Diffusional kurtosis imaging using a fast heuristic constrained linear least squares algorithm: a plugin for OsiriX

Diffusion Kurtosis Imaging (DKI) is a fairly new magnetic resonance imag-ing (MRI) technique that tackles the non-gaussian motion of water in biological tissues by taking into account the restrictions imposed by tissue microstructure, which are not considered in Diffusion Tensor Imaging (DTI), where the water diffusion is considered purely gaussian. As a result DKI provides more accurate information on biological structures and is able to detect important abnormalities which are not visible in standard DTI analysis. This work regards the development of a tool for DKI computation to be implemented as an OsiriX plugin. Thus, as OsiriX runs under Mac OS X, the pro-gram is written in Objective-C and also makes use of Apple’s Cocoa framework. The whole program is developed in the Xcode integrated development environ-ment (IDE). The plugin implements a fast heuristic constrained linear least squares al-gorithm (CLLS-H) for estimating the diffusion and kurtosis tensors, and offers the user the possibility to choose which maps are to be generated for not only standard DTI quantities such as Mean Diffusion (MD), Radial Diffusion (RD), Axial Diffusion (AD) and Fractional Anisotropy (FA), but also DKI metrics, Mean Kurtosis (MK), Radial Kurtosis (RK) and Axial Kurtosis (AK).The plugin was subjected to both a qualitative and a semi-quantitative analysis which yielded convincing results. A more accurate validation pro-cess is still being developed, after which, and with some few minor adjust-ments the plugin shall become a valid option for DKI computation

Efeitos de diferentes níveis de N, P e K sôbre cacaueiros jovens (Theorema cacao L.) em solução nutritiva

Cocoa seedlings were grown in nutrient solution in order to find out the effects of the levels of N, P, K in the substrate on growth, symptoms and chemical composition of the leaves. A 3x3x3 factorial design was used. The following conclusions can be drawn. 5.1. Among the three elements under study, only nitrogen had a positive, significant effect on growth as measured by height and dry weight. 5.2. The level of a given elements in the leaves did increase when its level in the nutrient solution was raised. On the other hand the N content was positively affected by the concentration of P in the substrate. 5.3. A decrease in the N/P and K/P rations in the leaves was observed when the nutrient solutions had, res-respectively, absence of K and N and high level both of K and N. The N/K ratio increased with the level of P in the substrate. 5.4 A highly significant positive correlation was found between N content in the leaves and dry weight. This was not the case however, insofar P and K are considered - no correlation whatsoever was observed.

Dietary modulation of plasma antioxidant deficiencies: effect of mediterranean diet

Estudi elaborat a partir d’una estada al National Research Institute for Food and Nutrition, Itàlia, des de novembre del 2006 fins a febrer del 2007. La capacitat antioxidant total (TAC) en plasma pot ser un bon biomarcador del estat antioxidant dels humans. Prenent les mostres de dos projectes diferents de recerca s’ha mesurat la TAC mitjançant el FRAP (ferric reductant antioxidant potencial) i el TRAP (total radical-trapping antioxidant parameter ). D’una banda el PREDIMED, és un estudi prospectiu aleatoritzat i controlat, amb una cohort d’ individus sense patología vascular coneguda, però amb un alt risc de patir-la. En aquest es valora la utilitat d’una intervenció dietética del tipus mediterrània en la prevenció primària de la malaltia cardiovascular. L’altre és el de biodisponibilitat en humans dels metabòlits dels polifenols presents en els solubles de cacau, un estudi crònic (28 dies) on es vol mesurar la influència de la llet en l’absorció dels polifenols del cacau, en voluntaris amb elevat risc de sofrir patologia cardiovascular.

The sand fly fauna (Diptera: Psychodidae: Phlebotominae) of a focus of cutaneous leishmaniasis in Ilhéus, state of Bahia, Brazil

The municipality of Ilhéus, State of Bahia, has a focus of cutaneous leishmaniasis where entomological studies were carried out to determine the sand fly species and their habits. Lutzomyia migonei, L. sallesi, L. tupynambai, L. schreiberi, L. intermedia, L. whitmani, L. yuilli yuilli, L. fischeri, L. pessoai, L. shannoni and L. misionensis were identified. Lutzomyia whitmani was the predominant species. Specimens were collected indoors, at peridomestic sites, in the cocoa plantations and in other types of collections. Females fed readily on humans and were attracted to domestic animals. Our evidence suggests that L. whitmani is a probable vector.

iCompound : una aplicació per l'estudi de la química sobre iOS

El treball de final de carrera és la culminació de molts anys d'estudi, i una oportunitat excel·lent de posar en pràctica molts dels coneixements adquirits. A més, poder treballar en l'àrea que ocupa (disseny d'aplicacions per iOS), ha estat la millor oportunitat per intentar crear una eina de qualitat per aquelles persones que, essent usuaris de dispositius mòbils d'Apple (iPhone, iPod, iPad), i estant lligats (d'una manera o altre) al món de la química, vulguin tenir a la seva disposició una aplicació que els ajudi a resoldre petits problemes lligats a aquesta disciplina científica.

