Study of Xenopus orthologs of novel genes expressed in the mouse AVE

info:eu-repo/semantics/publishedVersio

Desenvolvimento de sistemas celulares de peixe adequados ao estudo da mineralização in vitro

Os peixes foram recentemente reconhecidos como organismos modelo apropriados para o estudo da biologia de vertebrados, particularmente de processos relacionados com a mineralização tecidular e o desenvolvimento do esqueleto. Apesar de existirem alguns estudos in vivo, a identificação de mecanismos associados à calcificação em peixes tem sido prejudicada pelo facto de não existirem sistemas celulares para estudos in vitro. Este artigo descreve um protocolo simples e de baixo custo adequado ao desenvolvimento de culturas celulares mineralogénicas, derivadas de tecidos calcificados de peixes.Fish have been recently recognized as a suitable model organism to study vertebrate biology, in particular physiological processes such as tissue mineralization and skeletal development. Despite various studies in vivo, identification of mechanisms associated with calcification in fish has been largely hampered by the lack of suitable in vitro cell systems. We describe here a simple and inexpensive protocol to develop mineralogenic cell cultures from fish calcified tissues. This protocol was successfully used to develop the first fish cell lines capable of mineralizing their extracellular matrix (from the vertebra of gilthead seabream Sparus aurata) and, more recently, applied to develop additional fish mineralogenic cell cultures from different fishes. We also describe a variety of biochemical and histological methods to characterize extracellular matrix during in vitro mineralization, in particular mineral deposition, and a protocol to enhance DNA transfer into fish bone-derived cells. Finally, we present recent expression data obtained using these cell lines to further demonstrate their suitability to study mechanisms of in vitro mineralization

Anaerobic digestion of OMW : intermittent feeding strategy and LCFA oxidation profile

ManuscriptAn intermittent feeding strategy was applied to the anaerobic treatment of raw olive mill wastewater (OMW). Two reactors were operated under influent concentrations of 5 to 50 g COD L-1. Two and one batch (feed-less) periods were applied to reactor R1 and R2, respectively, operating in continuous thenceforth. It was demonstrated that the intermittent feeding of OMW improved the mineralization of accumulated Long Chain Fatty Acids (LCFA) inside the reactor. Nevertheless, LCFA accumulated again when the organic loading rate was increased from 2 to 3 and 5 kg COD m-3 d-1. The profiles of LCFA, obtained with OMW digestion, were different from previous studies with synthetic effluents. At the beginning of reactors operation, oleate was the main LCFA compound (~50%) followed by palmitate. Afterwards, a shift in the LCFA pattern accumulation was noticed for both reactors. At periods with higher OMW concentrations (30-50 g COD L-1, 3-5 kg COD m-3 d-1) palmitate was the main LCFA accumulated with 69% at R1 and 54% at R2. For real oily wastewaters, a periodically batch period could be a practical solution to maintain low values of LCFA inside the reactor. The addition of a nitrogen source was essential to enhance the methane yield

Strategies for lipids and phenolics degradation in the anaerobic treatment of olive mill wastewater

Strategies are proposed for the anaerobic treatment of lipid and phenolic-rich effluents, specifically the raw olive mill wastewater (OMW). Two reactors were operated under OMW influent concentrations from 5 to 48 g COD L-1 and Hydraulic Retention Time between 10 and 5 days. An intermittent feeding was applied whenever the reactors showed a severe decay in the methane yield. This strategy improved the mineralization of oleate and palmitate, which were the main accumulated Long Chain Fatty Acids (LCFA), and also promoted the removal of resilient phenolic compounds, reaching remarkable removal efficiencies of 60% and 81% for two parallel reactors at the end of a feed-less period. A maximum biogas production of 1.4 m3 m-3 d-1 at an Organic Loading Rate of 4.8 kg COD m-3 d-1 was obtained. Patterns of individual LCFA oxidation during the OMW anaerobic digestion are presented and discussed for the first time. The supplementation of a nitrogen source boosted immediately the methane yield from 21 and 18 to 76 and 93% in both reactors. The typical problems of sludge flotation and washout during the anaerobic treatment of this oily wastewater were overcome by biomass retention, according to the Inverted Anaerobic Sludge Blanket (IASB) reactor concepts. This work demonstrates that it is possible to avoid a previous detoxification step by implementing adequate operational strategies to the anaerobic treatment of OMW.The authors acknowledge the financial support of the “Fundação para a Ciência e a Tecnologia”, FCT/MCTES, through the project PTDC/ENR/69755/2006 and also through the grants given to Marta Gonçalves SFRH/BD/40746/2007 and José Carlos Costa SFRH/BDP/ 48962 /2008. The authors thank Tânia Ferreira for the help in LCFA analysis and Ana Cavaleiro for her scientific support

