A comparison of in-sample forecasting methods

In-sample forecasting is a recent continuous modification of well-known forecasting methods based on aggregated data. These aggregated methods are known as age-cohort methods in demography, economics, epidemiology and sociology and as chain ladder in non-life insurance. Data is organized in a two-way table with age and cohort as indices, but without measures of exposure. It has recently been established that such structured forecasting methods based on aggregated data can be interpreted as structured histogram estimators. Continuous in-sample forecasting transfers these classical forecasting models into a modern statistical world including smoothing methodology that is more efficient than smoothing via histograms. All in-sample forecasting estimators are collected and their performance is compared via a finite sample simulation study. All methods are extended via multiplicative bias correction. Asymptotic theory is being developed for the histogram-type method of sieves and for the multiplicatively corrected estimators. The multiplicative bias corrected estimators improve all other known in-sample forecasters in the simulation study. The density projection approach seems to have the best performance with forecasting based on survival densities being the runner-up

Stranger in a Land: Late-Antique and Medieval Narratives on Foreigners and Exile

International ConferenceCasa Árabe (Córdoba, Spain)4-6 March 202

New aspects in the phase behaviour of poly-N-isopropyl acrylamide: systematic temperature dependent shrinking of PNiPAM assemblies well beyond the LCST

We investigate the phase behaviour of aqueous dispersions of poly-N-isopropyl acrylamide (PNiPAM) microgels above their lower critical solution temperature (LCST) and find that beyond a well-defined concentration the systems exhibit a peculiar behaviour: the microgels assemble into space-spanning gels that shrink in time while maintaining the shape of the container in which they have been formed. Over a wide range of concentrations this shrinking behaviour is independent of PNiPAM concentration, but systematically depends on temperature in a temperature range significantly exceeding the LCST. The overall shrinking characteristics are consistent with those expected for scaffolds made of materials that exhibit thermal contraction. However, for the PNiPAM assemblies contraction is irreversible and can be as large as 90%. Such characteristics disclose complex interactions between fully collapsed PNiPAM and water well beyond the LCST, the origin of which has yet to be elucidated

Implementing Buurtzorg-derived models in the home care setting: a Scoping Review

Background Buurtzorg is a pioneering healthcare organization founded in the Netherlands. Buurtzorg has established independent, self-managing teams of nurses and promises high-quality home care at a lower cost through person-centered care, continuity of care, building trusting relationships, and networks in the neighborhood. Traditional home care services are increasingly reorganized according to the Buurtzorg-principles. Objectives This review aims to describe the experiences gathered during the implementation of the Buurtzorg-derived model outside the Netherlands. It further outlines their potential effects. Design Scoping Review Methods Several electronic databases were searched for relevant articles, supplemented by hand-searching and internet searches for gray literature. Various publication types that described the implementation of the Buurtzorg model or its outcomes in countries other than the Netherlands were included. The data were analyzed using qualitative content analysis. Two authors coded the data in several cycles and created categories and subcategories. Results The review identified 25 publications reporting the experiences or outcomes of Buurtzorg-derived models outside the Netherlands. Upon implementing elements of Buurtzorg, the home care organizations adopted a person-centered care approach, with improved communication with patients and family caregivers, and could establish new networks with other services. The main challenges were related to the self-managed working culture, the organizational framework, or national healthcare policies, which hindered the implementation process. Conclusions The implementation of Buurtzorg-derived models is complex, challenging, and requires adaptations on several levels: upskilling of networking and staffing competencies in teams, leadership and IT requirements in the organization, and policy changes in the healthcare system. Individualized approaches and solid conceptual preparation are required for implementation. Tweetable abstract Experiences with the implementation of Buurtzorg in home care services outside the Netherlands. A scoping review @HegeduesAnn

Fast sodium channel gating supports localized and efficient axonal action potential initiation

Action potentials (APs) are initiated in the proximal axon of most neurons. In myelinated axons, a 50-times higher sodium channel density in the initial segment compared to the soma may account for this phenomenon. However, little is known about sodium channel density and gating in proximal unmyelinated axons. To study the mechanisms underlying AP initiation in unmyelinated hippocampal mossy fibers of adult mice, we recorded sodium currents in axonal and somatic membrane patches. We demonstrate that sodium channel density in the proximal axon is approximately 5 times higher than in the soma. Furthermore, sodium channel activation and inactivation are approximately 2 times faster. Modeling revealed that the fast activation localized the initiation site to the proximal axon even upon strong synaptic stimulation, while fast inactivation contributed to energy-efficient membrane charging during APs. Thus, sodium channel gating and density in unmyelinated mossy fiber axons appear to be specialized for robust AP initiation and propagation with minimal current flow

Yield precursor in primary creep of colloidal gels

Predicting the time-dependent yielding of colloidal gels under constant stress enables control of their mechanical stability and transport. Using rotational rheometry, we show that the shear rate of colloidal gels during an early stage of deformation known as primary creep can forecast an eventual yielding. Irrespective of whether the gel strain-softens or strain-hardens, the shear rate before failure exhibits a characteristic power-law decrease as a function of time, distinct from the linear viscoelastic response. We model this early-stage behavior as a series of uncorrelated local plastic events that are thermally activated, which illuminates the exponential dependence of the yield time on the applied stress. This precursor to yield in the macroscopic shear rate provides a convenient tool to identify the fate of a gel well in advance of the actual yielding

Two Modes of Cluster Dynamics Govern the Viscoelasticity of Colloidal Gels

Colloidal gels formed by strongly attractive particles at low particle volume fractions are composed of space-spanning networks of uniformly sized clusters. We study the thermal fluctuations of the clusters using differential dynamic microscopy by decomposing them into two modes of dynamics, and link them to the macroscopic viscoelasticity via rheometry. The first mode, dominant at early times, represents the localized, elastic fluctuations of individual clusters. The second mode, pronounced at late times, reflects the collective, viscoelastic dynamics facilitated by the connectivity of the clusters. By mixing two types of particles of distinct attraction strengths in different proportions, we control the transition time at which the collective mode starts to dominate, and hence tune the frequency dependence of the linear viscoelastic moduli of the binary gels