Mechanisms of Photoaging and Cutaneous Photocarcinogenesis, and Photoprotective Strategies with Phytochemicals.

Photoaging and photocarcinogenesis are primarily due to solar ultraviolet (UV) radiation, which alters DNA, cellular antioxidant balance, signal transduction pathways, immunology, and the extracellular matrix (ECM). The DNA alterations include UV radiation induced thymine-thymine dimers and loss of tumor suppressor gene p53. UV radiation reduces cellular antioxidant status by generating reactive oxygen species (ROS), and the resultant oxidative stress alters signal transduction pathways such as the mitogen-activated protein kinase (MAPK), the nuclear factor-kappa beta (NF-κB)/p65, the janus kinase (JAK), signal transduction and activation of transcription (STAT) and the nuclear factor erythroid 2-related factor 2 (Nrf2). UV radiation induces pro-inflammatory genes and causes immunosuppression by depleting the number and activity of the epidermal Langerhans cells. Further, UV radiation remodels the ECM by increasing matrixmetalloproteinases (MMP) and reducing structural collagen and elastin. The photoprotective strategies to prevent/treat photoaging and photocarcinogenesis include oral or topical agents that act as sunscreens or counteract the effects of UV radiation on DNA, cellular antioxidant balance, signal transduction pathways, immunology and the ECM. Many of these agents are phytochemical derivatives and include polyphenols and non-polyphenols. The flavonoids are polyphenols and include catechins, isoflavones, proanthocyanidins, and anthocyanins, whereas the non-flavonoids comprise mono phenolic acids and stilbenes. The natural sources of polyphenols include tea, cocoa, grape/wine, soy, pomegranate, and Polypodium leucotomos. The non-phenolic phytochemicals include carotenoids, caffeine and sulphoraphance (SFN). In addition, there are other phytochemical derivatives or whole extracts such as baicalin, flavangenol, raspberry extract, and Photomorphe umbellata with photoprotective activity against UVB radiation, and thereby carcinogenesis.

iUOC

El document mostra tot el procés de creació d'una aplicació per a dispositius iPad per a la gestió de les activitats i documents d'assignatures de la UOC.

Rediscovery of the putatively extinct ant species Simopelta minima (Brandão) (Hymenoptera, Formicidae), with a discussion on rarity and conservation status of ant species

Simopelta minima (Brandão, 1989) was originally described based on four workers collected in soil samples from a small cocoa plantation in Ilhéus, state of Bahia, northeastern Brazil. In the subsequent years after the description, this cocoa plantation was eliminated and the species was then considered extinct by the Brazilian environmental institutions. The recent rediscovery of S. minima workers in subterranean pitfall trap samples from Viçosa, state of Minas Gerais, southeastern Brazil, over 1.000 km distant from type locality, suggests that the rarity and vulnerability status of some ant species may be explained by insufficient sampling of adequate microhabitats, in time and space.

Modification de la composition des cigarettes durant te XXe siècle: rôle de l'industrie du tabac et effet sur la dépendance tabagique [Chemicals added to cigarettes and their effects on tobacco dependence]

This paper summarizes data on the factors involved in addiction and dependence to cigarettes. Nicotine has been intensively studied by the tobacco industry, for instance for its addictive effect at the lowest possible rates. The addition of diammonium phosphate and urea produces an alcalinization of the pH of cigarette smoke, and promotes the absorption and the trans-membrane passage of nicotine. The taste, the smell of smoke, and the visual aspect of the pack of cigarettes are also sensory components that promote addiction. Finally, menthol, sugar, cocoa and liquorice added to cigarettes also play a role in dependence and addiction to cigarettes by, for instance, making an anesthetic effect on the airways.

Effect of dark chocolate on renal tissue oxygenation as measured by BOLD-MRI in healthy volunteers.

Background: Cocoa is rich in flavonoids, has anti-oxidative properties and increases the bioavailability of nitric oxide (NO). Adequate renal tissue oxygenation is crucial for the maintenance of renal function. The goal of this study was to investigate the effect of cocoa-rich dark chocolate (DC) on renal tissue oxygenation in humans, as compared to flavonoid-poor white chocolate (WC). Methods: Ten healthy volunteers with preserved kidney function (mean age ± SD 35 ± 12 years, 70% women, BMI 21 ± 3 kg/m2) underwent blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) before and 2 hours after the ingestion of 1 g/kg of DC (70% cocoa). Renal tissue oxygenation was determined by the measurement of R2* maps on 4 coronal slices covering both kidneys. The mean R2* (= 1/T2*) values in the medulla and cortex were calculated, a low R2* indicating high tissue oxygenation. Eight participants also underwent BOLD-MRI at least 1 week later, before and 2 hours after the intake of 1 g/kg WC. Results: The mean medullary R2* was lower after DC intake compared to baseline (28.2 ± 1.3 s-1 vs. 29.6 ± 1.3 s-1, p = 0.04), whereas cortical and medullary R2* values did not change after WC intake. The change in medullary R2* correlated with the level of circulating (epi)catechines, metabolites of flavonoids (r = 0.74, p = 0.037), and was independent of plasma renin activity. Conclusion: This study suggests for the first time an increase of renal medullary oxygenation after intake of dark chocolate. Whether this is linked to flavonoid-induced changes in renal perfusion or oxygen consumption, and whether cocoa has potentially renoprotective properties, merits further study.

