936 resultados para working memory capacity


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The antioxidant capacity of 2-(3,5-diaryl-4,5-dihydro-1H-pyrazol-1-yl)-4-phenylthiazoles was evaluated. The values of antioxidant capacities of compounds 2d and 2e were found to be, respectively, 2,700 +/- 150 and 3,135 +/- 230 TE by the ORAC method, corresponding to a significant antioxidant capacity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this study was to verify the capacity of the extracellular matrix (ECM) obtained from bone marrow of malnourished mice to sustain survival and to induce the proliferation of myeloid cells. We also verified the capacity of the tests to interact with in vitro hematopoietic cytokines. Male ""Swiss"" mice were submitted to protein malnutrition with a diet contents of 4% casein until they lost 20% of the original weight, while the group-control was kept with a diet content of 14% of casein. The bone marrow was extracted with 1.0 mg of aprotinin/mL in PBS. The proliferation tests were carried out with myeloid cell line FDCP-1, by the colorimetric method of reduction of the MTT. The obtained ECM from nourished and undernourished mice induced cellular proliferation in vitro. Tests performed with Il-3 and GM-CSF cytokines in a concentration of 10 and 500 rho g/mL displayed synergic and regulatory effects respectively. The ECM obtained from the malnourished group submitted to the binding to GM-CSF demonstrated higher cellular proliferation than the ECM obtained from the control group (p<0.05). The results suggest that the alterations in the composition of ECM of bone marrow caused by malnutrition might lead to modification of the GM-CSF activity modulation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this work was to characterize exotic fruits (cambuci, araca-boi, camu-camu, jaracatia, araca) and commercial frozen pulps (araca, cambuci, umbu, coquinho, pana, native passion fruit, cagaita) from Brazil in relation to their bioactive compounds contents and antioxidant capacity. Camu-camu (Myrciaria dubia) presented the highest vitamin C and total phenolics contents (397 and 1797 mg/100 g f.w., respectively) and the highest DPPH(center dot) scavenging capacity. Coquinho (Butia capitata) also showed a significant vitamin C content (43 mg/100 g f.w.). Among the commercial frozen pulps, cagaita presented the higher DPPH scavenging activity and inhibition of beta-carotene bleaching. A good correlation between total phenols and DPPH scavenging activity was found for fruits (r = 0.997) and commercial frozen pulps (r = 0.738). However, no correlation was found for total phenols and inhibition of beta-carotene bleaching. Quercetin and kaempferol derivatives were the main flavonoids present in all samples and cyanidin derivatives were detected only in camu-camu. Camu-camu and araca (Psidium guineensis) showed the highest total ellagic acid contents (48 and 63.5 mg/100 g f.w.). All commercial frozen pulps presented lower contents of bioactive compounds and antioxidant capacity than their respective fruits. According to our results, camu-camu and araca might be sources of bioactive compounds.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aims of this study were to evaluate whether air pollution during pre-natal and post-natal phases change habituation and short-term discriminative memories and if oxidants are involved in this process. As secondary objectives, it was to evaluate if the change of filtered to nonfiltered environment could protect the cortex of rats against oxidative stress as well as to modify the behavior of these animals. Wistar, male rats were divided into four groups (n = 12/group): pre and post-natal exposure until adulthood to filtered air (FA); pre-natal period to nonfiltered air (NFA-FA); until (21st post-natal day) and post-natal to filtered air until adulthood (PND21); prenatal to filtered air until PND21 and post-natal to nonfiltered air until adulthood (FA-NFA); pre and post-natal to nonfiltered air (NFA). After 150 days of air pollution exposure, animals were tested in the spontaneous object recognition test to evaluate short-term discriminative and habituation memories. Rats were euthanized; blood was collected for metal determination; cortex dissected for oxidative stress evaluation. There was a significant increase in malondialdehyde (MDA) levels in the NFA group when compared to other groups (FA: 1.730 +/- 0.217; NFA-FA: 1.101 +/- 0.217; FA-NFA: 1.014 +/- 0.300; NFA: 5.978 +/- 1.920 nmol MDA/mg total proteins; p = 0.007). NFA group presented a significant decrease in short-term discriminative (FA: 0.603 +/- 0.106; NFA-FA: 0.669 +/- 0.0666; FA-NFA: 0.374 +/- 0.178; NFA: -0.00631 +/- 0.106 sec; p = 0.006) and an improvement in habituation memories when compared to other groups. Therefore, exposure to air pollution during both those periods impairs short-term discriminative memory and cortical oxidative stress may mediate this process.