Browsing by Issue Date, starting with "2012-10"
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- Conhecimento das ciências para o ensino da célula: um estudo de caso instrumentalPublication . Santos, C. Susana; Monteiro, Rute; Ribeiro, Carlos MiguelPara se ser professor de Ciências da Natureza não é suficiente, por um lado, um conhecimento equiparável ao dos alunos, e por outro tampouco é suficiente um conhecimento enciclopédico sobre cada um dos tópicos de forma isolada, ou de um mero conjunto de estratégias gerais de gestão do espaço de sala de aula.
- Cilia at the node of mouse embryos sense fluid flow for left-right determination via Pkd2Publication . Yoshiba, Satoko; Shiratori, Hidetaka; Kuo, Ivana Y.; Kawasumi, Aiko; Shinohara, Kyosuke; Nonaka, Shigenori; Asai, Yasuko; Sasaki, Genta; Belo, José A.; Sasaki, Hiroshi; Nakai, Junichi; Dworniczak, Bernd; Ehrlich, Barbara E.; Pennekamp, Petra; Hamada, HiroshiUnidirectional fluid flow plays an essential role in the breaking of left-right (L-R) symmetry in mouse embryos, but it has remained unclear how the flow is sensed by the embryo. We report that the Ca2+ channel Polycystin-2 (Pkd2) is required specifically in the perinodal crown cells for sensing the nodal flow. Examination of mutant forms of Pkd2 shows that the ciliary localization of Pkd2 is essential for correct L-R patterning. Whereas Kif3a mutant embryos, which lack all cilia, failed to respond to an artificial flow, restoration of primary cilia in crown cells rescued the response to the flow. Our results thus suggest that nodal flow is sensed in a manner dependent on Pkd2 by the cilia of crown cells located at the edge of the node.
- Differential effects of clinically used derivatives and metabolites of artemisinin in the activation of constitutive androstane receptor isoformsPublication . Burk, O.; Piedade, R.; Ghebreghiorghis, L.; Fait, J. T.; Nussler, A. K.; Gil, J. P.; Windshuegel, B.; Schwab, M.BACKGROUND AND PURPOSE Widespread resistance to antimalarial drugs requires combination therapies with increasing risk of pharmacokinetic drugdrug interactions. Here, we explore the capacity of antimalarial drugs to induce drug metabolism via activation of constitutive androstane receptors (CAR) by ligand binding. EXPERIMENTAL APPROACH A total of 21 selected antimalarials and 11 major metabolites were screened for binding to CAR isoforms using cellular and in vitro CAR-coactivator interaction assays, combined with in silico molecular docking. Identified ligands were further characterized by cell-based assays and primary human hepatocytes were used to elucidate induction of gene expression. KEY RESULTS Only two artemisinin derivatives arteether and artemether, the metabolite deoxyartemisinin and artemisinin itself demonstrated agonist binding to the major isoforms CAR1 and CAR3, while arteether and artemether were also inverse agonists of CAR2. Dihydroartemisinin and artesunate acted as weak inverse agonists of CAR1. While arteether showed the highest activities in vitro, it was less active than artemisinin in inducing hepatic CYP3A4 gene expression in hepatocytes. CONCLUSIONS AND IMPLICATIONS Artemisinin derivatives and metabolites differentially affect the activities of CAR isoforms and of the pregnane X receptor (PXR). This negates a common effect of these drugs on CAR/PXR-dependent induction of drug metabolism and further provides an explanation for artemisinin consistently inducing cytochrome P450 genes in vivo, whereas arteether and artemether do not. All these drugs are metabolized very rapidly, but only artemisinin is converted to an enzyme-inducing metabolite. For better understanding of pharmacokinetic drugdrug interaction possibilities, the inducing properties of artemisinin metabolites should be considered.
- Memórias da formação nos primórdios da Escola do Magistério Primário de FaroPublication . Anica, AuríziaA formação de professores nas escolas do magistério primário procurou compatibilizar o inquestionável ideal educativo «humano» e «nacional» do Estado Novo com os princípios da «Escola Nova», criando uma margem de autonomia que os atores sociais usaram dando origem à construção de culturas organizacionais específicas. Pretende-se neste texto identificar as características específicas da cultura da Escola do Magistério Primário de Faro na primeira década do seu funcionamento e a relação desta escola com a transformação sociocultural da região no mesmo período, para isso recorrendo, entre outras fontes, a memórias escritas e orais de estudantes e de docentes desta instituição.
- A presença da linguagem escrita nos projetos curriculares de grupoPublication . Horta, Maria HelenaA abordagem à escrita também faz parte da educação pré-escolar. É papel do educador facilitar a emergência da linguagem escrita.
