940 resultados para Smooth Norms


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The member countries of the World Health Organization have endorsed its Global Strategy on Diet, Physical Activity, and Health. We assess the potential consumption impacts of these norms in the United States, France, and the United Kingdom using a mathematical programming approach. We find that adherence would involve large reductions in the consumption of fats and oils accompanying large rises in the consumption of fruits, vegetables, and cereal. Further, in the United Kingdom and the United States, but not France, sugar intakes would have to shrink considerably. Focusing on sub-populations within each country, we find that the least educated, not necessarily the poorest, would have to bear the highest burden of adjustment.

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Promotion of adherence to healthy-eating norms has become an important element of nutrition policy in the United States and other developed countries. We assess the potential consumption impacts of adherence to a set of recommended dietary norms in the United States using a mathematical programming approach. We find that adherence to recommended dietary norms would involve significant changes in diets, with large reductions in the consumption of fats and oils along with large increases in the consumption of fruits, vegetables, and cereals. Compliance with norms recommended by the World Health Organization for energy derived from sugar would involve sharp reductions in sugar intakes. We also analyze how dietary adjustments required vary across demographic groups. Most socio-demographic characteristics appear to have relatively little influence on the pattern of adjustment required to comply with norms, Income levels have little effect on required dietary adjustments. Education is the only characteristic to have a significant influence on the magnitude of adjustments required. The least educated rather than the poorest have to bear the highest burden of adjustment. Out- analysis suggests that fiscal measures like nutrient-based taxes may not be as regressive as commonly believed. Dissemination of healthy-eating norms to the less educated will be a key challenge for nutrition policy.

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Promotion of adherence to healthy-eating norms has become an important element of nutrition policy in the United States and other developed countries. We assess the potential consumption impacts of adherence to a set of recommended dietary norms in the United States using a mathematical programming approach. We find that adherence to recommended dietary norms would involve significant changes in diets, with large reductions in the consumption of fats and oils along with large increases in the consumption of fruits, vegetables, and cereals. Compliance with norms recommended by the World Health Organization for energy derived from sugar would involve sharp reductions in sugar intakes. We also analyze how dietary adjustments required vary across demographic groups. Most socio-demographic characteristics appear to have relatively little influence on the pattern of adjustment required to comply with norms, Income levels have little effect on required dietary adjustments. Education is the only characteristic to have a significant influence on the magnitude of adjustments required. The least educated rather than the poorest have to bear the highest burden of adjustment. Out- analysis suggests that fiscal measures like nutrient-based taxes may not be as regressive as commonly believed. Dissemination of healthy-eating norms to the less educated will be a key challenge for nutrition policy.

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The member countries of the World Health Organization (WHO) have recently endorsed its global strategy on diet, physical activity and health. The strategy emphasises the need to limit the consumption of saturated fats and trans-fatty acids, salt and sugars, and to increase consumption of fruits and vegetables in order to combat the growing burden of non-communicable diseases. This paper attempts a broad quantitative assessment of the consumption impacts of these norms in OECD countries using a mathematical programming approach. We find that adherence to the WHO norms would involve a significant decrease in the consumption of vegetable oils (30%), dairy products (28%), sugar (24%), animal fats (30%) and meat (pig meat, 13.5%, mutton and goat 14.5%) and a significant increase in the human consumption of cereals (31%), fruits (25%) and vegetables (21%). (c) 2005 Elsevier Ltd. All rights reserved.