Physical Fitness Differences Between Prepubescent Boys and Girls

The purpose of this study was to analyze in which physical capabilities boys and girls are closer or distant. An additional objective was to find which of the body fat, physical activity, and somatotype factors have a greater effect on prepubescent children's physical fitness. This was a cross-sectional study involving 312 children (10.8 ± 0.4 years). The physical fitness assessment employed sets of aerobic fitness, strength, flexibility, speed, agility, and balance. The boys presented higher values in all selected tests, except tests of balance and flexibility, in which girls scored better. Gender differences in the physical fitness were greatest in the explosive strength of upper (p ≤ 0.01, η(p)(2) = 0.09) and lower limbs (p ≤ 0.01, η(p)(2) = 0.08), although with a medium-size effect of gender, and smaller in the abdominal (p > 0.05, η(p)(2) = 0.007) and upper limbs (p > 0.05, η(p)(2) = 0.003) muscular endurance, and trunk extensor strength and flexibility (p > 0.05, η(p)(2) = 0.001). The endomorphic (p ≤ 0.01, η(p)(2) = 0.26) in the girls, and the ectomorphic (p ≤ 0.01, η(p)(2) = 0.31) and mesomorphic (p ≤ 0.01, η(p)(2) = 0.26) in the boys, had the high-sized effect on the physical fitness. The physical activity in the girls, and the endomorphic and body fat in the boys, did not have a significant effect. These findings can help in the planning of activities that take into account the success and motivation of both boys and girls and thus increase levels of physical activity and physical fitness at school. However, in prepubescent children, one cannot neglect the influence of genetic determinism, observed from the morphoconstitutional point of view.info:eu-repo/semantics/publishedVersio

Effects of Concurrent Training on Explosive Strength and VO2max in Prepubescent Children

The purpose of this study was to compare the effects of an 8-weeks training period of resistance training alone (GR), combined resistance and endurance training (GCON) and a control group (GC) on explosive strength and V(O2max) in a large sample of prepubescent boys and girls. 125 healthy children (58 boys, 67 girls), aged 10-11 years old (10.8±0.4 years) were assigned into 2 training groups to train twice a week for 8 weeks: GR (19 boys, 22 girls), GCON (21 boys, 24 girls) and a control group (GC: 18 boys, 21 girls; no training program). A significant but medium-sized increase from pre- to the post-training in the vertical jump (Effect size=0.22, F=34.44, p<0.01) and V(O2max) (Effect size=0.19, F=32.89, p<0.01) was observed. A significant large increase in the 1 kg (Effect size=0.53, F=202.17, p<0.01) and 3 kg (Effect size=0.48, F=132.1, p<0.01) ball throwing, standing long jump (Effect size=0.53, F=72.93, p<0.01) and running speed (Effect size=0.45, F=122.21, p<0.01) was also observed. The training group (GR and GCON) and sex factors did not significantly influence the evolution of strength variables from pre- to the post-training. The V(O2max) increased significantly only in GCON. Concurrent training is equally effective on training-induced explosive strength, and more efficient than resistance training only for V(O2max), in prepubescent boys and girls. This should be taken into consideration in order to optimize strength training school-based programs.info:eu-repo/semantics/publishedVersio

Unravelling the effect of strand orientation on exciton migration in conjugated polymers

