Asymptotic properties of SPS confidence regions

Sign-Perturbed Sums (SPS) is a system identification method that constructs non-asymptotic confidence regions for the parameters of linear regression models under mild statistical assumptions. One of its main features is that, for any finite number of data points and any user-specified probability, the constructed confidence region contains the true system parameter with exactly the user-chosen probability. In this paper we examine the size and the shape of the confidence regions, and we show that the regions are strongly consistent, i.e., they almost surely shrink around the true parameter as the number of data points increases. Furthermore, the confidence region is contained in a marginally inflated version of the confidence ellipsoid obtained from the asymptotic system identification theory. The results are also illustrated by a simulation example

Association of intervention outcomes with practice capacity for change: Subgroup analysis from a group randomized trial

<p>Abstract</p> <p>Background</p> <p>The relationship between health care practices' capacity for change and the results and sustainability of interventions to improve health care delivery is unclear.</p> <p>Methods</p> <p>In the setting of an intervention to increase preventive service delivery (PSD), we assessed practice capacity for change by rating motivation to change and instrumental ability to change on a one to four scale. After combining these ratings into a single score, random effects models tested its association with change in PSD rates from baseline to immediately after intervention completion and 12 months later.</p> <p>Results</p> <p>Our measure of practices' capacity for change varied widely at baseline (range 2–8; mean 4.8 ± 1.6). Practices with greater capacity for change delivered preventive services to eligible patients at higher rates after completion of the intervention (2.7% per unit increase in the combined effort score, p < 0.001). This relationship persisted for 12 months after the intervention ended (3.1%, p < 0.001).</p> <p>Conclusion</p> <p>Greater capacity for change is associated with a higher probability that a practice will attain and sustain desired outcomes. Future work to refine measures of this practice characteristic may be useful in planning and implementing interventions that result in sustained, evidence-based improvements in health care delivery.</p

Background Independence and Asymptotic Safety in Conformally Reduced Gravity

We analyze the conceptual role of background independence in the application of the effective average action to quantum gravity. Insisting on a background independent renormalization group (RG) flow the coarse graining operation must be defined in terms of an unspecified variable metric since no rigid metric of a fixed background spacetime is available. This leads to an extra field dependence in the functional RG equation and a significantly different RG flow in comparison to the standard flow equation with a rigid metric in the mode cutoff. The background independent RG flow can possess a non-Gaussian fixed point, for instance, even though the corresponding standard one does not. We demonstrate the importance of this universal, essentially kinematical effect by computing the RG flow of Quantum Einstein Gravity in the ``conformally reduced'' Einstein--Hilbert approximation which discards all degrees of freedom contained in the metric except the conformal one. Without the extra field dependence the resulting RG flow is that of a simple $\phi^4$-theory. Including it one obtains a flow with exactly the same qualitative properties as in the full Einstein--Hilbert truncation. In particular it possesses the non-Gaussian fixed point which is necessary for asymptotic safety.Comment: 4 figures

Experiments reveal enrichment of 11B in granitic melt resulting from tourmaline crystallisation

Tourmaline is the most common boron-rich mineral in magmatic systems. In this study, we determined experimentally the fractionation of boron isotopes between granitic melt and tourmaline for the first time. Our crystallisation experiments were performed using a boron-rich granitic glass (B2O3 ≈ 8 wt. %) at 660−800 °C, 300 MPa, and aH2O = 1, in which tourmaline occurs as the only boron-hosting mineral. Our experimental results at four different temperatures show a small and temperature-dependent boron isotope fractionation between granitic melt and tourmaline (Δ11Bmelt–Tur = þ0.90 ± 0.05 ‰ at 660 °C and þ0.23 ± 0.12 ‰ at 800 °C), and the temperature dependence can be defined as Δ11Bmelt–Tur = 4.51 × (1000/T [K]) − 3.94 (R2 = 0.96). Using these boron isotope fractionation factors, tourmaline can serve as a tracer to quantitatively interpret boron isotopic ratios in evolved magmatic systems. Our observation that 11B is enriched in granitic melt relative to tourmaline suggests that the δ11B of late-magmatic tourmaline should be higher than tourmaline that crystallised at an early stage, if B isotope fractionation is not affected by other processes, such as fluid loss. © 2022 The Authors

Primary Defects in β-Cell Function Further Exacerbated by Worsening of Insulin Resistance Mark the Development of Impaired Glucose Tolerance in Obese Adolescents

OBJECTIVE—Impaired glucose tolerance (IGT) is a pre-diabetic state of increasing prevalence among obese adolescents. The purpose of this study was to determine the natural history of progression from normal glucose tolerance (NGT) to IGT in obese adolescents