Higgs Inflation and the Refined dS Conjecture

The refined de Sitter derivative conjecture provides constraints to potentials that are low energy effective theories of quantum gravity. It can give direct bounds on inflationary scenarios and determine whether the theory is in the Landscape or the Swampland. We consider the `Higgs inflation' scenario taking the refined de Sitter derivative conjecture into account. Obtaining the critical lines for the potential, we find a conjecture parameter space in which the `Higgs inflation' is to be in the Landscape. Comparing with the model independent observational bounds from recent data we find that the observational bounds represent the Higgs inflation can be in the Landscape.Comment: 5 pages, 4 figures, Version to appear in PL

Factors Affecting the Self-directed Learning of Students at Clinical Practice Course for Advanced Practice Nurse

PurposeThe current study aimed to examine the casual relationships among belongingness during clinical practice, stress, satisfaction with clinical practice, and self-esteem, which are factors affecting the self-directed learning that results from the clinical practice of advanced practice nurse (APN) students.MethodsData were collected between April 5 and May 19, 2010, from 202 students in 11 APN training institutions located in and outside of Seoul, who were selected using convenience sampling. For hypothesis testing, the collected data were analyzed using AMOS 8.0.ResultsAnalysis of the path coefficients in this study showed that 37% of the variation in self-directed learning could be explained by variations in the model. Self-esteem and belongingness during clinical practice directly affected the self-directed learning of APN students, and belongingness also had an indirect effect via self-esteem. However, stress and satisfaction with clinical practice had no significant mediating effect on self-directed learning. At the same time, belongingness during clinical practice was found to be a good predictive factor to explain stress and satisfaction with clinical practice.ConclusionsThis study demonstrated the hierarchical relationship among belongingness, self-esteem, and self-directed learning based on the conceptual framework developed by Levett-Jones and Lathlean, thus proving the usefulness of this framework for application in the field. Therefore, this study found that there are needs of high self-esteem and belongingness in order to improve self-directed learning for APN students in clinical practice

The impact of Arctic sea ice loss on mid-Holocene climate.

Mid-Holocene climate was characterized by strong summer solar heating that decreased Arctic sea ice cover. Motivated by recent studies identifying Arctic sea ice loss as a key driver of future climate change, we separate the influences of Arctic sea ice loss on mid-Holocene climate. By performing idealized climate model perturbation experiments, we show that Arctic sea ice loss causes zonally asymmetric surface temperature responses especially in winter: sea ice loss warms North America and the North Pacific, which would otherwise be much colder due to weaker winter insolation. In contrast, over East Asia, sea ice loss slightly decreases the temperature in early winter. These temperature responses are associated with the weakening of mid-high latitude westerlies and polar stratospheric warming. Sea ice loss also weakens the Atlantic meridional overturning circulation, although this weakening signal diminishes after 150-200 years of model integration. These results suggest that mid-Holocene climate changes should be interpreted in terms of both Arctic sea ice cover and insolation forcing

Composite Hybrid Inflation: Dilaton and Waterfall Pions

We investigate the possibility that inflation originates from a composite field theory, in terms of an effective chiral Lagrangian involving a dilaton and pions. The walking dynamics of the theory constrain the potential in a specific way, where the anomalous dimensions of operators involving pions play a crucial role. For realistic values of the anomalous dimensions, we find a successful hybrid inflation occurring via the dilaton-inflaton, with the pions acting as waterfall fields. Compositeness consistency strongly constrain the model, predicting a dilaton scale $f_\chi \sim \mathcal{O} (1)$ in unit of the Planck scale, an inflation scale $H_\text{inf} \sim 10^{10}$ GeV, and the pion scale around $10^{14}$ GeV. We further discuss possible phenomenological consequences of this theory.Comment: 14 pages, 4 figure

Estimating baseline creatinine values to define acute kidney injury in critically ill pediatric patients

Background Acute kidney injury (AKI) is a common complication in critically ill children. However, the common lack of baseline serum creatinine values affects AKI diagnosis and staging. Several approaches for estimating baseline creatinine values in those patients were evaluated. Methods This single-center retrospective study enrolled pediatric patients with documented serum creatinine measurements within 3 months before admission and more than two serum creatinine measurements within 7 days after admission to the pediatric intensive care unit of a tertiary care children’s hospital between January 2016 and April 2020. Four different approaches for estimating AKI using serum creatinine measurements were compared: 1) back-calculation using age-adjusted normal reference glomerular filtration rates, 2) age-adjusted normal reference serum creatinine values, 3) minimum values measured within 7 days after admission, and 4) initial values upon admission. Results The approach using minimum values showed the best agreement with the measured baseline value, with the largest intraclass correlation coefficient (0.623), smallest bias (–0.04), and narrowest limit of agreement interval (1.032). For AKI diagnosis and staging, the minimum values were 80.8% and 76.1% accurate, respectively. The other estimated baseline values underestimated AKI and showed poor agreement with baseline values before admission, with a misclassification rate of up to 42% (p < 0.001). Conclusion Minimum values of serum creatinine measured within 7 days after hospital admission showed the best agreement with creatinine measured within 3 months before admission, indicating the possibility of using it as a baseline when baseline data are unavailable. Further large-scale studies are required to accurately diagnose AKI in critically ill children

Axion Quality Problem and Non-Minimal Gravitational Coupling in the Palatini Formulation

In axion models, the global U(1) Peccei-Quinn (PQ) symmetry is explicitly broken by non-perturbative effects of gravity, such as axionic wormholes. The gravitational violation of the PQ symmetry due to wormholes is large enough to invalidate the PQ mechanism, which is entitled as the axion quality problem. Recently, a novel solution to this quality problem was suggested, where the non-minimal coupling of the axion field to gravity $\xi$ is introduced to suppress the wormhole contribution. In this work, we revisit the problem in a different but equally valid formulation of gravity, namely the Palatini formulation, where the Ricci scalar is solely determined by connection. We first find the axionic wormhole solution in the Palatini formulation, taking the full dynamical radial mode as well as the axial mode, then show that the quality problem is still resolved with the non-minimal coupling $\xi$. The requested lower bound of $\xi$ in the Palatini formulation turns out to be slightly higher than that in the metric formulation.Comment: 7 pages, 6 figures, v2: matches published version in Phys. Rev.