654 research outputs found

    Towards the determination of the dimension of the critical surface in asymptotically safe gravity

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    We compute the beta functions of Higher Derivative Gravity within the Functional Renormalization Group approach, going beyond previously studied approximations. We find that the presence of a nontrivial Newtonian coupling induces, in addition to the free fixed point of the one-loop approximation, also two nontrivial fixed points, of which one has the right signs to be free from tachyons. Our results are consistent with earlier suggestions that the dimension of the critical surface for pure gravity is three

    Further evidence for asymptotic safety of quantum gravity

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    The asymptotic safety conjecture is examined for quantum gravity in four dimensions. Using the renormalisation group, we find evidence for an interacting UV fixed point for polynomial actions up to the 34th power in the Ricci scalar. The extrapolation to infinite polynomial order is given, and the self-consistency of the fixed point is established using a bootstrap test. All details of our analysis are provided. We also clarify further aspects such as stability, convergence, the role of boundary conditions, and a partial degeneracy of eigenvalues. Within this setting we find strong support for the conjecture

    Exploration of bivalent ligands targeting putative mu opioid receptor and chemokine receptor CCR5 dimerization

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    Modern antiretroviral therapies have provided HIV-1 infected patients longer lifespans and better quality of life. However, several neurological complications are now being seen in these patients due to HIV-1 associated injury of neurons by infected microglia and astrocytes. In addition, these effects can be further exacerbated with opiate use and abuse. One possible mechanism for such potentiation effects of opiates is the interaction of the mu opioid receptor (MOR) with the chemokine receptor CCR5 (CCR5), a known HIV-1 co-receptor, to form MOR-CCR5 heterodimer. In an attempt to understand this putative interaction and its relevance to neuroAIDS, we designed and synthesized a series of bivalent ligands targeting the putative CCR5-MOR heterodimer. To understand how these bivalent ligands may interact with the heterodimer, biological studies including calcium mobilization inhibition, binding affinity, HIV-1 invasion, and cell fusion assays were applied. In particular, HIV-1 infection assays using human peripheral blood mononuclear cells, macrophages, and astrocytes revealed a notable synergy in activity for one particular bivalent ligand. Further, a molecular model of the putative CCR5-MOR heterodimer was constructed, docked with the bivalent ligand, and molecular dynamics simulations of the complex was performed in a membrane-water system to help understand the biological observation

    Proximate determinants of fertility in Ethiopia: comparative analysis of the 2005 and 2011 DHS

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    Fertility is one of the elements in population dynamics that makes a significant contribution towards changing population size and structure over time. In Ethiopia, for the last 10 years the total fertility rate (TFR) has declined slightly from 5.5 to 4.8 children in 2011. But, the TFR in urban areas has increased from 2.4 to 2.6 per 1000 live births. The Bongaarts model was applied to estimate the indices of the four main proximate determinants of fertility. Bongaarts defines the TFR of a population as a function of the total fecundity rate (TF), index of marriage (Cm), index of contraception (Cc), index of postpartum infecundability (Ci), and index of abortion (Ca); this can be written as TFR = Cm × Cc × Ci × Ca × TF. In 2005, the index of married women in urban areas was lower than rural, but it was unfortunately the same in urban and rural areas in 2011. For the last decade, the index of postpartum infecundability had a great fertility reduction effect compared with the contraception index and marriage index in rural Ethiopia. The lower the four indices of proximate determinants, the more fertility will be reduced. As such, the Ethiopian government, international non-governmental organizations and policy-makers must pay attention to increase the prevalence of contraceptive use and educate society to fight against child marriage. Permanent contraceptive use, such as female sterilization, should be promoted; moreover, legal organizations and the community must work together to raise the legal age of marriage to 18 years.IS

    A Three-Step Model for Designing Initial Second Life-Based Foreign Language Learning Activities

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    Abstract The use of three-dimensional virtual worlds such as Second Life (SL) to support foreign language learning and teaching has been receiving increasing attention over the last decade. A review of the literature revealed a lack of activity design models for SL-based foreign language learning. This paper proposes a model that may be used by foreign language educators to design initial SL-based learning activities for their students. The suggested model integrates three language-learning features to contribute to effective language learning, to satisfy students' preference for working in groups, and to reduce SL's chances of crashing. The model also provides a mechanism for moderating SL's steep learning curve

    Linking Emergency Medical Services and Emergency Department Data to Improve Overdose Surveillance in North Carolina

