In the present paper Lagrangian Coherent Structures are detected in the Gulf of Trieste, i.e., a Gulf located in the north-eastern part of the Adriatic Sea. Lagrangian Coherent Structures are usually ...detected through Lyapunov exponent diagnostic tools. However, such diagnostics lack of a rigorous mathematical background and try to associate well-known classical dynamical system structures of autonomous dynamical systems to the features of fluid flows. Such flows are studied under the perspective of non-autonomous dynamical systems, neglecting diffusion. In this work we try to detect Lagrangian Coherent Structures, i.e., the key material lines that shape trajectory patterns, with both the established Finite-Time Lyapunov Exponents and the recently introduced rigorous mathematical definitions implemented in the publicly available MATLAB LCS Tool. A comparison between real and simulated drifter trajectories is considered, too.
The molecular basis underlying the clinical phenotype in bone diseases is customarily associated with abnormal extracellular matrix structure and/or properties. More recently, cellular malfunction ...has been identified as a concomitant causative factor and increased attention has focused on stem cells differentiation. Classic osteogenesis imperfecta (OI) is a prototype for heritable bone dysplasias: it has dominant genetic transmission and is caused by mutations in the genes coding for collagen I, the most abundant protein in bone. Using the Brtl mouse, a well‐characterized knockin model for moderately severe dominant OI, we demonstrated an impairment in the differentiation of bone marrow progenitor cells toward osteoblasts. In mutant mesenchymal stem cells (MSCs), the expression of early (Runx2 and Sp7) and late (Col1a1 and Ibsp) osteoblastic markers was significantly reduced with respect to wild type (WT). Conversely, mutant MSCs generated more colony‐forming unit‐adipocytes compared to WT, with more adipocytes per colony, and increased number and size of triglyceride drops per cell. Autophagy upregulation was also demonstrated in mutant adult MSCs differentiating toward osteogenic lineage as consequence of endoplasmic reticulum stress due to mutant collagen retention. Treatment of the Brtl mice with the proteasome inhibitor Bortezomib ameliorated both osteoblast differentiation in vitro and bone properties in vivo as demonstrated by colony‐forming unit‐osteoblasts assay and peripheral quantitative computed tomography analysis on long bones, respectively. This is the first report of impaired MSC differentiation to osteoblasts in OI, and it identifies a new potential target for the pharmacological treatment of the disorder. STEM CELLS2012;30:1465–1476
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