Continuum viscoplastic simulation of a granular column collapse on large slopes: μ(I) rheology and lateral wall effects

We simulate here dry granular flows resulting from the collapse of granular columns on an inclined channel (up to 22°) and compare precisely the results with laboratory experiments. Incompressibility is assumed despite the dilatancy observed in the experiments (up to 10%). The 2-D model is based on the so-called μ(I) rheology that induces a Drucker-Prager yield stress and a variable viscosity. A nonlinear Coulomb friction term, representing the friction on the lateral walls of the channel, is added to the model. We demonstrate that this term is crucial to accurately reproduce granular collapses on slopes ≳10°, whereas it remains of little effect on the horizontal slope. Quantitative comparison between the experimental and numerical changes with time of the thickness profiles and front velocity makes it possible to strongly constrain the rheology. In particular, we show that the use of a variable or a constant viscosity does not change significantly the results provided that these viscosities are of the same order. However, only a fine tuning of the constant viscosity (η=1 Pa s) makes it possible to predict the slow propagation phase observed experimentally at large slopes. Finally, we observed that small-scale instabilities develop when refining the mesh (also called ill-posed behavior, characterized in the work of Barker et al. [“Well-posed and ill-posed behaviour of the μ(I)-rheology for granular flow,” J. Fluid Mech. 779, 794–818 (2015)] and in the present work) associated with the mechanical model. The velocity field becomes stratified and the bands of high velocity gradient appear. These model instabilities are not avoided by using variable viscosity models such as the μ(I) rheology. However we show that the velocity range, the static-flowing transition, and the thickness profiles are almost not affected by them

BUDAYA KEDIRI DALAM PEMBELAJARAN MATEMATIKA (PENGEMBANGAN LEMBAR KEGIATAN SISWA (LKS) BERBASIS ETNOMATEMATIKA MELALUI PENDEKATAN SAINTIFIK)

Tujuan penelitian ini adalah untuk mengetahui pengembangan LKS berbasis etnomatematika melalui pendekatan saintifik yang dapat meningkatkan kualitas pembelajaran. Penelitian ini merupakan penelitian pengembangan (R & D) dengan menggunakan desain pengembangan ADDIE yang terdiri dari lima tahap yaitu Analysis (Analisis), Design (Perancangan), Development (Pengembangan), Implementation (Implementasi), dan Evaluation (Evaluasi). Dengan subyek penelitian siswa kelas VIII SMP Negeri 5 Kediri. Penelitian ini menggunakan beberapa instrumen diantaranya lembar penilaian oleh ahli media dan ahli materi, serta angket siswa. Luaran yang diharapkan berupa modul LKS matematika berbasis etnomatematika melalui pendekatan saitifik, sehingga dapat diketahui hasil kevalidan, kepraktisan dan keefektifan

New method to find corner and tangent vertices in sketches using parametric cubic curves approximation

Some recent approaches have been presented as simple and highly accurate corner finders in the sketches including curves, which is useful to support natural human-computer interaction, but these in most cases do not consider tangent vertices (smooth points between two geometric entities, present in engineering models), what implies an important drawback in the field of design. In this article we present a robust approach based on the approximation to parametric cubic curves of the stroke for further radius function calculation in order to detect corner and tangent vertices. We have called our approach Tangent and Corner Vertices Detection (TCVD), and it works in the following way. First, corner vertices are obtained as minimum radius peaks in the discrete radius function, where radius is obtained from differences. Second, approximated piecewise parametric curves on the stroke are obtained and the analytic radius function is calculated. Then, curves are obtained from stretches of the stroke that have a small radius. Finally, the tangent vertices are found between straight lines and curves or between curves, where no corner vertices are previously located. The radius function to obtain curves is calculated from approximated piecewise curves, which is much more noise free than discrete radius calculation. Several tests have been carried out to compare our approach to that of the current best benchmarked, and the obtained results show that our approach achieves a significant accuracy even better finding corner vertices, and moreover, tangent vertices are detected with an Accuracy near to 92% and a False Positive Rate near to 2%.Spanish Ministry of Science and Education and the FEDER Funds, through CUESKETCH (Ref. DPI2007-66755-C02-01) and HYMAS projects (Ref. DPI2010-19457) partially supported this work.Albert Gil, FE.; García Fernández-Pacheco, D.; Aleixos Borrás, MN. (2013). New method to find corner and tangent vertices in sketches using parametric cubic curves approximation. Pattern Recognition. 46(5):1433-1448. https://doi.org/10.1016/j.patcog.2012.11.006S1433144846

Evaluating case management for caregivers of children with spinal muscular atrophy type I and II—an exploratory, controlled, mixed-methods trial

IntroductionSpinal muscular atrophy (SMA) is a rare neuromuscular disease requiring various clinical specialists and therapists to provide care. Due to the disease's dynamic nature and the long distances between specialized centers and local providers, integrating care between disciplines can be challenging. Care that is inadequately integrated can compromise the quality of care and become a burden for patients and families. This trial aimed to improve the care of patients through a case management (CM) intervention.MethodsWe conducted an exploratory, controlled, two-arm trial with pre-, post-, and follow-up measures (process and outcome evaluation). Proof of efficacy based on statistical significance was not our primary study objective since we were investigating a rare disease. Primary outcomes were caregivers' HRQoL and caregiver-rated quality of care integration. Our secondary outcome was the children's HRQoL.ResultsQuestionnaires and semi-structured interviews yielded heterogeneous results depending on caregivers' level of experience and desire (or possibility) to delegate care tasks.DiscussionDespite differing perceptions, all participants supported the establishment of a care coordination model. We recommend CM immediately after diagnosis to provide the greatest benefit to families. We hope that our trial will support the further development of CM interventions that can be customized for specific diseases

The role of CSF1R-dependent macrophages in control of the intestinal stem cell niche

Colony-stimulating factor 1 (CSF1) controls the growth and differentiation of macrophages.CSF1R signaling has been implicated in the maintenance of the intestinal stem cell niche and differentiation of Paneth cells, but evidence of expression of CSF1R within the crypt is equivocal. Here we show that CSF1R-dependent macrophages influence intestinal epithelial differentiation and homeostasis. In the intestinal lamina propria CSF1R mRNA expression is restricted to macrophages which are intimately associated with the crypt epithelium, and is undetectable in Paneth cells. Macrophage ablation following CSF1R blockade affects Paneth cell differentiation and leads to a reduction of Lgr5 intestinal stem cells. The disturbances to the crypt caused by macrophage depletion adversely affect the subsequent differentiation of intestinal epithelial cell lineages. Goblet cell density is enhanced, whereas the development of M cells in Peyer's patches is impeded. We suggest that modification of the phenotype or abundance of macrophages in the gut wall alters the development of the intestinal epithelium and the ability to sample gut antigens