714 resultados para Stewart, Jerry


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This paper applies recently developed heterogeneous nonlinear and linear panel unit root tests that account for cross-sectional dependence to 24 OECD and 33 non-OECD countries’ consumption-income ratios over the period 1951–2003. We apply a recently developed methodology that facilitates the use of panel tests to identify which individual cross-sectional units are stationary and which are nonstationary. This extends evidence provided in the recent literature to consider both linear and nonlinear adjustment in panel unit root tests, to address the issue of cross-sectional dependence, and to substantially expand both time-series and cross sectional dimensions of the data analysed. We find that the majority (65%) of the series are nonstationary with slightly fewer OECD countries’ (61%) series exhibiting a unit root than non-OECD countries (68%).

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Faced with the problem of pricing complex contingent claims, an investor seeks to make his valuations robust to model uncertainty. We construct a notion of a model- uncertainty-induced utility function and show that model uncertainty increases the investor's eff ective risk aversion. Using the model-uncertainty-induced utility function, we extend the \No Good Deals" methodology of Cochrane and Sa a-Requejo [2000] to compute lower and upper good deal bounds in the presence of model uncertainty. We illustrate the methodology using some numerical examples.

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When an agent chooses between prospects, noise in information processing generates an effect akin to the winner’s curse. Statistically unbiased perception systematically overvalues the chosen action because it fails to account for the possibility that noise is responsible for making the preferred action appear to be optimal. The optimal perception patterns share key features with prospect theory, namely, overweighting of small probability events (and corresponding underweighting of high probability events), status quo bias, and reference-dependent S-shaped valuations. These biases arise to correct for the winner’s curse effect.

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The reported prevalence of late-life depressive symptoms varies widely between studies, a finding that might be attributed to cultural as well as methodological factors. The EURO-D scale was developed to allow valid comparison of prevalence and risk associations between European countries. This study used Confirmatory Factor Analysis (CFA) and Rasch models to assess whether the goal of measurement invariance had been achieved; using EURO-D scale data collected in 10 European countries as part of the Survey of Health, Ageing and Retirement in Europe (SHARE) (n = 22,777). The results suggested a two-factor solution (Affective Suffering and Motivation) after Principal Component Analysis (PCA) in 9 of the 10 countries. With CFA, in all countries, the two-factor solution had better overall goodness-of-fit than the one-factor solution. However, only the Affective Suffering subscale was equivalent across countries, while the Motivation subscale was not. The Rasch model indicated that the EURO-D was a hierarchical scale. While the calibration pattern was similar across countries, between countries agreement in item calibrations was stronger for the items loading on the affective suffering than the motivation factor. In conclusion, there is evidence to support the EURO-D as either a uni-dimensional or bi-dimensional scale measure of depressive symptoms in late-life across European countries. The Affective Suffering sub-component had more robust cross-cultural validity than the Motivation sub-component.

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Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or  ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention.

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Background Cruciferous vegetables have been suggested to protect against various cancers, though the issue is open to discussion. To further understand their role, we analyzed data from a network of case-control studies conducted in Italy and Switzerland. Patients and methods The studies included a total of 1468 cancers of the oral cavity/pharynx, 505 of the esophagus, 230 of the stomach, 2390 of the colorectum, 185 of the liver, 326 of the pancreas, 852 of the larynx, 3034 of the breast, 367 of the endometrium, 1031 of the ovary, 1294 of the prostate, 767 of the kidney, and 11 492 controls. All cancers were incident, histologically confirmed; controls were subjects admitted to the same network of hospitals as cases for a wide spectrum of acute nonneoplastic conditions. Results The multivariate odds ratio (OR) for consumption of cruciferous vegetables at least once a week as compared with no/occasional consumption was significantly reduced for cancer of the oral cavity/pharynx (OR = 0.83), esophagus (OR = 0.72), colorectum (OR = 0.83), breast (OR = 0.83), and kidney (OR = 0.68). The OR was below unity, but not significant, for stomach (OR = 0.90), liver (OR = 0.72), pancreatic (OR = 0.90), laryngeal (OR = 0.84), endometrial (OR = 0.93), ovarian (OR = 0.91), and prostate (OR = 0.87) cancer. Conclusion This large series of studies provides additional evidence of a favorable effect of cruciferous vegetables on several common cancers.

