Crackling Noise, Power Spectra and Disorder Induced Critical Scaling

Crackling noise is observed in many disordered non-equilibrium systems in response to slowly changing external conditions. Examples range from Barkhausen noise in magnets to acoustic emission in martensites to earthquakes. Using the non-equilibrium random field Ising model, we derive universal scaling predictions for the dependence of the associated power spectra on the disorder and field sweep rate, near an underlying disorder-induced non-equilibrium critical point. Our theory applies to certain systems in which the crackling noise results from avalanche-like response to a (slowly) increasing external driving force, and is characterized by a broad power law scaling regime of the power spectra. We compute the critical exponents and discuss the relevance of the results to experiments.Comment: 27 Latex Pages, 14 eps figure

Line and boundary tensions at the wetting transition: Two fluid phases on a substrate

We develop and analyze a mean‐field model free energy that describes two fluid phases on a substrate in order to calculate the (numerically) exact line and boundary tensions, on approach to the first‐order wetting transition. A theory based on the van der Waals theory of gas–liquid interfaces is used. We implement a multigrid algorithm to determine the two‐dimensional spatial variation of the density across the three‐phase and boundary regions, and hence, the line and boundary tensions. As the wetting transition is approached, the tensions approach the same, finite, positive limit with diverging slopes. We compare our results with those of recent related work.FWN – Publicaties zonder aanstelling Universiteit Leide

Psychological and Hierarchical Closeness as Opposing Factors in Whistleblowing: A Meta-Analysis

This is the final version. Available on open access from Springer via the DOI in this recordData Availability: The data and code that support the findings of this study are available on the Open Science Framework (OSF) at: https://osf.io/f7aj4/?view_only=11eb7c401e2b4fcc9d0e15f8e1b4de42.Although employees are an important means of detecting and preventing misconducts through whistleblowing, many witnesses choose to remain silent. One reason to remain silent is the discomfort of reporting a colleague. Intuitively, employees should be less likely to report a close or trusted colleague, but a previous review suggests that the opposite may actually be true. However, later studies have shown mixed effects of social closeness on whistleblowing. To gain a better understanding of how social closeness affects whistleblowing, we meta-analyzed 22 experimental studies on intentions to blow the whistle. Overall, the studies show no effect of social closeness on whistleblowing intentions, d =  − 0.21, p = .05. However, when separating the studies by type of closeness, we find that psychological closeness has a negative effect, d =  − 0.46, p < .001, while hierarchical closeness has a positive effect, d = .34, p < .001 on whistleblowing intentions. This means that employees are most likely to report misconduct if the perpetrator is at the same hierarchical level in the organization and not a close or trusted friend. Since close psychological bonds are more likely to develop between employees at the same hierarchical level, the two types of closeness may counteract each other. This dilemma could be part of the explanation why so many witnesses choose to remain silent

Self-organized criticality in the hysteresis of the Sherrington - Kirkpatrick model

We study hysteretic phenomena in random ferromagnets. We argue that the angle dependent magnetostatic (dipolar) terms introduce frustration and long range interactions in these systems. This makes it plausible that the Sherrington - Kirkpatrick model may be able to capture some of the relevant physics of these systems. We use scaling arguments, replica calculations and large scale numerical simulations to characterize the hysteresis of the zero temperature SK model. By constructing the distribution functions of the avalanche sizes, magnetization jumps and local fields, we conclude that the system exhibits self-organized criticality everywhere on the hysteresis loop.Comment: 4 pages, 4 eps figure

Boundary Tension - from Wetting Transition to Prewetting Critical Point

FWN – Publicaties zonder aanstelling Universiteit Leide

Follow-up of blood-pressure lowering and glucose control in type 2 diabetes.

BACKGROUND In the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) factorial trial, the combination of perindopril and indapamide reduced mortality among patients with type 2 diabetes, but intensive glucose control, targeting a glycated hemoglobin level of less than 6.5%, did not. We now report results of the 6-year post-trial follow-up. METHODS We invited surviving participants, who had previously been assigned to perindopril–indapamide or placebo and to intensive or standard glucose control (with the glucose-control comparison extending for an additional 6 months), to participate in a post-trial follow-up evaluation. The primary end points were death from any cause and major macrovascular events. RESULTS The baseline characteristics were similar among the 11,140 patients who originally underwent randomization and the 8494 patients who participated in the post-trial follow-up for a median of 5.9 years (blood-pressure–lowering comparison) or 5.4 years (glucose-control comparison). Between-group differences in blood pressure and glycated hemoglobin levels during the trial were no longer evident by the first post-trial visit. The reductions in the risk of death from any cause and of death from cardiovascular causes that had been observed in the group receiving active blood-pressure–lowering treatment during the trial were attenuated but significant at the end of the post-trial follow-up; the hazard ratios were 0.91 (95% confidence interval [CI], 0.84 to 0.99; P=0.03) and 0.88 (95% CI, 0.77 to 0.99; P=0.04), respectively. No differences were observed during follow-up in the risk of death from any cause or major macrovascular events between the intensive-glucose-control group and the standard-glucose-control group; the hazard ratios were 1.00 (95% CI, 0.92 to 1.08) and 1.00 (95% CI, 0.92 to 1.08), respectively. CONCLUSIONS The benefits with respect to mortality that had been observed among patients originally assigned to blood-pressure–lowering therapy were attenuated but still evident at the end of follow-up. There was no evidence that intensive glucose control during the trial led to long-term benefits with respect to mortality or macrovascular events

Rayleigh loops in the random-field Ising model on the Bethe lattice

We analyze the demagnetization properties of the random-field Ising model on the Bethe lattice focusing on the beahvior near the disorder induced phase transition. We derive an exact recursion relation for the magnetization and integrate it numerically. Our analysis shows that demagnetization is possible only in the continous high disorder phase, where at low field the loops are described by the Rayleigh law. In the low disorder phase, the saturation loop displays a discontinuity which is reflected by a non vanishing magnetization m_\infty after a series of nested loops. In this case, at low fields the loops are not symmetric and the Rayleigh law does not hold.Comment: 8pages, 6 figure

High sensitivity cardiac troponin T and N-terminal pro-BNP predict cardiovascular events and death in patients with type 2 diabetes mellitus

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