978 resultados para SINDROME DE DOWN


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We elucidate the dependence of purity and entanglement of two-photon states generated by spontaneous parametric down-conversion on the parameters of the source, such as crystal length, pump beam divergence, frequency bandwidth, and detectors angular aperture. The effect of crystal anisotropy is taken into account. Numerical simulations are presented for two types of commonly used source configurations. (C) 2009 Elsevier B.V. All rights reserved.

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The clear cell subtype of renal cell carcinoma (RCC) is the most lethal and prevalent cancer of the urinary system. To investigate the molecular changes associated with malignant transformation in clear cell RCC, the gene expression profiles of matched samples of tumor and adjacent non-neoplastic tissue were obtained from six patients. A custom-built cDNA microarray platform was used, comprising 2292 probes that map to exons of genes and 822 probes for noncoding RNAs mapping to intronic regions. Intronic transcription was detected in all normal and neoplastic renal tissues. A subset of 55 transcripts was significantly down-regulated in clear cell RCC relative to the matched nontumor tissue as determined by a combination of two statistical tests and leave-one-out patient cross-validation. Among the down-regulated transcripts, 49 mapped to untranslated or coding exons and 6 were intronic relative to known exons of protein-coding genes. Lower levels of expression of SIN3B, TRIP3, SYNJ2BP and NDE1 (P<0.02), and of intronic transcripts derived from SND1 and ACTN4 loci (P<0.05), were confirmed in clear cell RCC by Real-time RT-PCR. A subset of 25 transcripts was deregulated in additional six nonclear cell RCC samples, pointing to common transcriptional alterations in RCC irrespective of the histological subtype or differentiation state of the tumor. Our results indicate a novel set of tumor suppressor gene candidates, including noncoding intronic RNAs, which may play a significant role in malignant transformations of normal renal cells. (C) 2008 Wiley-Liss, Inc.

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Tempol (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy) has long been known to protect experimental animals from the injury associated with oxidative and inflammatory conditions. In the latter case, a parallel decrease in tissue protein nitration levels has been observed. Protein nitration represents a shift in nitric oxide actions from physiological to pathophysiological and potentially damaging pathways involving its derived oxidants such as nitrogen dioxide and peroxynitrite. In infectious diseases, protein tyrosine nitration of tissues and cells has been taken as evidence for the involvement of nitric oxide-derived oxidants in microbicidal mechanisms. To examine whether tempol inhibits the microbicidal action of macrophages, we investigated its effects on Leishmania amazonensis infection in vitro (RAW 264.7 murine macrophages) and in vivo (C57B1/6 mice). Tempol was administered in the drinking water at 2 mM throughout the experiments and shown to reach infected footpads as the nitroxide plus the hydroxylamine derivative by EPR analysis. At the time of maximum infection (6 weeks), tempol increased footpad lesion size (120%) and parasite burden (150%). In lesion extracts, tempol decreased overall nitric oxide products and expression of inducible nitric oxide synthase to about 80% of the levels in control animals. Nitric oxide-derived products produced by radical mechanisms, such as 3-nitrotyrosine and nitrosothiol, decreased to about 40% of the levels in control mice. The results indicate that tempol worsened L. amazonensis infection by a dual mechanism involving down-regulation of iNOS expression and scavenging of nitric oxide-derived oxidants. Thus, the development of therapeutic strategies based on nitroxides should take into account the potential risk of altering host resistance to parasite infection. (c) 2008 Elsevier Inc. All rights reserved.

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Access to high quality health care services plays an important part in the health of rural communities and individuals. This fact is reflected in efforts by governments to improve the quality of such services through better targeting of funds and more efficient management of services. In Australia, the difficulties experienced by rural communities in attracting and retaining doctors has long been recognized as a contributing factor to the relatively higher levels of morbidity and mortality in rural areas. However, this paper, based on a study of two small rural communities in Australia, suggests that resolving the health problems of rural communities will require more than simply increasing the quality and accessibility of health services. Health and well-being in such communities relates as much to the sense of community cohesion as it does to the direct provision of medical services. Over recent years, that cohesion has diminished, undermined in part by government policies that have fuelled an exodus from small rural communities to urban areas. Until governments begin to take an 'upside-down' perspective, focusing on building healthy communities rather than simply on building hospitals to make communities healthy, the disadvantages faced by rural people will continue to be exacerbated.