Influence of label information on dark chocolate acceptability

The aim of the present work was to study how the information on product labels influences consumer expectations and their acceptance and purchase intention of dark chocolate. Six samples of dark choco- late, varying in brand (premium and store brand) and in type of product (regular dark chocolate, single cocoa origin dark chocolate and high percentage of cocoa dark chocolate), were evaluated by 109 con- sumers who scored their liking and purchase intention under three conditions: blind (only tasting the products), expected (observing product label information) and informed (tasting the products together with provision of the label information). In the expected condition, consumer liking was mainly affected by the brand. In the blind condition, differences in liking were due to the type of product; the samples with a high percentage of cocoa were those less preferred by consumers. Under the informed condition, liking of dark chocolates varied depending on both brand and type of product. Premium brand chocolates generated high consumer expectations of chocolate acceptability, which were fulfilled by the sensory characteristics of the products. Store brand chocolates created lower expectations, but when they were tasted they were as acceptable as premium chocolates. Claims of a high percentage of cocoa and single cocoa origin on labels did not generate higher expectations than regular dark chocolates.

Wit Quiz. Plataforma de aprendizaje sobre dispositivos móviles

El artículo presenta el panorama actual de las nuevas tecnologías en el mundo de la educación.Del potencial que presentan las nuevas tecnologias y concretamente los dispositivos móviles, nace el proyecto KPAX, una plataforma tecnológica que soporte la incorporación de módulos independientes de aprendizaje basado en juegos.Wit Quiz es un caso práctico de dicho proyecto. Es un juego que integra las nuevas tecnologías con nuevas formas de aprendizaje informal. Se ha optado por una primera implementación sobre Iphone debido al éxito creciente de sus apps.La aplicación Wit Quiz ha sido desarrollada con cocoa, xcode y objective-c y permite una fácil gesión de sus contenidos gracias a la implementación de un servicio web.

When cholesterol is not cholesterol: a note on the enzymatic determination of its concentration in model systems containing vegetable extracts

Background: Experimental evidences demonstrate that vegetable derived extracts inhibit cholesterol absorption in the gastrointestinal tract. To further explore the mechanisms behind, we modeled duodenal contents with several vegetable extracts. Results: By employing a widely used cholesterol quantification method based on a cholesterol oxidase-peroxidase coupled reaction we analyzed the effects on cholesterol partition. Evidenced interferences were analyzed by studying specific and unspecific inhibitors of cholesterol oxidase-peroxidase coupled reaction. Cholesterol was also quantified by LC/MS. We found a significant interference of diverse (cocoa and tea-derived) extracts over this method. The interference was strongly dependent on model matrix: while as in phosphate buffered saline, the development of unspecific fluorescence was inhibitable by catalase (but not by heat denaturation), suggesting vegetable extract derived H2O2 production, in bile-containing model systems, this interference also comprised cholesterol-oxidase inhibition. Several strategies, such as cholesterol standard addition and use of suitable blanks containing vegetable extracts were tested. When those failed, the use of a mass-spectrometry based chromatographic assay allowed quantification of cholesterol in models of duodenal contents in the presence of vegetable extracts. Conclusions: We propose that the use of cholesterol-oxidase and/or peroxidase based systems for cholesterol analyses in foodstuffs should be accurately monitored, as important interferences in all the components of the enzymatic chain were evident. The use of adequate controls, standard addition and finally, chromatographic analyses solve these issues.

El canvi climàtic posa en perill el cafè i el cacau

PER A MOLTES PERSONES, beure cafè i menjar xocolata és un autèntic plaer. Tant les plantes de cafè com les de cacau es cultiven en unes zones molt concretes de la Terra, als cinturons tropicals, i en teoria representen una font de riquesa per als països productors. Tanmateix, la demanda creixent, combinada amb els efectes del canvi climàtic i les desigualtats econòmiques entre productors i consumidors, posen en perill aquests cultius. Així ho indiquen dos estudis publicats a la revista Plos One i un altre a Current Biology, que suggereixen que per mantenir la productivitat actual cal incrementar la diversitat genètica d"aquestes plantes i afavorir un model de comerç just.

Modificação por via enzimática da composição triglicerídica do óleo de piqui (Caryocar brasiliense Camb)

Piqui (Caryocar brasiliense Camb) oil was transformed into a cocoa butter-like fat through an enzymatic interesterification reaction using Lipozyme in the presence of stearic acid that was incorporated in the sn 1,3-3,1 position into triglyceride. Stearic acid incorporation was determined by HPLC, based on the quantification of the principal triglycerides (POP, POS e SOS) found in cocoa butter. The proposed process was feasible with a reaction time of 240 minutes with 10% of Lipozyme at 70ºC and substract weight ratio of 0,33 (stearic acid:piqui oil).