- Genetic association study of UCMA/GRP and OPTN genes (PDB6 locus) with Paget's disease of bonePublication . Michou, Laetitia; Conceicao, Natercia; Morissette, Jean; Gagnon, Edith; Miltenberger-Miltenyi, Gabriel; Siris, Ethel S.; Brown, Jacques P.; Leonor Cancela, M.We performed a genetic association study of rare variants and single nucleotide polymorphisms (SNPs) of UCMA/GRP and OPTN genes, in French-Canadian patients with Paget's disease of bone (PDB) and in healthy controls from the same population. We reproduced the variant found in the UCMA/GRP basal promoter and tested its functionality using in vitro transient transfection assays. Interestingly, this SNP rs17152980 appears to affect the transcription level of UCMA/GRP. In addition, we have identified five rare genetic variants in UCMA/GRP gene, four of them being population-specific, although none were found to be associated with PDB. Six Tag SNPs of UCMA/GRP gene were associated with PDB, particularly the SNP rs17152980 (uncorrected P = 3.8 x 10(-3)), although not significant after Bonferroni's correction. More importantly, we replicated the strong and statistically significant genetic association of two SNPs of the OPTN gene, the rs1561570 (uncorrected P = 5.7 x 10(-7)) and the rs2095388 (uncorrected P = 4.9 x 10(-3)), With PDB. In addition, we identified a very rare variant found to be located close to the basal promoter of the OPTN gene, at -232 bp from its distal transcription start site. Furthermore, depending on the type of allele present (G or A), the binding of several important nuclear factors such as the vitamin D or the retinoic acid receptors is predicted to be altered at this position, suggesting a significant effect in the regulation of transcription of the OPTN gene. In conclusion, we identified a functional SNP located in the basal promoter of the UCMA/GRP gene which provided a weak genetic association with PDB. In addition, we replicated the strong genetic association of two already known SNPs of the OPTN gene, with PDB in a founder effect population. We also identified a very rare variant in the promoter of OPTN, and through bioinformatic analysis, identified putative transcription factor binding sites likely to affect OPTN gene transcription. (C) 2012 Elsevier Inc. All rights reserved.
- Duffy phenotype and plasmodium vivax infections in humans and Apes, AfricaPublication . Culleton, Richard Leighton; Ferreira, Pedro Eduardo
- Advantages, limitations and solutions in the use of ERP systems (Enterprise Resource Planning). A case study in the hospitality industryPublication . Azevedo, Paula Serdeira; Romão, Mário; Rebelo, EfigénioEnterprise Resource Planning systems (ERP) have emerged as solutions oriented to manage organization´s resources in an integrated way. They allowed the automation of its department’s activities, made information available to users at the right time, supporting more accurately their decision-making needs. However, although the implementation of these systems has brought considerable benefits to users, they don’t cover all processes from all industries. Many organizations have recognized this limitation, and consequently felt the need to implement specific solutions to their industry, sector or line of business. From the collected case study business drivers and objectives, we then analyzed the advantages and limitations of ERP Systems in the hospitality industry, in order to understand how this industry uses ERP Systems and solves the challenge of integrating information spread through several heterogeneous information systems.
- Muscular hypertrophy of urinary bladders in dominant tilapia facilitates the control of aggression through urinary signalsPublication . Keller-Costa, Tina; Lopes, O. S.; Almeida, O. G.; Hubbard, Peter; Iacovella, A.; Lima, M.; Barata, E. N.; Canario, Adelino V. M.The urination pattern of the Mozambique tilapia (Oreochromis mossambicus) depends on social context, and the olfactory potency of urine released depends on social rank (males) and reproductive status (females). This strongly suggests that urine mediates chemical communication in this species. The current study tested, firstly, whether urine production rate depends on sex or social status and, secondly, whether differences in urination pattern and volume of urine stored are associated with variation in the morphology of the urinary bladder. Finally, the effect of urination during aggressive male–male interactions was assessed. Urine production in catheterized fish depended neither on sex nor social status (males). Nevertheless, males had larger kidneys than females. Dominant males had heavier urinary bladders than subordinate males or females, mainly due to enlarged muscle fibres, thicker urothelium and a thicker smooth muscle layer. In male pairs wherein urination was prevented by temporary constriction of the genital papillae, social interaction escalated to aggression (mouth-to-mouth fighting) more rapidly and frequently than control pairs. This was accompanied by elevated plasma testosterone and 11-ketotestosterone levels. In control encounters, the male that initiated the aggressive behaviour was usually the winner of the subsequent fight; this did not happen when the males could not urinate. These results suggest that the larger, more muscular bladder of dominant males is an adaptation, facilitating higher urination frequency, post-renal modulation and storage of larger urine volumes for longer. It is likely that urinary pheromones modulate aggression in male–male encounters by providing information on the social rank and/or motivation of the emitter; males are unlikely to invest in costly highly aggressive fights if they judge their opponent to be more dominant. Thus, a morphological explanation for the differing urination patterns of dominant and subordinant males, and females, has been provided, and a possible function for this behaviour in male–male interactions is suggested.
- An Indian scenario on renewable and sustainable energy sources with emphasis on algaePublication . Hemaiswarya, Shanmugam; Raja, R.; Carvalho, Isabel Saraiva de; Ravikumar, R.; Zambare, Vasudeo; Barh, DebmalyaIndia is the fifth largest primary energy consumer and fourth largest petroleum consumer after USA, China, and Japan. Despite the global economic crisis, India’s economy is expected to grow at 6 to 8 %/year. There is an extreme dependence on petroleum products with considerable risks and environmental issues. Petroleum-derived transport fuels are of limited availability and contribute to global warming, making renewable biofuel as the best alternative. The focus on biogas and biomass-based energy, such as bioethanol and biohydrogen, will enhance costeffectiveness and provide an opportunity for the rural community. Among all energy sources, microalgae have received, so far, more attention due to their facile adaptability to grow in the photobioreactors or open ponds, high yields, and multiple applications. Microalgae can produce a substantial amount of triacylglycerols as a storage lipid under photooxidative stress or other adverse environmental conditions. In addition to renewable biofuels, they can provide different types of highvalue bioproducts added to their advantages, such as higher photosynthetic efficiency, higher biomass production, and faster growth compared to any other energy crops. The viability of first-generation biofuels production is, however, questionable because of the conflict with food supply. In the future, biofuels should ideally create the environmental, economic, and social benefits to the communities and reflect energy efficiency so as to plan a road map for the industry to produce third-generation biofuels.
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