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    Introduction Linking emergency medical services (EMS) data to emergency department (ED) data enables assessing the continuum of care and evaluating patient outcomes. We developed novel methods to enhance linkage performance and analysis of EMS and ED data for opioid overdose surveillance in North Carolina. Methods We identified data on all EMS encounters in North Carolina during January 1–November 30, 2017, with documented naloxone administration and transportation to the ED. We linked these data with ED visit data in the North Carolina Disease Event Tracking and Epidemiologic Collection Tool. We manually reviewed a subset of data from 12 counties to create a gold standard that informed developing iterative linkage methods using demographic, time, and destination variables. We calculated the proportion of suspected opioid overdose EMS cases that received International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes for opioid overdose in the ED. Results We identified 12 088 EMS encounters of patients treated with naloxone and transported to the ED. The 12-county subset included 1781 linkage-eligible EMS encounters, with historical linkage of 65.4% (1165 of 1781) and 1.6% false linkages. Through iterative linkage methods, performance improved to 91.0% (1620 of 1781) with 0.1% false linkages. Among statewide EMS encounters with naloxone administration, the linkage improved from 47.1% to 91.1%. We found diagnosis codes for opioid overdose in the ED among 27.2% of statewide linked records. Practice Implications Through an iterative linkage approach, EMS–ED data linkage performance improved greatly while reducing the number of false linkages. Improved EMS–ED data linkage quality can enhance surveillance activities, inform emergency response practices, and improve quality of care through evaluating initial patient presentations, field interventions, and ultimate diagnoses

    Capillary pressure of van der Waals liquid nanodrops

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    The dependence of the surface tension on a nanodrop radius is important for the new-phase formation process. It is demonstrated that the famous Tolman formula is not unique and the size-dependence of the surface tension can distinct for different systems. The analysis is based on a relationship between the surface tension and disjoining pressure in nanodrops. It is shown that the van der Waals interactions do not affect the new-phase formation thermodynamics since the effect of the disjoining pressure and size-dependent component of the surface tension cancel each other.Comment: The paper is dedicated to the 80th anniversary of A.I. Rusano

    Radiofrequency volumetric thermal ablation of fibroids: A prospective, clinical analysis of two years' outcome from the Halt trial

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    Background: Although most myomas are asymptomatic, quality of life is compromised for many women with uterine fibroid disease. Twelve-month outcomes from the Halt Trial have been reported in the literature. Here we analyze the clinical success of radiofrequency volumetric thermal ablation (RFVTA) of symptomatic uterine fibroids at two years of follow up.Methods: Prospective, multicenter, outpatient interventional clinical trial of fibroid treatment by RFVTA in 124 premenopausal women (mean age, 42.4 ± 4.4 years) with symptomatic uterine fibroids and objectively confirmed heavy menstrual bleeding (≥160 to ≤500 mL).Outcome measures included: subject responses to validated questionnaires, treatment-emergent adverse events, and surgical re-intervention for fibroids at 24 months postprocedure. Continuous and categorical variables were summarized using descriptive statistics and means and percentages. Comparisons between visits were based on t-tests using repeated measures models. P-values < 0.05, adjusted for multiplicity, were statistically significant.Results: One hundred twelve subjects were followed through 24 months. Change in symptom severity from baseline was -35.7 (95% CI, -40.1 to -31.4; p<.001). Change in health-related quality of life (HRQL) was 40.9 (95% CI, 36.2 to 45.6; p < .001). HRQL subscores also improved significantly from baseline to 24 months in all categories (concern, activities, energy/mood, control, self-consciousness, and sexual function) [p<.001]. Six patients underwent surgical re-intervention for fibroid-related bleeding between 12 and 24 months providing a re-intervention rate of 4.8% (6/124).Conclusion: Radiofrequency volumetric thermal ablation of myomas significantly reduces symptom severity and improves quality of life with low surgical re-intervention through 24 months of follow up.Trial registration: ClinicalTrials.gov: NCT00874029. © 2013 Guido et al.; licensee BioMed Central Ltd

    FlyBase: enhancing Drosophila Gene Ontology annotations

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    FlyBase (http://flybase.org) is a database of Drosophila genetic and genomic information. Gene Ontology (GO) terms are used to describe three attributes of wild-type gene products: their molecular function, the biological processes in which they play a role, and their subcellular location. This article describes recent changes to the FlyBase GO annotation strategy that are improving the quality of the GO annotation data. Many of these changes stem from our participation in the GO Reference Genome Annotation Project—a multi-database collaboration producing comprehensive GO annotation sets for 12 diverse species
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