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Leukotrienes (LTs) are potent lipid mediators involved in the control of host defense. LTB(4) induces leukocyte accumulation, enhances phagocytosis and bacterial clearance, and increases NO synthesis. LTB(4) is also important in early effector T cell recruitment that is mediated by LTB(4) receptor 1, the high-affinity receptor for LTB(4). The aims of this study were to evaluate whether LTs are involved in the secondary immune response to vaccination in a murine model of Histoplasma capsulatum infection. Our results demonstrate that protection of wild-type mice immunized with cell-free Ags from H. capsulatum against histoplasmosis was associated with increased LTB(4) and IFN-gamma production as well as recruitment of memory T cells into the lungs. In contrast, cell-free Ag-immunized mice lacking 5-lipoxygenase(-/-), a critical enzyme involved in LT synthesis, displayed a marked decrease on recruitment of memory T cells to the lungs associated with increased synthesis of TGF-beta as well as IL-10. Strikingly, these effects were associated with increased mortality to 5-lipoxygenase(-/-)-infected mice. These data establish an important immunomodulatory role of LTs, in both the primary and secondary immune responses to histoplasmosis. The Journal of Immunology, 2008,181: 8544-8551.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purposes of this study were to evaluate in vitro the influence of different frequencies of Er:YAG laser on the human dentin caries removal capacity. Thirty fragments obtained from third molars were randomly assigned into three groups (n = 10) according to the laser frequency used: 4, 6, and 10 Hz. The caries lesion (+/-1 mm deep) was induced before the irradiation by S. mutans cultures for 6 weeks. The specimens of all groups were irradiated with 200 mJ of energy in noncontact and focused mode under constant refrigeration (water flow: 2.5 mL/min). Quantitative analysis of the caries removal was performed by DIAGNOdent (TM) and the Axion Vision (TM) software. Qualitative analysis was performed by Scanning electron microscope (SEM) and light microscope (LM). Data were analyzed by ANOVA and Fishers` tests. The DIAGNOdent (TM) revealed that the caries removal was similar with 4 and 6 Hz and was superior with 10 Hz (P < 0.05). The analysis with Axion Vision (TM) software revealed that the caries removal was similar with 6 and 10 Hz and the 4 Hz group promoted the lowest caries removal. Through SEM morphologic analysis, some specimens irradiated with 4 Hz presented, under the demineralized dentin, a disorganized collagenous matrix. The LM images revealed that all frequencies used promoted irregular caries removal, being observed over preparations with 6 and 10 Hz. It can be concluded that the increase of Er:YAG laser frequency provided a higher dentin caries removal without selectivity to the disorganized dentin. Microsc. Res. Tech. 74:281-286, 2011. (C) 2010 Wiley-Liss, Inc.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Oil-in-water (O/W) emulsions containing gel phase were developed with cupuassu and/or cocoa butter from Brazilian ecosystem. They were subjected to storage advanced stability tests (SAST) and to in vivo corneometry evaluation. The evaluated emulsions showed great performance in the evaluated conditions considering that no significant variation was observed. The moisturizing potential was advantageous even without the moisturizing active. The formulation was considered a good cosmetic moisturizing cream and a promise as a drug carrier.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Significant changes have marked Brazilian education in the period focused on by this research. Aiming to understand the configurations of the teaching profession in that period, this work focuses on the issue of the school success in the area of literacy by means of an analysis of the practices of literacy teachers who were at work between the 1950s and 1980s. The research is based on life-history accounts. The study aimed at describing the various experiences of these teachers identifying the knowledges and practices that sustained their successful literacy work as well as the various factors of a social, religious, political, familiar or other nature that, in the history of each of these teachers, favoured the development of a pedagogical style of literacy particular to each one of them. Despite the peculiarities and originality of each history, the success in the literacy process, as the defining feature of the profile of the four teachers, results from two main aspects: first, the autonomy that each one managed to keep in the development of his/her