369 research outputs found

    Developing a Simplified Consent Form for Biobanking

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    BACKGROUND: Consent forms have lengthened over time and become harder for participants to understand. We sought to demonstrate the feasibility of creating a simplified consent form for biobanking that comprises the minimum information necessary to meet ethical and regulatory requirements. We then gathered preliminary data concerning its content from hypothetical biobank participants. METHODOLOGY/PRINCIPAL FINDINGS: We followed basic principles of plain-language writing and incorporated into a 2-page form (not including the signature page) those elements of information required by federal regulations and recommended by best practice guidelines for biobanking. We then recruited diabetes patients from community-based practices and randomized half (n = 56) to read the 2-page form, first on paper and then a second time on a tablet computer. Participants were encouraged to use "More information" buttons on the electronic version whenever they had questions or desired further information. These buttons led to a series of "Frequently Asked Questions" (FAQs) that contained additional detailed information. Participants were asked to identify specific sentences in the FAQs they thought would be important if they were considering taking part in a biorepository. On average, participants identified 7 FAQ sentences as important (mean 6.6, SD 14.7, range: 0-71). No one sentence was highlighted by a majority of participants; further, 34 (60.7%) participants did not highlight any FAQ sentences. CONCLUSIONS: Our preliminary findings suggest that our 2-page form contains the information that most prospective participants identify as important. Combining simplified forms with supplemental material for those participants who desire more information could help minimize consent form length and complexity, allowing the most substantively material information to be better highlighted and enabling potential participants to read the form and ask questions more effectively

    Survival law in a potential model

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    The radial equation of a simple potential model has long been known to yield an exponential decay law in lowest order (Breit-Wigner) approximation. We demonstrate that if the calculation is extended to fourth order the decay law exhibits the quantum Zeno effect. This model has further been studied numerically to characterize the extra exponential time parameter which compliments the lifetime. We also investigate the inverse Zeno effect.Comment: 16 pages, 2 tables, 3 figures, AMS-Te

    Stability and instability in parametric resonance and quantum Zeno effect

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    A quantum mechanical version of a classical inverted pendulum is analyzed. The stabilization of the classical motion is reflected in the bounded evolution of the quantum mechanical operators in the Heisenberg picture. Interesting links with the quantum Zeno effect are discussed.Comment: 6 pages, 3 figure

    Transcription Factor Nrf1 Mediates the Proteasome Recovery Pathway after Proteasome Inhibition in Mammalian Cells

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    In Saccharomyces cerevisiae, chemical or genetic inhibition of proteasome activity induces new proteasome synthesis promoted by the transcription factor RPN4. This ensures that proteasome activity is matched to demand. This transcriptional feedback loop is conserved in mammals, but its molecular basis is not understood. Here, we report that nuclear factor erythroid-derived 2-related factor 1 (Nrf1), a transcription factor of the cap “n” collar basic leucine zipper family, but not the related Nrf2, is necessary for induced proteasome gene transcription in mouse embryonic fibroblasts (MEFs). Promoter-reporter assays revealed the importance of antioxidant response elements in Nrf1-mediated upregulation of proteasome subunit genes. Nrf1^(−/−) MEFs were impaired in the recovery of proteasome activity after transient treatment with the covalent proteasome inhibitor YU101, and knockdown of Nrf1 in human cancer cells enhanced cell killing by YU101. Taken together, our results suggest that Nrf1-mediated proteasome homeostasis could be an attractive target for therapeutic intervention in cancer

    The decay law can have an irregular character

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    Within a well-known decay model describing a particle confined initially within a spherical δ\delta potential shell, we consider the situation when the undecayed state has an unusual energy distribution decaying slowly as kk\to\infty; the simplest example corresponds to a wave function constant within the shell. We show that the non-decay probability as a function of time behaves then in a highly irregular, most likely fractal way.Comment: 4 pages, 3 eps figure

    Quantum Zeno effect in a probed downconversion process

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    The distorsion of a spontaneous downconvertion process caused by an auxiliary mode coupled to the idler wave is analyzed. In general, a strong coupling with the auxiliary mode tends to hinder the downconversion in the nonlinear medium. On the other hand, provided that the evolution is disturbed by the presence of a phase mismatch, the coupling may increase the speed of downconversion. These effects are interpreted as being manifestations of quantum Zeno or anti-Zeno effects, respectively, and they are understood by using the dressed modes picture of the device. The possibility of using the coupling as a nontrivial phase--matching technique is pointed out.Comment: 11 pages, 4 figure

    Quantum Zeno Dynamics

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    The evolution of a quantum system undergoing very frequent measurements takes place in a subspace of the total Hilbert space (quantum Zeno effect). The dynamical properties of this evolution are investigated and several examples are considered.Comment: 12 pages, 1 figur

    Mudanças da produção leiteira na geografia brasileira: o avanço do Sul.

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    Grandes transformações têm sido observadas na produção de leite no País nos últimos dez anos. Entre 2005 e 2015, a captação de leite brasileira saltou de 45 milhões para 66 milhões de litros de leite por dia (IBGE, 2016). No entanto, esta oferta não tem se expandido de maneira uniforme em todas as regiões brasileiras. Mudanças socioeconômicas, institucionais, tecnológicas e de mercado têm configurado uma nova geografia da produção de leite no Brasil. O sul brasileiro se consolida como a segunda macrobacia leiteira do País, porém é a mais dinâmica. É forte a concentração da produção leiteira no sudoeste do Paraná, oeste de Santa Catarina e norte/noroeste do Rio Grande do Sul. Mas a região não está livre de desafios e adversidades

    Temporal behavior and quantum Zeno time of an excited state of the hydrogen atom

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    The quantum "Zeno" time of the 2P-1S transition of the hydrogen atom is computed and found to be approximately 3.59 10^{-15}s (the lifetime is approximately 1.595 10^{-9}s). The temporal behavior of this system is analyzed in a purely quantum field theoretical framework and is compared to the exponential decay law.Comment: 11 page
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