The study of the average distance that singlet excitons travel during their lifetime in conjugated polymers has attracted considerable attention during the past decade, because of its importance in the functioning of many polymer-based optoelectronic devices, like solar cells and photodetectors. Intriguingly, different values of exciton diffusion length have been extracted from experiments on seemingly identical conjugated polymers. Here we use computer simulations to show that the observed discrepancies in the reported values of the exciton diffusion length may arise from differences in the orientation of conjugated polymer strands relative to the substrate surface, a factor which has been mostly overlooked. Our results show that, on pristine polymer nanodomains with conjugated strands perpendicular to the substrate surface, exciton migration length is approximately 30% and 40% lower than on those with parallel and random strand orientation relative to that surface, respectively, resulting from the different contents of physical traps present in nanodomains with different strand orientation. This work underlines the importance of molecular arrangement on exciton migration, and provides a novel theoretical framework for estimating the dependence of the exciton diffusion length with the orientation of conjugated polymers strands within the nanodomains, as well as helping the design of more efficient polymer-based optical and optoelectronic devices, such as optical sensors, photodiodes, photovoltaic cells and white light-emitting diodes.This work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PEST-C/FIS/UI607/2011, and under the projects CONC-REEQ/443/EEI/2005 and PEst-C-FIS/UI607/2011-2012. Two of us (H.M.G.C. and H. M. C. B.) are also indebted to FCT and POPH for financial support the post-doctoral grants SFRH/BPD/64554/2009 and SFRH/BPD/80561/2011

Senile Systemic Amyloidosis: An Underdiagnosed Disease

Senile systemic amyloidosis is caused by a non-mutated form of transthyretin with the heart being the major organ involved. This infiltrative cardiomyopathy usually presents as slowly progressive heart failure. An 82-year-old female patient was admitted for newly diagnosed heart failure. A year later she presented with decompensated heart failure and syncope. Inpatient work-up showed persistently elevated troponin and N-terminal-pro BNP levels, rapid progression to severe left ventricular concentric hypertrophy, and sinus pauses on the Holter. Cardiac MRI revealed diffuse late gadolinium enhancement in the left ventricle. The demonstration of amyloid protein with the clinical findings and complementary investigations allowed for the diagnosis of senile systemic amyloidosi

Influence of electrode degradation on organic solar cells functioning – a computational study

Recently, organic solar cells (OSC) have reached the efficiency of 10% becoming a reliable alternative to the conventional high cost inorganic solar cells. However, to gain a place in the competitive market of solar cells it is necessary to improve their lifetime. Due to the nature of the materials used, there are several degradation mechanisms [1] that lead to a decrease on device efficiency and thus to its failure, being of upmost importance to understand how they affect organic solar cells functioning. One of these mechanisms consists on electrodes degradation when in contact with air or water, leading to a change on electrode work function and thus of the energy levels at electrode/organic layer interface. As a result, the decrease on OSC efficiency has been attributed to a loss on the electrode´s ability in collecting charges from the active layer [2, 3]. However, it is unclear how a change on electrode’s work function affects the main optoelectronic mechanisms that rule the device performance [4], which can give some guidelines to prevent its failure. In order to clarify this issue we performed computational experiments with our improved mesoscopic model. Our results show that changing electrodes work function affects simultaneously all optoelectronic mechanisms that rule exciton and charges dynamics, and thus the device performance.Fundação para a Ciência e a Tecnologia (FCT

Optical properties of titanium oxycarbide thin films

The optical properties of TiC x O y thin films, deposited by reactive dc magnetron sputtering at different oxygen flow, were investigated by spectroscopic ellipsometry in the energy range of 0.75–4.5 eV. The dielectric functions measured in the energy range of intraband transitions were analyzed using the classical Drude theory. These results show that free plasma energy and the damping constant of the films depend strongly on film stoichiometry and on their oxygen content. The interband contribution to the optical conductivity of these films is in good agreement with the optical conductivity obtained from first principles calculations based on density functional theory. Both the experimental and the calculated results show that it is possible to significantly modify the optical properties of titanium oxycarbide by adjusting the oxygen content.Fundação para a Ciência e a Tecnologia (FCT) – Programa Operacional “Ciência , Tecnologia, Inovação” – CONC-REEQ/443/EEI/2005, PTDC/CTM/69362 e SFRH/BD/27569/200