Browsing by Issue Date, starting with "2013-06"
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- Medium factors affecting extracellular protease activity by Bacillus sp. HTS 102—A novel wild strain isolated from Portuguese merino woolPublication . Queiroga, Ana Catarina; Pintado, Manuela Estevez; Malcata, Francisco XavierThe synthesis of an extracellular protease by Bacillus sp. HTS102—a wild strain recently isolated from the wool of Portuguese Merino ewes, was optimized. This protease is thermostable and particularly resistant to harsh environmental conditions—and appears to bear a unique ability to hydrolyze keratin-rich solid materials. Following a preliminary screening for the most relevant medium factors involved in processing, a fractional factorial design (2VI 6-1) was applied to ascertain the effects of six relevant parameters— viz. yeast extract concentration, peptone level, inoculum size, stirring rate, temperature and pH. The concentrations of yeast extract and peptone, as well as the incubation temperature and pH were found to play significant roles; and the 2-factor interaction between yeast extract level and pH was also significant. A 2.2-fold increase in the overall level of protease synthesis was eventually attained, with the improved medium relative to the basal medium—which is noteworthy when compared with competing proteases and previous optimization efforts.
- Teatro espontâneo: um instrumento de sensibilização para os (futuros) administradoresPublication . Bezerra, Sefisa Quixadá; Viana, Rebeca Sales; Leonido, LeviA cada momento histórico a sociedade vive seus dilemas, o mais acentuado na atualidade é o resgate ao homem e as melhores possibilidades de lhe manter em estado de felicidade, viabilizando qualidade de vida e possibilitando resultados positivos. Nesse contexto, as ciências se apoiam a partir de estudos de objetos e conceitos correlatos, daí a interdisciplinaridade dominando as argumentações e a subjetividade proporcionando várias interpretações. Estudos anteriores tratavam o homem de forma mecanicista, o que lhe rendeu, ao longo dos anos, visão simplista e reducionista dos seus problemas e hoje, estende-se esse estudo, mas com uma mudança na abordagem, agora para o resgate às suas individualidades e a sua manutenção nos grupos sociais. Se buscará, como objetivo deste trabalho, apresentar a importância da manifestação de sentimentos e emoções através de um meio específico, o Teatro Espontâneo, para aprendizagem e reflexão. A prática foi desenvolvida com grupos de estudantes do terceiro período do curso de Administração e os referenciais teóricos principais foram os de Jacob Levi Moreno e Cecília Bergamini. A abordagem prática-vivencial a partir da realização de Teatro Espontâneo, possibilitou um pequeno recorte de manifestação de sentimentos, emoções e até conflitos acerca de posicionamentos e ações individuais, para aqueles que acreditamos que serão futuros gestores. Foi percebido, a partir da construção dos personagens, a relevância que deve ser dada aos aspetos comportamentais e a história de vida de cada partícipe envolvido em processos individuais e de gestão, acreditando na perspetiva grupal da construção de ambientes organizacionais mais justos e felizes partindo-se da auto perceção e auto reconhecimento dos seus integrantes.
- Complex 3D architectures using a textile technology for bone tissue engineering applicationsPublication . Ribeiro, V. P.; Ribeiro, A. S.; Silva, C. J.; Durães, N. F.; Bonifácio, G.; Correlo, V. M.; Marques, A. P.; Sousa, R. A.; Oliveira, A. L.; Reis, R. L.Textile-based technologies are particularly interesting in tissue engineering since they allow producing finely tuned fibre-based porous structures, offering superior control over the material design (size, porosity, fibre alignment) and manufacturing. Scaffolds with very reproducible and interconnected intra-architectural geometry can be processed increasing the surface area for cell attachment and tissue ingrowth. This work aims to evaluate the potential of recently developed 3D textile structures based on silk fibroin (SF) to support human Adipose-derived Stem Cells (hASCs) adhesion, proliferation and osteogenic differentiation. These cells constitute an emerging possibility for regenerative medicine, including for bone tissue regeneration. A comparative analysis was performed with a more stable polymeric system, polyethylene terephthalate (PET). SF and PET yarns were processed into 3D spacer structures using warp-knitting technology. The obtained complex 3D architectures are composed of two knitted layers assembled/spaced by a PET monofilament to increase the tri-dimensionality of the scaffold. Cells were able to attach to the fibres, proliferate and differentiate into the osteogenic lineage. hASCs were able to deeply penetrate into the scaffold and colonize its interior with great evidences of extracellular matrix mineralization (Fig.1). The efficiency and high level of control of the warpknitting technology together with the interesting structural properties of the resulting constructs makes this a very versatile and adaptable system to the specific bone tissue anatomy and function.