teaching work, particularly in the organisation of the teaching practices that indicated greater chances of a pupil`s learning to read and write; second, their trust in the capacity of every child for learning, independently of his/her social, economic and cultural conditions. Based on this evidence it is argued that the success of the pedagogical work, particularly during the early years of schooling, lies in an ethics of the teaching work with a double implication: first, it requires the teachers` dedication to their pupils, and second, it requires respect for the work of the teacher, so that she/he can maintain her/his autonomy and inventiveness. These aspects indicate the need for reflection on teaching work and a review of current teacher education policies, particularly the policies targeted at teachers working with literacy practices.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The influence of temporal association on the representation and recognition of objects was investigated. Observers were shown sequences of novel faces in which the identity of the face changed as the head rotated. As a result, observers showed a tendency to treat the views as if they were of the same person. Additional experiments revealed that this was only true if the training sequences depicted head rotations rather than jumbled views; in other words, the sequence had to be spatially as well as temporally smooth. Results suggest that we are continuously associating views of objects to support later recognition, and that we do so not only on the basis of the physical similarity, but also the correlated appearance in time of the objects.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study examines the historiography of the origins of rugby league in Australia. By accepting the inclusive nature of representation of the past as found in social memory theory, a wide range of sources ranging from histories written by academics to annuals, yearbooks and newspaper books are consulted. These sources reveal that there are several competing and conflicting accounts of the emergence of rugby league in Australia. These divergent accounts are used to facilitate a discussion of the role of narrative in sport history This article argues that narrative is an integral, not optional, feature of the production of history and that the historography of the origins of rugby league highlight the problematic nature of objectivity in history and the unavoidable, impositionalist role of the historian.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In 1984, George Orwell presented the future as a dystopian vision, where everyday existence was governed and redefined by an oppressive regime. Winston Smith's daily duties at the Ministry of Truth involved the invention, rewriting and erasing of fragments of history as a means of perpetuating contentment, uniformity and control. History, as Orwell described it in the novel 'was a palimpsest, scraped clean and reinscribed exactly as often as was necessary.' More that a quarter of a century after the publication of 1984, Michel Foucault discussed the cinematic representation and misrepresentation of French history and identity in terms of what he called the manipulation of 'popular memory'. In what was tantamount to a diluted version of Orwell's palimpsestic histories, Foucault stated that 'people are not shown what they were, but what they must remember having been.' This paper will investigate notions of memory, identity and the everyday through a discussion of the community of Celebration in Florida. Conceived in the 1990s, Celebration was designed around a fictionalised representation of pre 1940s small town America, using nostalgia for a mythologised past to create a sense of comfort, community and conformity among its residents. Adapting issues raised by Orwell, Foucault and Baudrillard, this paper will discuss the way in which architecture, like film and literature, can participate in what Foucault discussed as the manipulation of popular memory, inducing and exploiting a nostalgia for an everyday past that that never really existed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

University of Queensland Working Papers in Linguistics is an opportunity to share and showcase ongoing research by staff, students, and associates of UQ’s Linguistics program, housed in the School of English, Media Studies, and Art History. This, the first volume, covers a number of topics ranging from formal syntactic theory to second language acquisition, and is representative of the broad spectrum of research that is carried out at The University of Queensland. While the papers herein represent works in progress, they have all been reviewed by two peer assessors, and revised in accordance with the assessors’ reports.

Relevância:

20.00% 20.00%

Publicador: