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Clinical Psychophysical Assessment of the ON- and OFF-Systems of the Magnocellular and Parvocellular Visual Pathways  [PDF]
Marcelo Fernandes Costa
Neuroscience & Medicine (NM) , 2011, DOI: 10.4236/nm.2011.24043
Abstract: We developed a psychophysical paradigm for the clinical assessment of the contrast sensitivity (CS) mediated by the ON- and OFF-systems of the Magnocellular and Parvocellular pathways. We designed a stimulus considering two dimensions: two spatial frequencies (0.5 and 4.5 cpd) and two temporal rates of flicker (33 ms and 1500 ms). To evidence the ON- and OFF responses, the CS was measured for two polarities of light with luminance changes of 0.6 dB steps above and below the medium luminance grey background. We tested 38 healthy volunteers. The results shows that Magnocellular contrast sensitivity was higher than Parvocellular for the 33 ms flickering stimulus and the Parvocellular contrast sensitivity was higher than Magnocellular for 1500 ms stimuli. The reliability of the test was checked and confirmed. We concluded that the test performs a rapid measurement of the CS mediated by the ON and OFF systems of Magnocellular and Parvocellular pathways. It is useful in clinical protocols due to its high sensitivity and good reliability.
EVAR - 20 anos de história EVAR - 20 years of history
J. Fernandes e Fernandes
Angiologia e Cirurgia Vascular , 2011,
Abstract:
Enzymes in Food Processing: A Condensed Overview on Strategies for Better Biocatalysts
Pedro Fernandes
Enzyme Research , 2010, DOI: 10.4061/2010/862537
Abstract: Food and feed is possibly the area where processing anchored in biological agents has the deepest roots. Despite this, process improvement or design and implementation of novel approaches has been consistently performed, and more so in recent years, where significant advances in enzyme engineering and biocatalyst design have fastened the pace of such developments. This paper aims to provide an updated and succinct overview on the applications of enzymes in the food sector, and of progresses made, namely, within the scope of tapping for more efficient biocatalysts, through screening, structural modification, and immobilization of enzymes. Targeted improvements aim at enzymes with enhanced thermal and operational stability, improved specific activity, modification of pH-activity profiles, and increased product specificity, among others. This has been mostly achieved through protein engineering and enzyme immobilization, along with improvements in screening. The latter has been considerably improved due to the implementation of high-throughput techniques, and due to developments in protein expression and microbial cell culture. Expanding screening to relatively unexplored environments (marine, temperature extreme environments) has also contributed to the identification and development of more efficient biocatalysts. Technological aspects are considered, but economic aspects are also briefly addressed. 1. Introduction Food processing through the use of biological agents is historically a well-established approach. The earliest applications go back to 6,000 BC or earlier, with the brewing of beer, bread baking, and cheese and wine making, whereas the first purposeful microbial oxidation dates from 2,000 BC, with vinegar production [1–3]. Coming to modern days, in the late XIX, century Christian Hansen reported the use of rennet (a mixture of chymosin and pepsin) for cheese making, and production of bacterial amylases was started at Takamine (latter to become part of Genencor). Pectinases were used for juice clarification in the 1930s, and for a short period during World War II, invertase was also used for the production of invert sugar syrup in a process that pioneered the use of immobilized enzymes in the sugar industry [1]. Still, the large-scale application of enzymes only became really established in the 1960s, when the traditional acid hydrolysis of starch was replaced by an approach based in the use of amylases and amyloglucosidases (glucoamylases), a cocktail that some years latter would include glucose (xylose) isomerase [1, 2, 4, 5]. From then on,
Miniaturization in Biocatalysis
Pedro Fernandes
International Journal of Molecular Sciences , 2010, DOI: 10.3390/ijms11030858
Abstract: The use of biocatalysts for the production of both consumer goods and building blocks for chemical synthesis is consistently gaining relevance. A significant contribution for recent advances towards further implementation of enzymes and whole cells is related to the developments in miniature reactor technology and insights into flow behavior. Due to the high level of parallelization and reduced requirements of chemicals, intensive screening of biocatalysts and process variables has become more feasible and reproducibility of the bioconversion processes has been substantially improved. The present work aims to provide an overview of the applications of miniaturized reactors in bioconversion processes, considering multi-well plates and microfluidic devices, update information on the engineering characterization of the hardware used, and present perspective developments in this area of research.
Algumas reflex?es acerca dos saberes dos alunos em Portugal
Fernandes, Domingos;
Educa??o & Sociedade , 2008, DOI: 10.1590/S0101-73302008000100014
Abstract: this paper brings a discussion on issues that should be taken into account in the process of finding out what students know in the context of the portuguese education system. that process is too dependent on external assessment tools (i.e., national standardized examinations), whose limitations are well established in related works. there is a need to seriously consider internal assessment as it has the potential to provide us with a wider and deeper understanding of what students know. the discussion of the main features of external assessment allowed reflections on some contemporary challenges that must be faced by the portuguese society.