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An independent and detailed expert analysis of a decade of reforms (published 25 February) takes up the challenge made by Peter Mandelson in 1997 to “judge us after ten years of success in office. For one of the fruits of that success will be that Britain has become a more equal society.����”Commissioned by the Joseph Rowntree Foundation, the study, by a team led by LSE’s Centre for Analysis of Social Exclusion, shows sharp contrasts between different policy areas. Notable success stories include reductions in child and pensioner poverty, improved education outcomes for the poorest children and schools, and narrowing economic and other divides between deprived and other areas.But health inequalities continued to widen, gaps in incomes between the very top and very bottom grew, and poverty increased for working-age people without children.����In several policy areas there was a marked contrast between the first half of the New Labour period and the second half, when progress has slowed or even stalled.John Hills, one of the leaders of study, said, “Whether Britain has moved towards becoming a ‘more equal society’ depends on what you look at, and when. Where clear initiatives were taken, results followed. But as the growth of living standards slowed, even well before the recession, and public finances tightened, momentum seems to have been lost in several key areas.”Kitty Stewart added, “The government can take heart from achievements such as the reduction in child poverty up to 2004.����Recent data show that by then, child well-being in the UK had begun to move up the European league table from its dismal showing at the start of the decade that formed the basis of UNICEF’s damning 2007 report. But even with improved figures, Britain was still left with one of the highest rates of child poverty out of the 15 original EU members, and the latest figures show it had increased again by 2006/7.”����The study concludes that the decade from 1997 was favourable to an egalitarian agenda in several ways: the economy grew continuously; the government had large majorities and aspired to create more equality; and public attitudes surveys suggested pent-up demand for more public expenditure. But that environment now looks very uncertain, not just in the near future, but also in the longer term.����Fiscal pressures from an ageing society could further constrain resources available for redistribution, and public attitudes towards the benefit system have hardened while support for redistribution has declined.Hills added, “The 1980s and 1990s showed that hoping that rapid growth in living standards at the top would ‘trickle down’ to those at the bottom did not work.����The period since 1997 has shown that gains are possible through determined interventions, but they require intensive and continuous effort to be sustained.”JRF Chief Executive Julia Unwin added, “We know the potential impact the deepening recession will have on those already living in poverty. This book provides an important, timely and comprehensive assessment of where we are and what remains to be done.”