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What is already known about this subject center dot Flavonoids are largely recognized as potential inhibitors of platelet function, through nonspecific mechanisms such as antioxidant activity and/or inhibition of several enzymes and signalling proteins. center dot In addition, we, and few others, have shown that certain antiaggregant flavonoids may behave as specific TXA2 receptor (TP) ligands in platelets. center dot Whether flavonoids interact with TP isoforms in other cell types is not known, and direct evidence that flavonoid-TP interaction inhibits signalling downstream TP has not been shown. What this study adds center dot This study first demonstrates that certain flavonoids behave as ligands for both TP isoforms, not only in platelets, but also in human myometrium and in TP-transfected HEK 293T cells. center dot Differences in the effect of certain flavonoids in platelet signalling, induced by either U46619 or thrombin, suggest that abrogation of downstream TP signalling is related to their specific blockage of the TP, rather than to a nonspecific effect on tyrosine kinases or other signalling proteins. Flavonoids may affect platelet function by several mechanisms, including antagonism of TxA(2) receptors (TP). These TP are present in many tissues and modulate different signalling cascades. We explored whether flavonoids affect platelet TP signalling, and if they bind to TP expressed in other cell types. Platelets were treated with flavonoids, or other selected inhibitors, and then stimulated with U46619. Similar assays were performed in aspirinized platelets activated with thrombin. Effects on calcium release were analysed by fluorometry and changes in whole protein tyrosine phosphorylation and activation of ERK 1/2 by Western blot analysis. The binding of flavonoids to TP in platelets, human myometrium and TP alpha- and TP beta-transfected HEK 293T cells was explored using binding assays and the TP antagonist H-3-SQ29548. Apigenin, genistein, luteolin and quercetin impaired U46619-induced calcium mobilization in a concentration-dependent manner (IC50 10-30 mu M). These flavonoids caused a significant impairment of U46619-induced platelet tyrosine phosphorylation and of ERK 1/2 activation. By contrast, in aspirin-treated platelets all these flavonoids, except quercetin, displayed minor effects on thrombin-induced calcium mobilization, ERK 1/2 and total tyrosine phosphorylation. Finally, apigenin, genistein and luteolin inhibited by > 50% H-3-SQ29548 binding to different cell types. These data further suggest that flavonoids may inhibit platelet function by binding to TP and by subsequent abrogation of downstream signalling. Binding of these compounds to TP occurs in human myometrium and in TP-transfected HEK 293T cells and suggests that antagonism of TP might mediate the effects of flavonoids in different tissues.

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Oxidized low-density lipoproteins (LDL) play a central role in atherogenesis and induce expression of the antioxidant stress protein heme oxygenase 1 (HO-1). In the present study we investigated induction of HO-1 and adaptive increases in reduced glutathione (GSH) in human aortic smooth muscle cells (SMC) in response to moderately oxidized LDL (moxLDL, 100 mu g protein/ml, 24 h), a species containing high levels of lipid hydroperoxides. Expression and activity of HO-1 and GSH levels were elevated to a greater extent by moxLDL than highly oxidized LDL but unaffected by native or acetylated LDL. Inhibitors of protein kinase C (PKC) or mitogen-activated protein kinases (MAPK) p38(MAPK) and MEK or c-jun-NH2-terminal kinase (JNK) significantly attenuated induction of HO-1. Phosphorylation of p38(MAPK), extracellular signal-regulated kinase (ERK1/2), or JNK and nuclear translocation of the transcription factor Nrf2 were enhanced following acute exposure of SMC to rnoxLDL (100 mu g proteiri/ml, 1-2 h). Pretreatment of SMC with the antioxidant vitamin C (100 mu M, 24 h) attenuated the induction of HO-1 by moxLDL. Native and oxidized LDL did not alter basal levels of intracellular ATP, mitochondrial dehydrogenase activity, or expression of the lectin-like oxidized LDL receptor (LOX-1) in SMC. These findings demonstrate for the first time that activation of PKC, p38(MAPK), JNK, ERK1/2, and Nrf2 by oxidized LDL in human SMC leads to HO-1 induction, constituting an adaptive response against oxidative injury that can be ameliorated by vitamin C. (C) 2005 Elsevier Inc. All rights reserved.

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Abnormal vascular smooth muscle cell (VSMC) proliferation plays an important role in the pathogenesis of both atherosclerosis and restenosis. Recent studies suggest that high-dose salicylates, in addition to inhibiting cyclooxygenase activity, exert an antiproliferative effect on VSMC growth both in-vitro and in-vivo. However, whether all non-steroidal anti-inflammatory drugs (NSAIDs) exert similar anti proliferative effects on VSMCs, and do so via a common mechanism of action, remains to be shown. In this study, we demonstrate that the NSAIDs aspirin, sodium salicylate, diclofenac, ibuprofen, indometacin and sulindac induce a dose-dependent inhibition of proliferation in rat A10 VSMCs in the absence of significant cytotoxicity. Flow cytometric analyses showed that exposure of A10 cells to diclofenac, indometacin, ibuprofen and sulindac, in the presence of the mitotic inhibitor, nocodazole, led to a significant G0/G1 arrest. In contrast, the salicylates failed to induce a significant G1 arrest since flow cytometry profiles were not significantly different from control cells. Cyclin A levels were elevated, and hyperphosphorylated p107 was present at significant levels, in salicylate-treated A10 cells, consistent with a post-G1/S block, whereas cyclin A levels were low, and hypophosphorylated p107 was the dominant form, in cells treated with other NSAIDs consistent with a G1 arrest. The ubiquitously expressed cyclin-dependent kinase (CDK) inhibitors, p21 and p27, were increased in all NSAID-treated cells. Our results suggest that diclofenac, indometacin, ibuprofen and sulindac inhibit VSMC proliferation by arresting the cell cycle in the G1 phase, whereas the growth inhibitory effect of salicylates probably affects the late S and/or G2/M phases. Irrespective of mechanism, our results suggest that NSAIDs might be of benefit in the treatment of certain vasculoproliferative disorders.

