27 research outputs found

    Kinetically stabilized inflation

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    In this work, we propose a string-inspired two fields inflation model to address the fine-tuning problem that the standard inflation model suffers. The fast-rolling tachyon T\mathcal{T} originated from the D-brane and anti-D-brane pair annihilation locks the inflaton φ\varphi slowly rolling on a Higgs-like potential V(φ)=−mφ2φ2+λφ4V(\varphi)=-m_\varphi^2\varphi^2+\lambda \varphi^4 and drives a kinetically stabilized (KS) inflation. Our numerical simulation confirms such a solution is a dynamic attractor. In particular, for λ<0.8×10−3\lambda< 0.8\times 10^{-3}, the e-folding number contributed by the KS inflation phase can be larger than 6262 to solve the horizon and flatness problems of Big Bang theory. Notably, this KS inflation generates a nearly scale-invariant primordial curvature perturbations spectrum consistent with current cosmic microwave background (CMB) observations. It predicts a low tensor-to-scalar ratio, which the current primordial gravitational wave background (the B-modes in CMB) searches favor.Comment: 16 pages, 4 figure

    Transcriptional regulation of FoxO3 gene by glucocorticoids in murine myotubes.

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    Glucocorticoids and FoxO3 exert similar metabolic effects in skeletal muscle. FoxO3 gene expression was increased by dexamethasone (Dex), a synthetic glucocorticoid, both in vitro and in vivo. In C2C12 myotubes the increased expression is due to, at least in part, the elevated rate of FoxO3 gene transcription. In the mouse FoxO3 gene, we identified three glucocorticoid receptor (GR) binding regions (GBRs): one being upstream of the transcription start site, -17kbGBR; and two in introns, +45kbGBR and +71kbGBR. Together, these three GBRs contain four 15-bp glucocorticoid response elements (GREs). Micrococcal nuclease (MNase) assay revealed that Dex treatment increased the sensitivity to MNase in the GRE of +45kbGBR and +71kbGBR upon 30- and 60-min Dex treatment, respectively. Conversely, Dex treatment did not affect the chromatin structure near the -17kbGBR, in which the GRE is located in the linker region. Dex treatment also increased histone H3 and/or H4 acetylation in genomic regions near all three GBRs. Moreover, using chromatin conformation capture (3C) assay, we showed that Dex treatment increased the interaction between the -17kbGBR and two genomic regions: one located around +500 bp and the other around +73 kb. Finally, the transcriptional coregulator p300 was recruited to all three GBRs upon Dex treatment. The reduction of p300 expression decreased FoxO3 gene expression and Dex-stimulated interaction between distinct genomic regions of FoxO3 gene identified by 3C. Overall, our results demonstrate that glucocorticoids activated FoxO3 gene transcription through multiple GREs by chromatin structural change and DNA looping

    Kinetically stabilized inflation

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    Abstract In this work, we propose a string-inspired two fields inflation model to address the fine-tuning problem that the standard inflation model suffers. The fast-rolling tachyon T T \mathcal{T} originated from the D-brane and anti-D-brane pair annihilation locks the inflaton φ slowly rolling on a Higgs-like potential V φ = − m φ 2 φ 2 + λ φ 4 V(φ)=−mφ2φ2+λφ4 V\left(\varphi \right)=-{m}_{\varphi}^2{\varphi}^2+\lambda {\varphi}^4 and drives a kinetically stabilized (KS) inflation. Our numerical simulation confirms such a solution is a dynamic attractor. In particular, for λ < 0.8 × 10 −3, the e-folding number contributed by the KS inflation phase can be larger than 62 to solve the horizon and flatness problems of Big Bang theory. Notably, this KS inflation generates a nearly scale-invariant primordial curvature perturbations spectrum consistent with current cosmic microwave background (CMB) observations. It predicts a low tensor-to-scalar ratio, which the current primordial gravitational wave background (the B-modes in CMB) searches favor

    Higher-order multi-valued resolution

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    This paper introduces a multi-valued variant of higher-order resolution and proves it correct and complete with respect to a natural multi-valued variant of Henkin's general model semantics. This resolution method is parametric in the number of truth values as well as in the particular choice of the set of connectives (given by arbitrary truth tables) and even substitutional quantifiers. In the course of the completeness proof we establish a model existence theorem for this logical system. The work reported in this paper provides a basis for developing higher-order mechanizations for many non-classical logics. (orig.)Available from TIB Hannover: RO 7629(95-04) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

    Access, interest, and attitudes toward electronic communication for health care among patients in the medical safety net.

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    BackgroundElectronic and internet-based tools for patient-provider communication are becoming the standard of care, but disparities exist in their adoption among patients. The reasons for these disparities are unclear, and few studies have looked at the potential communication technologies have to benefit vulnerable patient populations.ObjectiveTo characterize access to, interest in, and attitudes toward internet-based communication in an ethnically, economically, and linguistically diverse group of patients from a large urban safety net clinic network.DesignObservational, cross-sectional studyParticipantsAdult patients (≥ 18 years) in six resource-limited community clinics in the San Francisco Department of Public Health (SFDPH) MAIN MEASURES: Current email use, interest in communicating electronically with health care professionals, barriers to and facilitators of electronic health-related communication, and demographic data-all self-reported via survey.Key resultsSixty percent of patients used email, 71 % were interested in using electronic communication with health care providers, and 19 % reported currently using email informally with these providers for health care. Those already using any email were more likely to express interest in using it for health matters. Most patients agreed electronic communication would improve clinic efficiency and overall communication with clinicians.ConclusionsA significant majority of safety net patients currently use email, text messaging, and the internet, and they expressed an interest in using these tools for electronic communication with their medical providers. This interest is currently unmet within safety net clinics that do not offer a patient portal or secure messaging. Tools such as email encounters and electronic patient portals should be implemented and supported to a greater extent in resource-poor settings, but this will require tailoring these tools to patients' language, literacy level, and experience with communication technology

    Transcriptional regulation of FoxO3 gene by glucocorticoids in murine myotubes

    No full text
    Glucocorticoids and FoxO3 exert similar metabolic effects in skeletal muscle. FoxO3 gene expression was increased by dexamethasone (Dex), a synthetic glucocorticoid, both in vitro and in vivo. In C2C12 myotubes the increased expression is due to, at least in part, the elevated rate of FoxO3 gene transcription. In the mouse FoxO3 gene, we identified three glucocorticoid receptor (GR) binding regions (GBRs): one being upstream of the transcription start site, −17kbGBR; and two in introns, +45kbGBR and +71kbGBR. Together, these three GBRs contain four 15-bp glucocorticoid response elements (GREs). Micrococcal nuclease (MNase) assay revealed that Dex treatment increased the sensitivity to MNase in the GRE of +45kbGBR and +71kbGBR upon 30- and 60-min Dex treatment, respectively. Conversely, Dex treatment did not affect the chromatin structure near the −17kbGBR, in which the GRE is located in the linker region. Dex treatment also increased histone H3 and/or H4 acetylation in genomic regions near all three GBRs. Moreover, using chromatin conformation capture (3C) assay, we showed that Dex treatment increased the interaction between the −17kbGBR and two genomic regions: one located around +500 bp and the other around +73 kb. Finally, the transcriptional coregulator p300 was recruited to all three GBRs upon Dex treatment. The reduction of p300 expression decreased FoxO3 gene expression and Dex-stimulated interaction between distinct genomic regions of FoxO3 gene identified by 3C. Overall, our results demonstrate that glucocorticoids activated FoxO3 gene transcription through multiple GREs by chromatin structural change and DNA looping
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