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PURPOSE: The aim of this study was to test whether oligonucleotide-targeted gene repair can correct the point mutation in genomic DNA of PDE6b(rd1) (rd1) mouse retinas in vivo. METHODS: Oligonucleotides (ODNs) of 25 nucleotide length and complementary to genomic sequence subsuming the rd1 point mutation in the gene encoding the beta-subunit of rod photoreceptor cGMP-phosphodiesterase (beta-PDE), were synthesized with a wild type nucleotide base at the rd1 point mutation position. Control ODNs contained the same nucleotide bases as the wild type ODNs but with varying degrees of sequence mismatch. We previously developed a repeatable and relatively non-invasive technique to enhance ODN delivery to photoreceptor nuclei using transpalpebral iontophoresis prior to intravitreal ODN injection. Three such treatments were performed on C3H/henJ (rd1) mouse pups before postnatal day (PN) 9. Treatment outcomes were evaluated at PN28 or PN33, when retinal degeneration was nearly complete in the untreated rd1 mice. The effect of treatment on photoreceptor survival was evaluated by counting the number of nuclei of photoreceptor cells and by assessing rhodopsin immunohistochemistry on flat-mount retinas and sections. Gene repair in the retina was quantified by allele-specific real time PCR and by detection of beta-PDE-immunoreactive photoreceptors. Confirmatory experiments were conducted using independent rd1 colonies in separate laboratories. These experiments had an additional negative control ODN that contained the rd1 mutant nucleotide base at the rd1 point mutation site such that the sole difference between treatment with wild type and control ODN was the single base at the rd1 point mutation site. RESULTS: Iontophoresis enhanced the penetration of intravitreally injected ODNs in all retinal layers. Using this delivery technique, significant survival of photoreceptors was observed in retinas from eyes treated with wild type ODNs but not control ODNs as demonstrated by cell counting and rhodopsin immunoreactivity at PN28. Beta-PDE immunoreactivity was present in retinas from eyes treated with wild type ODN but not from those treated with control ODNs. Gene correction demonstrated by allele-specific real time PCR and by counts of beta-PDE-immunoreactive cells was estimated at 0.2%. Independent confirmatory experiments showed that retinas from eyes treated with wild type ODN contained many more rhodopsin immunoreactive cells compared to retinas treated with control (rd1 sequence) ODN, even when harvested at PN33. CONCLUSIONS: Short ODNs can be delivered with repeatable efficiency to mouse photoreceptor cells in vivo using a combination of intravitreal injection and iontophoresis. Delivery of therapeutic ODNs to rd1 mouse eyes resulted in genomic DNA conversion from mutant to wild type sequence, low but observable beta-PDE immunoreactivity, and preservation of rhodopsin immunopositive cells in the outer nuclear layer, suggesting that ODN-directed gene repair occurred and preserved rod photoreceptor cells. Effects were not seen in eyes treated with buffer or with ODNs having the rd1 mutant sequence, a definitive control for this therapeutic approach. Importantly, critical experiments were confirmed in two laboratories by several different researchers using independent mouse colonies and ODN preparations from separate sources. These findings suggest that targeted gene repair can be achieved in the retina following enhanced ODN delivery.

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We tested the hypothesis that elevation in heart rate (HR) during submaximal exercise in the heat is related, in part, to increased percentage of maximal O(2) uptake (%Vo(2 max)) utilized due to reduced maximal O(2) uptake (Vo(2 max)) measured after exercise under the same thermal conditions. Peak O(2) uptake (Vo(2 peak)), O(2) uptake, and HR during submaximal exercise were measured in 22 male and female runners under four environmental conditions designed to manipulate HR during submaximal exercise and Vo(2 peak). The conditions involved walking for 20 min at approximately 33% of control Vo(2 max) in 25, 35, 40, and 45 degrees C followed immediately by measurement of Vo(2 peak) in the same thermal environment. Vo(2 peak) decreased progressively (3.77 +/- 0.19, 3.61 +/- 0.18, 3.44 +/- 0.17, and 3.13 +/- 0.16 l/min) and HR at the end of the submaximal exercise increased progressively (107 +/- 2, 112 +/- 2, 120 +/- 2, and 137 +/- 2 beats/min) with increasing ambient temperature (T(a)). HR and %Vo(2 peak) increased in an identical fashion with increasing T(a). We conclude that elevation in HR during submaximal exercise in the heat is related, in part, to the increase in %Vo(2 peak) utilized, which is caused by reduced Vo(2 peak) measured during exercise in the heat. At high T(a), the dissociation of HR from %Vo(2 peak) measured after sustained submaximal exercise is less than if Vo(2 max) is assumed to be unchanged during exercise in the heat.

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Open Education Resources are educational materials purposely made available for free use by others. They offer tremendous potential for reducing costs and increasing access to education especially in the developing world. This paper discusses issues of quality, localization, adaptation and integration that need to be addressed in order to make OER adoption a successful strategy.