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I review the thinking of Barbara Bolt in her recent book, which is informed by Martin Heidegger’s theory of art. Bolt argues that it is in the flux of art practice, where the artist responds bodily, with hands and eyes, to the encounter with the materials of practice, that visual art produces real material effects. That is, through the praxical encounter, art does not merely represent, it performs radically. Bolt thus argues for a materialist ontology of the work of visual art. I examine what Bolt means by ‘real material effects’ and ‘radical performativity’.

In developing my own project on the poetic response to visual art, particularly portraiture, I have freely adapted Heidegger’s theory of art to propose that the poet responds to the visual encounter in a manner similar to that of Heidegger’s preserver, by restraining usual knowing and looking. In this way the poet facilitates the emergence from the work of visual art of truth about being and earth, as defined by Heidegger. In my forthcoming article ‘Ekphrasis and illumination of painting’, I argue that the poet, like the artist, restrains seeing-as and operates in a mode approximating mere seeing, as these terms are defined by Heidegger and Wittgenstein.

In the present article I propose to examine the role of looking down and looking up in non-representational art, and in particular Bolt’s ‘oil stain paintings’ exhibited in the Forty-five Downstairs gallery in Melbourne in conjunction with the launch of her book.

I propose to expose some blind spots in the thinking which underpins theories derived from Heidegger. I will examine the way ‘representation’ has been constructed in twentieth-century thought, and will argue that Heideggerian truth and Bolt’s ‘real material effects’ result from the privileging of perception over knowledge. I will examine, with particular reference to portraiture, Bolt’s assertion that the referent can be rehabilitated in Western thought and traced in ‘real material effects’. I will argue that ‘representation’ is an unstable process occurring within and outside signification, and that this very instability enables us to confidently predict that all art produces ‘real material effects’, or in other words, Heideggerian truth.

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Deakin University in Australia is one of the leading providers of distance education in the South Pacific region. The School of Engineering offers four-year professional engineering-degree programs and three-year technologist programs. The over 600 total students studying engineering at Deakin fall into four categories:

• 18-19 year-old students fresh from high school, who largely study on-campus,
• older students in the technical workforce, seeking a university degree to upgrade their qualifications,
• industry-based students studying in university-industry partnership programs,
• overseas students studying either on-campus, or off-campus through education partners in Malaysia and Singapore.

Geographically these students form a very wide student base. The study programs are designed to produce multi-skilled, broadly focused engineers and technologists with multi-disciplinary technical competence, and the ability to take a systems approach to design and operational performance. A team of around 25 academic staff deliver courses in seven different majors in the general fields of manufacturing, environmental engineering, mechatronics, and computer systems. We discuss here the history of the School, its teaching philosophy, and its unique methods in delivering engineering education to a widely scattered student body.

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Alzheimer's disease is characterized by the accumulation of amyloid-ß peptide, which is cleaved from the amyloid-ß precursor protein (APP). Reduction in levels of the potentially toxic amyloid-ß has emerged as one of the most important therapeutic goals in Alzheimer's disease. Key targets for this goal are factors that affect the regulation of the APP gene. Recent in vivo and in vitro studies have illustrated the importance of copper in Alzheimer's disease neuropathogenesis and suggested a role for APP and amyloid-ß in copper homeostasis. We hypothesized that metals and in particular copper might alter APP gene expression. To test the hypothesis, we utilized human fibroblasts overexpressing the Menkes protein (MNK), a major mammalian copper efflux protein. MNK deletion fibroblasts have high intracellular copper, whereas MNK overexpressing fibroblasts have severely depleted intracellular copper. We demonstrate that copper depletion significantly reduced APP protein levels and down-regulated APP gene expression. Furthermore, APP promoter deletion constructs identified the copper-regulatory region between -490 and +104 of the APP gene promoter in both basal MNK overexpressing cells and in copper-chelated MNK deletion cells. Overall these data support the hypothesis that copper can regulate APP expression and further support a role for APP to function in copper homeostasis. Copper-regulated APP expression may also provide a potential therapeutic target in Alzheimer's disease.

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A look at the role that symbolism plays in the novel. In this case, as it is in many other great novels, we see that symbolism is used to enhance the mood and the atmosphere of the novel rather than adding anything of importance to the plot.