90 research outputs found

    Heritability of ECG biomarkers in the Netherlands twin registry measured from Holter ECGs

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    Introduction: The resting ECG is the most commonly used tool to assess cardiac electrophysiology. Previous studies have estimated heritability of ECG parameters based on these snapshots of the cardiac electrical activity. In this study we set out to determine whether analysis of heart rate specific data from Holter ECGs allows more complete assessment of the heritability of ECG parameters. Methods and Results: Holter ECGs were recorded from 221 twin pairs and analyzed using a multi-parameter beat binning approach. Heart rate dependent estimates of heritability for QRS duration, QT interval, Tpeak-Tend and Theight were calculated using structural equation modeling. QRS duration is largely determined by environmental factors whereas repolarization is primarily genetically determined. Heritability estimates of both QT interval and Theight were significantly higher when measured from Holter compared to resting ECGs and the heritability estimate of each was heart rate dependent. Analysis of the genetic contribution to correlation between repolarization parameters demonstrated that covariance of individual ECG parameters at different heart rates overlap but at each specific heart rate there was relatively little overlap in the genetic determinants of the different repolarization parameters. Conclusions: Here we present the first study of heritability of repolarization parameters measured from Holter ECGs. Our data demonstrate that higher heritability can be estimated from the Holter than the resting ECG and reveals rate dependence in the genetic-environmental determinants of the ECG that has not previously been tractable. Future applications include deeper dissection of the ECG of participants with inherited cardiac electrical disease.Emily C. Hodkinson, Melanie Neijts, Arash Sadrieh, Mohammad S. Imtiaz, Mathias Baumert, Rajesh N. Subbiah, Christopher S. Hayward, Dorret Boomsma, Gonneke Willemsen, JamieI.Vandenberg, Adam P. Hill, and Eco De Geu

    Understanding the Emergence of Public Debt

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    We use a controlled laboratory experiment with and without overlapping generations to study the emergence of public debt. Public debt is chosen by popular vote, pays for public goods, and is repaid with general taxes. With a single generation, public debt is accumulated prudently, never leading to over-indebtedness. With multiple generations, public debt is accumulated rapidly as soon as the burden of debt and the risk of over-indebtedness can be shifted to future generations. Debt ceiling mechanisms do not mitigate the debt problem. With overlapping generations, political debt cycles emerge, oscillating with the age of the majority of voters

    Summary Report of PQRI Workshop on Nanomaterial in Drug Products: Current Experience and Management of Potential Risks

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    At the Product Quality Research Institute (PQRI) Workshop held last January 14-15, 2014, participants from academia, industry, and governmental agencies involved in the development and regulation of nanomedicines discussed the current state of characterization, formulation development, manufacturing, and nonclinical safety evaluation of nanomaterial-containing drug products for human use. The workshop discussions identified areas where additional understanding of material attributes, absorption, biodistribution, cellular and tissue uptake, and disposition of nanosized particles would continue to inform their safe use in drug products. Analytical techniques and methods used for in vitro characterization and stability testing of formulations containing nanomaterials were discussed, along with their advantages and limitations. Areas where additional regulatory guidance and material characterization standards would help in the development and approval of nanomedicines were explored. Representatives from the US Food and Drug Administration (USFDA), Health Canada, and European Medicines Agency (EMA) presented information about the diversity of nanomaterials in approved and newly developed drug products. USFDA, Health Canada, and EMA regulators discussed the applicability of current regulatory policies in presentations and open discussion. Information contained in several of the recent EMA reflection papers was discussed in detail, along with their scope and intent to enhance scientific understanding about disposition, efficacy, and safety of nanomaterials introduced in vivo and regulatory requirements for testing and market authorization. Opportunities for interaction with regulatory agencies during the lifecycle of nanomedicines were also addressed at the meeting. This is a summary of the workshop presentations and discussions, including considerations for future regulatory guidance on drug products containing nanomaterials

    Social Costs of Inequality Heterogeneous Endowments in Public-Good Experiments

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    We compare voluntary contributions to the financing of a public good in a symmetric setting to those in asymmetric settings, in which four players have different, randomly allocated endowments. We observe that a weak asymmetry in the endowment distribution leads to the same contribution level as symmetry. Players tend to contribute the same proportion of their respective endowment. In a strongly asymmetric setting, where one player has a higher endowment than the three other players together, we observe significantly lower group contributions than in the other settings. The super-rich player does not contribute significantly more than what the others contribute on average and thus a much lower proportion of the endowment

    Trust, Welfare States and Income Equality: What Causes What?

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    The cross-country correlation between social trust and income equality is well documented, but few studies examine the direction of causality. We show theoretically that by facilitating cooperation, trust may increase efficiency and lead to more equal outcomes, while the feedback from inequality to trust is ambiguous. Using a structural equations model estimated on a large country sample, we find that trust has a positive effect on both market and net income equality. Larger welfare states lead to higher net equality but neither net income equality nor welfare state size seems to have a causal effect on trust. We conclude that while trust facilitates welfare state policies that may reduce net inequality, this decrease in inequality does not increase trust

    Inorganic UV filters

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    Nowadays, concern over skin cancer has been growing more and more, especially in tropical countries where the incidence of UVA/B radiation is higher. The correct use of sunscreen is the most efficient way to prevent the development of this disease. The ingredients of sunscreen can be organic and/or inorganic sun filters. Inorganic filters present some advantages over organic filters, such as photostability, non-irritability and broad spectrum protection. Nevertheless, inorganic filters have a whitening effect in sunscreen formulations owing to the high refractive index, decreasing their esthetic appeal. Many techniques have been developed to overcome this problem and among them, the use of nanotechnology stands out. The estimated amount of nanomaterial in use must increase from 2000 tons in 2004 to a projected 58000 tons in 2020. In this context, this article aims to analyze critically both the different features of the production of inorganic filters (synthesis routes proposed in recent years) and the permeability, the safety and other characteristics of the new generation of inorganic filters
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