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The adipocyte-derived protein adiponectin is highly heritable and inversely associated with risk of type 2 diabetes mellitus (T2D) and coronary heart disease (CHD). We meta-analyzed 3 genome-wide association studies for circulating adiponectin levels (n = 8,531) and sought validation of the lead single nucleotide polymorphisms (SNPs) in 5 additional cohorts (n = 6,202). Five SNPs were genome-wide significant in their relationship with adiponectin (P< or =5x10(-8)). We then tested whether these 5 SNPs were associated with risk of T2D and CHD using a Bonferroni-corrected threshold of P< or =0.011 to declare statistical significance for these disease associations. SNPs at the adiponectin-encoding ADIPOQ locus demonstrated the strongest associations with adiponectin levels (P-combined = 9.2x10(-19) for lead SNP, rs266717, n = 14,733). A novel variant in the ARL15 (ADP-ribosylation factor-like 15) gene was associated with lower circulating levels of adiponectin (rs4311394-G, P-combined = 2.9x10(-8), n = 14,733). This same risk allele at ARL15 was also associated with a higher risk of CHD (odds ratio [OR] = 1.12, P = 8.5x10(-6), n = 22,421) more nominally, an increased risk of T2D (OR = 1.11, P = 3.2x10(-3), n = 10,128), and several metabolic traits. Expression studies in humans indicated that ARL15 is well-expressed in skeletal muscle. These findings identify a novel protein, ARL15, which influences circulating adiponectin levels and may impact upon CHD risk.

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Raised blood pressure (BP) is a major risk factor for cardiovascular disease. Previous studies have identified 47 distinct genetic variants robustly associated with BP, but collectively these explain only a few percent of the heritability for BP phenotypes. To find additional BP loci, we used a bespoke gene-centric array to genotype an independent discovery sample of 25,118 individuals that combined hypertensive case-control and general population samples. We followed up four SNPs associated with BP at our p < 8.56 × 10(-7) study-specific significance threshold and six suggestively associated SNPs in a further 59,349 individuals. We identified and replicated a SNP at LSP1/TNNT3, a SNP at MTHFR-NPPB independent (r(2) = 0.33) of previous reports, and replicated SNPs at AGT and ATP2B1 reported previously. An analysis of combined discovery and follow-up data identified SNPs significantly associated with BP at p < 8.56 × 10(-7) at four further loci (NPR3, HFE, NOS3, and SOX6). The high number of discoveries made with modest genotyping effort can be attributed to using a large-scale yet targeted genotyping array and to the development of a weighting scheme that maximized power when meta-analyzing results from samples ascertained with extreme phenotypes, in combination with results from nonascertained or population samples. Chromatin immunoprecipitation and transcript expression data highlight potential gene regulatory mechanisms at the MTHFR and NOS3 loci. These results provide candidates for further study to help dissect mechanisms affecting BP and highlight the utility of studying SNPs and samples that are independent of those studied previously even when the sample size is smaller than that in previous studies.

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PURPOSE: Two mutations (R555Q and R124L) in the BIGH3 gene have been described in anterior or Bowman's layer dystrophies (CDB). The clinical, molecular, and ultrastructural findings of five families with CDB was reviewed to determine whether there is a consistent genotype:phenotype correlation. METHODS: Keratoplasty tissue from each patient was examined by light and electron microscopy (LM and EM). DNA was obtained, and exons 4 and 12 of BIGH3 were analyzed by polymerase chain reaction and single-stranded conformation polymorphism/heteroduplex analysis. Abnormally migrating products were analyzed by direct sequencing. RESULTS: In two families with type I CDB (CDBI), the R124L mutation was defined. There were light and ultrastructural features of superficial granular dystrophy and atypical banding of the "rod-shaped bodies" ultrastructurally. Patients from three families with "honeycomb" dystrophy were found to carry the R555Q mutation and had characteristic features of Bowman's dystrophy type II (CDBII). CONCLUSIONS: There is a strong genotype:phenotype correlation among CBDI (R124L) and CDBII (R555Q). LM and EM findings suggest that epithelial abnormalities may underlie the pathology of both conditions. The findings clarify the confusion over classification of the Bowman's layer dystrophies.