Wnt signalling and cancer stem cells

[Abstract] Intracellular signalling mediated by secreted Wnt proteins is essential for the establishment of cell fates and proper tissue patterning during embryo development and for the regulation of tissue homeostasis and stem cell function in adult tissues. Aberrant activation of Wnt signalling pathways has been directly linked to the genesis of different tumours. Here, the components and molecular mechanisms implicated in the transduction of Wnt signal, along with important results supporting a central role for this signalling pathway in stem cell function regulation and carcinogenesis will be briefly reviewed.Ministerio de Ciencia e Innovación; SAF2008-0060

Alterações morfológicas e acúmulo de compostos fenólicos em plantas de sorgo sob estresse de alumínio Changes in morfology and phenolics accumulation in sorghum (Sorghum bicolor (L.) Moench) plants under aluminum stress

Os efeitos do alumínio (Al+3) sobre a morfologia e o acúmulo de compostos fenólicos foram avaliados em duas cultivares de sorgo (Sorghum bicolor (L.) Moench) com tolerância diferencial ao Al+3. As plantas foram mantidas em solução nutritiva durante dez dias, na presença (185 mM) ou na ausência de Al+3. Os ápices radiculares foram coloridos com hematoxilina férrica, sendo a intensidade da coloração observada na presença do Al+3 muito próxima entre as cultivares, o que inviabiliza a aplicação desse teste, isoladamente, para discriminação entre o genótipo sensível e o tolerante ao Al+3. As análises da morfologia externa e interna dos ápices radiculares de plantas tratadas com Al+3 também foram muito similares entre as duas cultivares, não permitindo a utilização dessas características para seleção entre a cultivar sensível e a tolerante. O maior acúmulo de lignina e, principalmente, a menor produção de compostos fenólicos, observados na presença do Al+3 nas raízes das plantas da cultivar tolerante (BR006R), são parâmetros que possibilitam a discriminação das cultivares quanto à tolerância ao Al+3.<br>The Al+3 effects on the morphology and on the phenolics accumulation were evaluated in two sorghum cultivars exhibiting differential tolerance to Al+3. The plants were kept in nutrient solution, for ten days, in the presence (185 mM) or Al+3 absence. The root apexes were colored with ferric hematoxylin, and because the intensity of color development is very similar among evaluated cultivars, the use of this method as a selection parameter for Al+3-tolerance is not indicated. Analyses of superficial and internal morphology from tissues treated with Al+3 also expressed very similar alterations among the two cultivars, not allowing its use for selection between sensitive and Al+3-tolerant genotype. The higher lignin accumulation and, mainly, the lower phenolics production in roots of the BR006R cultivar in Al+3's presence, demonstrated the existence of differential tolerance among cultivars

Who Would Pay for Facebook? Self Esteem as a Predictor of User Behavior, Identity Construction and Valuation of Virtual Possessions

Abstract. Self-presentation is a major preoccupation in Facebook. Users carefully construct their online profile and assiduously edit postings on their wall in order to strategically shape their online persona. This study examines some psychological antecedents and consequences of such actions. In particular, we propose that users ’ self-esteem affects their sense of agency and self-monitoring tendencies, with the former leading to a fuller description of their profile and the latter contributing to more frequent customization of their wall. In turn, these behaviors are hypothesized to contribute to users ’ personal and social identity respectively, en route to affecting their valuation of Facebook as a virtual possession. Structural equation modeling analysis of survey data (N=221) largely supports this model and reveals that the personal identity reflected in one’s Facebook account is a major predictor of the degree to which one values it as a possession. We discuss the implications of “I ” vs. “Me ” in self-esteem with regard to virtual possessions in social networking environments

using microfluidic deoxyribozyme

Towards practical biomolecular computer