- Degradation of Fluoroquinolone Antibiotics and Identification of Metabolites/Transformation Products by LC-MS/MSPublication . Maia, Alexandra S.; Ribeiro, Ana R.; Amorim, Catarina L.; Barreiro, Juliana C.; Cass, Quezia B.; Castro, Paula M.L.; Tiritan, Maria E.Antibiotics are a therapeutic class widely found inenvironmental matrices and extensively studied due to its persistence and implications for multi-resistant bacteria development. Degradation of four fluoroquinolone antibiotics, namely Ofloxacin (OFL), Norfloxacin (NOR), Ciprofloxacin (CPF) and Moxifloxacin (MOX), at 10 mg L-1 using a mixed bacterial culture, was assessed for 60 days. The assays were followed by a developed and validated analytical method of HPLC with Fluorescence Detection using a Luna PFP (2) 3µm column. The optimized conditions allowed picturing metabolites/transformation products formation and accumulation during the process, stating an incomplete mineralization, also shown byfluoride release. OFL and MOX presented the highest (98.3%) and the lowest (80.5%) extent of degradation after 19 days of assay, respectively. Some of these intermediate compounds were identified by LCMS/MS in selected degradation samples. Most of the intermediates were already described as biodegradation and/or photodegradationproducts in different conditions, but new and/or unknown metabolites were also present.
- Unconventional fiscal policy at the zero boundPublication . Correia, Isabel; Farhi, Emmanuel; Nicolini, Juan Pablo; Teles, PedroWhen the zero lower bound on nominal interest rates binds, monetary policy cannot provide appropriate stimulus. We show that, in the standard New Keynesian model, tax policy can deliver such stimulus at no cost and in a time-consistent manner. There is no need to use inefficient policies such as wasteful public spending or future commitments to low interest rates.
- Os direitos de transmissão dos jogos de futebol face ao direito da concorrênciaPublication . Campos, Manuel Fontaine
- Research on markets for inventions and implications for R&D allocation strategiesPublication . Conti, Raffaele; Gambardella, Alfonso; Novelli, ElenaSeveral streams of literature have examined the phenomenon of “markets for inventions”, that is, the trade of elements of knowledge which are “disembodied” from individuals, organizations, and products. The aims of this paper are to bring together the various streams of research in this area and discuss their major assumptions and limitations, in order to provide a comprehensive framework for understanding the phenomenon, and identify promising paths for future research. We start our review by identifying the object of market exchange—that is, an invention whose knowledge has been codified and disembodied from individuals, organizations, or artifacts. We then identify those factors that enable firms to trade inventions, distinguishing between institutional-, firm-, and industry-level factors. We close our analysis of the extant literature by discussing the implications of markets for inventions for firm behavior and performance. Against this background, we highlight an important avenue for future research. A neglected implication of the development of invention markets is that firms are confronted with a wide variety of technological paths from which to choose, because the opportunity to acquire technologies on the market offers them a greater variety that can their internal R&D departments. However, the streams of research on markets for inventions and on R&D allocation strategies have been surprisingly disconnected so far. Hence, in the final section, we start to establish and explore the link between these literatures, and to identify a research agenda in this domain.
- Estado liberdade religiosa e laicidadePublication . Miranda, Jorge
- Sobre a relevância constitucional da famíliaPublication . Miranda, Jorge