A avalia??o das aprendizagens no Sistema Educativo Português
Fernandes, Domingos;
Educa??o e Pesquisa , 2007, DOI: 10.1590/S1517-97022007000300013
Abstract: the main purpose of this paper is to discuss the major features of the learning evaluation system as applied to pupils from the basic and secondary levels, such as proposed by the portuguese curriculum. the high failure rates observed are analyzed and stimulate various reflections, which take into account that the above mentioned system has features that should, in principle, contribute to help students progressing and not failing: a) the predominance of formative evaluation, aimed at regulating and improving the learning; b) the predominance of internal evaluation, with schools and teachers playing a major role in the pupil evaluation process; and c) the fact that decisions related to pupils' progress or failure only have to be made at the end of each cycle of mandatory schooling. the article also discusses the internal evaluations, of total responsibility of schools and teachers, and the external evaluations, namely those that have been carried out under the auspices of the international organizations. generally speaking, it can be said that the learning evaluation system defined in the portuguese curriculum has a progressive, and even innovative, character that tries to adapt to the reality of the education system. however, the study has shown that there is still a significant difference between what is legally proposed and what effectively takes place in the so-called "real system", that is, at the schools and classrooms. recommendations are therefore made to reduce, or perhaps eliminate, such discrepancies which, in the author's view, constitute one of the most important challenges that portuguese society has to face in the years to come.
Aspectos da natalidade no povoamento do centro-oeste paulista, século XIX
Fernandes, Edson;
História (S?o Paulo) , 2010, DOI: 10.1590/S0101-90742010000200013
Abstract: this work approaches the aspects of birth rate in a frontier territory. the west region of s?o paulo province, in its area delimitated by the tietê and the paranapanema rivers, was the frontier of the settlement during great part of the nineteenth century. the analysis from the parish and registry office in "len?óes" (a city in brazil) allowed us to mark out a family description in the frontier. through this, we can see that the illegitimacy was low, smaller rather than in other areas that were used as a parameter, going against what people could expect from a frontier area. the baptisms used to take place in a large quantity at the end of the year (november and december), followed by the initial month, january. there weren't marked seasonal variations related to the baptisms, although october, february and march were the months with less occurrence. while sunday was the preferred day by the parents for such a ceremony, concentrating approximately a third of them, friday was a day to be avoided.
Vacina antivariólica: seu primeiro século no Brasil (da vacina jenneriana à animal)
Fernandes, Tania;
História, Ciências, Saúde-Manguinhos , 1999, DOI: 10.1590/S0104-59701999000200002
Abstract: covering a period of roughly hundred years, the article looks at some of the more meaningful events during the period in which the small pox vaccine was institutionalized in brazil. discoveries and discussions then taking place in other countries are also examined, particularly as they influenced brazil. the process is followed from introduction of the human vaccine to the arrival of the animal vaccine and creation of the municipal vaccine institute - a private initiative by physician pedro affonso franco, also known as the bar?o de pedro affonso. adoption of the animal vaccine not only represented progress in controlling the disease but also spurred discussions that saw medical and political groups in brazil taking sides with either oswaldo cruz or the bar?o de pedro affonso. the debate continued within the academic and political arenas until the vaccine institute was made part of the manguinhos laboratories.
A intera??o naturante entre o demiurgo e o mundo, a quest?o dos "dois tipos de matéria" e a natureza da "implanta??o" da alma no corpo
Fernandes, Edrisi;
Kriterion: Revista de Filosofia , 2010, DOI: 10.1590/S0100-512X2010000200015
Abstract: in his commentary on the timaeus proclus says that in some occasions plato speaks of a model (from which the world is created) that is identical to the demiurge while in other occasions he suggests that the model is distinct from the demiurge. here, identity and difference refer to the similarity with or dissimilarity from the intelligible one, identified with eternity (stability; fixedness). however, plato also speaks in the timaeus that the cosmos is pretty and its constructor (the demiurge) is good inasmuch as he fixed his sight in the perpetual model. if we ask what is produced when the demiurge fixed his sight in a model that it is not identical to himself, we find the reply in the timaeus: envy, defects, disorder, limitation regarding intelligence and the soul, incompleteness, ugliness, and imperfection. plotinus, on his turn, mentions (enneads, ii.4) the existence of two types of matter, intelligible and sensible. the intelligible or divine matter is equivalent to the "indefinite dyad", identified with the procession of the no?s. for plotinus, though the intelligible matter is eternal and invariant, its archê is constituted by difference and movement - conditions that prepare the naturation of sensible matter. for proclus, the soul, an unfolding of the no?s, mediates between the intellect, intelligible matter and sensible matter. many interpreters seem to have understood inteligible matter as the matter of the soul, and to explain the interaction between the intelligible and the sensible many theories have appeared regarding the constitution of intelligible matter and about the nature of the "vehicle" or "vehicles" that would be associated with the soul's "descent" and incarnation.
O trabalho cooperativo num contexto de sala de aula
Fernandes,Elsa;
Análise Psicológica , 1997,
Abstract: the analyses of ways of cooperative work in mathematics classroom can bring a relevant contribution to the knowledge on school mathematics activity. one episode, extracted from a lesson where 7th grade students worked cooperatively, is analysed in this paper. the results show how within cooperative work students interacted with each other in a small community and how this process helped them in the understanding and making-sense of mathematical knowledge.
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