency (serum 25(OH)D levels less than 20 ng/ml) was 70%, while the mean serum 25(OH)D level was 20 ng/ml in summer and 16.4 ng/ml in winter. The average of seasonal serum 25(OH)D level changes were 6 ng/ml and 3 ng/ml in Stockholm, Sweden and Boston, MA, respectively. In addition, the prevalence of vitamin D deficiency increased 80% during winter (95CI: 1.1 – 2.9). There was no significant different in serum 25(OH)D levels among elderly populations between low latitude study site Boston, MA and high latitude site Stockholm, Sweden. There was no significant relation found in BMI, age and sex with serum 25(OH)D levels in the study. The seasonal serum 25(OH)D level changes was significantly different in the cross-sectional study design but not in the longitudinal study. CONCLUSION: Serum 25(OH)D levels were higher in the summer than in the winter among the elderly population resided in Boston, MA and Stockholm, Sweden.

Amphibians are declining worldwide in response to pressures that are too numerous, difficult and rapid to ameliorate in the wild before some taxa become extinct. Ex situ conservation, whereby animals are maintained in captivity until threats in the wild have been resolved, is the only means of saving up to five hundred amphibian species. Amongst political, financial and practical hurdles, the most fundamental problem for these programmes is lack of knowledge about how to maintain species successfully in captivity. Captive populations have failed to survive or reproduce and, furthermore, captive husbandry may produce animals unsuitable for reintroduction through intra or inter-generational changes. These problems entirely undermine initiatives and if ex situ programs are to succeed, evidence based captive husbandry is needed to support captive breeding programs. In this thesis, I quantify our ignorance of amphibian requirements in captivity. Furthermore, I present investigations into fundamental areas ofamphibian husbandry, about which we currently know very little. I investigate the relationship between amphibians and Ultraviolet B (UVB) radiation and examine the relationship between UVB provision and calcium provision and evaluate routes of dietary calcium supplementation. I also present data on the effects of enrichment and rearing environment on the growth, fitness, behaviour and dermal bacterial communities of captive amphibians. These results, from a range of areas of amphibian husbandry, together demonstrate the power of the captive environment to influence the phenotype and therefore the fitness of amphibians, even within single generations. Additionally, I provide some of the first data addressing key areas of amphibian husbandry that until now have been led mostly or entirely by anecdote and hearsay.

A luz do sol possui radiação ultravioleta (UV) que pode ser dividida em luz UVA, com comprimentos de onda na região de 400 a 320 nm; luz UV-B, na região de 320 a 290 nm e luz UV-C para radiações com comprimento de onda menor do que 290 nm, sendo esta última absorvida na atmosfera pelo ozônio. O ser humano dispõe de mecanismos protetores naturais contra as radiações solares, tal como a melanogênese. Entretanto, estes são insuficientes e, por isso, torna-se necessário proteger adequadamente a pele utilizando protetores solares, a fim de minimizar as lesões cutâneas causadas pela radiação solar. Quimicamente, a função dos protetores solares é a absorção da radiação UV, protegendo a pele dos efeitos da exposição à luz solar. Este trabalho visa a preparação de compostos de cério, via método Pechini, com a finalidade de utilizá-los como um componente inorgânico de protetores solares de elevado FPS, juntamente ou substituindo substâncias tais como ZnO e TiO2. A caracterização dos compostos deverá ser realizada por difratometria de raios X, microscopias de eletrônicas de varredura e transmissão, espectroscopia eletrônica de reflectância difusa (ERD) e testes de atividade catalítica e fotocatalítica, pelo método da determinação condutométrica (adaptação RANCIMAT®). / Sunlight emits ultraviolet radiation (UV) which is subdivided into three different UV wavelengths: UV-A band in the range of 400-320 nm; UV-B band in the range of 320-290 nm and UV-C band for radiations lesser than 290 nm. The latter is absorbed in the atmospheres ozone layer. Human beings have natural protective mechanisms against solar radiations, such as melanogenys. However, it has been reported that these mechanisms are insufficient to prevent skin damage. Thus, adequate the use of sunscreen (or UV filters) is needed in order to minimize cutaneous injuries caused by solar radiation. Chemically, the function of solar protectors relies on the absorption of UV radiation, which protects the skin from the effect of the exposition to solar light. The present study reports on the synthesis of CeO2-ZnO systems according to Pechini\'s method. Our objective is to further understand how ZnO modifies the CeO2 nanostructured as we search for a new UV filter material. The characterization of composites will be carried through by X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), diffuse reflectance spectroscopic and tests of catalytic activity and photocatalytic activity, for the method of the conductometric determination (RANCIMAT adaptation).

A novel marine active polypeptide (PCF), isolated from the gonochoric Chinese scallop, Chlamys farreri, has potential antioxidant and anti-apoptotic activity against ultraviolet irradiation. We investigated whether UVB-induced HaCaT cell apoptosis occurs via the mitochondrial pathways Apaf-1/caspase-9 and Smac/XIAP/caspase-3. We then investigated the molecular mechanisms controlling the anti-apoptotic effect of PCF. Pre-treatment with PCF and caspase-9 inhibitor significantly inhibited UVB-induced apoptosis in HaCaT cells based on a DNA fragmentation assay and Hoechst 33258 staining. The expression of Apaf-1 and the cleavage of procaspase-9 were dose-dependently reduced by 1.42-5.96 mmol/L PCF pretreatment in UVB-irradiated HaCaT cells. This was followed by inhibition of cleavage of procaspase-3, whose activation induced cell apoptosis. Meanwhile, PCF significantly and dose-dependently enhanced the activation of ATPase. Furthermore, we demonstrated that PCF strongly inhibited the release of Smac from the mitochondria to cytosol by reducing the degradation of XIAP dose-dependently. We conclude that the protective effect of PCF against UVB irradiation in HaCaT cells may be attributed to the inhibition of the Apaf-1/caspase-9 and Smac/XIAP/caspase-3 apoptotic signaling pathways.

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