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Abnormal vascular smooth muscle cell (VSMC) proliferation is known to play an important role in the pathogenesis of atherosclerosis, restenosis and instent stenosis. Recent studies suggest that salicylates, in addition to inhibiting cyclooxygenase activity, exert an antiproliferative effect on VSMC growth both in vitro and in vivo. However, whether all non-steroidal anti-inflammatory drugs (NSAID) exert similar antiproliferative effects on VSMCs, and do so via a common mechanism of action, remains unknown. In the present study, we demonstrated that the NSAIDs, aspirin, ibuprofen and sulindac induced a dose-dependent inhibition of proliferation in rat A10 VSMCs (IC50 = 1666 mumol/L, 937 mumol/L and 520 mumol/L, respectively). These drugs did not show significant cytotoxic effects as determined by LDH release assay, even at the highest concentrations tested (aspirin, 5000 mumol/L; ibuprofen, 2500 mumol/L; and sulindac, 1000 mumol/L). Flow cytometric analyses showed that a 48 h exposure of A10 VSMCs to ibuprofen (1000 mumol/L) and sulindac (750 mumol/L) led to a significant G1 arrest (from 68.7 +/- 2.0% of cells in G1 to 76.6 +/- 2.2% and 75.8 +/- 2.2%, respectively, p < 0.05). In contrast, aspirin (2500 mumol/L) failed to induce a significant G1 arrest (68.1 +/- 5.2%). Clearer evidence of a G1 block was obtained by treatment of cells with the mitotic inhibitor, nocodazole (40 ng/ml), for the final 24 h of the experiment. Under these conditions, aspirin still failed to induce a G1 arrest (from 25.9 +/- 10.9% of cells in G1 to 19.6 +/- 2.3%) whereas ibuprofen and sulindac led to a significant accumulation of cells in G1(51.8% +/- 17.2% and 54.1% +/- 10.6%, respectively, p < 0.05). These results indicate that ibuprofen and sulindac inhibit VSMC proliferation by arresting the cell cycle in the G1 phase whereas the effect of aspirin appears to be independent of any special phase of the cell cycle. Irrespective of mechanism, our results suggest that NSAIDs might be of benefit to the treatment of vascular proliferative disorders.

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User interfaces have the primary role of enabling access to information meeting individual users' needs. However, the user-systems interaction is still rigid, especially in support of complex environments where various types of users are involved. Among the approaches for improving user interface agility, we present a normative approach to the design interfaces of web applications, which allow delivering users personalized services according to parameters extracted from the simulation of norms in the social context. A case study in an e-Government context is used to illustrate the implications of the approach.

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The authors present an active vision system which performs a surveillance task in everyday dynamic scenes. The system is based around simple, rapid motion processors and a control strategy which uses both position and velocity information. The surveillance task is defined in terms of two separate behavioral subsystems, saccade and smooth pursuit, which are demonstrated individually on the system. It is shown how these and other elementary responses to 2D motion can be built up into behavior sequences, and how judicious close cooperation between vision and control results in smooth transitions between the behaviors. These ideas are demonstrated by an implementation of a saccade to smooth pursuit surveillance system on a high-performance robotic hand/eye platform.

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Methods for producing nonuniform transformations, or regradings, of discrete data are discussed. The transformations are useful in image processing, principally for enhancement and normalization of scenes. Regradings which “equidistribute” the histogram of the data, that is, which transform it into a constant function, are determined. Techniques for smoothing the regrading, dependent upon a continuously variable parameter, are presented. Generalized methods for constructing regradings such that the histogram of the data is transformed into any prescribed function are also discussed. Numerical algorithms for implementing the procedures and applications to specific examples are described.